MANUAL

HEAVY ARTILLERY

SERVICE,

UNITED STATES ARjif^

TIDBALL.
1880.

m AUl'HORITY.

[BY AUTHORITY.]

MANUAL

HEAVY ARTILLERY SERVICE.

PREPARED FOR THE USE OP THE

ARMY AND MILITIA OF THE UNITED STATES.

J. C. TIDBALL,

LIEUT.-COL. FIRST ARTILLERY, BVT. BRIG-GENL., U. S. A.,

COMMANDANT OF THE ARTILLERY SCHOOL,

FORTRESS MONROE.

THIRD EDITION.

WASHINGTON, D. 0. :

JAMES J. CIIAPMAX,

—AGENT.—

1884.

UF/S3

-rr

Entered according to Act of Congress, in the year 1880, Dy

James J. Chapman.

In the Office of the Librarian of Congress, at "Washington, D. O.

Press of Thomas McGill & Co.,

WASHINGTON, D. C.

-^PREFAEE.-^

The basis of this work, so far as the Service op the Piece
and the Mechanical Manoeuvres are concerned, has been the
"Circulars of the U. S. Artillery School," supplemented by the
unwritten customs and practices of that institution.

In Field Intrenchments, "Mahan's Field Fortifications"
was used as a reference, supplemented by the methods intro-
duced during the American civil war of 1861-65, and adopted
and practiced during the Franco - German and Russo - Turkish
wars.

In Submarine Mines, the works of Stotherd and of Sleeman
have been taken as authority.

In other parts of the work, Benton's "Ordnance and Gun-
nery," Eoberts' "Hand -Book of Artillery," "Ordnance Notes
and Memoranda," "Ordnance Instruction U. S. Navy," "Ord-
nance Manual U. S. Army," together with many other author-
ities, have been consulted.

In the labor of arranging and preparing the plates, and in
various other matters, I am indebted to Lieut. C. Chase, 3d artil-
lery ; and to Lieut. L. V. Caziarc, 2d artillery, for the admirably-
arranged Index.

J. O. T.

Fort Monroe, Va., June, 1880.

(iii)

M44/^J/I

IV PREFACE.

Report of the Staff of the U. S. Artillery School on a system of
instruction for heavy - artillery troops^ submitted by Major
J. C. Tidball, 2d artillery^ Brevet Brigadier- General, U. S. A.

Headquarters U. S. Artillery School,

Fort Monroe, Ta., November 17, 1879.

The Adjittant-G-eneral of the Army,
■Washington, D. O.

Sir : The MSS. for a system of instruction for heavy-artillery troops, pre-

eared by Major John O. Tidball, 2d artillery, Brevet Brigadier-G-eneral,
^ S. A., having, in accordance with the instructions of the General of the
Army contained in indorsement dated Headquarters of the Army, May 16,
1879, on Major TidbaU's letter of March 29, 1879, been referred to the Staff
of the U. S. Artillery School for examination, the Staff respectfully sub-
mits the following as its report thereon.

The work has evidently been designed to supply a want long felt in the
artillery service, and which has been pointed out in G-eneral Orders No. 3 of
1876, Headquarters of the Army, as being a regular and more comprehensive
system of instruction or manual for heavy-artUlery troops.

Its general divisions are :

1. Preliminary Instruction.

2. Service of the Piece.

3. Mechanical MancBuvres.

4. Care and Preservation of Artillery Material.

5. Transportation of Artillery.

6. Organization and Command of Artillery.

7. Employment of Artillery in Campaign.

8. Employment of ArtUlery against Armored Vessels and in Har>

bor Defense.

9. Field Intrenchments.

10. Attack upon Intrenchments.

11. Submarine Mines.

To which it is intended to add a short chapter on Artillery Salutes and
Ceremonies and Courtesies between land and naval forces, which has al-
ready been submitted to the G-eneral, of date October 18, 1879.

The Staff has the honor to report upon the various divisions of the work
as follows :

1. Preliminary Instruction. This embraces: 1st. Definitions of the
various kinds of artillery, and a tabular statement of the U. S. system foi
land service; 2d. The formation and marching drill of heavy-artillery
troops, — being "battery," "platoon," and "detachment movements," and
" subdivision movements," or those common to all three of such tactical
sub-units.

This section of the MSS. has met with critical trial, (with troops on the
drill-ground,) close scrutiny, and lengthy discussion, with a -view to deter-
mining what may be best calculated to insure to the service the best means
for the performance of duty devolving upon artillery troops.

It is found that the proposed marching drill is based upon that laid down
in the already-accepted foot drill for field artillery, and that the latter has
been modified only so far as the peculiarities of the heavy-artillery service
render necessary or desirable; such, for example, as emancipation from
the "lock step"; the omission of "section" movements as only essential for
field artillery ; the assimilation of the movements of the guides to those of

PREFACE. V

the infantry, and a discontinuance of the requirement from detachment
chiefs to repeat all commands, as tending toward confusion and being
entirely unnecessary.

The few additional movements are essentially adapted from the infantry
tactics, and render the proposed marchinjr drill complete.

It is the judgment of the Staff, that while the proposed drill is essential
for the service of heavy artillery, and also fully suited for all the duties of
artillery troops in garrison or elsewhere in the presence of guns, it is at the
same time so closely assimilated to the tactics of infantry in its principles
as to render the transition of heavy-artillery troops into infantry formations
a thing of quick and easy accomplishment. The same, moreover, may be
said in reference to its adaptation for the service of field guns, although its
departures from the authorized foot drill for field artillery are but slight,
and always in the direction of assimilation with the infantry tactics, which
is understood to be the published policy of the General of the Army in such
questions.

The Staff is therefore of the opinion that the adoption of this section of
the MSS. under consideration will in no way impair the efficiency of the
artillery regiments in the infantry duties which they may be called upon to
perform, while it will, on the other hand, facilitate the duties pertaining to
their special arm, because its tendency as a means of discipline and esprit
du corps is to strengthen and confirm habits of thought in that direction by
continually reminding the men of their weapon as artillerymen.

2. Service of the Piece ; 3. Mechanical Mancetjvres. These sections
embrace the drill for all classes of pieces known as heavy artillery, and the
MSS. are the result of several years' experience at the Artillery School, of
daily study, experiment, and observation.

The Staff has carefully examined, revised, and tested this section at the
guns, and is of the opinion that it meets the requirements for handling
the ordnance now in use.

4. Care and Preservatiox of Artillery Material ; 5. Transporta-
tion" OF Artillery. These sections embrace the care and preservation of
all classes of guns and their belongings, together with the care of stores
and of magazines; also the transportation of artillery under all circum-
stances of service, including railroad and water transportation for artillery
material and animals. The MSS. are the result of a life-time's extended
experience in the U. S. artillery service in peace and war. Much of the
matter is derived from actual experience in the war of 1861-65, and has
never been published in any book or report. The Staff is confident that it
supplies a vacancy in American military literature.

6. Organization and Command of Artillery; 7. Employsient op
Artillery in Campaign. These sections embrace all of a subject of great
magnitude, which is indicated by their titles, that there seems room for in
a book of the kind under consideration. It cannot be doubted that there is
to be found in the artillery of modern war the points of support with which
to counteract the effect of the open nature of infantry fighting consequent
upon the breech-loader, and that it is the stable element of battle of to-day
in the hands of a G-eneral, because the dispersed order of the infantry for
action renders command of that arm at all times difficult, and quite im-
possible as the fighting progresses. There can be no doubt, furthermore,
that the object which artillery has to attain must be comprehended from
the beginning of its action, and must not be left to chance. It is therefore
advantageous, to say the least, that there should be one command ; for the
reason that everything becomes simpler and the carrying out of the fight
more certain, because more unity of will pervades it.

To support this \'ipw, it is not deemed necessary here to expatiate upon
the advantages of the employment of nrtillery in large masses, because the
object is self-evident and is accepted by most officers of experience and cul-
ture as an established fact. These sections of the MSS. are the result of

VI PREFACE.

the war experiences of the American artillery, and have followed closely
the system pursued at the close of the war of 1861-65 in points of organiza-
tion and command, although the modified conditions of the battle of to-day
have presented a few corresponding modifications in the employment of artil-
lery which have been fully treated in addition. Although we have passed
through one of the most sanguinary conflicts of modern times, in which the
genius of the American soldier was severely tested, and the nature of the
"^ terrain'^ entirely difierent from any which is treated of in the text-books
heretofore used by our officers in study, and althoiigh we have been at pro-
found peace with the world for fourteen years, with ample leisure for such
undertakings, it is a singular fact that no American work is extant which is
based upon our experiences, giving authoritative instruction in the applica-
tion of our arms, beyond what is laid down in the drill-books.

Now, the necessity for such works is self-evident ; for although we are not
a warlike people, we possess an inherent military spirit which requires
direction to be available in the public defense, and such text-books tend to
imbue our armies with character and military intelligence when action is
required of them. This is especially so in the case of auxiliary troops, such
as volunteers and militia.

The Staff" is of opinion that these sections of the MSS. constitute a step in
the right direction ; and while the subject-matter pertains largely to field
artillery, it is not considered as tenable as against its publication in this
work, because it is germane to the artillery service in general and impor-
tant to be preserved. Moreover, there is no just reason in favor of such a
divorce between the light and heavy artillery service, any more than there
has been found one in favor of such a separation of the light and heavy
infantry of the past.

The proposed composition of an artillery force in regard to pieces of long
range, or for the development of curved fire in the field, is remembered by
the Staff" as identical with our practice in the war of 1861-65, and the princi-
ple involved is confirmed and strengthened by the m.ore recent experiences
of European nations, notably in the Franco-Grerman and Busso- Turkish
wars.

The increased zone of effective infantry fire calls imperatively for long-
range artillery of great accuracy and quick manipulation, so far as guns are
concerned ; while the universal use of field intrenchments, already rendered
necessary by a murderous infantry, demands with equal obstinacy the full
use and development of curved fire from mortars on the part of artillery,
both in the attack and defense.

The provision in the MSS. for the nse of such pieces as we now have in
service is therefore regarded by the Staff" as an advance toward meeting
these new questions as far as possible with economy, while it reserves for
future settlement the question of improved artillery material in view of
these demands. With these views, the Staff" cannot too strongly recom-
mend these sections of the MSS. for favorable consideration and publica-
tion.

8. Employment op Artillery against Armored Vessels and in Har-
bor Defense. This section embraces as much of this important subject as
will admit of a proper limit in size of the book under consideration. It is a
subject upon which little or nothing has been written, and the expressed
desire of the General of the Army that it should be included, is regarded as
sufficient reason for presenting it.

9. EiELD Intrencievients ; 10. Attack on Field Intrenchments, The
MSS, embrace in these sections as much of the subject-matter indicated by
their titles as is deemed essential.

It is necessarily a compilation upon a subject which is older than the
service itself, and the Staff" is informed that it is inserted upon the sugges-
tion of the General of the Army. Further comment, therefore, seems un-
called for.

PREFACE. Vll

11, SuBMARi>rE Mixes. This subject is not only important, but highly
essential to be understood by artillery troops, upon whom such service will
most likely devolve in war ; and while secrecy in the matter of particular
inventions may be desirable, such secrecy is easily within the control of the
governm.ent.

The Staff finds no reason against a publication of so much of the subject
of submarine mines as these MSS. embrace.

In conclusion, the Staff is of the opinion that, as a whole, Major Tidball's
work is full and complete for the present use of the artillery service ; that it
is in harmony with the experience of the Army in war as well as with the
spirit of its organization and instruction in peace ; and that it is calculated
and is probably invaluable,f or the instruction of volunteer and militia artil-
lery, upon whom much of the service of heavy artillery will devolve in any
war, and whose attention should undoubtedly be directed to such instruc-
tion in peace, rather than toward field-artillery drill merely, as is now the
custom.

In this latter connection the Staff respectfully invites attention to the fact
that the maintenance of miilitia field batteries in peace is expensive, and
never attended with warrantable success from the very nature of things,
and that this branch of artillery can only be kept up in efficiency by the
government.

With these views, the Staff of the U. S. Artillery School feels warranted
in submitting Major Tidball's work for the favorable consideration of proper
authority, recommending its immediate publication.

It is also respectfully recommended that the work be adopted for the
Army and for the Militia.

"We have the honor to be, very respectfully, your obedient servants.

Headquarters of the Army,

Washingtok, D. C, December 10, 1879.
Hon. Geo. W. McCrary,

Secretary of War.
Sir: I have carefully examined the manuscript copy of the proposed
Heavy Artillery Tactics prepared by General Tidball, and the reports and
papers relating thereto, and find —

1st. That the manuscript of the Tactics (a better designation would be
"Manual") consists of twelve parts.

********

As already indicated, it would seem that a modification of the title of the
work is desirable, and I would suggest the following, viz. :

"A Manual for the Heavy Artillery Service, prepared for the use of the
Amiy and Militia of the United States, by Major J. C. Tidball, 2d artillery,
Brevet Brigadier-General. U. S. A., 1879."

With the title thus modified, the work will consist of parts numbered I,
n. III, IV, Y, YIII, IX, X, XI, XII, or ten out oi the twelve parts prepared,
and I therefore recommend that it be published accordingly, as modified.

The degree of authority to be given it might be based upon that given
January 24, 1876, to Roberts' "Hand-Book," or thus:

"The Manual for Heavy Artillery Service pi'epared by Major J. O. Tid-
ball is hereby apjjroved, and will be adopted as a text-book at the Artillery
School at Fort Monroe, and used by the artillery companies (batteries)
garrisoning the sea-coast forts of the United States. (Signed) G. W. Mc-
Crary, Secretary of War."

I have the honor to be, your obedient servant,

(Signed) W. T. SHERMAN, General.

Approved: (Signed) GEORGE W. McCRARY,

Secretary of War,

CONTENTS.

PAGE.

Marching Manoeuvres 5

Definitions 34

Ammunition 41

Implements , 53

Aiming and Motion of Projectiles 56

Carriages and Platforms 65

Service of the Piece. (General Rules.) 79

Service of Siege Gun; Siege Howitzer; 10-inch Gun; 100-
pounder Parrott; 15-inch Gun; Flank-casemate How-
itzer; 8-inch Rifle (converted); 10-inch Siege Mortar;
8-inch Siege Mortar ; Coehorn Mortar ; 13-inch Mortar ;

10-inch Sea-Coast Mortar ; Gatling Guns 83

Target Practice 183

Telemeters and Pressure Plug 192

Mechanical Manoeuvres, (General Directions.) 199

Mechanical Manoeuvres with Siege Gun ; Siege Howitzer ; Siege

Mortars ; 13-inch Mortar 204

Cordage; Blocks and Tackles 231

Machines and Appliances for Moving Heavy Artillery 242

Mount and Dismount the Flank-casemate Howitzer; 15-inch

Gun; 10-inch Gun 271

Gun-lift; Shears; Derricks 2*79

Preservation of Artillery Material 293

Inspection of Cannon 301

Magazines and Store-houses 312

Transportation of Artillery 321

Harbor Defenses ; Strength and Composition of Batteries ; Artil-
lery against Armor 343

Field Intrenchments 357

Attack and Defense of Positions 403

Sieges; Defiles; Rivers; Demolition 407

Submarine Mines 425

Permanent Fortifications. (Outlines of) 458a

Salutes, Ceremonies, and Official Courtesies 459

Appendix 2 4 V «a

Index 479

Illustrations Plate 1 to 77

(viii)

HEAVY ARTILLERY,

U. S. Army, 1879.

1, By the term Artillery^ is understood all fire-arms discharged
from carriages, in contradistinction to small arms^ which are dis-
charged from the hand. It also denotes the particular troops
employed in the service of such fire-arms.

i. Artillery is known as Light Artillery and Heavy Artil-
lery, Light Artillery is formed into batteries and equipped for
field evolutions; Heavy Artillery embraces all artillery not so
formed and equipped.

3. In the land service of the United States there are three
kinds of pieces of Heavy Artillery^ viz. : tlie GuN, the Howit-
zer, and the Mortar.

4. They are distinguished, according to their principal use,
as Siege and as Sea-Coast Artillery.

5. Siege Artillery is used in the attack of places, and, as it
accompanies armies in their field operations, is mounted upon
carriages, which serve for its transportation.

It is also employed in the defense of field works. It is then
sometimes called Garrison Artillery.

6. Sea-Coast Artillery consists of the heaviest calibres, and is
used for the armament of permanent works, chiefly on the sea-
coast. Their carriages do not subserve the purpose of transpor-
tation.

7. For the service of Heavy Artillery there are four distinct
kinds of carriages required, viz. : the Siege, the Casemate,
the Barbette, and tlie Mortar.

8. The following are the kinds and calibres of Heavy AHillery
belonging to the present system of artillery for the land service
of the United States.

Note. — The term ''system," as here used, refers to tlie char-
acter and arrangements of the material of artillery, as adopted
by a nation at any particular epoch.

(1)

INTRODUCTION.

PIECES.

BiND.

Gun

Howitzer.

Mortar.

Calibke.

20-in.
15-in.
" ' 13-in.

12-in

10-in

4.5-in

8-in

5.8-in.— ( n a n k
casemate)....

15-in

13-in

10-in

8-in

Bore.

Smooth.

5.8-in. (Coehom)

Smooth.

Rifled.

Weight.

116,000
49,000
37,000
52,000
40,681
3,570
2,600

1,476

17,120

3,700

1,900

1,010

164

Designation.

Sea-coast.

Siege.

Sea-coast.

Siege.

In service^ hut not of the system.

G-nn. •••••••••

«<

lO-in

Smooth .

15,000

Sea-coast.

t( tt

tt <{

tt tt
tt tt

Siege.

8-in

8-in. (converted)
10-in. 300-pdr.1
8-in. 200-pdr. 1
6.4-in. 100-pdr. f
4.2-in. 30-pdr..

Rifled..
«

16,160

26,000

16,300

9,700

4,200

Parrott...

Note. — The 20-inch and 13-inch smooth-bore, and the 10 and
12 inch rifle guns, as likewise the 15-inch mortar, may be regard-
ed as experimental pieces, not more than two or three of each
kind having been cast. Carriages for them have not 5'^et been
determined; consequently instructions for their service must
be omitted.

The 4.5-inch siege gun, 8-inch siege howitzer, 5.8-inch (flank-
casemate) howitzer, the 5.8-inch (Coehorn) mortar,, and the 4.2-
inch (Parrott) siege gun are mounted on wooden carriages ; all
other pieces on iron carriages.

It is intended that the 15-inch smooth-bore and 12-inch rifle
guns shall have the same carriage ; the 10-inch smooth-bore and
8-inch rifle the same carriage.

The 10-inch smooth-bore and the 200-pounder (Parrott) have
the same carriage, and the 8-inch smooth-bore and lOO-pounder

INTRODUCTION. 8

<Parrott) have the same carriage. The 20-inch smooth-bore has
a separate carriage.

9. Instruction in Heavy Artillery is divided into ten parts,
viz. :

I. PREIilMINARY INSTRUCTION.

II. Service of the Piece.

III. Mechanical Manoeuvres.

IV. Care and Preservation of Artillery Mate-

rial.
V. Transportation of Artillery.
VI. Employment of Artillery against Armored

Vessels and in Harbor Defenses.
VII. Field Intrenchments.

VIII. Attack and Defense of Intrenched Positions.
IX. Submarine Mines.

X. Outlines of the General Properties of Per-
manent Works.
XI. Salutes and Ceremonies.

. > * , ) TOO

PRELIMINARY INSTRUCTION.

10. The officers and men for Heavy Artillery duties should
be thoroughly instructed in the *■" School of the Soldier," LigJit
Artillery and Infantry Tactics. The preliminary instructions
herein given are only such as are, in addition, necessary for the
more general duties of artillerymen.

11. The term piece^ as herein used, applies to cannon, wheth-
er gun, howitzer, or mortar. As a matter of convenience, it is
also used to designate both cannon and carriage when the can-
non is mounted.

Detachment,

12J. The men employed in the service of artillery are called
artillerymen.

The artillerymen for a single piece constitute a gun detach-
ment^ and vary in number with the size and kind of piece.

13. The detachment [Fig, 1, Plate I) is- composed of two
non-commissioned officers, and from two to ten privates. The
senior non-commissioned officer is called chief -of -detachment ;
the other, gunner. The privates are called cannoneers.

14. The detachment is formed in double rank, and told off
from the right as follows : No. 1 is on the right of the rear rank;
Xo. 2 in front of No. 1 ; No. 3 on the left of No. 1 ; No. 4 on
the left of No. 2 ; the other numbers follow in the same order,
€ven numbers in the front, odd in tlie rear rank. When, by
facing about, the front becomes the rear rank, the numbers of
the cannoneers do not change.

15. The chief-of -detachment., when in line, is on the right of
the front rank of his detachment. When, by facing about, the
front becomes the rear rank, he does not change to the other
flank, but steps forward into the rear (now become the front)
rank. When in column of files, he is as if he had faced with his
<letachment from line.

16. The gunner., in line, and in column of platoons, is two
yards in rear of the centre of his detachment, except when be-
longing to the left detachment of the battery in line., or of platoon
when in column of platoons., — ^in either of which cases he places
himself on the left of the front rank of his detachment, and is

(5)

6 PRELIMINARY INSTRUCTION.

tbe ,^ilde o^ that flauk of the battery or platoon ; in column of
dtetaohment^s'hy^ Jt^ioii a line with the front rank of his detach-
rteilt^^, on ilie flank towiuxls which the wheel was made, and one
-ynirii frcap jt ; in eohiem of files, he is as if he had faced with liis
;dr.*;ici'nn<:nf. fiy>jn line. When he is the left gnide of the battery
or platoon, and by Jacin^ about the front becomes the rear rank,
he does not quit his position on tlie flank of his detacliment, but
steps forward into the i-ear (now become the front) rank.

IT. Wlien, by wheeling: about, the riglit subdivision becomes
the left, the g^nnner who was the left i^^uide resumes his place in
rear of ins detachment, and the prunner of the detaclnnent which
has now become the left places himself on its left flank as guide
of the batterj' or platoon.

Flaioon.

18. T\\*o or more detachment^! form a platoon, commanded
by a lieutenant ; and, if ciiXMimstances will permit, the battery
will be divided into as many platoons as there are lieutenante
to Ci^mmand them.

Battery,

19. The term battery is now applied to what was formerly
called a oomi^>jiny. It is also used to designate a number of
pieces of ,ariillery in position for service; likewise the place in
a work when* they may bt» located ; and it further denoteii cer-
tain p<^itions in the manoeuvres with individual pieces. When-
ever this term is used, its meaning must be determined from the
context.

^O. The battery is assigned to specified pieces in the work,
the number dejHMiding on the strength of the K-ittery; the lat-
ter is divided into a like number of detachments, and these are
assigned to the individual pieces. Although thus assigned to the
service of specified pieces, the several detachments should be
Instnwjted for the service of any piece in the command. The
men of each detachment should be selected for their individual
fitness for the \^rticular piece.

^ 1 . The detachments receive permanent numbers, from right
to left, tlie first detj^chment being on the right.

Platoons are in like manner permanently designated.

^^ During the roanoBUvres, platoons temporarily change
tlieir numbers, when, by wheeling, or by facing, the original
rigiit btxx>mes the left. ' In column, they are numbered from
the head, the leading one bc^ng al\s^ys the ^A^.

9^ The men of cadi detachment fall in\according to lieight^
the tallest men on the right: thus bringing, as a genenal rwle*
Ihe ^longest men to the duties requin^ir ir^*atest stn">irtb.

PRELIMINARY INSTRUCTION.

Posts of officers^ non-commissioned officers^ 8fc.

24. {Figs. 2 and 3, Plate I.) The captain^ in line, is four yards
in front of the centre of the battery; in column, on the side of
the guide, or on the side towards whicii the subdivisions are
dressed, four yards from the flaniv and opposite tlie centre of the
column ; as instructor, he goes wherever his presence is neces-
sary.

SJ5. The senior lieutenant takes post with the right platoon ;
the next in rank with the left platoon ; the third with the sec-
ond from the right, and the fourth with the second from the
left.

Each lieutenant is chief ol the platoon with which he is posted :
and in line, and in column of platoons, is two yards in front of
the centre of his platoon ; in column of detachments, each is on
the side of the guide, or on the side towards which the subdivis-
ions are dressed, two yards from the flank of the column, and
opposite tiie centre of the platoon ; (they are always on the side
opposite that of the gunners: par, 23;) in column of tiles, each
as if he liad faced witii the battery from line, except tlie chief of
the leading platoon, who takes post by the side of the leading
guide.

St6. The first-sergeant^ in line, is on the rigiit of the battery,
aligned on the front rank and one yard from it; in column of
platoons and of detaclmients, he is on the same side as the cliief-
of-platoon, aligned on the front rank of the nearest subdivision
and one yard from it; in column of files, he is as if he had
faced with tlie battery from line. Wiien two or more batteries
are united in line, he is as explained in {see Battalion).

^H, Each chief -of -detachment is on the right of the front
rank of his detachment, as in par. 1;").

28. Each gunner is two yards in rear of the centre of his de-
tachment, except as provided in par. 16.

29. The trumpeters^ in line, are in one rank on the right of
the first-sergeant, and two yards from liim ; in column of pla-
toons and of detachments, they wheel to tlie side indicated, and
are either four yards in front of the centre of tlie leading subdi-
vision, or four yards in rear of the last subdivision, according as
the column has been formed towards their flank of the battery,
or the opposite ; in column of files, they are as if they had faced
with the battery from line, and the one in rear stepped to the
right, or left, of the other, according as they faced to the right
or left.

30. The guides of a battery or platoon are the non-commis-
sioned officers x>osted on its riglit and left ; the guides of a de-

8 PRELIMINARY INSTRUCTION.

tachment are the chief-of-detachment and the front-rank man
on the opposite flank.

31. Tlie chief s-of-detachnients and platoons give or repeat
commands only when it is prescribed. This rule is general.*

32. For the purpose of instruction in marcliing drills the de-
tachments are equalized, and should not consist of more than
eight cannoneers.

33. When the battery faces about in line, the first-sergeant
and the trumpeters face about, but do not change to the other
flank.

34. When the nnnr>er of platoons and detachments are so
reduced as to make surplus officers or non-commissioned officers,
these take their places two j^ards behind the rear rank, and, with
the gunners, act as file -closers; the ofticers, and likewise the
non-commissioned officers, distribute themselves at equal dis-
tances from right to left, according to rank.

35. It is the duty of file -closers to rectify mistakes, and in-
sure steadiness and promptness in the ranks.

36. In all changes of formation, as soon as the movement
permits, the officers and non-commissioned officers, whose posts
are changed, hasten by the shortest routes to their posts in the
new formation ; except, when in column of detachments, the
detachments are wheeled about, they do not change, unless
directed to do so by the instructor.

To form the battery.

31. At the soimding of the assembly^ the first-sergeant, facing
the battery and six yards in front of its centre, commands :

1. Fall in, 2. Left^ 3. Face, 4. Call rolls, 5. Report.

The batter}?^ being divided into permanent detachments, as
prescribed in par. 28, at the command fall in the chiefs-of-
detachment place themselves on the line facing to the right,
and at sufficient distance from each other for the formation of
the detachments; the men of each detachment fall in, facing
to the right, the front-rank men covering their chief; the sig-
nal iiaving ceased, the first-sergeant causes, if necessary, the
detachment to close up.

At the command face., all face to the left.

At the command call rolls., the chiefs-of-detachment step out
two 5'^ards in front of the centres of their detachments, face
towards them, call their rolls, and resume their places in the
ranks.

At the command report., the chiefs-of-detachment, standing
fast, report to the first-sergeant, in succession from right to left,

* See (e), Appendix 2.

PRELIMINARY INSTRUCTION. 9

the results of their roll-calls ; the first-sergeant then commands :
Call off, when each chief-of-detacliment steps promptly in
front of his detachment and faces toward it to see that the men
call oft' properly ; each man in turn calls out distinctly his num-
ber — owe, two^ three^ and so on ; the gunner calls last — gunner.

38. If tlie front and rear rank contain an unequal number
of cannoneers, the odd file is tlie left front-rank man, and the
vacant space is in rear of him until after calling ott"; the left
man of the rear rank then steps to his left and covers the left
front-rank man ; he, however, retains his number, and at the
piece takes the position belonging to it.

The first-sergeant then faces about, salutes the captain, or
other ofiicer acting in his place, reports the result of the roll-
calls, and takes his position in line.

39. If, for marching drills or any other special purpose, the de-
tachments are required of equal size, this is effected by transfer-
ring men from the stronger to the weaker detachments ; but for
ordinary service, such as marching to and from the place of exer-
cise with the pieces, the detachments need not be of equal size.*

40. When a battery is to form for ordinary garrison pur-
poses, such as fatigue duties. Or for roll-calls when the battery
is small in numbers, the first-sergeant places iiimself six yards
in front of the centre, facing towards the battery, and com-
mands : Fall in.

At the command yaZ^ in, the senior duty-sergeant places Iiim-
self, facing towards the right, at the point where the right of the
battery is to rest; the privates fall in, in two ranks, facing to
the rigiit, the front-rank men covering the senior duty-sergeant.

The second duty-sergeant takes his place in rear of the last
front-rank man, and the other non-commissioned officers place
themselves, facing in the same direction as the rest, in such
positions as, when they face to the left, will bring them equally
distributed along tiie line ; the first-sergeant commands : 1.
Left^ 2. Face, when the men face to the left; he then calls
the roll, reports, as in par. 38, and takes his post in lino ; at
the same time the officers take posts.

41. If the battery is to exercise at marching drill., after being
thus formed, the first-sergeant, before reporting, divides it into
the desired number of detachments of equal size, and assigns
the chiefs-of-detaclnnent and gunners to their respective detach-
ments, who take their posts accordingl}^ The detaclnnents call
off* as before.

If the exercise is to be at the pieces, the detachments are told
off' in sizes to suit the particulai* pieces, and the chiefs and gun-
ners are assigned as before.

See (a), Aj)pondix 2.

10 MARCHING MANCEUVRES.

42. The manoeuvres of a separate platoon are identical with
those of a battery, the command platoon being substituted for
battery.

43. The manoeuvres of a separate detachment are analogous
to those of a battery, the command detachment replacing that
of battery. The chief-of -detachment acts as instructor, and i&
replaced on the right flank of the detachment by the gunner.

44. The captain, or in liis absence the next officer in rank,
acts as instructor.

45. All movements not specially excepted may be executed
in double time. If the movement be from a halt, or when march-
ing in quick time, tlie command double time precedes the com-
mand march ; if marching, this command is omitted.

46. Officers, wlieu on duty with men, will habitually wear
their swords; when in r.mks, or when giving commands, the
sword must be drawn. Instruction in the use of the sword is
given in Light Artillery Tactics.

47. The trumpet signals and rules for using them are those
prescribed in Light Artillery Tactics.

48. When artillery is armed, equipped, and serving as either
cavalry or infantry, and organized into commands of these
arms, it will conform to the formation and tactics prescribed,
respectivelj'^, for these brandies of service.

Marching Manceuyres.

The following manoeuvres are those most essential, and gen-
erally used by Heavy Artillery troops. The principles embraced
in them will serve for more extended exercises.

To open ranks.

49. Being in line, at a halt, the instructor commands :

1. Rear open order., 2. March, 3. Front.

At the first command, the chiefs-of-detachment, and gunner
acting as left guide, step brisklj'' three yards to tlie rear to mark
the new alignment of tiie rear rank; the insti-uctor goes to tlie
riglit flank and sees that these non-commissioned officers are on
a line parallel to the front rank.

50. When the batterj?- is not divided into detachments, the
non-commissioned officer on the right and left flanks, respect-
ively, steps back to mark the line.

At the command march., the chiefs-of-platoon step forward
one yard, thus bringing themselves three yai'ds in front of the
battery. Should there be officers in the line of file-closers, they

MARCHING MANCEUVRES. 11

pass around the nearest flank and place themselves in the line
of officers opposite their former positions. The front-rank men
dress to the right ; the rear-rank men cast their e3^es to the right,
step backwards, halt a little in rear of alignment, and then dress
to the line established by the non-commissioned officers who
have stepped back ; the file-closers step back at the same time,
taking a distance of three yards from the rear rank.

The instructor superintends the alignment of the chiefs-of-
platoon and of the front rank, and tlie first-sergeant, or in his
absence the chief of the right detachment, that of the rear rank;
the instructor verities the alignment of the rear rank and of the
file-closers ; the chief s-of-platoon and file-closers cast their eyes
to the front as soon as their alignment is verified.

At the command fronts the non-commissioned officers who
have stepped back to mark the line for the rear rank resume
their places in the front rank, and the men cast their eyes to the
front; the first-sergeant returns to his post, and the instructor
places himself six yards in front of the centre of the battery^
facing to the front.*

To close ranks.

5SJ. Being at a halt, the instructor commands :

1. Close order ^ 2. MARCH.

. At the command march^ the chief s-of-platoon face about and
resume their posts in line ; the rear rank closes to facing dis-
tance, each man covering his front-rank man; the file-closers
move forward with the rear rank and take their posts in line ;
the instructor resumes his post in line.

Alignments.

53. Being in line, at a halt, with the ranks open, the in-
structor establishes two or four men as a basis for each rank, at
first in parallel and afterward in oblique directions to the front
of the battery. He then commands :

1. By file^ 2. RigM (or left\ 3. Dress, 4. Front; or, 1. By
jile^ 2. RigM (or left) backward^ 3. Dress, 4. Front; or,
1. Right (or left)^ 2. Dress, 3. Front; or, 1. Right (or
left) backward^ 2. Dress, 3. Front.

Each rank is aligned as explained in the School of the Soldier,
the rear rank remaining parallel to the front rank. The ranks
being closed, the alignments are repeated in the same manner.

In all alignments, the file-closers preserve their distances from,
the rear rank.

* See (b), (c), (d), Appeadix 2.

12 MARCHING MANCEUVRES.

To rest.

54. Being at a halt, the instructor commands :

1. Battery^ 2. Rest; or, 1. In place.^ 2. Rest.
To resume attention, the instructor commands:
1. Battery^ 2. Attention.

To dismiss the battery.

55. Being in line, at a halt, the instructor comm i:: Js : Dis-
miss THE BATTERY.

The officers return their swords and fall out; the first-sergeant
then commands :

1. Break ranks ^ 2. March.

To march in line,

56. The battery being at a halt, and correctly aligned, the
instructor commands :

1. Forward., 1. Guide {right ov left)., 3. March.

At the command forward., the guide selects two points on a
line passing through him and perpendicular to the front of the
batterj"; at the command march., the men step off with life ; the
guide observes with the greatest care tlie length and cadence of
the step, marches on the two points he has chosen, and selects
others in advance on the same line before reaching the first ; the
file-closers keep at their proper distances from the rear rank.

To halt the battery and to align it.
5'y. The instructor commands :
1. Battery, 2. Halt, 3. Right (or left), 4. Dress, 5. Front.

To march in the short step ; to mark time ; to change step ; to
side step ; to march backward ; to oblique in line ; to pass
from quick time to double time, and the reverse.

Executed as explained in the School of the Soldier, substi-
tuting, in the commands, battery for squad, wherever the latter
occurs.

58. In the oblique march, the ranks remain parallel to their
former position.

59. In marching in double time the left hand, instead of be-
ing raised, steadies the scabbard ; the sword, if drawn, is held
in a vertical position in the right hand.

MARCHING MANOEUVRES. 13^

To wheel the battery.

60. Being in line, at a lialt, the instructor commands :

1. Right (or left) wheel, 2. March, 3. Battery^ 4. Hai^T, 5. Left
(or right), 6. DRESS, 7. Front.

At the command march, the battery wheels to the right on a
fixed pivot; the left guide conducts the marching flank; the
right guide stands fast, so that tlie breast of the pivot-man may-
rest against his left arm at the completion of the wheel ; the
chiefs -of -platoon face about at the first command, step back-
ward at the second, and superintend tiie movements of tlieir
platoons, resuming their positions at the command front; the
instructor hastens by the shortest line to place himself directly
in front of the pivot-guide, and at a distance from him equal to
the length of the battery front, and faces to the late rear.

At the command/mZ^, given when the left guide is three yards
from the perpendicular, tlie battery halts; the left guide of the
battery advances quickly, places his loft elbow lightly against the
breast of the instructor, who establishes him on the line.

At the command dress, the men dress up to the line of the
guides; at the command y'ro/i^, the right guide places himself on
the right of the pivot-man.

61. To continue the march upon the completion of the wheel,
the instructor, without placing himself in front of the pivot-
guide, commands : 3. Forward, 4. March, 5. Guide right (or
left). The tiiird command is given when t he guide on the march-
ing flank is three yards from the perpendicular to the original!
front ; the fourth, the instant the wheel is completed ; and the
fifth immediately after. The guide on the pivot places himself
by the side of the pivot-man at the command /b?'warc?.

62. Marching in line, the instructor commands :

1. Right (or left) wheel, 2. March, 3. Forward, 4. March..

At the second command, the battery wheels to the right on a
movable pivot ; the command forward is given when tiie guide
is three yards from the perpendicular, and the fourth command;
at the instant the change of direction is completed.

In wheeling on a movable pivot, the command forward is given
in sufficient time to add march the instant the wheel is comple-
ted. This rule is general.

63. Marching in line, to eff'ect a slight change of direction,
the instructor commands :

' Incline to the right (or left).

The guide advances gradually the left shoulder, and marches-

14 MARCHING MANOEUVRES.

in the new direction ; all the files advance the left shoulder and
■conform to the movements of the guide, lengthening or shorten-
ing the step according as the change is towards the side of the
guide, or the opposite.

To march by the flank,

64. Being in line, at a halt, the instructor commands :
1. Right (or left\ 2. FACE, 3. Forward. 4. MARCH.

If marching, the instructor commands :

1. By the right (or left) flank^ 2. March.

The march in column of files is usually in quick time ; if neo-
•essary to march in double-time, the distance between files is
Increased to thirty-two inches, and, upon halting, the files close
to facing distance.

65. To halt the battery, and form it in line, the instructor
commands: 1. Battery^ 2. Halt, 3. Left (or right), 4. Face;
or, to form line and continue the march : 1. By the left (or right)
Jlank, 2. March, 3. Guide {right or left).

To oblique and to change direction in column of files. Exe-
cuted by the commands and means prescribed in the School of
the Soldier.

To form column of platoons to the right or left,

66. Being in line, at a halt, the instructor commands :

Platoons right (or left) wheel, 2. March.

At the first command, each chief-of-platoon, facing it, cautions
it : Right wheel.

At the command march, each platoon wheels to the right on a
fixed pivot, as explained for the wheel of a battery. Each chief,
superintending the wheel of his platoon, hastens to the point
where the left of his platoon is to rest on the completion of the
wheel; faces to the late rear, and when the marching flank
approaches him, commands : 1. Platoon, 2. Halt, 3. Left, 4.
Dress, 5. Front.

At the command halt, the guide on the marching flank places
his left arm against the breast of his chief, who then aligns the
platoon and takes his post in front of its centre, after command-
ing front. If marching, the movement is executed as just ex-
plained, the pivot-guides halting at the command march, mark
time in their places, and conform to the movements of the front
of the platoon.

67. In every case where a line is broken in platoons, the

MARCHING MANCEUVRES. 15

^nner of the left detacliment of each platoon, if not already
there, hastens to place himself on the left flank of his detach-
ment as soon as the movement will permit; he then becomes
the left guide of his platoon. Wlien the line is reformed, he
hastens to resume his former position.

68. To form column of platoons to the right or left and con-
tinue the march instead of halting, the instructor commands :

1. Continue the marcli^ 2. Platoons right (or left) wheels 3.
March, 4. Forward, 6. March, 6. Guide {right or left).

The movement is executed as before, except that each chief
remains in front of the centre of his platoon, and the platoons
move straiglit forward at the fifth command. The leading guide
prolongs accurately his line of march hj choosing successively
points in advance ; the other guides preserve with care the trace,
the step, and wheeling distance.

To put the column of platoons in march, and to halt the column.

69. The instructor commands :

1. Forward, 2. Guide {right or left), 3. March, and 1. Bat-
tery, 2. Halt.

To form line to the right or left from column of platoons.

TO. Being at a halt, the instructor commands :

1. Right (or left) into line wheel, 2. March, 3. Battery, 4.
Halt, 5. Left (or right), 6. Dress, 7. Front, 8. Guides,
9. Posts.

At the first command, each chief-of-platoon, facing it, cautions
it : Right wheel.

At the command march, the pivot-guides stand fast in their
places and the platoons wheel to the right on a fixed pivot. At
the command halt, given when the marching flanks arrive near
the line, the subdivisions halt ; the instructor places himself, fac-
ing to the right, on the prolongation of the line of the pivot-guides,
at the point where the marching flank of the leading subdivision
is to rest. At the command dress, the battery dresses up to the
line established bj' the pivot-guides and instructor, the left guide
of the leading subdivision touching the breast of the instructor
•with the left arm; the instructor superintends the alignment,
and gives the commund front upon its completion. At the com-
mand guides posts, the guides return to their places in line.

If marching, the movement is executed as just explained,
•except that, at the command march, the guides and pivot-men

16 MARCHING MANCEUVRES.

halt ; the pivot-men mark time and turn in their places, so as to
conform to the movement of the marching flank.

f 1. To form line and continue the marcii, the instructor
commands : 3. Forward^ 4. March, 5. Guide {right or left). At
the Q,ou\uiB,Vi(\. forward^ tlie pivot-guides take their places in line*

To form line to the front column of platoons.

72. Being at a halt, the instructor commands : 1. Right (or
left) front into line, 2. MARCH, 3. Front.

At the first command, the chief of the leading platoon com-
mands : 1. Forward, 2. Guide left; the other chiefs command :
Right oblique. At the command march, repeated by all the
chiefs, the leading platoon advances eighteen yards, when its
chief commands: 1. Platoon, 2. Halt, 3. Left, 4. Dress; the
other platoons oblique to the right until opposite their places in
line, when their chiefs command : 1. Forward, 2. March, 3.
Guide left, adding, as they arrive near the line : 3. Platoon, 4.
BLalt, 5. Left, 6. Dress; the instructor superintends the align-
ment from the left flank, and gives the command yVon^ upon its
completion.

If marching in quicJc time, the movement is executed as just
explained, the chief of the leading platoon commanding guide
left, if the guide be not already there.

If marching in quick time and the command be double time,
the instructor commands : Guide left immediately after the com-
mand march; the chief of the leading platoon does not halt it,
but cautions it to advance in quick time, and repeats the com-
mand for the guide ; each of the other chiefs repeats the com-
mand double time, and, when his platoon is about to arrive in
line, commands: 1. Quick time, in time to add: 2. March, the
instant it arrives abreast of the leading platoon.

If marching in double time, the chief of the leading platoon
commands : Quick time at the first command, and repeats the
other commands; the other subdivisions complete the movement
as before.

To form column of platoons from column of files.

•yS. The instructor commands :

1. Platoons, 2. Right (or left) front into line, 3. March, 4. Bat-
tery, 0. Halt.

At the command march, the leading guide of each platoon
moves straight to the front; all the files oblique to the right
until opposite their places in line, when each marches to the
front.

MARCHING MANCEUVRES. 17

The leading guide of eacli platoon moves forward until the
command halt^ which is given when he has advanced live yards ;
the other men halt on arriving in line ; each guide in rear places
himself on the right of the front rank upon the arrival of the last
file; the leading guide having halted, each chief dresses his
platoon to the left, and commands : Front when the last file
is aligned.

If the command be double time^ the instructor commands :
Guide left (or right) immediately after the command march j the
leading guide of each platoon moves forward in quick time ; tlie
other men oblique in double time, each taking the quick step
and dressing to the left upon arriving in line; the rear-rank
men then close to facing distance.

This movement is not executed when marching in double
time.

The instructor's command is right (or left) front into line^
according as the column of files is left, or right, in front.

T4. The column of files is right in front when the front-rank
men are on the left of their rear-rank men ; it is left in front
when the front-rank men are on the right of the rear-rank men.

To change direction in column of platoons.

75. Being in march, the instructor commands :

1. Column right (or left), 2. March.

At the first command, the chief of the leading platoon com-
mands : Right wheel; at the command march, which he repeats,
his platoon wheels to the right on a movable pivot, the chief
adding : 1. Forward, 2. March, upon tlie completion of the
wheel ; the other platoons march squarely up to the wheeling
point, and change direction by command of their chiefs as ex-
plained for the first.

76. In wheeling on a movable pivot, as the dress is always
toward the marching flank without command, whenever a Avheel
is executed toward the side of the guide, each chief, upon its
completion, cautions his platoon, guide right, or guide left, ac-
cording as the guide was right or left before the wheel.

77. In changing direction, each chief-of-platoon faces his
platoon while wheeling, and sees that the guide takes steps of
twenty-eight or thirty-three inches, and the pivot, steps of nine
or eleven inches, according to the gait.

Column half right (or half left) is similarly executed, each
chief giving the preparatory command right (or left) half wheel.

To make a small change of direction, the instructor cautions :
Incline to the right (or left).
2

18 MARCHING MANOEUVRES.

The leadin.^ guide advances his left shoulder and takes two
points a little to the right of those upon which he was mai'ching,
the men conforming to tlie new direction of the guide.

78. To put the column of platoons in march and change
direction at the same time, the instructor commands :

1. Forward^ 2. Guide {right or left)^ 3. Column right (or left)^

4. March.

To face the columii of platoons to the rear^ and to march to

the rear.

'^'9. Tlie instructor commands :

1. Platoons inght (or left) .about^ 2. March, 3. Battery^ 4.

Halt.

At the command march^ the platoons execute an about on a
fixed pivot; at the command halt^ each chief-of-platoon dresses
his platoon to the left, commands : Front, and then takes his
post.

To march to the rear after wheeling about, the instructor com-
mands :

3. Forward, 4. March, 5. Guide {left or right).

To form column of detachments to the right or left.

80. Being in line, the instructor commands :

1. Detachments right (or left), 2. March.

At the first command, the gunner, acting as left guide of the
battery, falls out and takes his place in rear of his detachment ;
at the command march, each detachment wheels to the right on
a fixed pivot ; upon the completion of the wheel, the front rank
of each take the full step (28 inches) ; the rear rank shortens the
step till it gains the distance of thirty-two inches from the front
rank ; the guide and dress of each detachment is, without fur-
ther command, towards the side opposite the gunners, i. e., to-
ward the wheeling flank; the leading guide prolongs accurately
his line of march by choosing successively points in advance ; the
other guides preserve with care the trace, the step, and wheel-

ing distance.

The gunners march one yard from the flank of their respective
detachments, and see that the ranks maintain accurately their
alignments and distances.

The positions of the officers, first - sergeant, gunners, and
trumpeters are as prescribed in pai^s. 26 to 33.

MARCHING MANCEUVRES. 19

To form column of detachments and halt.

81. The instructor commands :

1. Detachments right (or left)^ 2. March, 3. Battery., 4. HALT.

The fourth command is given the instant the front ranlc com-
plete the wheel ; the rear ranks fall back to thirty-two inches,
and all the ranks dress, without further command, toward the
marching flank.

82. In all wheelings by detachments, the forward march is
taken upon the completion of the movement, unless the com-
mand halt be given. This ride is general.

83. In column of detachments, the ranks dress toward the
flank opposite the gunners. This 7mle is general.

To march in column of detachments to the front from either flank.

84. Being in line, the instructor commands :

1. Right (or left) forward^ 2. Detachments right (or left)., 3.

March.

At the command march., the right detachment moves straight
to the front, with the guide to the left ; its rear rank, shortening
the step, falls back to thirty-two inches ; the other detachments
wheel to the right on a fixed pivot ; the second detachment,
when its wheel is nearly completed, wheels to the left on a
movable pivot, and follows the first detachment ; the other de-
tachments having wheeled to the right, move forward and wheel
to the left on a movable pivot on the same ground as the second.

Being in column of detachments., at a halt or marching., to change
the chief s-of-platoons and gunners from one fla7ik of the col-
umn to the other.

85. The instructor commands :

1. Officers and gunners change flank., 2. MARCH.

At the first command, the officers and gunners close into the
flanks of the column; and, at the command march., pass quickly
through the column between the detachments.

To put the column of detachment in march., and to halt the

column.

86. The instructor commands :

1. Forward., 2. MARCH, and 1. Battery., 2. Halt.

20 MARCHING MANCEUVRES.

To change direction in column of detachments.
Being in march, the instructor commands :

1. Column right (or left)^ 2. March.

At the command marc\ the leading rank wheels on a movable
pivot ; the wheel being completed, this rank retakes the step of
twenty-eight inches ; the other ranks move forward and wheel
on the same ground.

Column half right (or left) is similarly executed.

ST". To put the column of detachments in march, and change
direction at the same time, the instructor commands :

1. Forward^ 2. Column right (or left)^ 3. March.

To marcJi the column of detachments to the rear.

88. The instructor commands :

1. Detachments right (or left) about ^ 2. March.

The detachments wheel about on a fixed pivot ; the man on
the marching flank of the rear rank of each detachment pre-
serves the distance of thirty-two inches from his front-rank man ;
the man on the pivot flank closes up to his front-rank man,
covering him during the wlieel, and on its completion falls back
to thirty-two inches; tlie chief s - of - platoon and the gunners
oblique to the right or left in turning about, so as to preserve
their proper positions with reference to the column.

To form line from column of detachments.

89. To the right or left. Thebatterybeingat a halt, or march-
ing, the instructor commands :

1. Detachment right (or left)., 2. March, 3. Guide {right or
left)'., or, 3. Battery^ 4. HAliT, 5. Left (or right)^ 6. Dress,
7. Front.

At the command march., the detachments wheel to the right
on a fixed pivot. The rear rank of each detachment closes to
facing distance during the wheel, except when executed in double
time, and the line advances on the completion of the wheel.

If the line be formed towards the side from the chiefs-of-pla-
toon, they close to the flank of the column at the first command,
and, at the command march, pass quickly through the column
between their detachments; the gunners, at the same time, in
like manner, pass to the other side of the column.

When the command halt is given, tlie instructor; before dress-
ing the battery, places the leading guide on tlie line of the pivot-

MARCHING MAN(EUVRES. 21

men, and at a distance* from the leadin<y pivot-man sufficient to
admit the leading detaciiment; the battery is then dressed on
this guide and the pivot-men of the detachments.

90. On the right or left. The instructor commands :

1. On the right (or left) into line., 2. March, 3. Front.

At the command march, the leading detachment wheels to the
right on a movable pivot, and moves forward, dressing to the
right; the other detachments march a distance equal to their
front, beyond the wheeling point of the detachment next pre-
ceding, wheel to the right, and advance as explained for the
first. The leading detachment, having wheeled, advances five
yards and is halted by the command : 1. First detachment., 2.
Halt, 3. Right (or left)., 4. Dress, from the chief of its pla-
toon ; at the fourth command it dresses to the right ; the other
detachments halt and dress successively upon arriving in line ;
the rear rank of each detachment, upon halting, closes to facing
distance. The instructor places himself on the right to superin-
tend the movement, and after the last detachment dresses gives
the command yVo??^.

At the command /ron^, given when the last detachment com-
pletes dressing, all cast their eyes to the front.

The chiefs-of-platoon and gunners follow up the movements
and take their positions in line as the detachments successively
<3ome up to it. If the movement be executed on the side opposite
the gunners, each takes his place behind the detachment by
passing in front of the one next succeeding it.

91. To the front. The battery being at a halt, the instructor
commands :

1. Right (or left) front into line., 2. MARCH, 3. Front.

At the command march., the first detachment moves straight
to the front, dressing to the left; the other detachments oblique
to the right until opposite their places in line, when each marches
to the front. As soon as the leading detachment has advanced
five yards, the chief of its platoon commands : 1. First detach-
ment., 2. Halt, 3. Left (or right), 4. Dress; at the fourth
command it dresses to the left ; the other detachments halt, and
dress to the left upon arriving in line ; the rear ranks close to
facing distance upon halting. The gunner who is the left guide
of the battery in line places himself on the flank of his detach-
ment as soon as it halts upon reaching the line. The instructor
places himself on the left to superintend the movement, and
lifter the last detachment dresses gives the command front.

92. As a rule, this movement is made towards the side of

22 MARCHING MAN(EUVRES.

the chief s-of-platoon ; should it be made towards the opposite
side, the chiefs of the leading and last platoon take their posts
in line by passing* around the flanks of the batter}'- ; the chiefs of
the other platoons pass through the column as the oblique com-
mences; at the same time all the gunners pass through to the
opposite flank.

If marching in quick time, the leading detachment continues
to advance until halted, as before, and the other detachments
oblique, at the command march.

If marching in double time, or in quick time, and the com-
mand be double time., the instructor commands : Guide left im-
mediately after the command march; the leading detachment
moves to the front and continues the march in quick time, its
rear rank closing to facing distance ; the other detachments
oblique in double time, each taking the quick time and dressing
to the left upon arriving in line ; the rear rank, on arriving in
line, closes to facing distance.

To march the column of subdivisions by the flank.

93. If at a halt, the instructor commands :

1. Right (or left\ 2. Face, 3. Forward, 4. MARCH, 5. Guide

{right or left).

94. If marching:

1. By the {right or left) fla7ik, 2. MARCH, 3. Guide {left or

right).

The guides of the subdivisions preserve proper intervals, and
dress on the guide who conducts the guiding subdivision.

95. To resume the original direction, the instructor com-
mands :

1. By the left (or right) flank., 2. March; and for platoons, 3.
Guide {right or left).

To halt and resume the original front, the instructor com-
mands :

1. Battery, 2. Halt, 3. Left (or right), 4. Face.
To oblique in column of subdivisions.

96. The instructor commands:

1. Right (or left) oblique, 2. March.

During the oblique, the subdivisions preserve their parallel-
ism; the guide of each subdivision on the side towards which

MARCHING MANCEUVRES. 23

the oblique is made is the ^uicle of the subdivision ; the guide of
the leading subdivision is the guide of the column. The guides
keep on a line parallel to the original direction.

9T(, To resume the direct march, the instructor commands :

1. Forward, 2. March.

The guide is, without indication, on the side it was previous to
the oblique.

If the oblique be executed from a halt, the guide is announced
upon taking the direct march.

98. The battery being at a halt, in line, or in column of
subdivisions, to march it a short distance to the rear, the in-
structor commands: 1. Battery, 2. About, 3. Face; the chiefs-
of-detachment and the gunner acting as guide step into the rear,
now become the front, rank; the chiefs-of -platoon, now in rear,
remain there.

The original direction is resumed by again passing to the flank
march, or at once by the commands : 1. To the rear- 2. March ;
or, if at a halt, 1. Battery, 2. ABOUT, 3. Face; the guides and
chiefs-of-detachment in either case return to the front rank.

To form column of files from column of subdivisions.

99. Being at a halt, the instructor commands :

1. Right (or left), 2. Face, 3. Platoons (or detachments), 4.
Column left (or Column right), 5. March.

At the command face, all face to the right ; at the command
march, each subdivision column changes direction, and joins
upon the one which precedes it.

If marching, the instructor commands :

1. By the right (or left) flank, 2. Platoons (or detachments), 3.
Column left (or Columri right), 4. March.

At the command march, each subdivision faces to the right in
marching, changes direction, and joins upon the one which pre-
cedes it.

In both cases, if the movement is executed from column of
detachments the rear rank close in elbow to elbow, with the
front rank.

The route step.

100. Wlicn it is desired to give freedom and ease to the men
in marching, the instructor commands :

1. Route step, 2. March.

If in line or column of platoons, the rear rank falls back to

24 MARCHING MANCEUYRES.

thirty-two inches from the front ranlv ; the men are not required
to keep silence, nor keep the step, but each man covers the file
in his front, and, if armed, carries his piece at will.

To resume the attention, the instructor commands : 1. Battery.^
2. Attention. At the second command, the rear rank, if in
line or column of platoons, closes to facing distance, and all the
men take the step.

The battery may also be marched at rout step in column of
files, the distance between files being increased to thirt3^-two
inches. On resuming the attention, the leading file takes the
short step until the other files close to facing distance.

The batter}'^ in rout step changes direction by the same com-
mands as when in cadence step.

To form, single rank from double rank.

lOl. For special purposes it may be desired to make this
formation.
Being in line, at a halt, the instructor commands :

1. Form single rank^ 2. Detachments {right or left)^ 3. March.

At the command march^ all the detachments wheel to the
right; the front rank of the right detachment, upon completing
the wheel, continues the march with its guide on the wheeling
flank ; the other ranks halt, and successively resume the march
when at wheeling distance from the rank preceding it ; the rear-
most rank having its distance, the instructor commands :

1. Detachment left (or right) ^ 2. Mabch, 3. Battery, 4. Halt,
o. Left (or right)^ 6. Dress, 7. Front ; or, 3. Guide {right
or left).

103. Marching in column of detachments, to form single
rank, the instructor commands :

1. Form single rank^ 2. MARCH.

At the second command, the front rank of the leading detach-
ment continues the march ; the other ranks halt, and successively
resume the march when at wheeling distance; the rearmost
rank having its distance, line is formed as before.

103. In single rank, the relative positions of the ofliicers and
non-commissioned officers are the same as when in double rank,
and the battery performs, by the same commands and means,
all the movements of a double rank. The cannoneers retain
their original numbers.

In executing the rear open order^ the gunners step back to the
line marked by the guides for a supposed rear rank.

MARCHING MANCEUVRES. 25

To form double rank from single rank.
104. Being in line, at a halt, the instructor commands :
1. Form double rank^ 2. Detachments right (or left)^ 3. MabCH.

At the command march, the front and rear rank of each de-
tachment wheels separately to the rio-ht; the leading rank halts
th(^ instant the wheel is completed ; the other ranks continue the
march and halt successive!}', each rear rank upon closing to
facing distance from its front rank, and each front rank when
at wheeling distance from the rear rank of the preceding detach-
ment. When the column is put in march, the reai- rank of each
detachment falls back to thirty-two inches from the front rank.

In forming from single to doubles rank, the instructor wlieels
the detachments to the light or left, according as the front-rank
men are on the rigiit or left of their rear-rank men.

105. Marching in column of detachments at single-rank dis-
tance, the front-rank men of each detachment in front of their
rear-rank men, to form double rank, the instructor commands :

1. Form double, rank, 2. March.
At the command march, the leading rank of the first detach-
ment halts ; the other ranks continue the march, each halting in
the manner just explained.

To march to the pieces, or other place of exercise.

106. The front, in connection with a piece of artillery, is the
direction in which the muzzle points, except when the piece is
mounted on a traveling carriage and the carriage is limbered
up; in which case the front is in the direction in which the pole
points. The right or left is the right or left when looking towards
the front.

The battery being formed for drill, as prescribed in par. 37,
the instructor wheels it into column of detachment, or faces it
into column of files ; to the right if he is to approach the bat-
tery on the left, and to the left if he is to approach it on the
right. The column is directed so as to bring the detachments as
nearly as practicable four yards in the rear of the platforms of
the pieces. When the liead of column arrives at a distance of
four 5'ards from the left or right of the battery, the instructor
commands: Detachments opposite your pieces.

1st. Column of files. As each detachment arrives opposite its
piece, it is halted by the chief-of-detachment, who then com-
mands :

1. Left (or right), 2. Face, 3. Right, 4. DRESS, 5. FRONT.

26 MARCHING MANOaUVRES.

The detachment faces to the piece, and immediately the gun-
ner places himself by the side of the left front-rank cannoneer;
this is his place at all times when the detacliment is in this posi-
tion at the piece.

2d. Column of detachments. As each detachment arrives oppo-
site its piece, the chief-of-detachment halts it, and commands,
according as tlie battery has been approached on its left or right :
1. Left (or rigid) wheel, 2. MARCH, 3. Detachment^ 4. Haxt, o.
Right, 6. Dress, 7. Front; he then takes his post on the
right of the front rank.

As the detachment wheels, the gunner takes his post by the
side of the left front-rank cannoneer.

107. The centre of the detachment is four yards in rear of
the piece or centre of the platform.

Each chief-of-platoon places himself one j^ard in rear of the
centre of his platoon, or at such other place as he can best
observe his detachments.

To take posts.
{Figure 4, Flate II.)
lOS. The instructor commands :

1. Cannoneers to your posts ^ 2. MARCH.

At the first command, the chief of each detachment, stepping
two yards to the front and facing his detachment, commands :
1. Eighty 2. Face, 3. To your posts; the detachment having
faced at the command of its chief, the gunner steps to one side,
and at the command march by the instructor, repeated by the
chiefs-of-detachment. It files to the left, the two ranks separat-
ing, the rear rank marching to the right of the piece, and the
front rank to the left of it. As each man arrives at his post, he
halts and faces the piece, Kos. 1 and 2 one yard from the
epaulment, parapet, or scarp ; their breasts eighteen inches out-
side of the carriage ; the remaining numbers and the gunner
dressing respectively on ISTos. 1 and 2, at intervals of one yard,
except that between Xos. 4 and 6 and 3 and 5 there is an inter-
val of two yards; the gunner places himself in the interval
between Nos. 4 and 6.

With mortars, N'os. 1 and 2 are on a line with the muzzle, the
remaining number and the gunner being as before.

The chief-of-detachment is facing the piece, and two yards
in rear of the platform or rearmost part of the carriage ; while
superintending the exercises, he goes wherever his presence is
most required.

MARCHING MANCEUVRES. 27

109. As soon as the cannoneers are at their posts, the in-
structor commands :

Take equipments.

This is executed as hereinafter prescribed for each kind of
piece.

At the conclusion of the exercises he causes the implements
and equipments to be replaced as hereinafter prescribed tor each
case.

To rest.

no. The instructor commands :

1. In place^ 2. Rest; or, 1. Rest.

The cannoneer? lay down their handspilces, as explained in
par. 236.

In the first case, the men remain at their posts; in the second,,
they may leave their posts, but must remain near the piece.

To resume the exercise.

Ill, The Instructor commands :

1. Battery., 2. Attention.

All resume their posts and handspikes.

To change posts.

11^. The instructor commands :

1. Change posts, 2. March, 3. Call off.

At the first command, the cannoneers lay down their hand-
spikes, place their equipments on the parts of the carriage near-
est them, or on the platform, and face to their left. At the
command march, eacli cannoneer advances one post; N'o. 2, pass-
ing in rear of the piece, takes the place of N^o. 1 ; 'No. 1 of No.
3; No. 3 of No. 5, and so on. On arriving at their new posts
they face the piece and, without further command, take the
handspikes and equipments belonging to them; at the third
command, they call off according to their new numbers.

To leave the battery.

113. The instructor first causes the equipments to be re-
placed, as hereafter prescribed for each case, and then com-
mands :

1. Detachments rear, 2. MabCH.

At the first command, repeated by the chiefs-of-detachment,

:28 MARCHING MANOEUVRES.

the cannoneers upon the ri^ht of the piece face to their left, and
those upon the left to the right; at the commanfl march, repeat-
ed by the chiefs-of-detachraent, they march to the i-ear, the rank
with even numbers closing on that with odd numbers, change
direction to the right at the command : 1. Column righU 2.
March, from the chief-of-detachment, are halted, faced to the
front, and dressed to the right by him, so as to bring the centre
of the detachment on a line with the axis of the piece, or oppo-
site the middle of the platform, and four yards in rear of it. The
gunner takes his place on the left of the front rank.

To reform the battery and leave the pieces.

\st. Into column of files.

114. The instructor commands :

1. Detachments right (or left), 2. FACE, 3. Close, 4. March.

At the command face, the detachments face to the riofht. the
gunners taking their places in the rank of file-closers, and at the
command march, repeated by all the chiefs-of-detachment, (ex-
cept the leading one,) all the detachments close on the leading
one, which stands fast. As each detachment closes up to the one
in front of it, it is halted, by its chief, who then takes his post in
front of the leading file of the front rank.

2^. Into column of detachments.

H5. To form column of detachments, the instructor com-
mands: 1. Detachments right (or left) wheel, 2. March, 3.
Close to wheeling distance, 4. Guide {right or left), 5. March.

At the second command, each detachment wheels to the right
and is halted and dressed to the left by its chief; at the third
command, the chief of the leading detachment cautions it to
stand fast; at the fifth command, all the detachments in rear of
the first step off, and each is halted by its chief when at wheel-
ing distance from the preceding detachment.

The column is then marched from the battery by the com-
mands and means heretofore explained.

Formation of a Battalion.
{Figure 5, Plate II.)

116. When two or more batteries form together in line, the
first-sergeants take post beside and on the right of the front-rank
cannoneer of their batteries ; the chiefs of the right detachments,
stepping back for that purpose, take post in line of gunners in
retir of the right file of their detachments ; the first-sergeants

MARCHING MAN(EUVRES.

retain habitually this position during all battalion manoeuvres,
and are the guides of that flank of their batteries.

117. Gunners acting as left guides of batteries, except the
battery on the left flank, fall back and occupy their posts in
rear of their detachments.

lis. Batteries form without intervals; the first-sergeant of
each, except the right, touching the left front-rank cannoneer
of the battery on his right.

119. The trumpeters of all the batteries are united and take
post on the right of the battalion in two ranks, the left of the
front rank twelve yards to the right of the first-sergeant of the
right battery; when there is a band, they are as provided in
yar. 125.

In all other respects the several batteries have the formation
given xvipars. 24 to 36.

120. A battalion is composed of two or more batteries, not
exceeding twelve. When there are more than twelve batteries,
they are formed into two or more battalions, the batteries of
each regiment being kept, as far as practicable, together.

121. In forming the line, the batteries are posted from right
to left according to the following table; the numbers indicate
the relative rank of the battery commanders, the senior, or No..
1, being on the right of the line :

122. Batteries whose captains are absent are posted in line
according to the relative rank of the ofiicers present in command
of them. At the discretion of the commanding officer, a batter}''
whose captain is absent for a few days only may retain its place
according to his rank.

123. Batteries are designated numerically from right to left
when in line, and from front to rear when in column, j^rs^ hat-
tery^ second hatterij^ and so on.

30 MARCHING MANCEUVPtES.

The designations of batteries change when, by facing in the
opposite direction, the left becomes the right of the line, and the
rear the head of the column.

124. When a battalion is provided with colors there will be
a color-guard, composed of a color-sergeant and seven corporals,
which is posted as the left detachment of the right centre battery.
(Number 3 of the table.)

The front rank is composed of the color-sergeant and the three
senior corporals, one posted on his right and two on his left ; the
rear rank is composed of the fom* remaining corporals, placed
in order of rank from right to left.

The color-sergeant carries the national color. A regimental
color (when present) is carried by a sergeant, who takes the
place of the corporal on the left of the color-sergeant.

The color is to be carried only when the battalion is under
arms with muskets.

At the sounding of the assembly the color-guard forms at the
appointed place, and is marched, bj'^ commands of the color-
sergeant, to the place where the color is kept. The color-
sergeant receives the color and faces towards the guard ; the
senior corporal commands : 1. Present^ 2. Arms, at whicii the
guard salutes the color; the corporal then commands : 1. Carry^
2. Arms, after which the sergeant takes his position in the
guard ; the guard is then, by commands from the sergeant,
marched to the color-battery on its parade-ground.

On returning the color the same ceremonies are observed.

The color-bearer carries the heel of the color -lance in its
socket, supported at the right hip ; the right hand grasps the
staff at the height .of the shoulder, to hold it steady. The color-
bearer salutes with the color as follows :

{One.) Slip the right hand along the staff to the height of the
eye ; lower the staff by straightening the arm to its full extent,
the heel of the lance remaining at the hip.

{Two.) Bring back the lance to the habitual position.

At all occasions of ceremony the color is without its case.

When marching in double time, the color-bearer grasps the
color to the lance, raises the heel from the socket, and allows
the color, the lance sloping to the rear, to rest on the right
shoulder.*

Posts of Jield and staff officers.

125. The following is for a full regiment of twelve batteries ;
for a less number the same principles are observed :

{Figure 5, Plate II.)

The colonel is thirty j-ards in front of the line of captains,

See (p), Appendix 2.

MARCHING MANCEUVRES. 31

opposite the centre of the battalion. This distance, as also that
for the other tield ofticers, is reduced as the front of the battalion
IS diminished.

The lieutenant-colonel is twelve yards in front of the line of
captains, and opposite the centre of the three batteries on the
right ; the Jirst major occupies a like position with reference to
the three left batteries of the battalion ; the second major a like
position with reference to the three right centre batteries ; the
third major a like position with reference to the three left centre
batteries.

The adjutant is in line with the chief s-of-platoon, and three
yards outside the right flank of the battalion.

Other staff officers, in the order of rank from right to left, are
on the right of the adjutant, with one yard interval between
each.

The sergeant-major is three yards to the left of the front rank
of the battalion.

Other non-commissioned staff officers, when present, are on
the left of the sergeant-major, with one yard interval between
each.

The hand is formed in two or more ranks, with intervals be-
tween tiles, and distances between the ranks sufficient to permit
a free use of their instruments.

The trumpeters form the rear ranks of the band.

The band is posted on the right of the battalion, the left of its
front rank twelve yards from the right of the front rank of the
battalion.

The field and staff officers are mounted or on foot, as the com-
manding officer may direct.

1^6. When the battalion is in column onthe march, in cam-
paign, the colonel, lieutenant -colonel, second major, and staff
officers march at the head of the column ; the other two majors
and the non-commissioned staff at the rear; the band at the
head or rear, as the commanding officer maj?" direct. In all other
cases, when the line is broken into column, whether of batteries,
platoons, or detachments, the field officers, adjutant, and ser-
geant-major take post on the flank of the column on the side
next to the wheeling flank of the subdivision ; the colonel about
thirty yards from the centre of the column ; the lieutenant-col-
onel and majors six yards from the flank, each in line with the
subdivision in front of which he was posted in line; the adju-
tant and sergeant-major in their own wings abreast of and three
yards from the flank of the leading and rear subdivisions of the
column.

The staff officers (excepting the adjutant) wheel to the right

32 MARCHING MANOEUVRES.

(or left) and place themselves, with intervals of one yard, oppo-
site the centre of the leading subdivision, and six yards in front
of the leading captain, or six yards in rear of the gunners of the
last subdivision, according as the line has been broken to the
right or left.

The non-commissioned staff (excepting the sergeant-major)
occupy a similar position with reference to the other extremity
of the column.

The band wheels to the right (or left), and takes post in front
or rear of the column, as the colonel may direct.

In column of files, the field, stafi", and non-commissioned staff
officers, and the band, are as if each had faced with the battal-
ion.

To form the battalion.

121. The batteries being formed on their parade-grounds,
adjutanfs call is sounded, at which the adjutant and sergeant-
major, the latter on the left, each followed by a marker, march
to the battalion parade-ground, where they post the markers,
facing each other at a distance apart a little less than the front
of a battery ; the adjutant posts the marker nearest the right of
the line, the sergeant-major the one nearest the left ; each
marker holds his staff in front of him ; the adjutant and sergeant-
major draw swords, face about, and each proceeds battery dis-
tance towards his flank of the line ; they then face about and
cover the markers.

The color-battery is the first established, and is conducted by
its captain so as to arrive from the rear, parallel to the line of
markers. When it arrives at three yards from the line, the cap-
tain halts it ; dresses it to the left, against the markers ; com-
mands, /ro?i^, and takes his post in front.

The batteries of the right wing form successively from left to
right, each being brought upon the line and dressed to the left,
as explained for the color-battery ; the gunner of each battery,
acting as left guide, at the command halt^ returns to his post in
rear of his detachment; at the same time the right guide places
himself, facing the markers, and aligns himself on them, at bat-
tery distance from the right marker, or guide in front of him.
The first-sergeant takes the place of the chief-of-detachment who
has stepped out to mark the line. The adjutant assures the
position of the right guides, placing himself in their rear as they
successively arrive. The guides retain their positions on the line
until the command guides posts is given.

The batteries of the left wing form successively from right to
left, in a similar manner, and are dressed to the right ; the left

MARCHING MANCEUVRES. 33

instead of the right guides place themselves on the line, and are
assured in position by the sergeant-major. At the command
haU^ the first-sergeant and the chief of the right detachment take
their places, as per jt?ar. 116.

Both wings are formed simultaneouslj''.

To enable tlie captains to dress their batteries, the first-sergeants
step into tlie rear rank, eacli resuming his place in the front rank
as soon as the captain, after dressing his battery, takes his post
in front.

The field and staff and non-commissioned staff" officers take
their posts as the battalion is formed. The colonel faces towards
the line.

128. Before sounding adjutanfs call, the band takes a posi-
tion designated by the adjutant, and marches at the same time
as the batteries to its position in line.

Each captain commands : 1. Support, 2. Arms, as soon as the
captain next succeeding him in his own wing commands front;
the flank batteries support arms as soon as dressed.

The sergeant-major having assured the position of the left
guide of the left battery, takes his post on the left of the line.

129. The adjutant having assured the position of the right
guide of the right battery, places himself, facing towards the left
of the line, three yards in front of his post, and wlien the last
battery arriving on the line is brought to support arms, com-
mands : 1. Guides, 2. Posts. At this command, the guides and
markers take their posts in line, the latter stationing themselves
in the line of gunners on the right and left flanks of the battal-
ion ; the first-sergeants step a pace to the rear to permit the
guides and markers to pass through their intervals, after which
they retnrn to the front rank. The adjutant then passes along
the front in rear of the chief s-of-platoon, to the centre of the
line, turns to the right, halts midway between the captains and
the colonel, faces about, brings the battalion to a carry^ and a
present arms, resumes his front, salutes the colonel, and reports :
Sir ! The battalion is formed.

The colonel returns the salute with the right hand, directs the
adjutant : Take your post. Sir ! draws his sword, and commands :
1. Carry, 2. Arms.

The adjutant faces about, and returns to his post on the right,
passing in rear of the chiefs-of-platoon of the right wing.

130. The foregoing is the habitual formation of an artillery
battalion when serving as artillery, and will be used for occa-
sions of drill and ceremonies. Where battalion movements
become necessary or desirable, those embraced in the "School.
OF THE Battalion" [Infantry Tactics,] are prescribed, and

84 DEFINITIONS.

will be executed on the principles therein given, substitutins:
the commands detachments and battery iov ''\fours'''' and '''com-
pany'''' wherever they occnr.

Other difterences of detail will suggest themselves from the
marching drill heretofore given in this work, which, it is under-
stood, is the basis of movements for heavj^ artillery troops.

The skiimishing manoeuvres are those prescribed in Infantry
Tactics, substituting commands as above.

Chiefs-of-detachment and gunners remain with their detach-
ments in all deployments, exercising over the men such control
as will insure the maximum of efficiency.

Definitions.

{Figure 1, Plate III.)

131. Cannon. The term cannon is applied to all heavy fire-
arms discharged from carriages, in contradistinction to small
arms., which are discharged from the hand. The general form
of cannon is that of a truncated cone, the largest part being at
the breech, around the seat of the charge ; in those of recent
model, the exterior elements are curves, and there are neither
mouldings nor ornaments on the piece.

All heavy cannon in the U. S. land service are made of cast-
iron ; those pieces having greater calibres than that of the siege
gun are cast hollow, being cooled from the inside upon the prin-
ciple introduced by Rodman.

The w^ant of ductility in cast-iron is unfavorable to its endu-
rance under high vibratory strains ; and as the ballistic power
demanded of ordnance has greatly increased of late years, cast-
iron is no longer much used for forming the parts immediately
about the bore of heavy rifled guns, some other metal being sub-
stituted, the molecules of which accommodate themselves more
readily to new positions when under strain.

It has been found that cast-iron guns are greatly improved b\'
tubing them with some ductile and strong metal, as low steel or
wrought-iron. A large part of the energy that the powder gas
exerts on the surface of the bore is absorbed in expanding the
tube, and that which finally reaches the cast-iron being much
reduced in amount, and also spread over a surface relatively
much greater than that of the bore, is lai-gely within the limils
of safety for the comparatively brittle envelope. The ductile
metal of the tube also cushions the cast-iron against the effects
of severe vibration and shock.

Guns thus constructed have great power of endurance, and

DEFINITIONS. 35

when pnt to extreme test it has been found that the cast-iron
<jnsini^ does not burst explosivel3% but craclvs and gives way
without violence.

The 10-inch smooth-bore is converted into an S-inch rifle, and
the lo-inch smooth-bore into a 12-inch rifle, by this method.
{See 8-inch rifle, j^ar. 319.)

13^. The hore is the interior portion of the cannon, intended
to receive the charge and projectile. It is bored out with the
gi'eatest accuracy as to straightness, diameter, and smoothness.

133. The muzzle is the mouth of the bore. The face is the
terminating plane at the muzzle, perpendicular to the axis of
tlie bore.

134. The axis of a cannon, or of the bore, is the central line
of the bore.

135. The trunnions are two solid cylindrical arms project-
ing from the sides of the cannon for the purpose of supporting it
on its carriage. They are placed at or near the centre of grav-
itj^, on opposite sides of the piece, with their axes in the same
line, at right angles to the axis of the piece, and in the same
plane with that axis.

136. The rimbases are the shoulders forming the junction
between the trunnions and the piece. They serve to strengthen
the trunnions, and, being terminated, by planes at right angles
to the axes of the trunnions, prevent the piece from moving
sideways on the carriage.

137. The breech is the solid mass of metal behind the bot-
tom of the bore.

138. The base of the breech is the rear surface of the breech.

139. The ca5ca5Ze is the projection in rear of the breech. It
is composed of the knob and the neck; the latter unites the
knob to the base of the breech.

In heavy guns of recent model the cascable is quite rudiment-
ary, while in mortars it is entirely wanting.

The object of the cascable is to facilitate handling the piece
wlien mounting, dismounting, and transporting it.

140. The bodt/ of the piece is that part in rear of the trun-
nions.

141. The chase is that part of the piece in front of the trun-
nions.

142. The vent is the channel through which fire is commu-
nicated to the charge in the bore. Its diameter is two-tenths of
an inch, and it is generally situated in the plane passing through
the axis of the bore, perpendicular to the axis of the trunnions.

It is at riglit angles to the axis of the bore, and enters the lat-
ter at a distance from the bottom of one-fourth of the diameter

36 . DEFINITIONS.

of the bore. In mortars and sea-coast guns there are two vents^
each situated in a plane perpendicular to the axis of the trun-
nions, at equal distances on eacli side of the axis of the piece,-
and distant therefrom one-fourtli of the diameter of the bore.
The one on the left is bored entirely through ; the other stop&
short an inch from the bore. When the open vent becomes too
much enlarged by wear for further use, it is closed with melted
zinc and the other bored out. Each one should endure at least
live hundred service rounds.

In some pieces, a vent-piece^ usually of pure soft copper,
through which the vent has been bored, is screwed into the
breech. This is called hushing the vent.

143. The bottom of the bore is the interior termination of the
bore, and is a semi-ellipsoid.

144. The chamber^ or powder-chamber^ of a piece is that part
of the bottom of the bore in which the powder is lodged at the
time of firing. Formerly all mortars, howitzers, and shell guns
throwing projectiles of comparatively large size with small
charges, were provided with chambers smaller than the bore,
for the purpose of confining the powder into a small space.
In the present system the chamber is omitted from all pieces
except the flank casemate howitzer and the Coehorn mortar,
which are pieces of old pattern still retained in service.

It has been found experimentally that it is advantageous,
especially with rifles, to have the bore enlarged, instead of di-
minished, at the seat of the charge. This gives an air space
which diminishes the pressure upon the walls of the piece with-
out diminishing the velocity of the projectile.

The object sought for in the construction of modern artillery
is to secure great ballistic energy for the purpose of destroying
heavy armor. This is secured bj^ using heavy projectiles pro-
pelled with great velocity. But to obtain this result without
undue pressure on the piece, the character, as to density, shape,
and size of the grain, of the powder introduced is such as to
cause it to burn progressive!}', with an increasing volume of gas,
thus keeping up the pressure against the projectile as it moves
along the bore, without causing an undue pressure upon the
bore at anj' point. This gives a total eff'ect against the project-
ile greater than was obtained from any of the older and more
violent powders.

The charge of powder is much greater than formerlj'^ ; this
requires an increased length of bore, but it has been found
that an enlarged chamber, with suitable charge, is equivalent to
increase of length of bore, and that by these means the desired
velocity is obtained without undul.y increasing the length of the-

DEFINITIONS. 37

piece, or of producing a strain which it is not capable of stand-
ing.

145. The dispart is tlie clinerence between the semi-diameter
of the piece at the muzzle and at the thickest part, usuallj^ near
the vent.

146. A gun is a cannon intended to throw projectiles, either
solid or hollow, with large chai-ges of powder, for the purpose
of attaining great range, accuracy, and penetration. It is dis-
tinguished from other cannon by greater length and weight.

i4T. A howitzer is a cannon employed to throw hollow pro-
jectiles with comparativel}^ small charges of powder. It is
shorter and lighter than guns of the same calibre. The small-
ness of the charge and the great size of the projectile adapt it
advantageously to ricochet firing.

148. A mortar is a short and comparatively light cannon,
emplo3^ed to throw hollow projectiles at great angles of eleva-
tion. It is intended to produce eftect hj the force with which
the projectiles descend upon the object, and by the force with
which these explode. The great curvature of their fire gives
them power of reaching objects behind w;orks which would be
secure from direct fire.

149. Cannon are classified as smooth-bore and rifles. In the
former, spherical projectiles are used ; in the latter, elongated.

150. A rifle is a gun having a number of spiral grooves,
<ialled "rifles," cut into the surface of the bore. These grooves
are for the purpose of giving to the projectile a rotary motion
around its longitudinal axis. The portions of the bore between
the grooves are called "lands"; these, in the United States
service, are generally of about the same width as the grooves or
"rifles."

The object of the rotary or "rifle" motion is to increase the
range of the projectile by causing it to move through the air in
the direction of its length, or least resistance, and to give in-
creased accuracy by distributing the principal causes of devia-
tion around its axis of rotation.

The projectiles for rifle-cannon are generally made of cast-
iron, with a ring or cup aroiuid the base, made of bronze, or
some otiier metal capable of expansion. The projectile enters
the bore freely when loading, but the pressure of tiie discharge
expands the ring or cup and forces the latter into the grooves,
causing the projectile in its outward motion to follow the grooves,
thus imparting to it the desired rotary motion.

151. Twist is a term denoting the inclination of the
grooves to the axis of the bore. If the angle of inclination be
equal at all points, the twist is said to be uniform.

88 DEFINITIONS.

If the angle increases from the breech to the muzzle, the
twist is called increasing; if the reverse, decreasing.

The twist is measured by the length of bore corresponding to
a single revolution of the spiral. In practice, it means the dis-
tance passed over by the projectile while makhig one revolution
about its axis, and is expressed in feet.

152. Windage is the space left between the bore of the piece
and its projectile. It is measured by the difference of their
diameters, and is expressed in hundredths of an inch. Windage
is necessary in order to make allowance for the bore becoming
foul from firing ; for the mechanical impossibility of having all
projectiles of the exact size ; and when sabots are used, to give
room for the tin straps securing them. It facilitates loading,
and diminishes the danger of tlie piece bursting. Windage
increases slightly with the calibre ; it is much less for rifle than
for smooth-bore guns.

153. Calibre is the diameter of the bore. It is expressed in
inches, except for pieces of old pattern, wlien it is expressed in
terms of the weight of a solid cast-iron ball of the diameter of
the bore.

154. Preponderance is the excess of weight of the part of the
piece in rear of the trunnions over that in front. It is expressed
by the lifting force, in pounds, which must be applied at the
cascable to balance the piece upon the trunnions.

It is useful only for pieces mounted on travelling carriages, ta
keep them steady in transportation. For all other pieces of re-
cent model the axis of the trunnions intersects the axis of the
piece at the centre of gravity, thus enabling the piece to be ele-
vated and depressed with greater ease. The discharge does not
sensibly change the position of the piece before the projectile
leaves the bore.

The life of a piece is the number of rounds that it will stand
before becoming unserviceable. Cast-iron guns become unsafe
after 1,000 rounds.

155. Direct or horizontal fire is where the piece is discharged^
having but a small angle of elevation, and the projectile strikes
the object without touching the intermediate ground.

156. Curved or vertical fire is where the piece is discharged,,
having a great angle of elevation, as are mortars, and the pro-
jectile effects its work chiefly by the force of its fall.

15*7. Ricocliet fire is where the projectile strikes the ground
or water and rebounds. Projectiles will ricochet upon ground
of ordinary firmness when the angle of fall does not exceed 10°;
or upon water, at 4° or 5°.

158. Rolling fire is where the axis of the piece is parallel, or

DEFINITIONS. 39

nearly so, with the groancl or water, aiicl the projectile rebounds
over the surface in a succession of ricochets.

159. Plujiging jirc is where the object fired at is situated
below the piece.

160. The point of fall is the point first struck by the pro-
jectile.

161. The angle of fall is the angle made, at the point of fall,
by the tangent to the trajectory with a horizontal line in the
plane of fire. It is always greater than the angle of elevation of
the piece.

16S. The elevation of a piece is the inclination of its axis
above the horizon. It is measured by the angle included be-
tween the axis of the bore and the horizontal line in the plane
of fire at the muzzle. It is expressed in degrees.

163. The depression of a piece is the reverse of its elevation.

164. Range is the horizontal distance from the muzzle of a
piece to the point where the projectile first strikes.

165. Extreme range is the distance from the piece to the point
at which the projectile is brought to a state of rest.

Greatest range of a piece is the farthest distance to which it
will throw a projectile, the piece being mounted on its appropri-
ate carriage. All ranges are expressed in yards. In air, the
maximum range, under ordinary circumstances, is obtained from
an angle not far from 34°.

166. Velocity is the rate of motion of a projectile. It is ex-
pressed in feet for the space which the projectile would pass over
in one second of time, supposing it to have a uniform rate of
motion during this second.

Initial velocity^ or, more properly, muzzle velocity^ is the velocity
at the muzzle of the piece.

Remaining velocity is the velocity at any other point of its flight.

Terminal velocity is the velocity with which it strikes the ob-
ject.

16T. Energy. This term, when used in connection with a
projectile, means the resistance it is capable of overcoming at
the time of striking an object. The resistance overcome is the
work performed, and is made manifest by the crusiiing effect of
the blow, or bj^ the penetration of the projectile. It implies
both pressure and motion, and is expressed in foot pounds,
which, for convenience, are reduced to tons of 2,240 pounds
each. It is the living force of mechanics, expressed mathemat-
ically hy to v"^ . , . , . , ^ - . ..1 • 1

— ^ ; m which w;=weight of pro3ectue ni pounds;

^ 9

u=velocity of projectile in feet;

(^=gi-avity, which, in the latitude of
New York, is equal 32.16.

40 DEFINITIONS.

To apply this formula, suppose a projectile weighing 500
pounds strilies the side of an ironclad with a velocity of 1,000

y. 2

feet, we have -^f^ff^ =7773631. 8 foot pounds; by dividing

2240, gives 3470.35 foot tons as the force or energy of the blow.

It has been ascertained by experiment that the resistance of-
fered by armor plates to penetration by a given weight of pro-
jectile, the energy of which is constant, varies directly as the
diameter or circumference of the projectile ; hence, in order to
find the penetrative power of a shot, it is customary to divide its
energy by the number of inches in its circumference, and when
projectiles are compared in this way they can be classed as re-
gards their power of penetration. It will be seen that because
a shot has great energy it does not necessarily have great pene-
trative power, the latter depending so largely on its diameter.

For obtaining the penetration in wrought-iron, Captain N'o-
ble's formula is used ; which is —

w v^

^~ 452617 X d in which

5=number of foot tons per inch of the projectile's circum-
ference,
cZ==diameter of projectile in inches,
«=1.384,
a;=depth of penetration.

168. The line of metal is the profile cut from the upper sur-
face of the piece by a vertical plane passing through the axis of
the bore.

{Fig. 1, Plate IV.)

169. The natural line of sight is the right line passing
through the highest point of the line of metal at the muzzle,
and tiie highest point of the same line in rear of the trunnions.

170. An artificial line of sight is the right line containing
the guiding points of the sights.

I'il. The line of fire is the axis of the bore prolonged in the
dii-ection of the muzzle.

1'72. The plane of fire is the vertical plane containing the
line of fires.

1*73. The angle of fire is the angle included between the
line of fire and horizon.

1 7'4. The plane of sight is the vertical plane containing the
line of sight. It may "be, but is not necessarily, either coincident
or parallel with the plane of fires.

175. The trajectory is the curved line traced by the project-
ile in its passage through the air ; it lies wholly below the line

GUNPOWDER. 41

of fire. Ill nearly all pieces, the natural line of si<?ht cuts the
trajectory at two points; the first point is near the muzzle, and
the second farther to the front.

1'16. Point-blank and point-blank range are terms formerly
supposed to possess great importance in gunnery.

The point-blank is the point at which the line of sight inter-
sects the trajector}^ the second time ; or, more practically speak-
ing, it is that point which, being aimed at, is struck by the pro-
jectile.

The natural point-blank corresponds to the natural line of
sight when this line is horizontal, and the distance of this point
from the muzzle is called the point-blank range.

An artificial point-blank is one corresponding to an artificial
line of sight.

I'^'V. Deviation is when the projectile does not move strictly
in the plane of fire, but inclines to the right or left of it. Wind
blowing across the line of fire is one great cause of deviation.

1 'Y8. Drifts or dirivation^ is tlie deviation peculiar to rifle
projectiles, the divergence being on the side towards which the
grooves twist. It is a constantly increasing, divergence from the
plane of fire, and is allowed for, in aiming, by means of a lateral
motion given to the rear sight. (See par. 319.)

l'^9. Recoil is the running back of the carriage after dis-
•charge. The space passed over after the gun is fired is also
termed the recoil; it is expressed in feet.

The directrix is tiie centre line in the plane of fire of an em-
brasure or platform.

AMMUNITION.

Gunpowder.

ISO. Gunpowder is the agent employed in modern warfare
to propel projectiles from cannon and small arms, and gener-
ally as the bursting-charge of projectiles ; for the explosion of
mines ; blasting purposes, &c. It is a mechanical mixture giv-
ing light, heat, and gas in the combustion or chemical union of
its ingredients.

Explosion is a phenomenon arising from the sudden enlarge-
ment of the volume of a body; as, in the case of gunpowder, a
solid body is rapidly converted into a gas many times its volume.
If the body is confined in a limited space and exploded, great
heat is developed and a vast expansion or propelling force pro-
duced, the volume of gas being many times greater than that of
the powder.

42 GUNPOWDER.

In the United States service, gunpowder is obtained from
private manufacturers. It is distinouislied by granulation ; irreg-
ular, as musket, mortar^ cannon^ and mammoth; regular, as cubic-
al^ and the molded powders^ i. e., pellet^ hexagonal^ 2i\\i\ prismatic
(perforated hexagonal prisms). In all of these, the proportion of
the ingredients are the same ; they differ only in tlie size and
shape of grain, density, and details of manufacture.

Musket powder is used for small arms ; mortar for field guns ;
cannon for light siege guns, and the larger-grained and special
powders for heavy sea-coast guns.

Note. — Special powders are now being experimented with for
both field and siege guns.

Materials.

The materials required are potassium nitrate {nitre)^ charcoal^
and sulphur. They should be of the greatest possible purity to-
insure excellence of qualit}'' and guard against accidents in
manufacture. The proportions by weight of the ingredients
used in the United States service powder are: {ff nitre; {\%
charcoal ; 10 sulphur.

It is essential to the successful and uniform manufacture of
powder that the ingredients should be procured in their rough
state, and be refined and prepared for use at the factory. This is
also necessary as a security against accidents at the mills. All
foreign matter must be carefully excluded, and every precaution
taken against their introduction in handling and moving the
refined materials.

General qualities.

Gunpowder should be of an even-sized grain, angular and
irregular in form, without sharp corners, and very hard. When
new, it should leave no trace of dust when poured on the back
of the hand, and when flashed in quantities of ten grains on a
clean plate it should leave no bead or foulness. It should give
the required initial velocity to the ball, and not more than the
maximum pressure on the gun, and should absorb but little
moisture from the air.

A compact shape of grain, approaching the cube or sphere, is
desirable. Elongated flat scales are objectionable. The number
of grains in several weighed samples should be counted.

Size of grain.

The size of the grain is tested b}^ standard sieves made of sheet
brass pierced with round holes. Two sieves are used for each
kind of powder : N"os. 1 and 2 for musket, 3 and 4 for mortar, 5
and 6 for cannon, and 7 and 8 for mammoth powder. {Figs. 2
and 3, Plate IV.)

GUNPOWDER. 4^

Diameter of holes for musket powder, l^o. 1, 0.03 in.; ^o. 2,
0.06 ill.

Diameter of holes for mortar powder, N'o. 3, 0.10 in.; N"o. 4^
0.25 in.

Diameter of holes for cannon powder, No. 5, 0.25 in.; No. 6,^
0.5 in.

Diameter of holes for mammoth powder, No. 7, 0.75 in.; No.
8, 0.9 in.

Hexagonal, ") Dimensions of these powders vary with the calibre
Cubical, > of the gun in which they are used, and have not as
Prismatic. J yet been definitely determined upon in our service.

Specific gravity.

The specific gravity of gunpowder varies from 1.65 to 1.8. It
is important that it should be determined with accuracy. Alco-
hol, and water saturated with saltpetre, have been used for this
purpose; but they do not furnish accurate results. Mercury
only is to be relied upon.

Hardness is tested by breaking the grains between the fingers,
and is judged of only by experience.

Muzzle^ or initial velocity.

This is determined by any of the electro-ballistic machines
available ; the Boulong^ chronograph is one of the simplest and
most generally used for proof of powder. For a full description
and use of the instrument, see Ordnance Memoranda, No. 25.

Strain upon the gun.

This is determined by the Rodman pressure-gauge. For de-
scription and use of the instrument, see Ordnance Memoranda,
No. 25.

Determination of moisture and resistance to moisture.

The amount of moisture in powder is determined by drying
samples in an oven with a water bottom.

The powder is subjected to heat as long as it loses weight, the
loss indicating the percentage of moisture driven off. On being
removed from the oven it should be transferred at once to per-
fectly clean, dry, air-tight weighing bottles.

Tlie ability to resist moisture is determined by subjecting
samples which have been dried to exposure, first in open air,
then in a hygroscope containing a solution of nitre at 100° cooled
to 80° Fahr.

Tile hj-^groscope is an air-tight box in which the powder is

44 GUNPOWDER.

subjected to a damp atmosphere at a uniform temperature for
24 hours.

The powder to be tested is placed in circular cups of copper
with fine wire-gauze bottoms, affording free access of moisture
to all parts of the sample under test. The percentage of gain
is determined by weighing the powder in carefully-prepared
bottles on opening the hygroscope. A careful record is kept of
the barometer, hj^grometer, external, and maximum and mini-
mum internal .thermometers.

Incorporation.

On breaking the grains, a fine uniform ashen-gray color
throughout should appear; the grain texture should be close,
without white specks even when magnified. For "flashing" on
glass or porcelain plates, the powder should be in small conical
heaps. Small copper measures for fine-grain powders, inverted
on the plates, keeps the heap nearly the same at each trial. If
the incorporation is good, only smoke marks remain on the
plate after flashing ; if bad, specks of undecomposed nitre and
sulphur will form a dirty residue. The test requires experience
to insure success.

Inspection report.

The report of inspection should show the place and date of
fabrication and of proof, the kind of powder and its general
qualities, as the number of grains in 100 grs. ; its specific grav-
ity ; whether hard or soft, round or angular, of uniform or irreg-
ular size; whether free from dust or not; the initial velocities
and pressures per square inch obtained in each fire ; the amount
of moisture absorbed ; and, finally, the height of the barometer
and hygrometer at the time of proof.

Marks on the barrels.

Each barrel is marked on both heads (in white oil-colors, the
head painted black) with the number of the barrel, the name of
the manufacturer, year of fabrication, and the kind of powder,
cannon^ mortar., or musket^ &c., the mean initial velocity, the
pressure per square inch on the pressure-piston, and density.
Each time the powder is proved, the initial velocity is marked
below tlie former proofs, and the date of the trial opposite it.
Each barrel contains 100 pounds.

SPECIAL POWDERS.

181. For some years it has been a recognized fact that the
ignition, combustion, and explosive effect of gunpowder depend,

GUNPOWDER. 45*

in a great degree, on the size, shape, and density of the grain,
and that guns of different calibres require for their most efficient
service powders differing in these features, in order to secure the
best results. The rapid increase in weight of projectiles with
the increase in calibre of guns, and the comparatively smaller
power of resistance of the guns, renders it necessary that the
rate of combustion of the charge be regulated so as to reduce
the strains on the guns as much as possible, while at the same
time preserving high initial velocity to the projectile, thus ren-
dering practicable the use of the heaviest guns, projectiles, and
charges.

The amount of gas evolved at the first instant of inflammation
and combustion is measurably controlled by the size and form of
grains, offering a lesser surface of ignition, and the increased
density, offering greater resistance to the penetration of the hot
gases through the grains, graduates its rapidity of burning. The
form of grain affecting the amount of surface exposed to com-
bustion — that shape which offers a comparatively small surface
at the first instant of ignition, increasing progressively — is theo-
retically the best.

Expei-iments have settled the important part plaj'^ed by pow-
ders suited in the above qualities to the guns in which they are
to be used, and have led to the adoption of large-grain powders
in heavy guns, resulting in the production, among the best, of
mammoth, pebble, cubical, hexagonal, and perforated prismatic
powders. {Figs. 4, 5, 6, 7, Plate IV.)

Hexagonal powder.

This powder has been found to give the best results when
used in pieces of heavy calibre. The uniform size of grain, and
their polyhedral shape, insure great uniformitj' in position and
size of the interstices in the make-up of the cartridge ; this in-
sures, with a uniform density of grain, a high degree of uniform-
ity in pressures and velocities from given charges of powder and
weights of projectiles. The powder used is composed of United
States standard proportions of the ingredients, with a specific
gravity of 1.7511. Its shape and dimensions are given on Plate
IF, Figs. 8, 9.

The proportions of tlie ingredients of hexagonal powder con-
form to the United States standard, and up to the completion of
the incorporation in the wheel mill, its manufacture is like that
of ordinary powder.

Mealing. The wheel mill cake is revolved in a cylinder of wire-
wove cloth, with wooden balls, until it is mealed.

Pressing. The mealed powder is then carefully pressed be-

46 GUNPOWDER.

tweeii horizontal metallic plates or dies. The powder comes
out in a sheet or cake of polj^hedral granules united along their
vertical edges, the dies being nearly perfect dodecahedrons.

Graining. The press-cake is passed between rollers armed
with brass cutting teeth at an angle of from 60° and 120° to the
axis, which cut the cake into granules, their cross-section being
almost hexagonal, whence the powder derives its name.

The powder is then sent to the glazing-mill and glazed ; after
which it is brpshed and dried. The powder is now minutely-
examined, its specific gravity taken, and a count made of the
granulation ; a variation of two granules to the pound is enough
to condemn the powder, the granulation being 72 to the pound.
It is packed in barrels in the usual manner, and is fired in car-
tridge-bags as other powder.

Mammoth poioder.

This powder is formed by breaking up mill cake. Exact uni-
formity of size and shape of grains does not therefore exist. The
average granulation is 85 to the pound. {Fig. 3, Plate IV.)

Prismatic powder.

This variety is formed by pressing mealed powder into prisms.
The hexagon is usually adopted, as it offers a good shape for
piling, and the angles are sufficiently obtuse to prevent spawl-
ing at the edges. In order to insure uniform and progressive
combustion, each prism is perforated with a small hole through
its axis; formerly several holes were pierced.

Cubical powder.

This powder is of a regular cubical grain, being formed by
cutting press-cake in two directions at right angles to each other.
Each grain is 0.75 inch in size. The granulation is about 72 to
the pound. {Fig. 4, Plate IV.)

It is important to observe tliat the proper kind of powder is
used in the guns for which intended.

182. The system of classification in use in the ^N'avy differs
somewhat from that employed in the Army. The hexagonal,
cubical, and mammoth are about the same; but N^avy rifle cor-
responds nearly to Army cannon., and the N^avy cannon is the
nearest equivalent to Arm}^ mortar.

In exchanging powder witli the IN'avy, it is necessary to ob-
serve these distinctions.

Powder barrels should never be openedyCxcept when required
for use, as grains of powder falling between the staves would

PROJECTILES. 47

prevent their being tightened. Samples must be taken from
the buno-.

183. For ordinaiy examination, the flashing test^ heretofore
mentioned, is a ready way of ascertaining- whether the powder
is of good quality and in good condition.

If powder has been much damaged by damp it will be caked,
and a close inspection will generally detect a white appearance
on the grains, due to nitre having been dissolved and deposited
in crystals on the surface.

Powder sometimes becomes caked by being tightly packed in
cartridges, or for want of being rolled when in barrels. It will
then readily crumble into its original grains by being pressed in
the hand ; but if the grains break or appear friable, the powder
is unfit for service.

This latter characteristic indicates that the caking has resulted
from dampness, and is to be carefuU}' distinguished from the
former.

Fressure,

184. The pressure of gunpowder, when fired in its own space,
is placed at about 95,000 pounds to the square inch. When, how-
ever, the powder gas expands in the bore of the gun, though the
proportion of the products of combustion are the same, the ten-
sion is greatly less.

185. Cartridge-bags are sacks for containing charges of pow-
der when put into the piece. They should be made entirely from
either woolen or silken stuff; the fabric should be soft, and
closely woven, to prevent the powder from sifting through.
The seams should be sewed with woolen 5^arn or silk.

Pkojectiles.

186. Projectiles for the U. S. artiller}'' service are made of
cast-iron, a material combining in a greater degree than any
other the essential qualities of hardness, strength, density, and
cheapness.

Projectiles are classified as spherical and elongated. The first
are used exclusively in smooth-bore guns ; the second in rifles.

They are furtlier classified, according to their structure and
mode of operation, as solid^ hollow^ and case-shot.

18'V. Solid projectiles produce tlieir eftect from impact alone,
and as they can be fired with the greatest charge that the piece
will bear, are used when great range, accuracy, and penetration
are required. They are the only projectiles that can be used
with effect against very strong walls, or armor-plated vessels.

48 PROJECTILES.

Under the head of hollow projectiles are included shells for
gims, howitzers, and mortars.

188. Shells have less strength to resist shock from the dis-
charge of the piece and from impact ; they are therefore gen-
erally iired with smaller charges of powder than solid shot.
The weight of a shell is generally about two-thirds that of a
solid shot of the same calibre. They are charged with mortar
powder, which, exploding with violence, produces great destruc-
tion to both animate and inanimate objects.

The principal parts of a shell are :

First. The cavity., used to hold the bursting charge ; or burst-
ing charge and incendiary composition, when the intention is to
destroy by setting fire to objects.

Second. The fuse-Jiole^ which is used for inserting the charge,
and to hold the fuse whicli communicates fire to it.

Spherical shells have two small shallow holes, one on each side
of the fuse-hole, into whicli are inserted the shell-hooks when
loading. These holes are called eai^s.

Shells for mortars, being fired with lighter charges than those
for guns, have less thickness of metal.

Spherical shells for guns are reinforced on the inside, around
the fuse-hole, to prevent the fuse-plug from being driven in b}''
the force of the discharge. This reinforce serves, in some meas-
ure, to compensate for the loss of weight on that side of the shell
caused by the fuse-hole, thus rendering the shell more accurate
in flight.

189. Case-shot is a projectile similar to a shell, but with
much less thickness of metal. It is filled with leaden bullets,
which are secured against moving loosely about by having their
interstices filled with melted sulphur. Through the fuse-hole,
a hole is bored into this mass of bullets and sulphur sufficient to
contain a bursting charge. This projectile is intended only for
use against troops. The fuse is so regulated as to burst the shell
a short distance in front of the object, when the bullets and
fragments, separating, move forward in a sheaf form, and pro-
duce effect as from musketry.

The charge for case-shot should be only sufficient to rupture
the case.

190. Elongated projectiles are used exclusively for rifle guns,
and, like the spherical, may be either solid or hollow. There
are in service various patterns, each known, genorally, by the
name of the inventor. They all, however, have a general re-
semblance to each other, and consist of a cylindrical body sur-
mounted by a conoidal head. To the base is attached a ring or
cup of some softer metal, which, expanding from the force of

PROJECTILES. 49

the discharge, enters the grooves of the piece and causes the pro-
jectile to take a rotary motion about its axis.

The fuse-hole, which is in the pointed end, is coincident with
the axis. The fuse-plug is screwed into the fuse-hole.

The most approved pattern is known as the Butler projectile,
{Fig. 1, Plate F,) the sabot of which consists of a bronze ring
screwed upon the base. In this ring an aiuiular groove is cut ;
the gas from the charge acting on this channeleur forces the
exterior lip into the grooves of the bore, while the interior is
forced still tighter upon the body of the projectile, thus prevent-
ing it from stripping.

191. A cored shot is an elongated projectile having a cavity
in the body of it. This cavity is for the purpose of throwing the
centre of gravity towards the front end of the projectile, thus
insuring greater steadiness of flight.

The hollow projectiles are either shells or case-shot, both of
which, in their construction and use, are similar to those hereto-
fore described for smooth-bore guns.

Rifle projectiles have a length of two to three times their
diameter, depending upon the pattern, and whether solid or
hollow, the latter being generally the longest.

192. A canister is a projectile consisting of a hollow tin cyl-
inder filled with cast-iron or leaden balls, which vary in size
and number with the kind and calibre of piece. The cylinder is
closed at the bottom with a thick cast-iron plate, and at the top
by one of sheet iron. The balls are packed in with dry sawdust.
Canister is not effective at a greater distance than 400 yards,
and, with the exception of flank howitzers, is but little used for
heavy artillery.

193. Grape-shot. A stand of grape is composed of nine cast-
iron balls, disposed in three layers of three balls each. They
are held together by two circular iron plates, united by a bolt
passing through their centres. Around this bolt the balls are
held by two iron rings. The plates have a diameter correspond-
ing to the calibres of the gun in which the grape is to be used.
The size of the balls depends, likewise, upon the calibre of the
gun.

Grape is not fired from rifle guns, and has but limited use for
those of smooth-bore ; the modern musket and Gatling being
much more effective than either canister or grape.

194. A carcass is a spherical shell, having three additional
holes, of the same dimensions as the fuse-hole, pierced at equal
distances apart in the upper hemisphere of the shell. The shell
is filled with a composition which burns, with intense power,
from eight to ten minutes, and the flame, issuing from the holes,

' 4

50 FUSES.

fires whatever is combustible within reach. It is used in bom-
bardments for setting lire to shipping, magazines, camps, &c.

When the prepared carcass is not to be had, a common shell,
either spherical or elongated, may be substituted bj'" placing in
the bottom of it a bursting charge contained in a bag ; over this,
carcass composition is driven until the sliell is nearly tilled ; four
or five strands of quick-match are then inserted, and secured by
driving more composition upon them. These shells, after burn-
ing as a carcass, explode.

Port-fire composition is suitable for filling them. '

195. AJire-hall is a projectile of an oval shape, formed of a
sack of canvas filled with combustible composiUon, which, in
burning, emits a bright fl.ame. It contains a loaded shell, and
is used for lighting up the enemy's works. It is fired from a
mortar.

Fuses.

196. A fuse is the contrivance for igniting the charge of a
hollow projectile, after it has left the piece, upon being fired.

They are divided into four classes, viz.: the time-fuse, the
percussion-fuse, the concussion-fuse, and the combination-fuse.

191". The time-fuse^ now used for heavy artillery, is com-
posed of a paper case inclosing a column of compact composi-
tion, which is ignited by the flame from the charge in the piece.
It burns for a certain time, at the end of which it communicates
the flame to the charge in the projectile. The paper case is made
slightly conical to insure a close fit and to prevent it from being
driven through and into the projectile. It is inserted, at the
time of loading the piece, into a metal or wooden fuse-plug pre-
viously driven or screwed into the fuse-hole of the projectile.
The composition has the same ingredients as gunpowder, the
proportions being varied to suit the required rate of combustion.
To insure ignition, it is primed at the larger end with rifle pow-
der. They are furnished from arsenals in water-proof packages,
each package being marked with the number of seconds required
for the burning of the fuse ; this time varies from twn to twenty
seconds per inch. The paper case is graduated into seconds,
which enables the fuse to be cut to a length corresponding to
any intermediate time. All fuses of this kind are of the same
diameter and are two inches in length.

When it is to be used for ricochet tiring, especially over water,
a plug, known as the water-cap fuse-plu^, is used. This is con-
structed to prevent the burning composition from being extin-
guished when the projectile strikes, and consists of a brass plug

PRIMERS. 51

■firmly driven or screwed into the fuse-hole of the projectile; the
paper fuse is inserted at the time of loading the piece, after
wiiich a water-cap is screwed into the plug.

The water-cap is of brass, and is perforated with a crooked
channel, tilled with mealed powder; the mealed powder com-
municates fire to the paper fuse, and the angles of the channel
break the force of the -water or dirt. The top of the cap has a
recess filled with a priming of mealed powder, covered by a pro-
tecting disk of lead or paper, which is pulled off immediately
before inserting the projectile into the piece. For security
against accidental ignition, a small leaden plug is placed in the
Inner end of the fuse-plug, where it remains until it is driven
out by the shock from the discharge of the piece.

Fuse-plugs for mortar shells are generally turned from some
hard wood ; these are made to fit closel}^ by rasping them off to
the exact size.

The paper time-fuse is used for either smooth-bore or rifle
pieces.

198. The percussion-fuse is used only for rifle projectiles,
and is ignited by the striking of the point of the shell against an
object. There are many varieties of this fuse, all consisting,
essentially, of a brass or pewter fuse-plug containing a plunger.
This plunger does not move in its place until the sudden arrest-
ing of the shell, by striking, causes it to break its fastening, and,
by its inertia, is driven against a priming of fulminate, which,
•exploding, communicates flame to the charge of the shell.

199. The concussion-fuse is made to operate by the shock
of the discharge of the piece. There are also manj'^ varieties of
this kind of fuse, all of which are composed essentially of a
plunger, which, by its inertia, when the shell starts to move in
the bore, breaks its fastenings, and, striking against a priming
of fulminate, explodes it and communicates fire to a time-fuse
inclosed in the same fuse-plug. The time-fuse is cut or set to
burn the required time ; it then communicates flame to the
eharge in the shell.

Concussion-fuses are seldom used except for rifle projectiles.

The combination-fuse is one combining the principle of action
of the three former. There are, also, a great variety of this kind
of fuse, all of which are more or less complicated.

Primers.

200. The friction-primer is a device for communicating fire
through the vent to the charge in the piece. It is composed of
two brass tubes soldered together at right angles. The shorter

52 SABOTS.

tube contains a small quantity of friction composition, in contact
with whicli, and contained also in the short tube, is a serrated'
wire, which wire is doubled at its other extremity into a loop
forming an ej^e for the hook of the lanyard; the long tube is
filled with rifle powder, and has its lower extremity closed with
wax. {Fig. 2, Plate V.)

The long tube is inserted in the vent; a pull upon the lanyard
disengages the serrated wire, which, by its friction upon the
composition, causes the latter to ignite, and thus communicating
fire to the rifle powder in the long tube, explodes the cartridge
in the piece.

The charge of rifle powder has suflScient force to pass the
flame through the longest vent and penetrate several thicknesses
of cartridge-cloth.

{Fig, 3, Plate V.)

201. The electric-primer 'is, an invention for firing cannon by
means of electricity. It consists of the long tube of the friction-
primer split at one end to receive a short but larger piece of brass
tube, to which it is soldered. The larger piece incloses a cylin-
drical piece of hard wood, slotted midway of its length and per-
forated at each end to receive short pieces of copper wire, which
are connected across the slot by a coiled piece of fine platinum
wire. The outer ends of the copper wires project a few inches
to connect the wires of the primer with the terminal wires of
the battery. When thus connected, the batter}'' current heats
the platinum sufficiently to ignite a small piece of loose gun-
cotton, which, together with the platinum wire, occupies the
slotted portion of the wooden cylinder. The ignited gun-cotton
communicates flame to the powder in the long tube.

'20S. Sabots are circular blocks of wood, fastened with tini
straps to iiollow projectiles for smooth-bore guns. Their object
is to prevent the projectile from turning in the bore and bring-
ing the fuse in contact with the charge of the piece. The diam-
eter of the sabot corresponds to that of the projectile ; it has a
shallow dish-shaped cavity for the projectile to rest in, and is
always attached to the side opposite the fuse-hole.

When the piece is flred, the fragments of the sabot fly a short
distance from the muzzle ; consequently it is dangerous to use
this kind of ammunition when firing over the heads of our own
troops. Owing to the liability of premature explosions, the same
objection applies to hollow projectiles of every variety.

The metallic ring, or cup, attached to the base of rifled project-
iles for the purpose of expanding into the grooves of the piece
and giving rotary motion to the projectile, is also called a sabots

IMPLEMENTS. 53

BIPLEMENTS.

203. Implements for artillery are those instruments employed
In loading, pointing, and firing cannon, and in mechanical ma-
noeuvres therewith.

Equipments are those things used for the same object, but
which are carried by tlie individual men.

S04. Gunner''s quadrant {Fig. 10, Plate IV) is an instrument
for giving elevation or depression to a piece. It consists of a
graduated quarter of a circle of sheet brass, of six inches radius,
attached to a straight brass bar twenty-two inches long. It has
an arm carrying a spirit-level at its middle, and a vernier and
clamp screw at its movable end. The arc is graduated to half
degrees, and the vernier reads to five minutes. To get a required
elevation, the vernier is set at the indicated degree ; the brass bar
is next inserted in the bore parallel to the axis; the piece is then
elevated or depressed until the level is horizontal. The elevation
may likewise be obtained by applying the bar to the face of the
piece, care being taken to have it in a plane parallel to the plane
of fire. The latter is the mode of using it with mortars.

The difficulty of applying the quadrant to the muzzle of guns,
especially to those in embrasure, has suggested that a metallic
ledge be attached to the end of a trunnion ; upon this ledge the
bar of the quadrant is applied when the elevation is to be given.
The top of the ledge is parallel with the axis of the bore.

205. Gunner''s level is an instrument for marking the line of
metal on a piece. Until within a very recent period it was re-
quired with all pieces, but since the application of sights to guns
its use is confined solely to mortars ; and owing to the fact that
these pieces are left rough and unturned on the exterior, the line
of metal marked, in the usual manner, with the gunner's level
and a chalk-line, is, at best, but a crude and imperfect method of
obtaining a line of sight. {Fig. 11, Plate lY.)

The method of using this instrument is readily understood by
an inspection of it.

Sponge. This is a woolen brush, attached to a stafi*, used in
cleaning the bore of cannon, and for extinguishing an}'- burning
fragments of cartridge that may remain after firing. For field
pieces the sponge and rammer-heads are on the opposite ends of
the same staff"; for siege and sea-coast pieces they are attached
to separate staves.

With pieces of less than eight inches calibre the sponge-head
<5onsists of a cylindrical block of wood about three calibres in
length ; upon this is tacked the woolen stuff" forming the sponge.
For pieces of larger calibre a spring-head {Fig. 4, Plate V) is
used. This consists of three pieces of sheet iron, so fashioned as

54 IMPLEMENTS.

to form, when put too^ether, a semi-ellipsoid corresponding to the-
bottom of the bore of the piece for which intended. To these
plates is attached the sponge material, which is secured bj^ pack-
thread stitching through holes in the iron. Each plate is at-
tached to the staff by a steel strap ; these by their spring allow
the plates to close together and enter the bore with a tight fit.
The necessary size is thus secured without the greater weight of
solid wooden heads.

Sponges are protected from the weather by canvas covers,
which are painted. They are preserved from moths by the same
means used for cartridge-bags. {Par. 568.)

The rammer. This is used for shoving the cartridge and pro-
jectile to their place in the bore of the piece. For small calibres
the head of the rammer is a short cylindrical piece of tough wood,
fixed to the end of a staff"; for the larger calibres it consists of a
wooden ring bound with iron or copper and attached to the staff
b}' three iron prongs or straps. (Fig. 5, Plate V.) This secures
lightness with the necessary size.

The ladle is a copper scoop {Fig. 6, Plate V) attached to a
staff. It is used for scooping out the powder of a cartridge
which maj'" have become broken when withdrawing it from the
bore.

The worm {Fig. 7, Plate V) is a species of double cork-screw
attached to a staff, and is used for withdrawing cartridges from
pieces.

The pass-box is a wooden or metallic box M^ith a lid and han-
dles, used for carrying cartridges from the service magazine to
the piece. The boxes are of varioii.s sizes to suit the calibre of
the piece, one cartridge being carried at a time.

The budge-barrel is a barrel, to the top of which is attached
a leather cover, which is gathered with a draw-string like the
mouth of a satchel. It is used with pieces requiring small-sized
cartridges, to carry them from the magazine to near the pieces
to be served.

The priming-wire is used to clear the vent and prick a hole in
the cartridge. This latter is not, however, an absolute essential,
as the explosion of the primer, as now made, will, with ordinary
cartridges, carry flame to the powder.

The vent-gimlet is a long gimlet for removing obstructions
from the vent.

The vent-punch is an instrument for the same purpose. As
these instruments are made of hardened steel, great care must
be observed in using them, that they do not break in the vent
and spike the piece.

The fuse-setter is a brass drift for driving wooden fuse-plugs
into shells.

IMPLEMENTS. OD

Fuse-wrench is a three-pronged wrench used for setthig fuse-
phigs that are to be screwed uito the shell. One prong con-
tains forks for the fnse-plng, and another one smaller forks for
the water-cap.

Fuse-block^ sometimes called fuse-gauge, {Fig. 8, Plate F,) is
a simple contrivance for holding paper time-fuses when being
cut. It consists of two blocks of wood lunged together so as to
open and shut after the manner of a book. In each end is a
recess into which the fuse is placed, and whore it is securely
held by pressing the blocks tightly together. The fuse is put in
with the small end extending out of the end of the block, the
point at which it is to be cut being even with the end of the
block.

Along one side of the recess is attached a brass scale. This
was intended for fuses of obsolete pattern. As now made, each
fuse is divided into as many equal parts as the number of sec-
onds for which its entire length (two inches) is intended to burn.
These parts are marked, and are the guides in cutting the fuse ;
the latter operation being performed with the fuse-knife^ which
is a sharp thin-bladed knife, (preferably a shoe-knife,) or a
fine saw. (See Fuses, ^ar. 196.;

Fuse-plug extractor. This is an instrument for extracting
fuse-plugs after they have been driven. It is a stout screw,
which may be screwed into the fuse-hole of the plug, which is
then pulled out by means of a screw operating after the manner
of certain kinds of cork-screws.

Fuse-reamer is used to enlarge the hole in a fuse-plug so as to
make it of proper size for the paper fuse.

Powder-measures are made of copper, of cylindrical form and
of various sizes, for the purpose of determining the charges for
shells and cannon by measurement. Each measure is marked
with the weight of mortar powder which it holds. They come
in sets, holding from one ounce up to several pounds, and fit
together in a nest.

Lanyard is a strong cord, one end of which has a small iron
hook and the other a wooden handle. It is used for exploding
the friction-primer when a piece is to be fired.

Shell-hooks is an implement constructed to fasten into the
ears of a shell for the purpose of lifting it to the muzzle of the
piece.

Gunner'' s pouch and pi'imer-pouch are made of leather, and are
attached to the person by a strap buckling around the waist.

Cartridge-pouch is made of leather, and is carried suspended
from the shoulder to the opposite side. It is used when small
cartridges are required, for carrying them from the magazine or
budge-barrel to tlie piece.

OG MOTION OP PROJECTILES.

Sight-pouch is a long, slender case, used sometimes for carry-
ing the breech sight. It is suspended from the shoulder.

Handspikes. With siege guns and mortars, wooden hand-
spikes are used for manoeuvering tliem. Tliose for mortars are
shod with iron, which is turned up in a way to prevent slipping
on the platform.

Guns with iron carriages have iron handspikes, made to fit
into tlie mortises of the truck- wheels.

Elevating-har is a stout bar of iron with one end squared and
made to fit into the ratchets on the breech of the piece for the
pui-pose of giving elevation. It is operated as a lever, the fulcrum
being the ratchet-posts of the carriage.

The implements and machines used for mechanical manoeu-
vres., for the inspection., and for the aiming of cannon, are de-
scribed under those lieads respectively.

MOTION OF PROJECTILES AND DEYIATINa

CAUSES.

S06. A projectile fired from a cannon is acted on by four
distinct forces, viz.: First, the projectile force ; second, the force
of gravity ; third, the resistance of the air ; fourth, the friction
against the surface of the bore.

With tlie exception of gravity, none of these forces are con-
stant, varying not only for different pieces, but for different shots
from the same piece.

The projectile force is that produced by the combustion of the
powder in the piece, causing sudden development of gas, the
expanding force of which, acting on the projectile, impels it
forward and out of the piece. It is physically impossible to ob-
tain exact uniformity in the charges. In practice tliere will
ahvays be a difference in weight and shape in the cartridges,
and in pushing them home, greater pressure will be applied at
one time than at anotliei-, thus causing want of uniformity in
combustion. The temperature of the piece, arising from pre-
vious discharges and from the temperature of tlie air or rays of
the sun ; the nature of the projectile and its movement in the
bore ; the condition of the bore with respect to humidity and
foulness, — all have more or less influence on the combustion of
the powder, and consequently on the velocity and range. Above
all, however, is the want of uniformity in the quality of powder.
In this respect considerable latitude must be allowed in the size
and density of grain or pellet, in the manipulation of the ingre-
dients, and in its condition resulting from age, moisture, and
handling. With small charges, especially with fine-grained

MOTION OF PROJECTILES.

powder, it is possible to so mix the contents of different barrels
for any series of shots as to secure a fair degree of uniformity for
that particular occasion ; but with charges requiring large quanti-
ties of powder, this, except to a limited degree, is impracticable.

The force of gravity. As soon as the projectile leaves the muz-
zle of the piece this force has free power to act, and draws the
projectile downwards, causing it to describe a curve.

The resistance of the air. The projectile, in passing thi-ough the
air, meets from it a resistance depending in intensity upon the
velocity, the shape of the projectile, and density of the air. This
resistance consumes a portion of the projectile force, whicli, being
gradually diminished, causes the projectile to pass over unequal
spaces in equal intervals of time. These spaces gradually diminish-
ing, give to the trajectory unequal curvatures in its two branches,
that of the last pai't being much more curved than the first.

Atmospheric resistance increases as the square of the velocity,
and with the cross-section of the projectile exposed to the action
of the resistance.

It is manifest that the resistance due to the atmosphere varies
with the density of the latter, and this depends upon and varies
with the temperature, the humidity, and the barometric press-
ure. The retarding effect of rain is evident.

The foregoing influences operate principally in a vertical di-
rection, and therefore affect only the range. Other influences
affect lateral accurac}'^, among which may be mentioned wind.,
the velocity and force of which are classified as follows :

Telocity.

Pressure on

Common designations of the force

1 square

In 1 hour.

In 1 sec'd.

foot.

of the wind.

Miles.

Feet.

Lbs.

1.47

0.005

Hardly perceptible.

2
3

2.93
4.40

.020 \
.044 5

Just perceptible.

4
5

5.87
7.33

.079?
.123 5

G-entle, pleasant wind.

10
15

14.67
22.00

.492 \
1.107 5

Pleasant, brisk breeze.

20
25

29.34
36.67

1.9G8>
3.075^

Very brisk.

30
35

44.01
51.34

4.429 \
6.027 5

High wind.

40
45

58.68
66.01

7.873?
9.963 5

Yery high.

73.35

12.300

A stoma or tempest.

88.02

17.715

A great storm.

117.36

31.490

A hurricane.

100

146.70

49.200

A hurricane that tears up trees.

carries buildings before it, &c.

68 MOTION OF PROJECTILES.

It is evident from the foregoing' that the effect of wind, on so
large a body as a cannon projectile, is considerable. This effect
is in direct proportion to tlie strength of the wind and the time
of flight of the projectile.

When the wind crosses the plane of fire, the deviation of
spherical projectiles is on the side towards which the wind is
moving ; with elongated projectiles, especially shells and cored
shot, the wind has a slight tendency to cause them to go in the
opposite direction. Wind coming from the left tends, therefore,
to correct the drift of rifle projectiles, the latter being always
to the right ; when coming from the right it augments the drift.
A front wind diminishes the range; when coming from the rear
it increases, but to a very slight degree, the range.

When the range is great the projectile may have to traverse
several currents of air of different directions and velocities. This
would have the effect of giving a waving motion to the pro-
jectile.

The condition of the atmosphere with reference to mirage has
a marked influence upon accuracy of aiming; for it is evident
that a projectile will not strike the object if the piece is directed
only at the reflected image of it.

Aberrations arising from atmospheric influences are so nu-
merous and subtle as to make it impracticable to formulate them
into tables useful for practical gunnery. Practice at small-arm
tiring, as now conducted at rifle-ranges, leads to habits of obser-
vation and exercise of sound judgment highly advantageous ta
the artillerist.

Friction against the hore. The projectile, in passing along the
bore, experiences more or less friction ; this has a retarding
effect, varying the velocity and consequently the range. The
unequal degree of friction at different parts of the bore may
cause the projectile to leave the muzzle with a greater pressure
on one side than on the other, forcing it to deviate from the
true line of fire. This is more particularly the case with spher-
ical projectiles, in which there is considerable windage and bal-
loting, than with rifle projectiles.

Resistance from rifling. The cup or sabot of an elongated
projectile, expanding from the pressure of the gas, fills the
grooves, which, being inclined to the axis of the bore, offer
resistance to the forward motion of the projectile. That side of
each groove towards the muzzle is the one against which the
expanded sabot constantly impinges, and is called the driving
side.

Owing to the mechanical impossibility of constructing guns
and projectiles of exact uniformity, a certain departure from

AIMING. 59

the true dimensions is allowed in receiving- them from tlie
manufacturer. This, to a certain degree, prevents uniformity
in firino'. Ronohness of tlie bore and projectile, especially with
rifles, influences velocity, accuracy, and i-ange. Tlie bore be-
comes foul from firing, and this foulness is hard and roui>:h or
soft and unctions, depending on the humidity of the atmosphei-e.^
or whether the sponge is moist or dry. Witli rifle projectiles,
lubrication, or tlie want of it, has a marked effect upon their
range and accuracy.

Want of uniformity in the density, weight, figure, and centre
of gravity of projectiles, are other sources of error in firing.

In many instances these various sources of aberration may
combine in such manner as to partly neuti'alize each other. On
the other hand, they may so fall together as to produce the
maximum degree of inaccuracy.

In addition to the foregoing, there are other sources of error
in firing, which, although exceeding!}^ minute, nevertheless exist.
Among these may be mentioned the influence of the axial rota-
tion of the earth; the spring of the carriage; the dip of the muz-
zle ; the effect of the rays of the sun in heating one side of the
piece more than the opposite side, and a like effect on the pro-
jectile.

From the foregoing, it must be evident that exact uniformity
of firing with any piece is an impossibility. It is b}'' practice
alone that the artillerist can be brought to distinguisli between
inherent defects and faults of gunnery which lie may correct.

Aiming.

20 1". To aim a piece of artillery is to give it such a direction
and elevation as will cause the projectile to strike the object^
and the rule is : first give the direction, and then the elevation.

With the exception of mortars, all modern pieces are furnished
with two sights : a front one and a rear one. These are situated
either on the line of metal ^ or slightly to the right of it in a plane
parallel to the plane of lire.

The front sight is securely attached to the piece by means of
a screw, and for the heavier class of guns is over the axis of the
trunnions.

The rear sight is on the breech, fitting into a socket attached
to the piece with screws, and when the gun is to be discharged
is removed from the socket.

For the 10 and 15 inch guns the breech sight is without grad-
uation, and serves merely to give direction to the piece, the ele-

60 AIMING.

vation being given by means of the elevating-arc, or, when prac-
ticable, with the quadrant applied in the muzzle.

208. For siege and Parrott guns the breech sights are grad-
uated to correspond to degrees and parts of degrees of elevation
of tlie axis of the bore, and have a slide to move up or down.
This slide has a screw thread cut on one end of it, upon wiiich
works a nut with four short arms ; through each of these arms
is a small hole for sighting. The screw upon the slide is for
the purpose of giving lateral motion, when allowing for drift.

Each kind of gun has its particular breech sight, but, as there
are in service many of old or experimental pattern, they should
be veritied for the particular pieces upon which they are to be
used. This is done by directing the piece at some well-defined
point at a distance of 1000 yards or more, and on the same hori-
zontal plane with the axis of the trunnions. A straight-edge
and spirit-level applied to the face of a trunnion suflSces for this
operation. Place the slide of the breech sight at any degree of
the graduation, and, sighting through it at the object, give the
piece the corresponding elevation. Insert the gunner's quad-
rant into the bore, and ascertain from it the inclination of the
axis of the piece. If the reading on the breech sight corre-
sponds to that of the quadrant, the former is correct. The line
of sight passing through the zero of the breech sight is parallel
to the line of fire.

209. For 10 and 15 inch guns an elevating-arc is used. This
•consists of a strip of brass attached to the base of the breech
parallel to the ratchets. It is graduated into degrees and parts
of degrees, and a pointer, attaclied to the ratchet-post, indicates
the elevation or depression of the piece. When the pointer is at
zero, the axis of the piece is horizontal. Besides the graduation
on the arc, the ranges in yards for the ordinary charges for shot
and shell are given.

In batteries for garrison and sea-coast defense, where the
platforms ai-e fixed, the line of metal may be considered as per-
manent; but with siege guns, mounted on traveling carriages,
the wheels are liable to vary in position from unevenness of
ground, or unequal settling in newly -constructed platforms.
This line is constantly changing, and approximates the higher
wheel in proportion to the difierenceof level between tiie wheels ;
hence, to secure accuracy of fire, allow^ance must be made by
observing where the shots strike and correcting the aim accord-
ingly. Deviation from this cause is always towards the side of
the lowest wheel.

210. All range tables are made out with reference to the
horizontal plane passing through the axis of the trunnions;

AIMING.

when the object to be fired at is situated on a plane lower than
this, an allowance must be made for this difference of level by
deducting from the elevation laid down in the table of ranges.

The following table is calculated for cases in which the piece
h above the object; it will also serve with sufficient degree of
approximation for cases in wliich the piece is below tlie object,
by simply reversing the method of application ; ^. e., by adding,
instead of subtracting, the quantity due to the height and. dis-
tance.

Yards.

lOCO
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
3000
3500
4000
4500
5000

HEIGHT.

1 Ft. 2 Ft.

1.1

1.
.9
.9

1.3

1.2

1.1

4 Ft.

8 Ft.

16 Ft.

o /

4.6

9.2

18.3

4.2

8.3

16.7

3.8

7.6

15.3

3.5

14.1

3.3

6.5

13.1

6.1

12.2

2.9

5.7

11.4

2.7

5.4

10.8

2.5

5.1

10.2

2.4

4.8

9.6

2.3

4.6

9.2

2.2

4.3

8.7

2.1

4.2

8.4

7.9

1.9

3.8

7.6

1.8

3.6

7.3

1.5

6.1

1.3

2.6

5.2

1.1

2.3

4.6

4.1

1.8

3.7

Ft. 64 Ft.

36.7
33.3
30.6
28.2
26.2
24.4
22.9
21.6
20.4
19.3
18.3
17.5
16.7
15.9
15.3
14.7
12.2
10.4
9.2
8.1
7.3

13.3
6.7
1.1

56.4

52.4

48.9

45.8

43.1

40.7

38.6

36.7

34.9

33.3

31.9

30.6

29.3

24.4

21.

18.3

16.3

14.7

96 Ft.

50.
40.
31.7
24.6
18.6
13.3
8.7
4.7
1.1
57.9
55.
52.4
50.
47.8
45.8
44.
36.7
31.4
27.5
24.4
22.

"When the height of the piece above the water or horizontal
plane is known, the angle of depression for different distances
can be found thus : Find the angle for any height not given in
the table, as follows : divide tlie given height into parts, which
are found in the table, using the largest numbers possible ; and
add the angles corresponding to those parts, for the required
distance. Example : Required the angle for distance 1000 yards
and height 130 feet. 130 feet gives the parts 96^ 32% and 2';
the sum of tlie angles for these heights is 1° 50^+ 36.7^+2.3^=
2° 29^; the amount to be deducted from the elevation as given
in the table of ranges for the particular piece used.

62 AIMING.

211. Owing to the great range at which rifled guns are used,
and of the accuracy of lire demanded of them, it is important
that they should be provided with aiming apparatus more per-
fect than the coarse and clumsy sights heretofore supposed to
be sufficient for artillery purposes.

The Lorain sight, {Plate F/,) of which the following is a brief
description, combines the properties most desirable in a sight
for heavy rifled guns.

This instrument is essentially a transit with a vertical and
horizontal limb, the former to give the required elevation or
depression, and the latter to give proper allowance for drift.

The telescope (A) has a top, a front and rear open sight (a a%
used to bring the object aimed at within the field of view.

The vertical limb (B) is graduated to degrees. The least count
of the vernier (6) is six minutes.

The tangent screw (C) elevates or depresses the telescope.

The horizontal limb (D) has a scale of 20° on each side of the
zero, which is graduated to degrees.

The standards (E E^ are supported by the horizontal limb.

The tangent screw (F) moves the horizontal limb to right or
left.

The base of the instrument (Gr) has on it the vernier (g) of hori-
zontal limb, the least count of which is six minutes.

When in use, this instrument sits in a seat (H) which is screwed
on to the right trunnion of the gun.

This seat is so placed that the plane of its top is parallel to the
horizontal plane through the axis of the bore. When the verti-
cal limb is at zero, the axis of the telescope will be parallel to
the axis of the bore, if the zero of the horizontal limb coincides
with the mark (I) on the seat.

This mark (I) is on a movable piece (K) attached to seat, and
its position is easily determined.

The elevations given with this sight and with a quadrant do
not agree, the latter being measured from the horizontal and
the former from the line from sight to object. In firing from
above an object, the telescopic sight requires more elevation
than the quadrant. If from below an object, it requires less
elevation than the quadrant.

When the piece is to be fired, the instrument is lifted out of
its seat. One instrument suffices for three or four guns, it being
-carried from piece to piece as they are prepared for firing. For
short range and rapid firing, the pieces should, in addition, have
the ordinary sighting arrangements.

Note. — The proper place for the sight is on the left trunnion ;
t)ut as, with carriages now constructed, it would be interfered
with by the crane, it is placed on the right trunnion.

AIMING MORTARS. 63

Aiming mortars »

S12. Mortars, like other cannon, are aimed by first giving
the direction and then the elevation.

The elevation, which is nsuallj'^ that of the greatest range of
projectiles in vaciio^ viz., 45°, is determined by applying the
quadrant to the face of the piece, and raising or lowering the
breech until that number of degrees is indicated.

The charge of powder is varied to suit the required range.

To give the shell, for the same range, a greater velocity in the
descending branch of its trajectory, the mortar is sometimes
fired at an angle of 60^, in which case the charge of powder must
be increased accordingly.

As mortars are usually masked from the object to be bom-
barded by an epaulment or parapet, difierent means from those
used with guns become necessarj' for giving them their direction.

There are several processes employed, all of which, however,
are reduced to determining practically two fixed points which
shall be in line with the piece and the object, and sufficiently
near to be readily distinguished by the person pointing tlie
mortar. These points determine a vertical plane whicli, when
including the line of metal, becomes the plane of fire.

The various methods are I'xplained in pa7's. 342 and 343.

213. The following is a description of Dyer's pointing appa-
ratus, and instructions for its use.

This method is easy of application, and is especiallj' adapted
for use with mortars mounted on centre-pintle carriages; it is
also readily adapted for use with mortars mounted on ordinary
and temporary platforms. Practically it is independent of the
distance from the crest of the parapet to the platform. The
method is as follows :

Find the point where the vertical plane containing the directrix
of the platform cuts the interior crest of the parapet. At this
point establish a level plate containing an arc graduated both
ways from the point where the vertical plane cuts it, the centre
"being the point first established on the interior crest. An arm
with two vertical sights revolves about this point as a centre,
and determines, by means of an indicator attached to the front of
the arm, the angle made by any object with the vertical plane
through the centre, called the plane of the zeros. The mortar
being given the same angle with the plane of the zeros, the plane
of fire will practically intersect the object.

To apply this method to a mortar mounted on a centre-pintle
•carriage : On the rear of the platform, with the centre of the
pintle as a centre, describe an arc. Find the point where the

64 RICOCHET FIRING.

plane of the zeros cuts this arc, and mark the point zero. Divide
the arc both ways from the point into degrees and parts of de-
grees. An indicator attached to the centre of the rear transom
(in the vertical plane containing tlie axis of the piece) will always
mark the degrees to the right or left of the plane of the zeros.

{Plate VII.)

Description of the pointing instrument.

A horizontal iron plate is permanently established on the par-
apet, the rear edge being on the crest and the centre in the
plane of the zeros.

In order that the same instrument may be used at different
places in a work, or be removed when not in use, a detachable
plate containing the graduation and sights is adjusted to the
permanent plate, as sliown in Fig. 1. P is a pintle on the de-
tached plate which fits into a socket in the permanent one. L L
are levels on the detached plate J inch below the upper surface
of the plate. S S are leveling screws. By the use of this plate
the index arm will always be made to move in a horizontal plane.

Application of fhe method.

1st. Place the plate containing the graduated arc on its bed^
and level it by means of the tangent screws ; then place the arm,
to which the sights are attached, on the plate. Traverse the
chassis until the index on the rear transom indicates the required
number of degrees as indicated by the instrument.

If the arm of the instrument be to the right of the zero, traverse
the chassis to the left ; and vice versa.

For the successful operation of this method with the centre-
pintle mortar carriage, it is essential that the guides of the top-
carriage should fit true and snug to the chassis rails.

Ricochet Firing.

*J14. The angle of fall of projectiles in vacuo is equal to the
angle of elevation; but in air the angle of fall is somewhat
greater.

It is known from experience that a projectile falling upon
ground of ordinary firmness, at an angle not greater than ten
degrees, or upon water at four or five degrees, will generally
make one or more bounds. In this case the projectile is said to
ricochet.

The purpose to be sought in ricochet firing is to cause the
projectile to bound along near the surface of the ground or water^

CARRIAGES. 65

and thus increase the chances of hitting the object to be clestroyecl.
It is chiefly advantageous against troops in the field, and against
boats and unarmored vessels. With the exception, however, of
occasional use against the latter objects, it is generalh'^ but inci-
dental to direct firing. Owing to the inequalities dt ground, it is
uncertain of effect when employed against objects on land.

Spherical projectiles are more certain of ricochet than those of
elongated form ; with the latter the first graze usually causes
them to tumble, after which their motion is both feeble and
erratic.

The pieces principally employed for ricochet firing are the
8-inch howitzer and the 8 and 10 inch siege mortars. The first
two may be used when the angle of fall is less than ten degrees,
and the latter when the angle of fall is less than fifteen degrees.
With the howitzer, a range of 2000 yards may be obtained; with
the mortars, the limit of ricochet is about 1000 yards.

With the 15-inch gun, the most effective ricochet upon smooth
water is obtained from two degrees elevation; this, with the
piece fifteen feet above the water, will cause the first graze to
take place at a distance of about 1500 yards, giving a rebound
of about 800 yards in length and 100 feet in height. The next
rebound will be about 500 yards in length, after which they rap-
idly diminish until towards the last, when the projectile appears
to almost roll upon the surface of the water. The extreme range
at this elevation is about 4000 yards, and the number of distinct
ricochets about thirty-five.

The slightest roughness of the water has a decided effect upon
ricochet, diminishing both accuracy and range.

With elongated projectiles, after the first strike, the course is
quite erratic, and they are, therefore, entirely unsuited for accu-
rate ricochet firing.

CAERIAGES.

5215. Carriages for artillery are classified as traveling and
stationary. The former are for artillery that is to be moved from
place to place; the latter, for that occupying fixed positions.

Strength, durability, and facility in serving the pieces are the
chief requisites for all carriages.

Stationary carriages consist of two parts : the carriage — or, as
it is usually called, the top-carriage — and the chassis, and, with
the exception of that for the flank-casemate howitzer, are all
constructed of wrought-iron.

216. The top-carriage {Fig. 1, Plate VIII) is composed of two

66 CARRIAGES.

cheeks, held together by two plates of boiler iron, called the
front and rear transoms. Each cheek is formed of two plates
of boiler iron cut to a trianoular shape, separated by interposing
at the edges the vertical portion of a T-shaped bar. The hor-
izontal branches project over each side to form a double flange,
giving stifthess to the cheeks. Flat bars of iron are placed
between the plates at suitable intervals to stiffen the cheeks in
the direction in which the weight and recoil of the piece bear
upon them. All these parts are held together by screw bolts.

The piece rests between the cheeks, and is supported on them
by the trunnions, which work in circular cavities called trunnion-
heds. This permits the piece to have free play for purposes of
elevation and depression.

For most pieces, the motion of the top-carriage to and from
battery is regulated by a pair of truck-wheels, one on each side,
which work on an eccentric axle placed underneath and a little
in front of the axis of the trunnions.

The wheels are thrown into gear by means of handspikes in-
serted into sockets upon the ends of the eccentric axle ; the
wheels then rest upon the top of the chassis rails, and only the
rear part of the soles of the top-carriage rest on the chassis rails
and have sliding friction. The wheels are thrown out of gear in
the same manner ; the entire soles then have sliding friction upon
the chassis rails, thus checking recoil.

In the 15-inch gun carriage there are two pairs of truck-wheels,
one pah" being placed in front, as just described, and the other
pair near the rear end of the carriage; the rear wheels only are
on eccentric axles, and wlien these are out of gear the soles of
the top-carriage rest fairly on the chassis rails, and the motion
is on sliding friction. When the rear wheels are in gear the
front wheels also touch the chassis rails, and the top-carriage
moves on rolling friction. To prevent the rear wheels from
working out of gear while the gun is being run from battery, or
jumping in gear when the piece is fired, pawls are provided for
locking the rear axle.

"When the rear wheels are in gear^ motion is communicated
to the carriage by means of a handspike on each end of the
front axle. This handspike carries a double pawl, which works
in ratchets or cogs on the truck-wheels. The handspike is
arranged with a counterpoise, consisting of a heavy piece of
iron on the short arm of the lever.

In the 10 and 15 inch guns, as also in mortars, the elevation
and depression are given by means of a lever, called the elevat-
ing-bar. The point of this bar works in ratchets cut in the
breech of the piece. The fulcrum — usually called the ratchet-

CARRIAGES. 67

post — rests on the rear transom of the ^"un carriage. It is of
cast-iron, and has several notches for adjusting the position of
tlie elevating-bar.

Carriages for the 8-inch rifle (converted) have an improved
elevating apparatus. This is described in par. 320.

Guns of the Parrott pattern have an elevating screw. This is
attached to the rear transom of the carriage at its lower end,
while the nut is connected to the cascable of tlie gun. The
screw is worked by a handle passing througli it above the nut.
Both screw and nut admit of movements by whicli the screw can
take any position required in the various degrees of elevation.

Slf • Chassis. The chassis is the movable railway on which
the top-carriage moves to and from battery. It is composed of
two wrought-iron rails inclined three degrees to the horizon, and
united b}^ transoms, as in the top-carriage. In addition to the
transoms, there are several diagonal braces, to give stitlness to
the chassis. {Fig. 1, Plate Vltl.)

For the 10-inch gun and all smaller carriages, the chassis rails
are single beams of rolled iron, 15 inches deep; for all calibres
above, the rails are built up of long rectangular pieces of boiler
plate and T-iron, in a manner similar to that of the cheeks of
tlie top-carriage.

Traverse-wheels. The chassis is supported by wheels, which
allow of its having a horizontal motion, for the purpose of giv-
ing the piece a proper direction when aiming.

Traverse circles. The traverse-wheels roll on circular bars
of iron resting on a bed of masonry or wood.

Pintle. This is an upright journal, around which the chassis
traverses. It is a stout cylinder of wrought-iron, inserted in and
firmlj'^ fastened to a block of stone called the pintle Mode. When
wooden platforms are used it is fastened as described in par.

The centre-pintle carriage is one in which the chassis is attach-
ed to the pintle at its middle, and revolves around it through tlie
entire circumference of the circle. The traverse circles are con-
sequently continuous. By this arrangement a much greater
horizontal field of fire is secured.

Thii front-pintle carriage is one in which the chassis is attached
to the pintle by its front transom ; the traverse circles are seg-
ments of circles.

The^m^Ze key is a stout key of iron passing through the pintle,
to prevent the chassis from jumping oft" when the piece is dis-
cliarged. The pintle is surrounded by a plate firmly bolted to
the block ; this plate is called the pintle plate., or friction plate.

68 CARRIAGES.

Hurters and counter-hurters. These are flat pieces of iron bolt-
ed, — the first to the front and the latter to the rear part of th&
chassis rails, to check the motion of the top-carriage when the
piece is run in battery^ and wlien it recoils upon being fired.

In carriages of Improved model the hurters and counter-hurt-
ers are stout bufi'ers of gutta-percha, which, absorbing the shock,
prevent racking of the carriage.

Guides are stout claws of iron bolted to the cheeks of the top-
carriage, and, catching under the flanges of the chassis rails, pre-
vent the carriage from slipping or jumping otf.

Through the chassis, immediately over the pintle, runs an
eccentric axle, carrying upon each end a truck-wheel. This axle
and wheels are for the purpose of throwing the chassis in gear^
thus raising the pintle transom from the friction plate and allow-
ing the carriage to be traversed with freedom.

It is prescribed that the chassis shall be out of gear when the
piece is fired. This, however, is not necessary, and the omission
of it when firing saves much time and labor. The lighter class
of carriages are without the arrangement just described.

In the improved pattern of carriages the axle and truck-wheels
above mentioned are replaced by two stout rollers attached to
bolsters on the front end of the chassis. These rollers move upon
the friction plate, and give firm support and easy motion to the
chassis.

Casemate carriages differ from barbette carriages in being
much lower, but their mode of construction is essentially the
same. The pintle is placed immediately under the throat of the
embrasure, and the chassis is connected to it by a bar of iron
called the tongue.

Recoil checks. For the 10-inch smooth-bore and all below that
calibre, recoil is checked simply by the inclination of the chassis
rails and the sliding friction thereon of the top-carriage. To
increase this friction, the rails should be sanded with sand free
from pebbles.

318. Pneumatic buffers or air-cylinders are devices for check-
ing recoil through the agency of atmospheric air. At present,
only the 15-inch gun is thus provided.

Between the front ends of the chassis rails are attached two
cast-iron cylinders each 110 inches long, with an interior diame-
ter of 14.25 inches. The ends of the cylinders are closed with
tight-fitting heads secured with screw bolts. A piston works in
each cylinder. The rods of the pistons pass out through the rear
cylinder heads and are attached, by nuts, to a heavy transom on
the rear end of the top-carriage. The cylinders have the same

CARRIAGES. 69

inclination as the chassis rails, and are secured to the latter by
three cylinder transoms.

Wlien the piece recoils tlie piston-rod is withdrawn, and the
air contained in the cylinder compressed between the piston and
the rear head of the cylinder, A small hole in the front head
admits air to supply the vacuum in front of the piston.

The air in rear of the piston thus forms an elastic cushion,
offering but slight resistance to the first movement of recoil, but
gradually increasing in resisting force as the carriage moves
back, until finally the force of recoil is overcome and the top-
carriage is brought to a state of rest. The shock of recoil is to
a great extent absorbed without sudden strain to the carriage.

The top-carriage must be out of gear when the piece is dis-
charged ; it then moves on the chassis with sliding friction. This,
together with the inclination of the chassis rails, assists in check-
ing the recoil. When the carriage is in good running order, it
generally runs forward a short distance by the reaction of the
compressed air after recoil.

To run the piece in battery^ the top-carriage is thrown into
gear ; it then moves forward, the air is compressed in front of
the pistons, and, escaping gradually through the small holes in
the heads of the cylinders, allows the carriage to move forward
with a gentle motion.

The weight of the air-cylinders with attachments is about
5000 pounds.

51 9. Hydraulic buffer. This is a recoil check, in construction
veiy similar to the air-cylinder. A liquid is used instead of air,
but the principles of operation are similar.

At present these buffers are furnished only with the (convert-
ed) 8 -inch rifle, and are described in connection therewith.
(See par. 320.) Water or any other free-flowing liquid answers
for filling the cylinder. In cold weather a non-freezing liquid,
-as a mixture of glycerine and water, methyl and water, or some
of the non-freezing oils, must be used. The greatest care must
be observed to have in the cylinder the exact amount required.
The difficulty of properly regulating all of these matters makes
the hydraulic buffer greatly inferior to the air-cylinders.

520. Friction bars. This device for absorbiug recoil is sup-
plied only with the experimental 8-inch rifle (converted). It is
described \npar. 320.

3^21. Depressing carriages. These are carriages that permit
the gun to lire over a parapet in the usual manner, and, upon
recoil, allow the piece to descend behind the parapet, where it
ican be reloaded in safety.

70 CARRIAGES.

Various plans for effecting this have been proposed, but none
actually adopted, in the U. S. service. The King carria<?e^
mounting- a lo-inch gun, has, however, been tested and found
to work efflclentl3^ This consists in lowering the rear end of
the chassis until it nearly touches the ground,' thus forming an
inclined plane at an angle of about 30^ to the horizon. The top-
carriage is attached to a counterpoise by a band composed of
wire ropes. This counterpoise is a heavy mass of metal descend-
ing into a well in front of the pintle.

The carriage that has been adopted, and hereafter to be fur-
nished for barbette service, has an increase of 15 inches in
height over those of old pattern. This modification is effected by
inserting sections, similar in construction to the chassis rail, be-
tween the rails and feet, props, and fork of the low chassis. The
increase of height thus gained admits of a corresponding depres-
sion of the terre-plein, and consequently greater protection be-
hind the parapet for the cannoneers. The gun, nevertheless, is
exposed as before. Depressing carriages are intended to protect
the piece and carriage as well as the cannoneers.

The accuracy of modern artillery fire increases the danger to
the guns with which a work is armed; and the disabling of a
piece by the enemy's fire is of greater moment now than for-
merly, when works were garnished with a greater number, and
of such small size as to be readily replaced when injured.

2!iJ2, Mortar carriages. These are constructed and put to-
gether in a manner similar to the top-carriages for guns. At
the ends of each cheek are projections, called front and rear
notches, underneath which the cannoneers embar with their
handspikes to move the carriage. On those for siege mortars
there are also two front and two rear manoeuvering bolts for the
same purpose. The bottom part of each cheek, resting on the
platform, is called the shoe ; the front and rear ends being desig-
nated the toe and heel, respectively.

Carriages for siege mortars are without truck-wheels, and rest
directlj'^ on the platform. Sea-coast mortars have two truck-
wheels on an eccentric axle, for manoeuvering the carriage on
the platform, and manoeuvering bolts are omitted. {Figs. -1, 2^
3, 4, Plate IX.)

The centre -pintle mortar carriage is described in par. 370.

^23. The flank-casemate carriage ( Fig. 2, Plate VIII) con-
sists of two cheeks of wood united by two iron transoms. The
chassis consist of two wooden rails three inches apart, and joined
by four transoms and assembling bolts.

To the rear end of the top-carriage is attached an eccentric:

PLATFORMS. 71

roller, and to each cheek, in front, a roller which, when the
eccentric roller is in gear^ rests on the chassis rails, givino* to
the cari'iag'e rolling friction. The piece is then easily run in and
out of batter3% the cannoneers applying themselves to rings and
handles on the sides of the cheeks.

The front end of the chassis rests on the sole of the embrasure,
and is provided with a lunette, through which a pintle drops into
the masonry beneath. The rear of the chassis is supported by
an iron fork, to the lower extremity of each prong of which is
attached a small traverse-wheel.

For description of traveling gun carriages, see Siege Gun,
par. 231, et seq.

PLATFORMS.

224. To insure accuracy of fire with heavy guns and mortars,
it is absolutely necessary to have solid and substantial platforms.

For casemate and barbette batteries in fortifications, fixed
platforms are constructed with the works.

The barbette platform consists essentially of the pintle block,
which is of granite firmly imbedded in concrete ; in the block is
inserted the pintle, of iron, and around this is the friction plate
for the pintle transom of the chassis to rest upon. Traverse
circles, of iron, form level and smooth tracks, upon which the
traverse-wheels run.

The pintle of a casemate 'Carriage is inserted in a hole in the
sole of the embrasure, and is lifted out when the chassis is to be
removed. The chassis is attached to it by a tongue, and is pro-
vided with a front set of traverse-wheels.

Platforms for siege pieces are supplied by the Ordnance De-
partment, and, as they accompany troops in the field, it is
desirable to have them as light as is compatible with sufficient
strength to endure the shock of firing. Those hereafter describ-
ed combine, in a high degree, the essential qualities of strength
and portability. All the pieces composing them are of the same
dimensions, and, as the weight of each piece is only fifty pounds,
a soldier can carry one from the depot to the batteries, or any
moderate distance, in addition to his arms and equipments.

Another platform for mortars is described, which is very sim-
ple, strong, and well suited to positions where trees or timber
can be easily procured. This is designated the rail platform.

PLATFORMS FOR SIEGE GUNS.

Platfokm for a Siege Gun or Howitzeb.
{Fig. ], Plate X.)
225. Dimensions, &c., of siege jjlatforms.
Guns and howitzers.

Names of Pieces.

Hurter

Sleepers

Deck-planks

Stakes (securing)....
Stakes (implement).

Stakes (pointing)

Eye-bolts (iron)

Total weight.

«M .S

Op-

Inch.

108

•d

Inch,

5
5
5
3.5
2

0-75

Inch,

3.5
3.5
3.5

r'nd

Lbs.

612

1836

2579

Kind op TntBaB

Used.

Yellow pine.

When the piece is to be fired constantly in one direction, it is
best to give the platform an inclination to the rear. This pre-
vents excessive recoil, and also serves to carry off water from
rain. The degree of inclination is not absolute. In the follow-
ing it is given as one and a half inches to the yard.

When the piece is to be travei-sed over a wide field of fire, the
platform should be perfectlj^ level ; the recoil is then checked
b}' placing a bag of earth or a pile of sods at a proper distance
(about five feet) behind each wheel.

Tlie following is the method of laying the platform when it
has an inclination. To lay it horizontally, simply omit what is
said with reference to tlie slope :

The direction in which the piece is to fire is established by
stretching a cord over the centre of the place where the plat-
form is to be laid. This line is the directrix of the platform.

Prepare a bed for the platform by excavating the earth so
that it will have the proper inclination to the rear and be per-
fectly level across. The earth, if not already firm, should be
well rammed.

Lay the outside sleepers parallel to the directrix, their outside
edges being fifty-four inches distant from it. The four other
sleepers are laid parallel to these, the edge of each fifteen and a

PLATFORMS FOR SIEGE GUNS. 73

half inches from the edge of the next. The upper surface of
the front ends of these sleepers is fifty inches below the sole of
the embrasure, and they are laid with an elevation to the rear
of one and a half inches to the yard, or four and a half inches
in their whole length. This elevation is determined by placing
a block four and a half inches high on the front end of the
sleeper, and laying a straight-edge, with a level on it, from this
block to the rear end ; the earth is then arranged so as to bring
the level true in this position.

The next set of sleepers are laid against and inside of the first,
overlapping them three feet, having the rear ends inclined out-
wards, so that the outer edges of the exterior ones shall each be
fifty-four inches from the directrix, and the space between the
rear edges of the others the same as in the first set, viz., fifteen
and a half inches from the edge of one to the edge of the next :
all having an elevation to the rear of one and a half inches to
the yard, and perfectly level across. The earth is then rammed
firmly around the sleepers and made even with their upper
surface. The first deck-plank, with a hole through each end for
the eye-bolts, is laid in place, perpendicular to the directrix, its
holes corresponding with those in the sleepers. The hurter is
placed on it, and the bolts driven through the corresponding
holes in these pieces. The hurter should be so placed as to pre-
vent the wheels from striking against the epaulment when the
piece is in battery.

If. the interior slope has a base of two-sevenths of its height,
the inner edge of the hurter should be two and a half inches
from the foot of the slope. The other planks are laid, each be-
ing forced against the preceding, with the dowels fitting into
their respective holes ; the last plank has holes for the eye-bolts.
B3'' drawing out or driving in the outside sleepers, the holes
through their rear ends are made to correspond with those in
the last deck-plank. The bolts are then driven.

Drive stakes in rear of each sleeper, leaving their tops level
with the upper surface of the platform. Raise, ram, and level
the earth in rear of the platform, so as to have a plain hard sur-
face to support the trail when the recoil is great.

The earth should be raised nearly as high as the platform at
the sides, and well rammed, giving it a slight inclination out-
ward to allow water to run off. The platform is fifteen feet
long and nine feet wide.

Instead of twelve sleepers, each nine feet long, it is preferable
to use six. each fifteen feet Ions:.

FIELD PLATFORM.

226.

Field Platform.
Dimensions^ 8^c.

Names of
Pieces.

m
o
o

Op.

P
o

Kind of Timbbb

Used,

Hiirter

Sleepers

W heel-planks

Trail-plank

4
2
1
9
8

Inch.

96
108
120

Inch.

0.75
1.25

Inch.

3.5
3.5

2.25
2.25
r'nd
1.25

Lbs.

44
204
160

Yellow pine.

Beech, yel. pine or oak.

Iron.

Hickory or oak.

Eye-holts

Securing stakes.
Total ■wpis'ht

500

{Fig. 2, Plate X.)

This platform is for siege guns and howitzers when serving
with an army in the field, and the method of constructing it
indicates the way in which platforms may be extemporized from
sucli material as may be at hand.

To lay this platform, level off the ground and mark the di-
rectrix; dig trenches for the sleepers; place the latter in the
trenches so that tlie holes for the eye-bolts will correspond in
place to those in the wheel-planks ; place the wheel-planks in
position, and drive in the eye-bolts. The front eye-bolts pass
thi'ough and secure the hurter; apply the level and make the
structure perfectly level; secure the front sleeper with stakes;
it is well to secure also the rear ends of the wheel-planks with.
stakes; lay on the trail-plank and secure it with an eye-bolt to
the third sleeper; ram the dirt well in around the sleepers.

To check recoil, place sacks of earth or piles of sods ovgr the
eye-bolts of the third sleeper, or a stick of timber, similar to a
sleeper, laid across will effect the same object.

This platform admits a change of direction of about ten de-
grees on each side of the directrix, thus covering as much of a
field of fire as is ordinarily required. To make this change of
direction, slightly loosen or remove the earth about the three rear
sleepers, and heave the rear ends of the wheel-planks over with
handspikes. The platform then has the position indicated by
the dotted lines in the fio-ure.

SIEGE MORTAR PLATFORM.

22-^.

Siege Moetar Platform.

Names of Pieces.

Sleepers

Deck-planks

Stakes (securing)
Stakes (pointing)
Eye-bolts (iron)...

t»

Inch.

Lbs.

105

3.5

252

108

3.5

1070

3.5

.75

r'nd

Kind op Timbek
Used.

|- Yellow pine.

{Fig. 3, Plate X.)

This platform is composed of six sleepers and twenty-one
deck-planks. It is laid level, and the front and rear deck-planks
are connected by eye-bolts to each sleeper. A bed for the plat-
form is first prepared by leveling off the ground, and, if not
already solid, the earth should be well rammed. This bed
should be sunk only so deep as to allow the upper surface of the
platform to be slightly above the surrounding ground, for drain-
age. The sleepers are laid parallel to the directrix or plane of
fire, three on each side of it, at equal distances apart, so that the
holes in their ends shall correspond to the holes in the front and
rear deck-planks. The front deck-plank is laid first, and the
eye-bolts driven to secure it; the remaining planks are driven
up against it, and the last secured, like the first, with eye-bolts.
At the rear end of each sleeper a securing stake is driven.

The earth, on all sides, should be raised nearly as high as the
platform, and well rammed, giving it a slight inclination out-
wards, to allow the water to run off.

It is of the first importance that the upper surface of the plat-
form should be level and true.

RAIL PLATFORM.

Kail Platform for Siege Mortars.
{Fig. 4, Plate X.)
338. Dimensions, &c., of the rail platform.

Nambs of Pieces.

Siege Moktaks.

Kind op Timbkb
Used.

a>
o

05
'P-
«t-l

o
d

1
g

CI pp-np-po ....„„......„.,

Inch.

108

Inch.

11.5
10
3.5

Inch.

8.5
10
3

Lbs.

■Yellow pine.

Rails ■.

Stakes (securing)....
Platform complete.

825

This platform consists of three sleepers and two rails for the
shoes of the mortar to rest on. It is very strong, and easily
constructed and laid.

The rails and sleepers are notched and fitted together as rep-
resented in the figure. The distance between the centre lines of
the rails is equal to that between the centre lines of the cheeks
of the mortar carriage. The pieces are put together at the bat-
tery, and the earth is excavated eight inches in depth, and of
suitable length and width to receive the platform. The bottom
of this excavation is made perfectly level. The directrix being
accurately marked by stakes, the platform is placed in position,
its centre line coinciding with a cord stretched between the
stakes marking the directrix. The earth is filled in as high as tlie
upper surface of the sleepers and firmly rammed; stakes are
driven in the rear angles formed by the sleepers and the rails,
and one at the rear end of each rail.

PLATFORMS FOR SEA-COAST MORTARS.

Platforms for Sea-goast Mortars.

13-inch mortars.

229. The size of the platform is 15 feet by 15 feet by 2 feet
2 inches.

Dimensions of parts.

Nances of Pieces.

Deck-timbers.

Sleepers

Bolts

Nuts

"Wood screws.

Iron plates....

Plankiiig

15
15
56
56

501
2

or 3
15

Inch.

180

3
180.
180
180

Inch.

12
12

5.16

Inch.

r'nd

0.5

Kemarks.

The timber for
these platforms to
be of oak, or heart
yellow pine.

Note. — The above is the thickness of the iron plates furnished ;
but they are entirely too thin, ciirlino^ up with the weight of the
mortar. The}^ should be at least 0.75 inch thick.

To lay the platform, a pit is dug 2 feet deep and about 18 feet
square on the bottom. The earth on the bottom is well rammed
and levelled. The two-inch planking is laid level on the rammed
earth, perpendicular to the directrix. The cylindrical bolts are
put in the sleepers, and the sleepers, with bolt-heads down, are
laid compactly on, and perpendicular to the planking and par-
allel to tha directrix. As the deck-timbers are laid the bolts pass
through the holes in them. These timbers are laid compactly
upon the sleepers, perpendicular to the directrix. The nuts are
put on the bolts and screwed down. Both the nut and bolt-
heads are countersunk. The iron plates are laid parallel to the
directrix, and secured firmly with screws to the deck-timbers,
covering nine feet in the centre of the platform and leaving three
feet on each side uncovered. The earth is then filled in, and
rammed compactly around the platform, with a slight inclina-
tion outwards, so as to shed water. The platform for the cen-
tre-pintle chassis is 17 feet square ; the bottom of the pit must
therefore be 20 feet square.

PLATFORMS FOR SEA-COAST MORTARS.

10-inch sea-coast mortar.

The size of this platform is 12 feet by 12 feet by 1 foot 8
inches.

Dimensions oj" parts.

Names of Pieces.

Deck-timbers

Sleepers

Bolts

Nuts

Wood screws.
Iron plates...
Planking.......

Op.

12
44
44
204
2
12

Inch.

144

Inch.

12
12

5.16

Inch.

9
r'nd

2
r'nd
0.5

Kemabks.

The timber for
these platforms to
be of oak, or heart
yellow pine.

To lay the platform, a pit is dug 1 foot 6 inches deep by 15 feet
«qnare ; the remainder of the operation is similar to that for the
13-inch mortar.

For descriptions of wooden platforms for sea-coast guns, see
^ar. 635.

iart ^mnA.

SERVICE OF THE PIECE.

The service of the piece consists of all the operations required
in loading, pointing, and discharging it.

General Rules.

S30. To avoid repetitions, and to secure easy reference, the
following general rules are inserted collectively. The pai*a-
graphs referred to belong to some particular piece — generally
the siege gun — and illustrate the application of the rule.

I. The implements and equipments required for a piece are
taken to it by the detachment when going to the exercises, or
they may be placed there previous to that time.

They are removed, at the conclusion of the exercises, by the
same means, and returned to their proper places in the store-
house.

It is the especial duty of the chief-of-detachment to see that
all that appertains to his piece is complete and in good order.

II. At the conclusion of the exercises, and previous to leaving
■a. battery, the officer in charge will dress it, giving the pieces, on
the same line, a uniform alignment, direction, and depression.
Pieces must never he left loaded.

III. The detachments are marched to the battery, and the
cannoneers posted at their pieces as prescribed in par. 106.

IV. When the equipments are distributed, the gunner buckles
the strap of his pouch around his waist, wearing the pouch in
such position as to interfere as little as possible with his move-
ments.

The cannoneer who wears it, buckles on the primer-pouch in
like manner.

The gunner removes the vent-cover, and clears the vent with
the priming-wire.

Cartridge-pouches are carried suspended from the left shoulder
to the right side. {Par. 256.)

V. In loading, the gunner closes the vent by applying the
second finger of the left hand tightly upon it, and holding it
there from the moment the sponge is introduced in the muzzle
until the rammer is withdrawn after the projectile is home,
{Par. 238.)

VI. When, in loading, the sponge or the rammer is found to

(79)

80 GENERAL RULES.

be home at the fourth motion, then what is prescribed for the
sixth will be executed at i\\e fourth. {Par. 239.)

VII. In sponging or in ramming, the knee on the side toward
which the effort is made is always bent, the other straightened.
The weight of the body is added, as much as possible, to the
effort exerted by the arms. {Par. 239.)

VIII. When the sponge fits so tightly as to be difficult to
move in the bore, ]S"os. 1 and 2 may use both hands in inserting
and withdrawing it. {Par. 240.)

IX. Cartridges are inserted into the bore, bottom foremost
and seams to the sides. {Par. 240.)

X. All projectiles having fuses are inserted in th.e bore so that
the fuse shall be towards the muzzle. {Par. 241.)

XI. A primer is prepared for insertion in the vent by holding
it between the thumb and forefinger of the left hand; the lan-
yard, wound upon its handle, is held in the right hand, the hook
hy the thumb and forefinger; the hook is attached by passing
it upward through the eye of the primer; the hook and primer,
thus attached, are held by the thumb and forefinger of the right
hand ; the primer is pushed into the vent by the thumb.

After the primer has been inserted in the vent, the cannoneer
who fires the piece drops the handle, allowing the lanyard to
uncoil as he steps back to the position from which he is to fire ;
holds the handle, with the cord slightly stretched, passing be-
tween the middle fingers of his right hand, back up, and breaks
to his left and rear a full pace with the left foot, the left hand
hanging naturally by his side. {Par. 243.)

XII. In aiming guns and howitzers, the gunner places the
breech sight in its seat or socket, and aims through it ; gives the
proper direction by causing the trail to be moved, commanding
left or right, tapping, at the same time, on the right side of
the breech for the trail to be moved to the left, and on the left
side for it to be moved to the right. The cannoneers at the trail
will closely observe the motions of the gunner. {Par. 243.)

With mortars, the gunner signals, with his hands, the direc-
tion in which he wishes the carriage moved. {Par. 347.)

When the piece is pointed, the gunner raises both hands as a
signal ; the cannoneers moving the piece then unbar and resume
th(dr posts.

XIII. At the command j^re, the cannoneer who discharges
the piece turns his face from it, pulls the lanyard quickly, but
steadily, and fires. Immediatelj^ after the discharge he resumes
the erect position, rewinds the lanyard upon its handle, returns
it to his pouch, and resumes his post. {Par. 244.)

XIV. The gunner, after pointing, goes where he can best
observe the effect of the shot; after which he resumes his post.
{Par. 243.)

GENERAL RULES. 81

XY. Ammunition is not used wiien exercising hy the num-
bers. {Par, 244.)

XVIi At the command cease firing., pieces that are loaded
remain so until further orders ; those that are partly loaded — if
with the cartridge only — the cartridge is rammed home ; if the
projectile has been inserted, it likewise is rammed home. In
both cases the priming-wire is left in the vent, as an indication
that the piece is loaded.

If the piece is not loaded, it is sponged out. All the cannon-
eers resume their posts. {Par, 247.)

XVII. When ammunition is used, the instructor, before giv-
ing the command load., will specify : with blank cartridges —
with solid shot — with shell — with case-shot. {Par. 248.)

XVIII. To secure piece., the gunner puts on the vent-cover,
and No. 2 replaces the tompion in the muzzle. {Par. 249.)

XIX. Sponge and rammer staves are permanently marked
with a white ring, to show — with the sponge, wlien it is at the
bottom of the bore; with the rammer, when the projectile is
home. {Par. 253.) •

XX. Rifle projectiles are always to be lubricated previous to
loading. They are then easily pushed home, and their range and
accuracy are increased. {Par. 254.)

XXI. After each twentieth discharge (or thereabouts) with a
rifled piece, the bore is washed out and sponged dry.

XXII. When an implement is taken up for any purpose it is
returned to its prescribed place by the person using it, at the
completion of the duty, unless otherwise specified.

XXIII. Cannoneers and the gunner resume their proper posts
after the completion of any duty, unless otherwise especially
directed.

XXIV. With all pieces having traversing carriages, pinch-
bars are used for making delicate adjustments in pointing, and
iron wheel-chocks for holding the traverse-wheels securely in
position. {Par. 340.)

XXV. Gunners, chiefs-of-detachment, and chief s-of-platoon,
give or repeat commands only when it is so prescribed.

XXVI. The habitual post of the chief-of-detachment is as
specified in par. 106. He has, under the instructor, or officer
immediately over him, general supervision of all duties perform-
ed by liis detachment. During firings he looks after the supply
of ammunition, and sees tliat tliose engaged in preparing and
serving it to the piece perform their duties properly.

XXVII. All ammunition must be prepared for firing at tlie
service magazine. Projectiles will be carefully cleaned of all
rust, dirt, or protuberances liable to cause them to stick, or injure
the bore.

82 GENERAL RULES.

XXVIII. Ill the service of a batterj'" of several pieces, the
pieces are designated Nos. 1, 2, 3, &c., from right to left ; these
numbers are independent of the pei^manent numbers assigned to
pieces in a worlv.

In directing the pieces to be fired, they are always designated
by their battery numbers ; as, Number^ one — Fire ; Number two —
Fire, &c.

When the wind comes from the riofht, the firing should com-
mence on the left, and reciprocally.

XXIX. Under the fire of the enemy, the men will be direct-
ed to cover themselves by the parapet or traverses as much as
may be consistent with the execution of tlieir duties.

XXX. Previous to proceeding with any exercise with the
pieces, and frequently at other times during the exercises, the
instructor, assisted by the other officers, will explain to the men
the nomenclature of everytliing appertaining thereto ; the appli-
cation and use of the various parts, machines, and implements
used ; the. names and use of tlie different parts of the work ad-
jacent to the piece ; the kinds of ammunition used ; charges of
powder ; kinds of fire ; and, generally, all matters that assist in
making the men efficient artillerists.

XXXI. In time of actual service, in front of an enemy, two
or more detachments, for eacli piece, are necessary, and all
should be instructed. These detachments will be designated
First reliefs Second reliefs &c. ; and in all battery formations, as
roll-calls, parades, &c., will fall in together in the order of their
numbers from right to left.

XXXn. In aiming, first get a clear view of the object, and
see that the piece is approximately in the line of fire before look-
ing through the sights ; then look over or through the sights, and
if the object be not in the line, instantly give the command to
move the trail to tlie right or left.

Always aim quickly, as the eye will not then become wearied.

XXXIII. The prop upon which the sponge and rammer are
supported is a low trestle, or simply a block of wood sufficiently
high to prevent the sponge taking up dirt from the ground. The
rammer is always laid on tlie side nearest the piece. {Par. 233.)

XXXIV. To prevent the projectile from starting forward,
guns should be given at least five degrees elevation previous to
being run into battery, and running into batteiy should be done
so as to prevent sudden jar against the hurters. {Par. 242.)

XXXV. In case the friction-primer explodes without discharg-
ing the piece, care must be taken not to approach the piece too
soon — not less than five seconds — as it may only hang fire, and
the recoil would injure any one in the way of it. {Par. 252.)

XXXVI. Sponges, after the first fire, should always be moist-

SERVICE OF SIEGE GUN.

€ned. This not only assists in extinguishing anj'- fragments of
-cartridge that might remain burning in the bore, but it prevents
4lie residuum of burnt powder from hardening on the surface of
the bore. Fresli water is preferable to salt for moistening the
sponge.

XXXVII. In all exercises for instruction, duties should be
performed as nearly as possible as in actual service, and not by
pretense only. To do this, in the service of the piece a dummy
cartridge should be used, together with actual projectiles. 'J'lie
cartridge may be made of canvas or stout gunny-sacking, filled
to the proper weight with coal broken to the size of the powder
used for the piece. A worm serves for withdrawing the car-
tridge.

A strong lanyard attached to the fuse-plug will serve to with-
draw the projectile. The free end of the lanyard remains out of
the muzzle as the projectile is pushed liome.

SERVICE OF SIEaE GUN.

{Fig. 1, Plate XL)

Description of Piece.

331. Gun, cast-iron; muzzle-loading rifle; twist, uniform,
one turn in 15 feet.

Number^ weights^ and dimensions.

Designation.

Calibre

Length of piece

Maximum diameter..

Minimum diameter ,

Length of bore (calibres)

Number of grooves

Width of grooves

Width of lands

Depth of grooves

Windage

Initial velocity (feet)

Charge (cannon powder)

Solid shot

Shen (unfilled)

Weight of piece

Preponderance

Carriage and limber

Piece, carriage, limber, and implements

Horses to transport (good roads)

" " (inferior roads)

No.

26.5
9.

1280

8.
10.

Lbs. Inch.

85.

25.

3570

300

3650

7400

4.5
133.
15.6
9.

0.97
0.6
0.075
0.05

SERVICE OF SIEGE GUN.

The nomenclature of the carriage for the siege gun and siege
howitzer is similar to that for light field pieces as laid down in
*'Light Artillery Tactics" ; it is therefore omitted in this book^

Ranges in yards.

Elevation.

Shot.

Shell.

Time of

Flight.

1°

540

533

1.37

1°

30^

790

781

2.05

2°

1017

1005

2.69

2°

30^

1240

1224

3.32

3°

1445

1414

3.94

3°

30^

1639

1593

4.54

4°

1823

1762

5.14

5°

2170

2071

6.3

6°

2485

2354

7.42

2780

2610

8.51

8°

3056

2844

9.57

9°

3313

3061

10.6

10°

3556

3265

11.59

The gun, on its platform, admits of 9° 30^ elevation and 10«^
30^ depression. On level ground it admits of 12° elevation and
10° depression. By digging a trench for the trail to run in, a
still greater elevation may be obtained.

In works, it is fired from a wooden platform. {Pai\ 223.) In
the field, it may be fired without a platform, when the ground
is level and firm; or a temporary platform may be extemporized
from such beams, planks, or logs as maj^ be at hand.

To serve the piece.

332. Eight men are required : one chief-of-detachment, one
gunner, and six cannoneers.
The implements and equipments are arranged as follows :

Three on each side of the piece ;
leaning against the parapet, in
line with cannoneers.

One yard behind, and parallel to
the cannoneers of the right ; sup-
ported on a prop, heads turned
from the epaulment.

Handspikes.

Sponge..
Kammer

}

SERVICE OF SIEGE GUN. 85

Pass-box Behind and near iN"©. 4.

T» . r^ \ Containini^ friction-primers and lan-

irTimer-poucn j- ^^^^, suspended from cascable.

^ , , 1 Containins: priminsr-wire ; suspend-

Gunner's poucli | ^^^ f,om cascable^

c- ui I, 1 Containino^ breech siffht: suspended

Sig:ht-pouch I f,om cascable.

1^, 1 u 1 \ ^"® ^'^ e.^dh side of piece, near the

wneei-cnocKs | ^^^^^ ^1 ^^^^ liurter.

Vent-cover Covering the vent.

Tompion In the muzzle.

T. \ Leaning against the parapet near

^^^0^ / 1^0.2.

Tj n , -, 1 Containing cartridges ; at a safe and

Kucige-oarrei ^ convenient place near the piece.

Sponge-bucket INTear sponge and rammer.

Fuse-gauge 1

Fuse-knife |

Fuse-wrench }- In filling-room of service magazine.

Fuse-reamer I

One lanj^ard (extra) J

!233. To each two pieces there should be

One worm

One hammer-wrench

One gunner's quadrant..
One vent-punch

In filling-room of service magazine.

One vent-gimlet.
One gunner's level....
One gunner's pincers.

When there is no parapet, the handspikes are placed, three on
each side, standing between the cheeks and wheels of the car-
riage, in front of and resting against the axle-tree.

The solid shot are piled on the left of the piece against the par-
apet ; the other projectiles are in the filling-room of the service
magazine ; the fuses, cartridges, and primers are in the service
magazine.

To distribute the equipments.

234. The instructor commands : 1. Take equipments.

The gunner steps to the cascable ; takes off the vent-cover,
handing it to !N'o. 2 to place against the parapet outside of his

86 SERVICE OF SIEGE GUN.

post ; gives the primer-pouch to No. 3 ; equips himself with the
sight-pouch and his own pouch; clears the vent; levels the piece^
and resumes his post.

'No. 3 equips himself with the primer-pouch. These rules are
general for all guns.

Nos. 1 and 2, after passing two handspikes each to ]S"os. 3 and
4, take one each, for himself. ISTos. 5 and 6 receive theirs froni
]N"os. 3 and 4.

235. The handspike is held in both hands, diagonally across
the bod}^; the hand nearest the parapet grasping it near the
small end and at the height of the shoulder, back of the hand
down, elbow touching the body; the other hand back up, the
arm extended naturally; the butt of the handspike resting on
the ground, on the side of the cannoneer farthest from the para-
pet, and in line with his toes.

236. When a cannoneer lays down his handspik(^ he places
it directly before him, about six inches in front, and parallel to
the alignment, the small end toward the parapet; and whenever
he thus lays it down for the discliarge of any particular duty, he
takes it up after having completed the duty.

23'7. The service of the piece is executed as follows: The
piece being in battery, the instructor commands :

1. From battery.

The gunner moves two yards to his right.

^NTos. 1, 2, 3, 4, 5 and 6, all facing from the parapet, embar
with their handspikes; N'os. 1 and 2 under the front of the
wheels; Nos. 3 and 4 through the rear spokes of the wheels,
near the felly, under and perpendicular to the cheeks; N"os. 5
and 6 under and perpendicular to the mancBuvering bolts.

When all are ready, the gunner gives the command: Heave,
which will be repeated as often as may be necessary, and sees
that N'os. 5 and 6 guide the trail in prolongation of the directrix •
of the embrasure, and as soon as the face of the piece is about
one yard from the parapet, commands : Halt, at which all un-
bar and resume their posts. If the platform has a slope, N^os. 1
and 2 chock the wheels in front.

1. By the numbers., 2. Load.

23S. N"os. 1, 2, 3, and 4 lay down their handspikes; No. 2
takes out the tompion, and places it near the vent-cover.

No. 1 turns to his left, steps over the sponge and rammer;
faces to the piece ; takes the sponge with both hands, the backs^
down, the right hand three feet from the sponge-head, the left

SERVICE OF SIEGE GUN. 87

liaiicl eio:liteeii inches nearer to it; returns to the piece, entering
the staft" in tlie embrasure ; places the left foot in line with tlie
face of the piece, lialf-way between it and the wheel ; breaks to
the right with the right foot, the lieels on a line parallel to the
piece, the left leg straightened, the right knee bent, the body
erect upon the hips, and'inserts the sponge-head in the muzzle;
the stall" in prolongation of the bore, supported by the riglit hand,
the right arm extended, the left hand hanging naturally by the
side.

ISTo. 2 steps to the muzzle, and occupies a position on the left
of the piece corresponding to that of ISTo. 1 on the right. He
seizes the staff with the left hand, back down, near to and out-
side the hand of !N^o. 1.

]^o. 3 faces about, steps over the rammer, and seizes the staff
with both hands, as prescribed for ISTo. 1 with the sponge, and
stands ready to exchange staves with ISTo. 1.

No. 4, taking the pass-box, goes for a cartridge and projectile ;
returns, and places himself, facing the piece, about eighteen
inches to the rear and right of ISTo. 2.

The gunner places himself near the stock, his left foot ad-
vanced; closes the vent with the second finger of the left hand,
bending well forward to cover himself by the breech, and with
the elevating screw adjusts the piece conveniently for loading.

This rule for closing the vent is general for all guns and how-
itzers.

239. In the meantime, Nos. 1 and 2 insert the sponge by
the following motions, at the commands Two — Three — Four —
Five— Six :

Two. They insert the sponge as far as the hand of N"o. 1,
bodies erect, shoulders square.

Three. They slide their hands along the staff and seize it at
arm's-length.

Four. They force the sponge down as prescribed for two.

Five. They repeat three.

Six. They push the sponge to the bottom of the bore. ISTo. 1
replaces the left hand on the staff, back up, six inches nearer
the muzzle than the right ; N'o. 2 places the right hand, back
up, between the hands of N'o. 1, and botli then quickly change
their other hands so as to seize the staff with the back of the
hand up.

If, in executing these motions, or the corresponding ones with
the rammer, it be found that the sponge or rammer is at home
at the fourth motion, then what is prescribed for the sixth mo-
tion will be performed at the fourth. This rule is general.

The knee on the side toward which the effort is made is always

S8 SERVICE OF SIEGE GUN.

bent, the other straightened, and the weight of the body added,
as much as possible, to the effort exerted by the arms. This rule
is general.

1. Sponge.

340. !N'os. 1 and 2, pressing the sponge firml}^ against the bot-
tom of the bore, turn it three times from right to left, and three
times from left toriglit; replace the hands by their sides, and
withdraw the sponge by the same commands, but by motions
contrary to those prescribed for inserting it. When the sponge
fits so tightly that it is hard to move in the bore, ISTos. 1 and 2
may use both hands. 2^his rule is general.

No. 2 quits the staff, and turning towards IS'o. 4, receives from
him the cartridge, which he takes in both hands, and introduces
it into the bore, bottom foremost, seams to the side; he then
grasps tlie rammer in the way prescribed for the sponge.

This rule^ with reference to the bottom and seams of the car-
tridge^ is general.

No. 1, meanwhile, rising upon both legs, turns towards his
left ; passes the sponge above the rammer with the left hand to
No. 3, and, receiving tlie i-aramer with his right, presents it as
prescribed for tiie sponge, except tliat he rests the rammer-head
against tlie right side of the face of the piece.

No. 3, as soon as the sponge is withdrawn, passes the rammer
under the sponge into the embrasure with the right hand ; re-
ceives the sponge from No. 1 with the left; replaces it upon the
prop, and resumes his post.

No. 4, setting down the projectile and pass-box, takes out the
cartridge and hands it to No. 2, the choke to the front ; returns
the pass-box to its place, and takes up the projectile.

Nos. 1 and 2 force home the cartridge by the same commands
and motions as for the sponge.

1. Kajvi.

S41. Nos. 1 and 2 slide their hands along the staff to the full
extent of their arms ; grasp it firmly ; throw the weight of their
bodies upon the staff" and press the cartridge home. No. 2 quits
the staff, and turning towards No. 4, receives from him the pro-
jectile. No. 1, meanwhile, throws out the rammer, and holds it
with both hands, the head against the riglit side of the face of
the piece.

No. 2, receiving the projectile, introduces it into the bore, base
foremost, and reseizes the staff with the left hand. No. 4 re-
sumes his post.

SERVICE OF SIEGE GUN. 89

l^os. 1 and 2 force home the projectile bj'- the same commands
and motions as prescribed for tiie cartridge. At the command
ram it is pressed tightly down against tlie cartridge. No. 2
quits the rammer ; sweeps, if necessary, the platform on liis own
side; passes the broom to N^o. 1, and resumes his post. N"o. 1
throws out the rammer, and places it on the prop below the
sponge ; sweeps, if necessary, liis side of the platform ; returns
the broom to N'o. 2, and resumes his post.

The gunner pricks, leaving the priming-wire in the vent ; re-
sumes his post, and adjusts the breech sight to the distance of
the object to be fired at.

1. In battery.

242. N'os. 1 and 2 unchoclc the wheels, (if they have been
xjhocked,) and with Nos. 3, 4, 5, and 6, all facing towards the
epaulment, embar; IS^os. 1 and 2 through the front spokes of the
wheels, near the fellies, under and perpendicular to the cheeks ;
Nos. 3 and 4 under the rear of the wheels, and Nos. 5 and 6
under and perpendicular to the stock, near the trail. All being
read}'-, the gunner commands : Heave, and the piece is run into
battery, Nos. 5 and 6 being careful to guide the muzzle into the
middle of the embrasure. As soon as the wheels touch the hurt-
er, he commands : Haxt. All unbar, and Nos. 1, 2, 3, and 4
resume their posts.

1. Aim.

243. ISTo. 3 lays down his handspike ; passes the hook of the
lanyard through the eye of a primer from below upward, and
holds the handle of the lanyard in the right hand, the hook be-
tween the thumb and forefinger. This rule for preparing the
primer and holding the lanyard is general.

Kos. 5 and 6, facing towards the epaulment, embar under and
perpendicular to the stock near the manoeuvering bolts.

The gunner, placing himself at the stock, as at the command
load.1 withdraws the priming-wire ; places the breech sight in
its socket; sights through it, and, aided by N"os. 5 and 6, gives
the direction, causing the trail to be moved by commanding
Left, or Right, tapping, at the same time, on the right side "of
the breech for No. 5 to move the trail to the left, or on the left
side for No. 6 to move it to the right; and by the elevating
screw gives the proper elevation, rectifying, if necessary, the
direction.

The moment the piece is correctly aimed, he rises on the left
leg and gives the command Ready, making a signal with both

90 SERVICE OE SIEGE GUN.

hands, at which ]N"os. 5 and 6 unbar and resume their posts^
The gunner, taking the breech sight, goes to tlie windward to
observe the effect of the shot.

These rules^ as to the method of aiming^ are general.

No. 3 inserts the primer in the vent; drops the handle, allow-
ing the lanyard to uncoil as he steps back to his post, holding it
slightly stretched with the rigiit hand, the cord passing between
the middle fingers, back of the hand up, and breaks to his left
and rear a full pace with his left foot, the left hand hangings
naturally by his side.

These rules for holding the lanyard and breaking off by the
cannoneer who fires the piece are general.

At the command Eeady, Nos. 1 and 2, laying down their
handspikes, take, each, a chock in the hand nearest the epaul-
ment, and breaking oflf sideways witli the foot farthest from
the epaulment, stand ready to chock the wheels after the
recoil.

1. Number one (or the like), 2. Fire.

244. N'o. 3, turning his face from the piece, pulls the lanyard
quickly, but steadily, and fires the piece.

Immediately after the recoil of the piece, N"os. 1 and 2 chock
the wheels and resume the erect position ; No. 3 resumes the erect
position, rewinds the lanyard upon its handle, returns it to his
pouch, and resumes his post. The gunner having observed the
effect of the shot, returns to his post.

These rules., as far as they relate to the cannoneer who discharges
the piece., and to the gunner., are general.

Ammunition is not used when exercising by the numbers.
This rule is general.

To load without the numbers,

245. The instructor commands : Load.

At this command the piece is run from battery, loaded, run
into battery, and prepared for firing by the following commands
from the gunner: From battery— Load — In battery —
Aim — Keady.

The instructor commands :

1. Number one (or the like), 2. Fire.

At which the piece is discharged. All of these operations are
executed as before explained, except that Nos. 1 and 2 sponge
and ram without the numbers.

SERVICE OF SIEGE GUN. 91.

To load and jive continuously.
The instructor commands :

1. Commence^ 2. Firing.

246. The gunner gives the same command as in the preced-
ing paragraph, with the additional one of Fire, and continues-
to load and fire until the instructor commands :

1. Cease. 2. Firing.

24T. The firing then ceases ; pieces that are loaded remain
so until f m-ther orders ; those that are partly loaded — if with the
cartridge only, have the cartridge rammed home; if Avith the
projectile, it likewise is rammed home. In both cases the prim-
ing-wire is left in the vent. If the piece has no load in it, it is
sponged out; all the cannoneers then resume tiieir posts.

If it is intended to discontinue the firing, the instructor directs
the chiefs-of- detachment to have the charges withdrawn and
the pieces run into battery.

These rules are general.

Tlie projectile may be withdrawn by depressing tiie muzzle
and raising the trail until the muzzle knocks against the ground.
Should it not then slide out, allow the piece to stand until (if
the atmosphere is moist) the residuum of burnt powder in the
bore becomes unctions; then depress the muzzle and raise the
trail as before. If the projectile still refuses to slide out, the
piece will liave to be discharged; or if it is not desirable to dis-
charge it, the charge may be drowned out by pouring water in
at the muzzle, afterwards draining it out and pouring a small
quantity of fine-grain powder in at the vent and firing it.

Cartridges are withdrawn by means of the worm.

248. Before giving the command load^ or commence firing.,
the instructor, when ammunition is used, will specify : with blank
cartridges — with solid shot — witJi shell — or, with case-shot. This
rule is general.

To change posts. As explained in^ar. 112.

To secure piece.
The piece being in battery^ the instructor commands :

Secure piece.

349. No. 2 replaces the tompion in the muzzle. The gunner
puts on the vent-cover, which he receives from ITg. 2, and de-
presses the muzzle. This rule is general.

'i)2 ORGANIZATION OF SIEGE GUN BATTERY.

To replace equipments.

The instructor coraiiiaiuls :

Replace equipments.

S50. IN'os. 1 and 2 replace the handspikes against the para-
pet, those of Nos. 3, 4, 5, and 6 being passed to them by Nos. 3
mid 4. The gunner hangs the pouches on the cascable.

To serve the piece with reduced numbers,

351. The smallest number of men with which a siege gun
can be served with facility is five — one gunner and four can-
noneers.

In this case !N"os. 5 and 6 are dispensed with, and the piece is
run to and from battery as explained for the siege howitzer.
{Pars. 264 and 268.)

With four men — one gunner and three cannoneers — N^os. 1, 2,
and 3, in running the piece to and from battery, perform duties
as before, and the gunner that of No. 4. In loading, No. 2, in
addition to his own duties, performs tliose of No. 4.

With three men — one gunner and two cannoneers — Nos. 1, 2,
-and the gunner perform duties as above. In loading. No. 1 per-
forms the duties of No. 3 as well as his own. No. 2 performs
those of No. 4, as in tlie preceding case.

When No. 2 serves ammunition, he goes for the cartridge,
and places the pass-box behind his post before assisting No. 1.
to sponge.

^5^. In all firings, when a primer fails, the gunner, after
Tvaiting a few moments to see that the piece is not hanging fire,
steps in front of the left wheel and, reaching over, pricks; No.
3, reaching over the right wheel, gives him a fresh primer to
which he has hooked his lanj^ard.

!353. Sponge and rammer staves are marked with a white
ring painted around them, to sliow — with the sponge, when it
is at the bottom of the bore ; with the rammer, when the pro-
jectile is home. This rule is general.

254. Rifle projectiles are always to be lubricated previous
to loading; they are then easily pushed home, and their range
and accuracy of flight increased. This rule is general.

Organization of Siege Gtuns into Batteries for
Field Service.

255. It has been found from actual experience that the
-4.5-inch siege gun is capable of accompanying an army in the

ORGANIZATION OF SIEGE GUN BATTERY. 93

field with almost the same facility as the 12-pouiicler. Its great
range, power, and accnracy endow it with many advantages
wiien nsed as a liea\y field-piece, and it should form a portion
of the artillery of every army organized for campaign purposes.

For this service the pieces are organized into batteries of four
or six guns each, and equipped after the manner of light field
batteries.

Each piece is furnished with two caissons of the usual pattern,
having, however, only two partitions in each half-chest ; these
are parallel to and 4.5 inclies from each side — the outer spaces
for projectiles, the inner for cartridges. This arrangement
allows 16 rounds for eacli chest, 48 per caisson and 96 per gun.
A tray in each chest serves to carry pouches, primers, and fuses.
One spare wheel is carried for the caissons of eacli two pieces.
Caissons not carrying spare wheels, carry picket- ropes and
forage. The picket-rope should be in sections; each section
long enough to accommodate tlie horses of one piece and its two
caissons, together with a proportional share of spare and other
horses. This requires eacli section to be 35 yards long. The
ends of tlie ropes should be provided with hooks ; these, besides
enabling them to be used more conveniently as picket-ropes,
allow of their being used as drag-ropes for extricating carriages
from difficult places on the march.

Light-artillery harness is used, but, owing to the weight of the
pole, breast-liooks of extra strength are provided for the "w heel-
horses. The swing team being attached to lead-bars, wheel-
traces are required for it.

The implements for the piece are as follows :

256. Six handspikes; small ends under sweep-bar, resting
on axle, large ends resting on splinter-bar, and secured by a
leatlier strap passing from the hounds, through loops on the
handspikes, to bucldes on the fork ; or by a rope passed through
rings on the handspikes and around through staples on the
liounds and fork.

One sliori roller ; on the stock between the lunette bolts;
secured by a rope passing through a hole in the axis of the roller
and fastened to the stock.

One trace-rope ; two half-hitches in the middle around the
cascable ; ends turned around the manoeuvering bolts, and cross-
ing to take up the slack. This secures the piece from sliding on
its carriage.

Tlie sponge and rammer heads are upon the same staff, which
is cut to the shortest practicable length. Two sponges and ram-
mers are allowed to each piece, and, together with one worm for
each two pieces, are carried upon the sides of the piece, secured

^4 ORGANIZATION OF SIEGE GUN BATTERY.

by two stout leather straps buckled around the chase and the
body of the gun.

The service of the piece, so far as spono-ing and ramming are
-concerned, is similar to that for light field-pieces.

The sponge-bucket is carried in the same manner as for light
field-pieces. One fuse-wrench, one fuse-gauge, one fuse-knife,
one fuse-reamer, and one pair of gunner's pincers for each piece
are carried in the trays of the limber chests of the caisson.

A cartridge-pouch is used instead of pass-box, and is carried
by JSTo. 4 suspended from the left shoulder to the right side.

Large and heavy horses, particularly for wheel-teams, are
selected for the guns. Except where the roads are unusually
good, ten are allowed to each piece. Each horse, botli for piece
and caissons, is provided with a nose-bag, carried as for a ligiit
field battery, and one watering-bucket is allowed for each pair
of horses, carried — those for the pieces on hooks attached to the
rear axle ; those for caissons as in light artillery.

One lifting-jack for each two pieces is carried on one of the
caissons belonging to these pieces. The lifting-jack weighs 160
pounds, and is carried on a caisson having no spare wheel.

Each caisson is supplied with axes, shovels, picks, paulines,
&c., as for a light field battery.

Two hundred rounds of ammunition are allowed for each piece ;
that not contained in the caissons is carried in transportation-
wagons.

One spare gun carriage, with limber complete, drawn by six
horses, accompanies each battery.

Three spare poles for the limber of the piece, ironed and fitted
ready for insertion, are cariied on the spare carriage.

Each battery is furnished with a battery-wagon and forge.
These contain supplies as hereinafter prescribed.

The spare carriage, battery-wagon, forge, ammunition, and
baggage-wagons form a train, and, on the march, usually accom-
pany the light-artillery train.

The cannoneers carry their equipments and march by the side
of the piece, as in a light field battery.

In place of the shoe (which is entirely useless) a stout rope,
attached to the ring-bolt of the lock-chain, is substituted. This
rope, passed around the felly with tw^o or tliree turns, is held by
a cannoneer walking by the side of the piece. In this manner
he is enabled to let the wheel go as it approaches the bottom of
a descent.

ORGANIZATION OF SIEGE GUN BATTERY.

Composition of a siege battery of six pieces organized and
equipped for campaign service.

Captains

Lieutenants-
Sergeants

Corporals

Artificers ,

Trumpeters..

G-uidon

Drivers

Cannoneers,..
Spare liorses.

Total.

183

150

191

C Including first-sergeant,
< quartermaster, stable,
( and veterin'y sergeants.
j \ 3 blacksmiths, 2 saddlers,
\ 1 wheelwright.

For 6 pieces, 12 caissons, 1
spare carriage, 1 battery
wagon, and 1 forge.

25 1". On dry and firm ground the siege gun may be fired as
an ordinary field-piece ; under all other circumstances it requires
a platform. When time permits, a good platform may be im-
provised from material found in tiie vicinit}^; but to provide
against every emergency, a platform for each piece should be
carried with the battery, or at least with the train, when easily
accessible.

The platform is the one described in par. 226. These are
carried in transportation-wagons, each wagon carrying three
platforms.

The supply of projectiles should be about equally divided be-
tween solid shot, time, and percussion shells; i. e., one-third
solid shot, one-third time-fuse shells, and the remaining third
percussion shells. It is unnecessary to have either case-shot or
•canister.

Each piece is provided with a field-glass and telemeter.

ORGANIZATION OF SIEGE GUN BATTERY.

258. The following are the supplies carried in the battery-
wagon and forge for a battery of six gnns :

Forge A.

Contents op Limbeb-chbst,
(Smith's tools and stores.)

Horseshoes, ISTos. 2 and 3 lbs.

Horseshoes, Nos. 2 and 3 lbs.

Horseshoe nails, Nos. 2 and 3.. lbs.

Washers and nuts, No. 2

Washers and nuts, No. 3

Washers and nuts. No. 4

Nails, No. 1, C lbs.

Nails, No. 2, C lbs.

Tire-bolts

Keys for ammunition chests

Linch-washers (caisson)

Liinch-pins (caisson)

Liinch-jjins (for piece)

Chains, Nos. 1 and 2 feet.

Cold-shut /S' links. No. 3

Cold-shut /Slinks, No. 5 ,

Hand cold-chisels

Hardie

Files, assorted, with handles

Buttress ,

Hand-punches, round and square-
Screw-wrench

Hand screw-driver ,

Hand vise

Smith's calipers, pair ,

Dfe^s!pairs:}Nos. 1, 2, 3, and 4

Wood screws, 1 in.. No. 14.. ..gross.

Q,uart can of sperm oil

Borax lbs.

Fire-shovel ,

Poker ,

Split broom

Hand-hammers

Riveting-hammer

Nailing-hammer ,

Sledge-hammer

Chisels for hot iron

Chisels for cold iron

Smith's tongs

Fore-punch

Creaser

Fuller

Nail-claw

Round-punch

Tap- wrench

Die-stock

Nave-bands, developed

Tire-bands, developed

No.

■f

Lbs.

100

100.00

100

100.00

50.00

5.25

3.20

2.15

1.00

5.00

5
8

1.80
7.30

8.37

1.54

2.50

2.00

0.75

10.00

1.50

2.00

2.42

0.32

1.00

0.40

f 4

1.50

1 4

1.83

2.10

2.70

3.05

1.90

1.25

6.50

1.05

1.80

10.50

3.00

15.00

1.00

2.40

5.00

2.10

3.75

6.25

11.75

2.75

Place.

Box A 1.
Box A 3.

Box A 2, large divis-
[ion.

'In box A 2, 91.11 lbs.

fin box A 4, 28.52 lbs.

{■Inbox A 5, 80.05 lbs.

In Box A 5, 80.05 lbs.

ORGANIZATION OF SIEGE GUN BATTERY.

Forge A. — (continued.)

Contents of Limber-chest.
(Smith's tools and stores.)

Shoeing-tiaranier ,

Pincers, pair

Rasps (12 inches)

Shoeing-knif e

Toe-knife

Pritchel

Nail-punch

Olinching-pin

Oil-stone

Leather aprons...
Horse-tail brush..

Iron square

Padlock

Tar-bucket

Boxes

Tow for packing.

Total

-(^

No.

ffl

0.82

2.00

2.15

0.33

0.30

0.85

0.80

1.00

1.60

3.00

1.00

2.00

0.50

7.00

53.45

5.00

484.38

Place.

-In shoeing-hox, 12.75
lbs.

Fastened on inside
of the chest-cover
with two copper
clamps.

On the chest.

On its hook.

One pound of horseshoe nails, No. 3, contains 140 nails; one
pound of horseshoe nails, Xo. 2, contains 112 nails; one hun-
dred pounds of horseshoes, contain 90 shoes.

Contents of forge-body.

Tools and Stobes.

Square iron, J^ in. and 1 in

Flat iron, 11^ in. x 5^, 1 in. x >$, IM

in. X 1J$ X M in

Round iron, % in

Cast-steel, % in. square

English blistered-steel

Boxes 5 and 6, containing :

Horseshoes, Nos. 2 and 3

Horseshoe nails, Nos. 2 and 3

Water-bucket

"Watering-bucket (leather)

Anyil

Vise

Bituminous coal

Coal-shovel

Padlock

Tow

Total.

No.

Weig't.
Lbs.

100

200

100

250

5
842

Place.

In the iron-room.
Bars not more than
3 feet long. Square
iron in two bun-
dles.

• In iron-room.

On its hook.
On the vise.
On the fireplace.
On stock of forge.

• In the coal-box.
On coal-box.

ORGANIZATION OF SIEGE GUN BATTERY.

1. Anvil-block, carried on the hearth of the forge, and secured
by liaving a hole through its axis, through which is passed a
lashing-rope.

Contents of limber-chesty Battery-wagon C.

Tools and Stores.

Oarriage-maTcer's tools .

Hand-saw

Tenon-saw (14 in.)

Jack-plane

Smoothinff-iJlane

Brace, with 24 bits

Spokeshave

Grange

Plane-irons

Saw-set

Rule (2 feet)

G-imlets

Compasses, pair

Chalk-line

Brad-awls

Scriber

Saw-flies (4% in.)

Wood-flies (10 in.)

Wood-rasp (10 in.)

Trying-square (8 in.)

Hand screw-driver

Oil-stone

Broad-axe

Hand-axe

Claw-hatchet

Claw-hammer

Pincers (small), pair

Table vise

Framing-chisels (1 in. and 2 in.)...
Firmer-chisels (54 in. and m in.)..
Framing-gouges (1 in. and 1% in.).
Augers and handles (H in., ^ in.,

% in., 1 in., 2 in.)

Screw-wrench

Felling-axe.

Adze

Frame-saw

Q,uart can of sperm oil.

Compass-saw

Tacks (carpenters'), M.

Measuring-tape

Chalk

with handles.

No.

2
1
1
1
1
1
1
2
1
1

12
1
1
2
1

12
2
1
1
1
1
1
1
1
1
1
1
2
2
2

5
1
1
1
1
1
1
5
1

Libs.

4.00
1.50
4.15
1.80
4.35
0.30
0.30
1.05
0.25
0.14
0.95
0.18
0.10
0.17
0.15
0.87
1.12
0.40
0.60
0.32
1.50
6.00
5.00

.00
.50
.06
.80
.00
1.00
2.60

4.50
2.42
6.00
3.30
4.50
2.70

5.00

2,00

Place.

> Fastened to the in-

> side of chest cover.

-In box O 1,17.20 lbs.

'In box O 2,32.23 lbs.

In box C 3, 23.25 lbs.

ORGANIZATION OF SIEGE GUN BATTERY.

Contents of limber-chest. Battery-wagon C, — (continued.)

Tools and Stores.

Saddler^s tools and stores.

Mallet

Clam

Hammer

Shoe-knives

Half -romid knife

Shears, pair

Sandstones

Rule (2 feet)

Needles, assorted

Collar-needles

Thimbles

Awls

Awl-handles

Punches, assorted

Pincers, pairs

Pliers, pairs.^

Claw-tools

Creasers

G-auge-knife

Scissors, pair

Compass, pair

Strap-awls

Saddler's mallet

Saddler's clam

Bristles

Saddler's thread

Bees-wax

Black-wax

Patent thread

Shoe thread lbs-
Buckles, assorted (0.75 in. to 1.5

in.) doz...

Tacks (iron and copper), assorted.

Hand-saws

Tenon-saws

Blades for frame-saws

Total.

No.

1
1
1
2
1
1
2
1

100
5
4

36
6
6
3
6
2
1
1
1
1
3
1
1

Lbs.

1.75
5.00
0.65
0.20
0.28
0.47
0.30

0.50
0.75
1.00
6.75

0.75

0.25

1.75
5.00
2.00
2.00
3.00
5.00
5.00
2.00

Place.

1.00

10.00

2..00

' In box O 4.

173.00 !

100

ORGANIZATION OF SIEGE GUN BATTERY.

Contents of wagon-body.

Tools and Stores.

Grrindstone, 14-in. x 4 in...
Axbor and crank for do...

Pintles (for piece)

Horse-collars (assorted)...

Girths

Lead-traces

Whips (artillery)

Wheel-traces

Currycombs

Horse-brushes

Nose-bags

Saddle-blankets ,

Spurs and straps pairs.

Halters and straps ,

Watering-bridles

Bridles (artillery) ,

Hame-straps

Harness-leather sides...

Bridle-leather sides..,

Sash-cord pieces...

Pole-yoke

Elevating screw

Saw, cross-cut (6 feet)

Rope-trace, feet... "
Block (treble) for

above

Block (double) for

above

Watering-b uckets ,

c3 " o

o d d <

No.

1
1
1

10
20
15
5
10
15
15
10
20
5

200

fee

Lbs.

?60

35
45
12
75

2
48
12
12
11
60

5
65
12
18

50
33
10
13
32
12

Tools and Stores.

Fuse-wrenches

Fuse-gauges

Fuse-knives

Fuse-reamers

G-unner's pincers

Vent-punches

Breech sights

Priming-wires

(runner's gimlets

Primer-pouches

Castile-soap

Handspikes

Tallow

Staves — sponge and ram-
mer (lashed to body of

wagon outside)

*Neat's-foot oil gal

*Grease, wheel (1-ib cans)

Nails, (4, 6, 8, and 10-pen-
ny)

Claw-hatchet

Spirit-level (carpenter's)..

Sperm or wax candles....

Rammer-heads

Sponge-heads

Sponges

Sponge-covers

Lanyards for friction-
primers

Dark lanterns

Common lanterns

Total.

No.

Lbs.

36
30

11
50
70

20
2

3
4.60

1100

*In Boxes.

The battery- wa.^on here mentioned is that furnished from the
arsenals; but, bein^ cumbersome and quite misultable for field
service, it is better to utilize its body and limber-cliest by plac-
ing them on the running gear of the army transportation-wagon.
The limber-chest can be attached to the front part of the wagon-
bod}^ by strong iron brackets, and serves as a seat for the diiver.
A similar chest can be placed, in like manner, on the rear end
in place of the forage-rack. In the front cliest is carried tlie
carriage-maker's outfit, and in the rear one that of the saddler.

On the middle of each side of the body may be attached a

ORGANIZATION OF SIEGE GUN BATTERY.

101

«mall chest for horse medicines, or su^h •.other «?mall ftrijloles as
may be required of easy access.

When the wagon is thus arranged it is, as f9,^i,ly,d)NT.w^i hyfour
liorses as the other by six, and one djriyejr, r^sjK^^dooJbltilii'^s, 's
sufficient. ' ' • . v . ->,.'>

The arrangement for attaching the draught-horses to siege-
gun carriages being similar to that for the army transportation-
wngon, the harness used witli the latter will answer for the for-
mer. A driver is required for each pair of horses, as in light field
-artillery.

The officers, first-sergeant, and chiefs -of -detachment are
mounted and equipped as for light artillery.

When in the presence of the enemy, the ammunition-wagons
are kept out of range of his fire, but always near enough to be
easily reached by the caissons for replenishing ammunition
'Chests.

The battery should be repainted once a year, usually in the
spring. To do this, a battery complete, of six pieces, requires :
120 lbs. olive paint; 15 lbs. black paint; 10 galls, linseed oil; 3
galls, spirits turpentine; 12 paint brushes (assorted).

Harness, when exposed constantly to the weather, should be
•oiled once in four months, requiring each time 6 gallons neat's-
foot oil and 30 lbs. tallow.

The tallow is melted and mixed with the oil. The harness
should be well soaked and washed, and the mixture applied
warm and thoroughly rubbed in while the leather is still damp.

259. The following list contains a fair supply of horse medi-
-cines for a battery of six pieces :

-Assafetida .~. 2 pounds.

Aloes 2 pounds.

Adhesive plaster 1 yard.

Aqua ammonia 1 quart.

Alum 1 pound.

IBluestone 1 pound.

Borax «.. 1 pound.

British oil 12 bottles.

Blister liquid % quart.

•Calomel % pound.

Condition powders 2 pounds.

Cerate, simple 2 pounds,

•G-lauber salts 10 pounds.

Flax-seed, ground 8 pounds.

Laudanum 1 quart.

Xard 5 pounds.

Xiunar caustic % ounce.

Mercurial ointment ~.. 1 pound.

Mustang liniment 6 bottles.

Nitre l pound.

Olive oil 2 quarts.

Opodeldoc 6 bottles.

Rosin 1 pound.

Spirits turpentine 2 quarts.

Spirits nitre 1 quart.

Flour of sulphur ^ pound.

Sugar of lead 2 pounds.

Tartar emetic U pound.

Tar 1 quart.

Whisky 2 gallons.

Farrier's needles 4

Farrier's scissors 1

Horse-fleam 1

Lancet 1

Syringe 1

These should be put up, as far as practicable, in metallic cans
:and in strong bottles. When the battery-wagon is arranged as

102

SIEGE HOWITZER — SERVICE.

before described, a I^'ey^ will be packed and carried in the boxes-
attached to th'i side^ 4>f cthe, body ; otherwise they will be carried
ill boxes inside of the body. . .

0,TTA;^TilvMA$TER'S STORES.

260. In addition to the wagons, horses, harness, &c., here-
tofore mentioned, there will be required for the battery the fol-
lowing :

3 wall tents.

3 wall-tent flies.

3 sets wall-tent poles and pins.
75 shelter tents (double).
10 camp-kettles.
10 mess-pans.

2 trumpets, cords and tassels.

1 company clothing-book.

1 company order-book.

1 company descriptive-book.

1 company morning report-book.

These articles, excepting the trumpets, are carried in a trans-
portation-wagon ; the same wagon will, in addition, carry two-
days' full rations for the men of the battery.
The forage is carried in transportation-wagons.

Service of Siege Howitzer.
{Plate 12.)
Description of Piece. ,

261. Howitzer, cast-iron; smooth-bore; muzzle-loader.

Number^ weights^ and dimensions.

Designation".

Calibre

Weight

Length

Diameter (maximum)

Diameter (minimum)

Length of bore (calibres.)

Windage

Charge (cannon powder)

Shell (empty)

Preponderance

Weight of piece, carriage, limber, and imple'ts..
Horses to transport

No.

5.81

Lbs.

2600.

4.
45.

580;.
6660.

Inch.

60.

17.5

15.

'6'Xi

SIEGE HOWITZER — SERVICE.

103

Ranges in yards.

Elevatiox.

Degrees.

1
2
3

5
12.5
15

Shell.

Range.

Lbs.

Yds.

435

618

720

992

1150

2280

2300

Time of
Flight.

Seconds.

1.33

Bursting charge of shell, 1 lb. ; charge to blow out fuse-plug,
4 oz.

The howitzer on its platform admits of 13 degrees elevation
and 10 degrees depression.

In works, it is fired from a wooden platform ; or when the
ground is level and firm, it may be fired without. It is used
chiefly in field works for flank defense.

To serve the piece.

262. Six men are required : one chief-of-detachment, one
gunner, and four cannoneers.
The implements and equipments are arranged as follows :

Two on each side of piece ; leaning
against parapet, in line with can-
noneers.

One yard behind, and parallel to

Handspikes

}

Sponge..
Rammer

the cannoneers of the right ; sup-

ported on a prop, head towards
the parapet.
Cartridge-pouch Suspended from cascable.

Primpr nonoh I Containing f riction.primers and lan-

rrmier-poucn | ^^^,^ . g^gpen^j^^j f^om cascable.

6-"-'« PO-h } ^TalZ^caST""' "^'''"'■

Sigl^t-pouoh I'^Cmtfcabr' ''"''• ""'""'"'

Wheel-chocks.

}

One on each side of the
the end of the hurter.

piece, near

104 rflEGE HOWITZEll — SERVICE.

Vent-cover Covering the vent.

Tompion , In the muzzle.

T, 1 Leanino' a^^ainst the parapet, near

tj , , , ■) Containing cartridges ; at a safe and

Uuage-Darrei j- convenient place near the piece.

Pair of sleeves "]

Shell-hooks I In a basket or on a shelf, against the

Plummet [ parapet, near Ko. 2.

Splints J

Sponge-bucket Kear sponge and rammer.

Grummet-wad On end of hurter, near No. 2.

Fuse-gauge

Fuse-knife

Fuse-wrench - In filling-room of service magazine.

Fuse-reamer |

One lanyard (extra) J

To each two pieces there should be

One worm

One hammer-wrench...
One gunner's quadrant

One vent-punch

One vent-gimlet

One gunner's level

One gunner's pincers...

If the piece is without elevating screw, a wooden quoin is nec-
essary, and this is under the breech.

For the purpose of instruction, a cartridge-bag filled with saw-
dust, and a priming-wire bent into a hook, for withdrawing it,
are provided, and are in tlie basket.

When there is no parapet the handspikes are placed, three on
each side, standing between the cheeks and wheels of the car-
riage, in front of and resting against the axle-tree.

The projectiles are in the filling-room of the service magazine ;
the fuses, cartridges, and primers are in the service magazine.

To distribute the equipments,

^63. The instructor commands :

1. Take equipments.

The gunner steps to the breech; takes off the vent-covet,
handing it to No. 2 to place against the parapet, outside of hia

- In filling-room of service magazine.

SIEGE HOWITZER — SERVICE. 105

post; gives the priraer-poiich to l^o. 3, and the cartridge-poiicli
to ]^o. 4; equips himself with tlie sight- pouch and his own
pouch ; clears the vent, levels the piece, and resumes his post.
No. 3 equips iiimself with the primer-pouch.

No. 4, after equipping himself with the cartridge-pouch, assists
No. 2 to put on the sleeves.

Nos. 1 and 2, after passing a handspike eacli to Nos. 3 and 4,
take one each, for himself. The handspikes are held and laid
<3own as prescribed in pars. 235 and 236. The gunner directs
No. 3 to embar under and raise the breech to enable him to level
the piece ; applies his level to ascertain the highest point of
metal at the base, which he marks with chalk. In case there is
no sight upon the muzzle, he does the same at the latter place,
and snaps a chalk-line between to mark the line of metal.

!264. The service of the piece is executed as foUovvs : The
piece being in battery, the instructor commands :

1. From battery.

The gunner moves two yards to his right; Nos. 1, 2, 3, and 4,
^11 facing from the epaiilment, embar; Nos. 1 and 2 through the
rear spokes of the wiieels, near the felly, under and perpendicu-
lar to the cheeks ; Nos. 3 and 4 under and perpendicular to the
manoeuvering bolts. All being ready, the gunner commands :
Heave, which is repeated as often as may be necessary. He
«ees that Nos. 3 and 4 guide the trail in prolongation of the direc-
trix of the embrasure, and as soon as the wheels are about one
yard from the parapet commands: Halt. If the platform has
an inclination, Nos. 1 and 2 chock the wheels in front. All re-
sume their posts.

1. By the numbers., 2. Load.

265. Nos. 1, 2, and 4 lay down their handspikes ; No. 2 takes
out the tompion and places it near the vent-cover, and resumes
his post ; No. 1 faces to his right, and seizes the sponge-staft' at its
middle with the right hand, back up ; places himself at the muz-
zle, forces the sponge to the bottom of the bore, and grasps the
staff with both hands, the back of the right up and that of the
left down.

No. 3, facing towards the parapet, embars under the breech
or knob of the cascable, and assists the gunner in adjusting the
piece conveniently for loading.

No. 4 goes for a cartridge and shell ; puts the cartridge in his
pouch; takes the shell in both hands; returns and places it on
the grummet-wad, and stands, facing the piece, about eighteen
inches to the rear and left of No. 2.

106 SIEGE HOWITZER SERVICE.

The gunner places himself near the stock, as in ^ar. 238, and
closes the vent; adjusts the piece to about one degree elevation,
and makes a signal for ISTo. 3 to unbar.

1. Sponge.

366. No. 1, pressing the sponge firmly against the bottom of
the bore, turns it three times from right to left, and three times
from left to right ; draws it out, turns the sponge-head over to-
wards the front, and places the rammer-head against the right
side of the face of the piece, holding the staff in both hands, the
back of the right down and that of the left up; as soon as the
cartridge is inserted, he enters the rammer and pushes the car-
tridge home.

No. 4 gives the cartridge to No. 2, who, having placed him-
self between the wheel and piece, inserts it into the muzzle.
As soon as No. 4 has given the cartridge to No. 2, he takes tlie
shell-hooks and engages them in the ears of the shell in readi-
ness for No. 2, who, making a face and a half to his left, takes
hold of the shell-hooks, raises the sliell and, making a face and
a half to his right, stands in readiness to insert it into the boi-e,
as soon as No. 1 has pushed home the cartridge.

1. Kam.

S6'^. No. 1 sets the cartridge home by pressing firmly upon
it; throws out the rammer, replaces it on the prop, and re-
sumes liis post.

No. 2 introduces tlie shell into the bore, keeping the arms of
the shell-hook in a vertical plane, and sets the shell carefully
against the cartridge, taking care that the fuse is in the axis of
the piece. Canister is shoved home by hand.

Double charges of canister may be fired.

If the piece is to be fired horizontally, or at an angle of de-
pression, No. 4 hands a splint to No. 2, who presses it under the
shell ; replaces the tongs and, if necessary, sweeps his side of
the platform ; passes the broom to No. 1, and resumes his post.

No. 1 sweeps his side of the platform, passes the broom back
to No. 2, and resumes his post.

No. 4, after passing the shell to No. 2, resumes his post.

Tlie gunner pricks, leaves the priming-wire in the vent, and",
resuming his post, adjusts the breech sight to the distance.

1. In battery.

26§. Nos. 1 and 2 unchock the wlieels, and Nos. 3 and 4,.
all facing towards rhe epauhnent, embar ; Nos. 1 and 2 through
the front spokes of the wheels, near tlie felly, under and perpen-

SIEGE HOWITZER — SERVICE. 107

dicular to the cheeks ; I^os. 3 and 4 niider and perpendicular to
the stock, guidhig the muzzle of the piece into tlie middle of the
embrasure. The gunner commands: Heave, and, as soon as
the wheels touch the iiurter, Halt, when all unbar and resume
their posts.

1. Aim.

269. 'No. 3 lays down his handspike and prepares a primer.

Nos. 1 and 4, facing towards the parapet, embar under and
perpendicular to the stock, near the manceuvering bolts ; N"o. 2,
facing in the same direction, embars under the breech or knob
of the cascable.

The gunner, placing himself at the stock, as at the command
load^ withdraws tiie priming-wire, places the centre point of the
breech sight accurately upon the chalk-mark on the breech, and,
sighting through it, gives the direction. Nos. 1 and 4 move the
trail to the left or right at the command Left or Right from
the gunner.

The moment the piece is correctly aimed, the gunner rises,,
and commands : Ready, making a signal with both hands, at
which IN^os. 1, 2, and 4 unbar and resume their posts.

The gunner, taking with him the breech sight, goes to a good
place to observe the effect of the shot.

At the command Ready, No. 3 inserts the primer in the vent ;
Nos. 1 and 2, laying down their handspikes, take each a chock
in the hand nearest the parapet, and, breaking off with the foot
farthest from the parapet, stand ready to chock the wheel after
the recoil.

Tiie breech sight at present used with the howitzer is one of
obsolete pattern.

When sights similar to those used for siege guns are supplied^
the method of aiming will be the same as for the gun.

When the piece is masked, by an epaulment, from the object,
the direction is given as explained for mortars. {Par. 343.)

1. Number one (or the like), 2. Fire.
fiKO, Executed as in par. 244.

To load without the numbers, and to Jire.
S*^!. Executed as \npar. 245.

To unload.
272. The piece having been run from battery, the instructor
directs No. 2 to take out the shell and cartridge, No. 4 carrying-
them to their place in rear of the piece ; No. 3, v/ith his hand-
spike, raises the breech until the shell rolls to the muzzle, where-
it is caught by No. 2, who hands it to No. 4.

108

10-INCH GUN — SERVICE.

To load and fire continuously,
273. Executed as in par. 246.

To cease firing,
3T4. Executed as mpar. 247.

To secure piece and to replace equipments.

Executed as in pars. 249 and 250.

The howitzer is prepared for campaign service as explained
for the siege gun, with such modifications as readily suggest
themselves.

275. For transportation, the shells are carried uncharged.
To charge them, two men and the following implements, in ad-
dition, are required, viz.: One set of powder-measures^ one fun-
nel^ one fuse-mallet^ one fuse-setter, one rasp., two grummet-wads,
two wipers, one bridge-barrel, together with a supply of fuse-
plugs and tow.

The fuse-plugs are of wood, and the tow is to stop the fuse-
holes until the shells are to be taken to the piece. The shells
should be well cleansed on the outside from rust and dirt. This
is done at the filling-room of the service magazine.

Note. — The shells for the howitzer should be strapped to sa-
bots, in which case the loading would be greatly facilitated.

The foregoing exercise is for ammunition as now furnished.

For the service of the siege howitzer, when used as a mortar,
see par. 45S.

Service of a 10-inch Smooth-bore G-tjn in barbette.

{Fig. 1, Plate 8.)

Description of Piece.
^'^6, Gun, cast-iron ; muzzle-loader.

Number, weights, and dimensions.

Dbsigxation.

No.

Lbs.

Inch.

Calibre — ~^

Length of piece

Maximum diameter

Minimum diameter

Length of bore (calibres)

Windage

Initial velocity (feet)

Charge (cannon powder)

Solid shot

Shell (unfilled)

"Weight of piece

Preponderance

10.5
1275!

10.

136.6

32.

16.2

0.13

128

102

15,000

10-INCH GUN — SERVICE.

109

Carriage, wrought - iron ; front pintle, without air-cj^linders
or other recoil checks. The new-pattern carriage will be pro-
vided with pneumatic buffers. The top -carriage will weigh*^
2500 pounds, and the chassis 3500 pounds.

Ranges in yards.

Elevation.

Shot.

Shell.

Time.

Charge.

Seconds.

1°

00^^

511

504

1.33

1°

30^^

724

708

1.95

2°

00^^

916

886

2.56

2°

30^^

1090

1048

3.15

3°

00^^

1251

1195

7.71

3°

30^^

1401

1330

4.25

.- -n

00^^

1539

1455

4.79

00^^

1793

1680

5.83

"^ '^

6°

00^^

2019

1879

6.82

00^^

2255

2057

7.78

8°

00^-'

2414

2217

8.71

9°

00'^

2587

2363

9.60

;::

10°

00^^

2749

2498

10.46

15°

00^^

3429

»o

20°

00^^

3976

......

T—

Truck handspikes (iron).
Elevating-bar (iron)

Sponge...
Kammer

}

The piece admits of 30 degrees elevation and 6 degrees depres-
sion. Its platform is a permanent portion of the fortification.

To serve the piece.

^KK, Eight men are necessary : one chief-of-detachment, one
gunner, and six cannoneers.

The implements and equipments are arranged as follows :

Two on each side of the carriage^
on hooks.

Laid on the carriajre over the rear
notches, and perpendicular to the
piece ; handle to the left.

One yard behind the cannoneers ot
the right ; supported upon a prop,
the sponge and rammer -heads^
turned from the pai'apet and in-
clined slightly from the piece.

Pass-box One yard in rear of No. 4.

110 10-INCH GUN — SERVICE.

}
}

Containing f nction-primers and lan-

Primer-pouch [• 5'ard; suspended from ratchet-
post.
Containing breech sight and prim-

Ounner's pouch y ing-wire ; suspended from ratchet-
post.

Chocks (iron) One on eacii hurter.

Vent-cover.... Covering vent.

Tompion In the muzzle.

Shell-hooks Behind and near 'No. 5.

Sponge-hucket IS'oar sponge.

■r. ^ r^ 1 \ Containing cartridges; at a safe and

Jiua^e-oarrei | convenient place near the piece.

When several pieces are served together, there will be one
quadrant^ one worm^ one ladle^ one hammer-wrench^ two vent-
punches^ one gunner'' s pincers^ two lanyards (extra), and two
vent-gimlets to each battery of not exceeding six pieces. Tliese,
together with the primers and fuses, are kept in the fillhig-room
of the service magazine, where the sliells are prepared for firing
and brought to the piece as required.

The powder is kept in the service magazine.

The shells are strapped to sabots. The fuse-plug is of metal,
and at the time of inserting the shell into the piece the paper or
lead cap is pulled from the top of the wnter-cap. The solid shot
are kept piled convenient to the piece. All the projectiles should
be carefully cleansed of dirt, lumps of rust, or other protuber-
ances before inserting in the gun. Stands of grape are also
provided for occasional use, and are kept convenient to the
piece.

To distribute the equipments,

3f S. The instructor commands :

1. Take equipments.

The gunner mounts upon the chassis; takes off the vent-
cover, hands it to No. 2 to place against the parapet in rear of
his post ; gives the primiM-pouch to No. 3, equips himself with
his own pouch, and clears the vent. No. 4 mounts upon the
chassis, takes the elevating-bar, and, under the direction of the
gunner, adjusts the piece conveniently for loading and resumes
his post, taking with him the bar, which he lays on the ground
in rear of him, perpendicular to the piece. No. 3 equips himself
with the primer-pouch. The handspikes, when not in use, re-
:main on the hooks.

10-INCH GUN — SERVICE. Ill

The instructor causes the service to be executed by the follow-
ing commands :

1. From battery.

3^79. The gunner places himself two paces in rear of the
chassis and commands : In-Gear. l!^os. 3 and 4 take hand-
spilves from the hooks, embar in the eccentric sockets of the top-
carriage, and, assisted by Nos. 5 and 6, throw the wheels in gear
at the command Heave by the gunner. The gunner then com-
mands : Embar. ]N"os. 3 and 4 withdraw their handspikes and
insert them in the rear and uppermost mortises of the truck-
wheels; Nos. 5 and 6 seize the handspikes with both hands above
the hands of ^os. 3 and 4, all breaking to the rear with the foot
nearest the carriage. The gunner then commands: Heave.
^os. 3, 4, 5, and 6, acting together, bear down upon the hand-
spikes and move the carriage to the rear; Nos. 1 and 2 follow
up with the chocks. The gunner commands: Embar. ISTos.
5 and 6 let go the handspikes; Nos. 3 and 4 withdraw them, and
embar as before. The gnnner commands : Heave, which will
be executed as before. The commands embar and heave will be
repeated by the gnnner until the face of the piece is about one
yard from the parapet, when the gunner commands : 1. Halt,
2. OUT-OF-GEAR. Nos. 1 and 2 chock the wheels ; Nos. 3 and
4 withdraw their handspikes, insert them in the eccentric sockets,
and at the command Heave by the gunner throw the wheels
out of gear, leaving the handspikes in the sockets. All resume
their posts.

1. By the numbers, 2. Load.

280. No. 2 takes out the tompion, and places it b}'' the para-
pet in rear of his post. The gunner mounts upon the chassis
and closes the vent.

No. 1 turns to his left, steps over the sponge and rammer,
faces the piece, takes the sponge-stafF with both hands, backs
down, the right hand three feet from the sponge-head, the left
hand eighteen inches from it; returns to the piece, raising the
sponge-staff over the crest of the parapet ; places the left foot
on the rail of the chassis, and the right foot upon the parapet, or
upon a step placed for the purpose against it ; inserts the sponge-
head into the muzzle, the staff in prolongation of the bore, sup-
ported by the right hand, the right arm extended, the left hand
hanging naturally by his side.

No. 2 takes a position on the left of the piece corresponding
to that of No. 1 on the right, and seizes the staff with the left
hand, back down, near to and outside the hand of No. 1.

No. 3 faces to his rear, steps over the rammer, and, facing

112 10-INCH GUN — SERVICE.

about, seizes the statF with both hands, as prescribed for No. 1
with the sponge; he then stands ready to exchange staves with
No. 1.

No. 4, taking the pass-box, goes for a cartridge ; returns ancJ
places himself, facing the piece, to the right and rear of No. 2.

No. 6, taking a handspike, goes for the shell, followed by
No. 5 with the siiell-hooks; No. 5 attaches the shell-hooks to the
projectile, and No. 6 passes the handspike through the ring, or,
if the sliell is provided with a rope handle, through the loop of
the handle; both seize the handspike. No. 5 in front, and, bring-
ing the shell up on the left of the piece, place themselves parallel
to the parapet, No. 5 behind and near No. 2.

In the meanwhile, Nos. 1 and 2 insert the sponge in the bore
by the following motions, at the commands two — three— four —
five — six :

Two. They insert the sponge as far as the hand of No. 1,.
bodies erect, shoulders square.

Three. They slide their hands along the staff and seize it
at arm's-length.

Four. Ttiey force the sponge down as prescribed for two.

Five. They repeat what is prescribed for three.

Six. They push the sponge to the bottom of the bore. No. 1
replaces the left hand on the staff, back up, six inches nearer the
muzzle than the right; No. 2 places the right hand, back up^
between the hands of No. 1; both numbers then change the
other hand so as to seize the staff back up.

]. Sponge.

281. Nos. 1 and 2, pressing the sponge firmly against the
bottom of the bore, turn it three times from right to left, and
three times from left to right; drop the hands farthest from tlie
parapet by their sides, and withdraw the sponge by similar
commands, but by motions contrary to those prescribed for in-
serting it.

No. 2 quits the staff, and, turning to No. 4, receives from him
the cartridge, which he introduces into the bore ; he then grasps
the rammer in the way presci-ibed for the sponge.

In the meanwhile. No. 1, turning to his left, passes the sponge
above the rammer to No. 3, and, receiving the rammer from
No. 3, presents it as prescribed for the sponge, except that, re-
taining hold with his left hand, he rests the rammer-head against
the right side of the face of the piece.

No. 3, as soon as the sponge is withdrawn, passes the rammer
in front of No. 1 onto the parapet, receives the sponge from
No. 1, repl'ices it upon the prop, and resumes his post.

No. 4 takes the cartridge from the pass-box and hands it to

10-INCH GUN — SERVICE. 113

No. 2, the choke to the front ; returns the pass-box to its place,
and resumes his post.

I^os. 1 and 2 force tlie cartridge home by the same commands
and motions as in sponging.

1. Kam.

282. Nos. 1 and 2 slide their hands along the staff to the
full extent of their arms, and, grasping it firmly, throw the
weight of their bodies upon the staff to force the cartridge
tightly home ; No. 2 then quits the rammer, which jN"o. 1 throws
out and lays upon the parapet.

In the meantime, Nos. 5 and 6, carrying the shell as before
prescribed, step between tlie parapet and the face of the piece ;
No. 6 gives his end of the handspike to No. 2 ; No. 5 gives his
end to No. 1, and then places himself on the platform in front
of the shell ; Nos. 1 and 2 raise the shell until it is opposite the
muzzle; No. 5, applying his hands under it, raises the sabot
and inserts it into the muzzle; No. 5 then resumes his post;
No. 2 withdraws the handspike and passes it to No. 6, who
replaces it on the hooks and resumes his post ; No. 2 passes the
shell-hooks to No. 5, who replaces them.

Nos. 1 and 2, taking up the rammer, apply its head and force
the shell down by commands and motions similar to those pre-
scribed for the cartridge; at the command Ram it is pressed
tightly down against the cartridge; No. 2 quits the rammer and
resumes his post ; No. 1 throws out the rammer, replaces it on
the prop, and resumes his post.

As soon as No. 4 has delivered the cartridge, he mounts upon
the chassis, embars through the ratchet-post with the elevating-
bar, and, when the projectile is home, gives the piece an eleva-
tion of about 5 degrees, — this for the purpose of preventing the
displacement of the projectile when the piece is run into battery;
No. 4 replaces the elevating-bar and resumes his post ; the gun-
ner pricks, leaving the priming-wire in the vent.

1. In battery.

2§3. The gunner commands: In-Gear. Nos. 1 and 2 un-
chock the wheels and place the chocks on the hurters; Nos. 3
and 4 seize the handspike and, at the command Heave by the
gunner, bear down slowly until the piece is in motion, regulat-
ing it by alternately throwing the wheels in and out of gear, or
partially so. As soon as the carriage strikes the hurters, the
gunner commands : 1. Out-of-gear, 2. Heave. Nos. 3 and
4 throvr the wheels out of gear, withdraw their handspikes, re-
place them on the hooks, and resume their posts. If the car-
riage does not move when in gear, the gunner directs No. 3 to

114 10-INCH GUN — SERVICE.

slightly engage a handspike in a rear mortise of the truck-wheel
and gently urge the carriage forward. Care must be exercised
in this operation that the handspike does not fly forward with
violence.

As soon as the carriage strikes the hurters, N"os. 1 and 2 lock
the wheels with the toggles.

1. Aim.

284. The gunner commands: 1. Chassis in-gear, 2.
Heave. At the first command, Nos. 3 and 4 embar in the
sockets of the eccentrics, and at the second command, assisted
by N'os. 1 and 2, throw the chassis-wheels in gear, and, leaving
the handspikes in the sockets, resume their posts ; N"os. 5 and 6
embar in the traverse-wlieels. The gunner withdraws the prim-
ing-wire, places the breech sight in the socket, and, sighting
through it, gives the direction ; Nos. 5 and 6 move tlie trail to
the left or right at the command left or right from the gunner.

When the direction has been given, the gunner commands ;
1. Chassis OUT-OF-GEAR, 2. Heave. At the first command,
N'os. 1 and 2 seize the handspikes, and at the second throw the
wheels out of gear, return the handspilves to their hooks, and
resume their posts. Nos. 5 and 6 unbar, return their liand-
spikes to the hooks, and resume their posts.

No. 3 passes the hook of the lanyard through the eye of a
primer, holds the handle of the lanyard with the right hand,
the hook between the thumb and forefinger, and stands ready
to hand it to the gunner. IS^o. 4 mounts upon the chassis and,
embarring through the ratchet-post with the elevating-bar, raises
or lowers the breech as directed by the gunner.

When the piece is correctly aimed, tiie gunner commands :
Ready, makes a signal with both hands, removes the breech
sight with his left hand, and, receiving the primer from ]^o. 3 in
his right, inserts it in the vent, dismounts from the chassis, and
goes where he can best observe the eff'ect of the shot ; jN'os. 1 and
2 break ofi* sideways with the foot farthest from the parapet ;
N'o. 3 drops tlie handle, allowing the lanj^ard to pass through his
fingers, steps back obliquely three yards to the rear, and breaks
off to his left and rear with the left foot, left hand hanging nat-
urally by the side ; N'o. 4 resumes his post, taking with him the
elevating-bar, which he lays on the ground as before.

1. Number one (or the like), 2. Fire.

285. N"o. 3, turning his face from the piece, pulls the lan-
yard quickly, but steadily, and fires. Immediately after the dis-
charge, Nos. 1, 2, and 3 resume the erect position ; JS'o. 3 rewinds
the lanyard and replaces it in the pouch. The gunner, having
observed the eft'ect of the shot, returns to his post.

100-POUNDER PARROTT — SERVICE. 115

To load without the numbers^ and to fire.
As explained in par. 245.

To load and fire continuously^ and to cease firing^
As explained in ^ar^. 246 and 247.

To secure the piece.
As explained in par, 249.

To replace equipments,

386. Executed as in par. 250, except that the gunner re-
places the pouches on the ratchet-post, instead of the knob of
the cascable.

Note 1. — The piece may be fired with safety when the chassis
is in gear. This part of the prescribed service may, therefore,
be omitted.

2. The flooring-planks extend over but a portion of the chassis,
making it exceedingly inconvenient to load the piece when in
its proper position. To remedy this defect, cut boards to the
proper length and fit them in crossways between the rails of the
chassis, resting on the lower flanges of the rails.

3. Solid shot for this piece are without ears ; they cannot, there-
fore, be carried by means of shell-hooks. The ladle for hot shot
i{sometimes to be found at posts) answers for carrying and lifting
the shot to the muzzle.

Service of the 100-pounder Parrott.

28*^. The 100-pounder Parrott rifle is mounted on a carriage
of similar construction to that of the 10-inch smooth-bore, and the
service of it is nearly identical with the foregoing, except that,
in bringing up the projectile, a rope strap is used instead of shell-
hooks ; and excepting, also, that in pointing, No. 4, instead of
using an elevating-bar, assists the gunner in giving the elevation
by means of the elevating screw.

Remarks.

288. All guns of the Parrott system are of cast-iron, i-ein-
forced at the seat of the charge by a wrought-iron jacket, which
IS shrank on. The one, two, and three hundred pounders have
no preponderance. The depth of grooves in all of them is 0.10
inch, with increasing twist.

The ;J00-pounder weighs 26,000 ponnds^; has 15 grooves. The
*200-pounder weighs 16,800 pounds; has 11 grooves. The 100-
pounder weighs 9,700 pounds; has 9 grooves. Tiie charge for

116

100-POUNDER PARROTT — SERVICE.

the first is 25 pounds, for the second 16 pounds hexagonal, and?
for the third 10 pounds cannon powder.

Ranges: \00-poundcr.

Charge : 10 pounds cannon powder. Projectile : Parrott shelly,
filled, 100 pounds. Initial velocity : 1.080 feet.

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10-INCH GUN — CASEMATE — SERVICE. 117

2S9. When a gnn, mounted on an iron carriage, is loaded,
rand it is not desired to tire it, the projectile may be withdrawn
by running tlie piece from battery, depressing tlie muzzle as far
as possible, and then allowing it to run into battery against the
hurters, thus Jarring the projectile forward.

The cartridge is withdrawn with the worm ; should it burst,
the powder is scooped out with the ladle.

290. In all carriages for heavy guns, when no means for
checking the recoil are provided, the rails should be sanded, but
the sand should be free from gravel.

Service of a 10-inch Smooth-bore Gun in casemate.

Description of piece.

Identical with the same gun in barbette, as given mpar, 276.

Carriage, wrought-iron (chassis and top) ; front pintle ; with-
out air-cylinders or other recoil check. Weight of top-carriage,
1500 pounds ; weight of chassis, 3000 pounds.

The piece, when in battery, in the ordinary casemate embra-
sure, admits of 7 degrees elevation and 6 degrees depression.

The new-pattern carriage and chassis will be provided with
air-cylinders. The former will weigh 1459 pounds ; the latter,
5310 pounds.

The ranges are identical with the same gun in barbette. {Par,
276.) The ammunition is the same, and is kept and served in
the same manner. {Par. 'ill.)

To serve the piece,

S91. Eight men are necessary : one chief-of-detachment, one
gunner, and six cannoneers. The implements and equipments
are arranged as specified in par. 277.

To distribute the equipments,
292. The instructor commands :

1. Take equipments.

The gunner steps to the side of the chassis, takes off the vent-
•cover, hands it to ^NTo. 2 to place against the scarp in rear of
his post, gives the primer-pouch to No. 3, equips himself with
his own pouch, and clears the vent. No. 4 monnts upon the
chassis, takes the elevating-bar and, under the direction of the

118 10-INCH GUN — CASEMATE — SERVICE.

gunner, adjusts the piece conveniently for loading, and resume*
his post, taking with him the bar, which he lays on the pave-
ment in rear of his post, perpendicular to the piece.

ISTo. 3 equips himself with the primer-pouch. The handspikes^
when not in use, remain on the hooks.

To serve the piece.

The instructor commands :

1. From battery.
Executed as in par. 279.

1. By the numbers^ 2. Load.

Executed as in par. 280, except that i^os. 1 and 3 pass the
sponge and rammer staves into the embrasure, instead of over
the crest of the parapet.

1. Sponge.

Executed as m par. 281.

1. Ram.

Executed as in par. 282, except that N"o. 1 lays the rammer-^
staff upon the sole of the embrasure, instead of on the parapet,

1*..In battery.

Executed as in par. 283.

1. Aim.

l!^os. 5 and 6 embar in the rear traverse-wheels. The gunner,
mounting upon the chassis, withdraws the priming-wire, places^
the breech sight in the socket, and gives the direction. Nos. 5
and 6 will, when necessary, be assisted by Nos. 1 and 2. *

The remaining operations of pointing are as explained in par,
284.

1. Number one (or the like), 2. Fire.

Executed as in par. 285. *

To load without the numbers^ and to jire.

To load and jire continuously^ and to cease firing^ and to 8&^

cure the piece.

All executed as in pars. 245, 246, 247, and 286.

15-INCH GUN — CENTRE PINTLE — SERVICE. 119

Seryice of a 15-inch Gun mounted on a centre-
pintle CARRIAGE.
Description of piece.
393. Gun, cast-iron ; muzzle-loader ; smooth-bore.

Desigkatiox.

No.

Lbs.

Inch.

Calibre

Weight

Preponderance

Length of piece

Length of bore (calibres)

Maximum diameter

Minimum diameter

"Windage ....,,

Charge (mammoth or hexagonal powder) for

shot

for shell

Solid shot

Shell (unfilled)

Initial velocity (feet)

Weight of top-carriage

Weight of chassis

Carriage — wrought-iron (chassis with two air-
cylinders to check recoil)

49,000
00

190

"4*8

0.13

100

450

330

1.534

5,800
15,450

Kanges in yards.

Shot.

Shell.

«H fee

-(J
>

Charge.

Deg's.

Y'rds.

Deg's,

Y'rds.

Sees.

100 pounds of mammoth

769

600

1.44

powder for solid shot, and

1332

1073

2.79

60 pounds for shell.

1819

1467

4.1

2235

1800

5.28

To fill shell: 12 pounds of

2601

2094

6.44

mortar powder.

2926

2355

7.58

3221

2590

8.07

Pressure per square inch, av-

3491

2804

9.68

erage, 19,500 pounds.

3735

3000

10.69

3959

3171

11.63

Length of cartridge :

4890

3916

16.30

100 pounds=30 inches.

5579

4458

20.52

60 pounds=18 inches.

120 15-INCH GUN — CENTRE PINTLE — SERVICE.

CouQterpoise handspikes
(iron)

Truck handspikes (iron)... >

Elevating-bar (iron)

Sponge .. ,
Rammer

Primer-pouch.

Gunner's pouch.

}

The piece admits of 25 degrees elevation and 6 degrees depres-
sion. The platform is a permanent portion of the work.

To serve the piece.

394. Twelve men are required : one chief-of-detachment, one
gunner, and ten cannoneers.
The implements and equipments are arranged as follows :

One on each side of piece, attached
to socket on front axle by a set-
screw. A rope is attached to the
small end of tliese handspikes for
heaving on when running the
piece from battery. When not
in use, the free end of the rope is
hung by an eye to a hook on the
cheek of the carriage.

Two on each side of piece ; on hooks
upon the sides of the chassis.

Lying on the cari-iage, upon the
rear notches, and perpendicular
to the piece, handle to the left.

One yard behind the cannoneers of
the right ; the sponge and ram-
mer-heads turned from the para-
pet, inclined slightly fi-om the
piece, and supported on a prop.

Pass-box Two yards in rear of No. 7.

") Containing friction - primers and
lanyard ; hung on step of the
ratchet-post.
Containing breech sight and prim-
ing-wire ; hung on step of ratchet-
j post.

Chocks (iron) One on each hurter.

Vent-cover Covering vent.

Tompion In muzzle.

Carrying-bar (wood) Two yards in rear of ^o. 10.

Shell-hooks Two yards in rear of N'o. 4.

Sponge-bucket l!^ear sponge.

°Sra,!d''S.-.°:". } Attached to the crane.
There not being suflScient space for them when the carriage

15-INCH GUN — CENTRE PINTLE — SERVICE. 121

runs from battery, neither handspikes, elevating-bar, nor any
equipments will be placed on the floor-boards of the chassis.

Wlieh several pieces are served together, there will be one
quadrant^ one worm, one ladle^ one hammer-wrench^ two vent-
punches^ one gunner'' s pincers^ two lanyards (extra), and two
vent-gimlets to each battery of not exceeding six pieces. Tiiese
will be kept in the filling-room of the service magazine.

The cartridges are in the service magazine, and are brought
to the piece as wanted. The shells are in the filling-room of the
service magazine, and are likewise brought up when required.
The shells are strapped to sabots. The fuse-plugs are of metal,
and at the time of inserting the shell into the piece the paper cap
should be pulled from the top of the fuse-primer. The solid shot
are kept convenient to the piece. The projectiles should be
carefully freed from dirt, lumps of rust, or any other pri^iuber-
ances that might prevent their easy insertion into the bore of
the piece.

To distribute the equipments,

295. The instructor commands :

1. Take equipments.

The gunner mounts upon the chassis, takes off' the vent-
cover, hands it to No. 2, who places it against the parapet, near
his post ; gives the primer-poucii to No. 3, equips himself with
his own pouch, and clears the vent; Nos. 1 and 2 remove the
plugs from the front ends of the air-cylinders.

Nos. 5 and 6 hook the ropes to the counterpoise handspikes,
and, securing the free end to the hooks on the cheeks, mount
upon the chassis. Under the direction of the gunner. No. 6
takes the elevating -bar, embars with it through the ratchet-
post, and, assisted by No. 5, gives tlie piece an elevation of about
one degree ; replaces the elevating-bar, and, together with No.
5 and the gunner, resumes his post.

The service of the piece is executed as follows. The instructor
commands :

1. From battery.

296. The gunner mounts upon the chassis, and commands:
In-gear.

Nos. 3 and 4 adjust the pawls of the counterpoise handspikes
so that they will clear the ratchets of the truck-wheels; Nos. 5
and 6 take down the ropes and raise the handspikes until Nos. 3
and 4 engage the pawls in the ratchets.

In the meanwhile, Nos. 9 and 10 insert each a handspike into
the sockets of the rear truck-wheels, and, mounting upon the

122 15-INCH GUN — CENTRE PINTLE — SERVICE.

steps of the chassis, unlock the rear axle, and at the command
Heave from the gunner, assisted by j^os. 7 and 8, throw the
rear truck-wheels in gear.

IS'os. 9 and 10 relock the axle, and return the handspikes to-
the hooks.

The gunner then commands : Embar.

Xos. 5 and 6 raise the counterpoise handspikes until nearly
vertical, when N'os. 3 and 4 engage the pawls into the ratchets.

N'os. 3 and 5 seize the counterpoise handspikes, and N"os. 7
and 9 the ropes on the right of the piece ; and !N"os. 4, 6, 8, and
10 apply themselves, in like manner, upon the left. AH take
hold from front to rear in the ascending order of their numbers^

At the command Heave from the gunner, the handspikes are
forced down, and the top-carriage moves a short distance to the
rear.

JTos. 1 and 2 follow up the movement and keep the wheel-
chocks closely applied to the wheels. The gunner gives alter-
nately the commands embar and lieave^ until the muzzle of the
piece is over the front part of the chassis; he then commands :
Halt. At this command, Nos. 3 and 4 clear the p^wls from the
ratchets, and Nos. 5 and 6 raise the handspikes and secure the
ropes to the hooks.

The gunner then commands : Out-OF-GEAR. Nos. 9 and 10
mount upon the steps of the chassis, unlock the axle, and, at the
command Heave from the gunner, throw the wheels out of gear,,
and, leaving the handspikes in the sockets, resume their posts.

1. By the numbers^ 2. Load.

29 T. ISTos. 1 and 2 mount upon the front of the chassis and
upon the steps of the parapet wall ; No. 2 removes the tompion
and hands it to '^o. 4, who places it against the parapet, in rear
of the post of No. 2.

No. 3 brings up the sponge, passes it to No. 1, and mounts
upon the steps of the parapet wall, outside of No. 1, to assist
Nos. 1 and 2 in sponging and ramming. The sponge-head is
inserted in the muzzle.

No. 5, bringing up the rammer behind No. 1, stands ready to
hand it to No. 3, and to take the sponge from No. 3 after the
sponging is completed.

Nos. 7 and 9, taking the pass-box, go for the cartridge ; Nos.
4, 6, 8, and 10 go for the projectile, No. 4 carr3'ing the shell-
hooks and No. 10 tiie carrying-bar. In returningv the projectile
is brought up on the left of the piece. No. 4 in advance and the
other numbers in their order in rear. The cartridge, in the
pass-box, is brought up on the right of the piece.

15-INCH GUN — CENTRE PINTLE — SERVICE. 123

The projectile is placed under the crane; the carrying-bar re-
tni-ned to its place by No. 10, who then resumes his post; the
pulley is attached to the shell-liooks by ISTo. 4; Nos. 6 and 8 rnn
lip tiie projectile, l^o. 4 steadying it. In the meanwhile — the
gunner stopping the vent — the sponging is executed by I^os. 1
and 2, assisted by No. 3, at commands from the instructor of
two — three— four^ &c.

Two. Insert the sponge as far as the hand of N"o. 1, bodies
erect, shoulders square.

Three. Slide the hand along the staff and seize it at arm's-
length.

FOUB. Force the sponge down as prescribed for two.

Five. Repeat what was done at three.

Six. Push the sponge to the bottom of the bore. !N"o. 1 seizes
the staff witli the left hand, back up, six inches nearer the muz-
zle than the right ; No. 2 places the right hand, back up, between
the hands of No. 1 ; both then change their other hands so as to
grasp the staff with backs up.

1. Sponge.

29 S. Nos. 1, 2, and 3, pressing the sponge firmly against the
bottom of the bore, turn it tln-ee times from right to left, and
three times from left to right. The sponge is withdrawn at the
commands two — three— four— Jive^ &c., b}'^ motions contrary to
those prescribed for inserting it. As soon as tlie sponge is with-
drawn, No. 3, turning towards the left, passes the sponge, with
both hands, behind No. 1 to No. o, and receives from liim the
rammer; Nos. 1 and 2 take the cartridge from Nos. 7 and 9,
and insert it in the bore ; Nos. 7 and 9 replace the pass-box and
i-esume their posts ; No. 5 replaces the sponge on the prop and
resumes his post ; as soon as the cartridge is inserted. No. 3 places
the rammer-head against it in the bore. The cartridge is forced
down by Nos. 1, 2, and 3, at the commands and by the motions
prescribed for the sponge.

1. Ram.

1299. The cartridge is set home by strong pressure, not hy a
blow; Nos. 1 and 3 throw out the rammer; No. 2, quitting the
staff, assists No. 4 in swinging the crane round to bring the
projectile in front of the muzzle ; the rammer-head is placed
against the projectile, whicii is pushed into the bore by Nos. 1,
2. 3, and 4; No. 4 withdraws the shell-hooks, and resumes his
post; Nos. 1, 2, and 3 force the projectile home by motions and
commands as explained for the cartridge; Nos. 6 and 8 swing
the crane back; secure it and the pulley against the cheek; No..

124 15- INCH GUN — CENTRE PINTLE — SERVICE.

S resumes his post, and I^o. 6 mounts upon the chassis. The
rammer is tin-own out and passed by No. 3. to ^"0. 5, who places
it on tlie prop; INTos. 1, 2, 3, and 5 then resume tlieir posts. The
gunner, assisted by No. 6, gives the piece an elevation of about
five degrees, after which he pricks the cartridge, leaving the
priming-wire in the vent. No. 6 resumes his post.

1. In battery.

300. The gunner commands: In-GEAR. Nos. 1 and 2 un-
chock the wheels; Nos. 3 and 4 see that the handspike pawls
are clear of the ratchets; Nos. 9 and 10 mount upon the steps,
unlock the axle, seize the rear handspikes, and, at the command
Heave bj'^ the gunner, bear down slowly (assisted if necessary
by 7 and 8) until the piece is in motion, and regulate it by alter-
nately throwing the wljeels in and out of gear sufficient!}^ for
that purpose. The front wlieels are not chocked by ISTos. 1 and

\2 unless the gunner so directs. As soon as the cari-iage strikes
the hurter, the gunner commands : 1. Out-of-gear, 2. Heave.
Nos. 9 and 10 throw the wheels out of gear, secure the axle with
the pawl, and, returning the handspikes to the hooks on the
chassis, resume their posts.

Should the carriage not move when the wheels are thrown in
gear, the gunner directs ]^os. 3, 4, 5, and 6 to lower the hand-
spikes and engage the upper arm of the handspike pawl in the
ratchet, and by raising the handspike urge the piece forward.

1. Aim.

301. The gunner commands: 1. CHASSIS in-Gear, 2.
Heave. Xos. 7 and 8 take the handspikes, embar in the sock-
ets of the eccentrics of the chassis, and, assisted by N'os. 9 and
10, throw the wheels in gear; they then embar with the same
handspikes in the mortises of the rear set of the front traverse-
wheels ; Nos. 1 and 2 embar in the front set ; Nos. 5 and 6
mount on the chassis to assist the gunner in giving the eleva-
tion ; No. 3 passes the hook of tiie lanyard through tlie eye of a
primer, and stands ready to hand it to the gunner.

The gunner places the breech sight in the socket, and, sight-
ing through it, gives the direction, commanding: Muzzle
RIGHT, or Muzzle left, for Nos. 1, 2, 7, and 8 to traverse the
chassis to the right or to the left.

The direction" being given, the gunner commands : 1. Chas-
sis out-of-gear, 2. Heave. At the first command, Nos. 1
and 2 return their handspikes to their hooks and resume their
posts ; Nos. 7 and 8 embar in the sockets of the eccentrics of
the chassis, and, assisted by Il^os. 9 and 10, at the command

15-INCH GUN — CENTRE PINTLE — SERVICE. 125-

Ae«2;e throw the chassis out of gear; Nos. 7 and 8 then replace-
their handspikes, and, with Nos. 9 and 10, resume then- posts.

Note. — The piece can be fired with safety when tlie chassis is
in gear. The omission of this part of the exercise saves much
time and labor.

The gunner next causes No. 6, assisted by N"o. o, to give the
required elevation to the piece, and commands : Ready. Xos.
5 and 6 resume their posts, No. 6 taking with him the elevating-
bar, which he places in rear of him on the ground, perpendicular
to the piece. The gunner withdraws the priming-wire, receives
the primer from Ko. 3, inserts it in the vent, takes the breech-
sight with him, and goes where he can best observe the eftect of
the shot.

The chief-of-detachment, or in his absence the gunner, then
commands: 1. Detachment bear, 2. March. At the first
command, the cannoneers, except No. 3, face from the epaul-
ment, and, at the command march^ they march to the rear as
explained in par. 113; No. 3 drops the handle, allowing the
lanyard to pass through his fingers, and steps back three j^ards
obliquely from the piece, breaks off with his left foot to his left
and rear, the left hand by the side.

1. Number one (or the like), 2. Fire.

302. No. 3, turning his face from the piece, pulls the lan-
yard quickly, but steadily, and fires; immediately after the dis-
charge he resumes the erect position; rewinding his lanyard,,
returns it to his poucli and joins ins detachment. The gunner,
having observed the effect of the shot, returns to liis post.

As soon as the piece is discharged, unless otherwise directed,
the cannoneers resume their posts by command of the chief-of-
detachment. or in his absence the gunner : 1. Cannoneers to your-
posts., 2. Right., 3. FACE, 4. MARCH. Executed as explained in
par. 108.

To load witliout the numbers^ and to fire,

303. Executed as prescribed in par. 245.

To load and fire continuously, and to cease firing.

304. Executed as explained in pars. 246 and 247.

When the piece is loaded, and it is not desired to fire it, the
charge is withdrawn as explained in par. 289.

To secure the piece.

305. Executed as explained in par. 286, adding:

The gunner hangs the pouches on the ratchet-post, Nos. 1 ancR

126 15-INCH GUN — FRONT PINTLE — SERVICE.

.2 replace the plugs in the front ends of the air-cylinders, and
JN'os. 5 and 6 detach the ropes from the handspikes.

Service of a 15-tnch G-un mounted on a front-
pintle CARRIAGE.

Description of piece.

306. This piece is identical with the same gun mounted on
a centre-pintle carriage. {Par. 293.)

The top-carriage is the same in both cases ; the chassis alone
■differs.

Weight of front-pintle chassis, including geared traverse-
wheels, 17,000 pounds.

There are two kinds of geared traverse-wheels, differing, how-
ever, only in height and weight. The axis of the trunnions of
the gun mounted on the highest is 8 feet 5.25 inches above the
pintle-block, and 10 feet 11.25 inches above the terre-plein. Upon
the other carriage it is 7 feet 2,25 inches above the pintle-block,
and 9 feet 5.25 inches above the terre-plein.

The piece admits of 25 degrees elevation and 6 degrees de-
pression.

The platform is a permanent part of the work.

The ranges are as given in par. 293.

The same number of men are required as for the gun mounted
on a centre-pintle carriage. The implements and equipments
are likewise the same.

Service of the piece.

307. Executed as for the centre-pintle carriage {pars. 295
to 305), except as follows :

1st. After what is prescribed under the head ram has been
completed, and before the piece is run into battery, the gunner
commands : 1. Chassis in-gear, 2. Heave. At the first com-
mand, N'os. 3 and 4 embar with the handspikes in the sockets
of the chassis eccentrics, and at the second command, assisted
by I^os. 1, 2, 7, and 8, throw the wheels in gear.

2d. At the command aim^ the direction is given (under the
direction of the gunner) by Nos. 7, 8, 9, and 10, who man the
•cninks of the geared traverse-wheels. At the command Chassis
OUT-OF-GEAR, Heave, the chassis is thrown out of gear by Xos.
1, 2, 3, 4, 7, and 8, J^os. 3 and 4 embarring with the handspikes.

The piece is then run into battery as explained in par. 300 ;

15-INCH GUN — FRONT PINTLE — SERVICE. 127

after which the elevation is g,iven as explained in same para-
graph.

JSfote. — Tlie piece can be fired with safetj" when the chassis is
in gear. The omission of this part of the exercise saves mnch
time and labor.

Remarks.

308. The foregoing instructions, for both the front and the
centre pintle carriages, are for those of the most recent model.
There are, however, in service, various patterns, — steps in im-
provement,— the chief difference between them being in the
arrangement of the means for running the piece from and into
battery. Only slight modifications in the foregoing instructions
are necessary to adapt them to any of the patterns, and these
will readily suggest themselves to the instructor.

The front axle of the top-carriage is not eccentric ; the rear
one is. The front part of the sole of each shoe is cut away to a
point a few inches in rear of the front axle, and to a depth ot
.•ibout half an inch. When the rear wheels are out of gear, the
front wheels do not touch the chassis rails ; but when the rear
wheels are thrown into gear, the rear part of the carriage is
slightly raised, and the front part of the carriage is, in conse-
quence of the soles being cut away, lowered; the front wheels
then touch the chassis rails and support the weight of the front
part of the carriage, and the whole moves with rolling, friction
upon the front and rear truck-wheels. The wheels are out of
gear when the gun is fired ; the recoil is then on sliding fric-
tion.

The front axle is furnished, at each end, with a brass sleeve,
to which the counterpoise handspike is firmly attached. A pawl
is attached to the handspike, and engages into ratchets in the
truck-wheels. Bearing down upon the handspikes forces the
wheels to turn, and communicates motion to the carriage.

The handspike pawls are engaged in the ratchet of the truck-
wheels onl}^ when it is desired to give motion to the carriage ;
at all other times they must be kept clear of the ratchets. Tliis
is accomplished by a spring catch attached to each one, and ma-
nipulated by ]N"os. 3 and 4 on their respective sides. To prevent
the rear truck-wheels of the carriage from working out of gear
while the gun is being run from battery, or jumping in gear
when the gun is fired, pawls are provided for locking the rear
axle. The elevation is given by means of the elevating arc.

With a well-instructed detachment, the 15-inch gun can be
fired twelve times in an hour, allowing time for deliberate point-
ing.

128

FLANK-CASEMATE HOWITZER — SERVICE.

The carriage and chassis for the front and centre pintle have
the same dimensions, viz.:

Length of chassis 19 feet 7 inches.

Widtli of chassis 5 feet 2 inches.

Depth of chassis rail 1 foot 8 inches.

Length of carriage.. 8 feet 8 inches.

Inclination of chassis rails 3 degrees.

Service of a 24-pounder Howitzer mounted on a
flank-casemate carriage.

{Fig, 2, Plate 8.)

Description of Piece.

309. Howitzer, cast-iron ; smooth-bore ; chambered ; muz-
zle-loader.

Designation.

Calibre

Weight

Preponderance

Length of piece

Length of bore (in calibres)

Length of chamber

Diameter of chamber

Windage

Charge (cannon powder)

Shell (empty)

Weight of canister

Carriage (top and chassis), wooden ; without re-
coil checks

No.

9.15

Lbs.

1475
70

2
16
20.5

Inch.

4.75
4.62
0.14

Kanoes in yards.

Case

Elevation.

Shell.

Shot.

Time.

Chakgb 2 IiBS.

Oo 0'

295

Canister is used for sweeping

1° C

516

the ditch in front of the cur-

20 0'

600

tain ; and for this the piece

3° 30'

......

880

should be depressed 1 to 2

5° 0'

1322

degrees.

5° 30'

1050

The piece admits of 7 degrees elevation and 9 degrees depres-
sion. The platform is a permanent part of the work.

FLANK-CASEMATE HOWITZER — SERVICE. 129

To serve the piece.

Four men are necessary : one chief-of-detachment, one gunner,
and two cannoneers.

The implements and equipments are arranged as follows :

Roller handspike (iron)... } ^^iXi'^To't'" "" """'" '''''"' "^

}

Leaning against the scarp wall, be-

Sponge and rammer [■ hind No. 1; the rammer-head

upon the pavement.

} Containing breech sight, chalk and
chalk-line, and priming-wire ; sus-
pended from knob of cascable.

Cartridge-pouch Suspended from knob of cascable.

} Containing primers and two lan-
yards; suspended from knob of
cascable.

Sponge-bucket Behind and near N'o. 1.

Vent-cover Covering the vent.

Tompion In the muzzle.

} Containing cartridges; at the safest
and most convenient place near
the piece.

When several pieces are served together, there will be one
worm, one ZacZZe, one hammer-wrench^ two vent-punches^ two
vent-gimlets^ and one gunner''s pincers to each battery of not
exceeding six pieces. These will be kept in the filling-room of
the service magazine.

The rounds of canister are arranged against the scarp wall,
behind No. 2. The shells are at the filling-room of service mag-
azine, or other safe position, and are brought as required to the
place prescribed for the budge-barrel. They are strapped to
sabots. The fuse-plug is of wood.

To cause the equipments to he distributed,

310. The instructor commands :

1. Take equipments.

The gunner equips himself with his own pouch ; gives the
primer-pouch to No. 1 and the cartridge-pouch to No. 2 ; takes
ofi" the vent-cover, and places it against the scarp wall beside
the canister; applies his level to ascertain the highest point at
the breech and muzzle, and, with the assistance of No. 2, snaps

130 FLANK-CASEMATE HOWITZER — SERVICE.

the clialk-line to mark the line of metal; clears the vent; takes
the roller handspike in the right hand, and resumes his post,
holding the handspike vertically by the right side, its lower end
on the pavement, the arm extended naturally.

!N'o. 1 equips himself with the primer-pouch. ISTo. 2 equips
himself with the cartridge-pouch, which he wears from the left
shoulder to the right side.

The service of the piece is executed hy the following commands
from, the instinictor :

1. From battery.

311. The gunner, embarring in the left mortise, presses the
roller under the rear transom, and, holding down the handspike
with his right hand, seizes the left handle with the left ; Xos. 1
and 2 lay hold of the manoeuvering rings and handles.

All being ready, the gunner commands : Heave, and the car-
riage is run to the rear until the face of the piece is about one
yard from the wall, when, disengaging the roller, he commands
Halt, leaving the handspike in the socket. All resume their
posts.

1. By the numbers^ 2. Load.

312. The gunner places himself at the breech; breaks to
the rear with the right foot; closes the. vent with the second
finger of the right hand, and manages the elevating screw with
the left.

N'o. 2 removes the tompion and places it against the scarp, near
his post.

iSTo. 1 seizes the sponge-staff at its middle, brings it across his
body, plants the left foot opposite the muzzle, close to the
carriage, and breaks off with the right foot ; at the same time
throwing the sponge-staff into the left hand, back down, and
extending both hands towards the ends of the staff, enters the
rammer-head into the embrasure, introduces the sponge into
the muzzle, and drops the left hand by the side. He then forces
the sponge to the bottom of the chamber with three motions, at
the commands TWO— three — FOUR.

N'o. 2 goes for a cartridge and returns to his post. If shells
are used, he brings a shell at the same time.

1. Sponge.

313. [N'o. 1, using both hands, backs up, sponges the cham-
ber carefully, withdraws the sponge, pressing it against the lower
surface of the bore ; turns it over, stepping to his left for this pur-
pose, and rests the rammer-head against the right side of the

FLANK-CASEMATE HOWITZER — SERVICE. 131

■face of the piece, back of the right hand down, that of (he left
up. No. 2 introduces the cartridge. No. 1 sets it home by the
same commands and motions as for sponging.

1. Ram.

314. jN"o. 1, throwing the weight of his body on the staif,
forces the cartridge tightly home and throws out the rammer,
holding it as before, the rammer-head against the right side of
the face of the piece.

No. 2 introduces the canister or shell, and resumes his post.

No. 1 sets the canister or shell home with care ; throws out
the rammer, replaces it, and resumes his post.

The gunner, rising up, pricks, leaving the priming-wire in the
vent, and resumes his post.

1. In battery.

315. All apply themselves to the carriage as prescribed in
par. 311, and ease the piece into battery. As soon as it touches
the hurters, the gunner commands : Halt, and all resume their
posts.

1. Aim.

316. No. 1 makes ready a primer; No. 2 goes to the rear of
the chassis, and takes hold of it to traverse it. The gunner with-
draws the priming-wire ; aims the piece, directing No. 2 to tra-
verse it to the right or left; gives the command Ready, making
a signal with both hands, at which No. 2 resnmes his post ; takes
with him the roller handspike and resumes his post. No. 1 in-
«erts the primer in the vent and steps back obliquely tlu-ee yards
to the rear, and breaks oft' with the left foot to his left and rear.

1. Number one (or the like), 2. Fire.

317. No. 1, turning his face from the piece, pulls the lanyard
and fires it; he then resumes his post.

To load without the numbers,, and to fire.

To load and fire continuously., and to cease firing.

To secure the piece.

Executed as explained for the siege gun, m pars. 245, 246,
^nd 247.

Remarks.

31$. In repelling assaults, double charges of canister are
iised ; the charge of powder remaining the same.

The effective range of canister is not over four hundred yards.

132 8-inch rifle — service.

Service of an 8-incii Eifle (converted).

Description of gun.

{Fig. 2, Plate 3.)

319. This piece is composed, essentially, of two parts: the-
case^ f, which is the 10-inch smooth-bore (described in par. 276>
bored up to a diameter of 13.5 inches, and a lining-tube of coiled
wrought-iron.

The tube consists of two parts, called, respectively, the A and
B tubes. The former extends the entire length of the bore, and
contains the rifling; the latter, or B tube, is shrunk upon the
inner, or A tube, which has its exterior portion cut away for that
purpose. A double tube is thus formed, extending 32.75 inches
from the rear end. The two tubes, united in this manner, have
the same exterior diameter throughout the entire length, and
are made to fit accurately the bore of the cast-iron casing.

The bottom of the tube is closed with a wrought-iron cup-
shaped plug, p, screwed into the A tube. The tube is inserted
into the casing from the muzzle, and is secured from working
out by a muzzle-collar, 5, screwed in at the face of the piece ;
and from turning in the casing by a steel pin, ';^, tapped through
the casing and into the tube.

A shallow and narrow gas-channel is cut spirally around the
exterior of the reduced portion of the A tube, communicating
with star-grooves cut in the end of the barrel, and with the gas-
escape, or indicator^ bored obliquely through the breech of the
casing opposite the vent.

Should the inner tube split, under the action of firing, the fact
w^ould be indicated by the escape of gas through this hole, and
timely warning thus be given of the injury sustained by the gun..

The rifling consists of fifteen lands and grooves, each of equal
width, viz.: 0.8377 inches. Depth of grooves: 0.075 inches-
Twist : uniform, one turn in 40 feet.

There is no chamber proper to the gun. The rifling stops
at a point 10 inches from the bottom of the bore, the diameter
of the unrifled portion being equal to that of the rifled portion
across lands.

The old vent of the case is closed by a wrought-iron screw-
plug, and 2.75 inches nearer the muzzle a new one is bored par-
allel to tlie vertical plane through the axis of the bore, and dis-
tant therefrom 2.5 inches. The axis of the vent enters the bore
at 3.5 inches from the bottom.

Length of bore 117.25 inches.

Weight of piece 16,160 pounds.

Counter-preponderance 630 pounds.

8-INCH RIFLE — SERVICE.

183

The counter-preponderance is corrected b}' an eccentric ring
of bronze attaclied to eacli trunnion.

Weight of projectile (averaj^e) 180 pounds.

Weight of ciiar2:e (hexagonal powder) 35 pounds.

Initial velocity 1.430 feet.

Pressure upon square inch of bore 33,000 pounds.

Penetration against armor at 1000 yards.... 7.42 inches.
Penetration against armor at 1800 yards.... 6.75 inches.

Ranges.

Charge : 35 pounds hexagonal powder.

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134

8-INCH RIFLE — SERVICE.

It has been found that the 10-inch carriage, upon which this^
piece is mounted, is not sufficiently stout to stand many dis-
charges with a charge of 35 pounds.

Charges of 25 pounds will penetrate any wooden ship at or-
dinary ranges, but are of no effect against iron-clads. The car-
riages will stand this charge without serious damage.

Ranges.
Charge : 25 pounds hexagonal powder.

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Length of cartridge : 35 lbs. = 24 inches; 25 lbs. = 18 inches^

8-INCri RIFLE — SERVICE. 135

Note. — The carriages upon which these pieces are mounted
. «"e those altered from the 10-iiich barbette-gnn carriage, and
Cans far are only experimental.

Description of Carriage.

{Plates 13, 14.)
DistinguisMng features.

3I20. Carriages !N'os. 1 and 2 have friction-bars for checking
recoil. !N"os. 3 and 4 have hydraulic cylinders for the same ob-
ject. ^Nos. 3 and 4 have a geared windlass, with cranks and
handles, attached to the rear part of the chassis. Nos. 1 and 2
are without windlass. Xo. 1 is distinguished from No. 2 by the
absence of the ratchet-post, and by having, instead, for elevat-
ing, a circular toothed arc operated by a hand-wheel and pin-
ions upon the left cheek of the carriage. ^N'o. 2 has the ratchet-
post, but no toothed arc.

Carriage No. 3 is distinguished from No. 4 by having a w^eclge-
shaped incline bolted to the top of each rail of the chassis, near
the rear end, and by having a iiand-lever on the outside of each
chassis rail, for the purpose of uncoupling the top-carriage from
the chassis.

Specific features.

Carriages Nos. 1, 2, and 4 have, on the rear part of the top-
carriage, an eccentric axle, with truck-wheels. No. 3 has, in-
stead, two wheels or rollers, each having its own eccentric axle.
In none are the front axles eccentric.

For checking recoil in carriages Nos. 1 and 2, the top-carriage
is supplied with a box-clamp having two friction-plates, which
act upon a broad wrought -iron rail, one- sixteenth of an inch
thicker at its rear than at its front end. This rail is attached to
the chassis in front by a transom which takes the place of the
hurters ; and in I'ear, by a rod and rubber spring which permits
a slight play to prevent buckling. Eubber counter-hurters ai-e
secuieil to each top-rail of the chassis. When the gun is run
from batterj% it is retained in tiiat position b}' means of the
clamp; by relieving the pressure, the gun runs into batter}^, a
sliglit movement of the compressor-bar stopping it when desired.

The piece is run from battery in the same manner as the 10-
inch smooth-bore, except that with carriage No. 1 the position
of the elevating-wheel renders it necessary to insert the left
handspike into the front mortises of tiie truck-wheel.

To check recoil in carriages Nos. 3 and 4, an hydraulic hufVcj-
is securely placed in the front portion of the chassis. It coiisUis

136 8-INCH RIFLE — SERVICE.

of a cast-iron C3'^UiKler 78 inches long, witli an interior diameter
of 8 inches, closed at either end by a cast-iron cap.

^N'ear the rear end of the top of the cjdinder is a liole for the
purpose of tilling it with water, or some non-freezing liquid. A
hole in the front end, closed with a screw-plug, permits the fluid
to be withdrawn.

IS'ine and one-half gallons (precisely) of fluid are required.

A wrought-iron piston-rod passes through the rear cap, and is
secured to the rear of the top-carriage by a wrought-iron cross-
head.

The piston-head, of wrought-iron, 0.25 inches thick, is pierced
near its circumference, on opposite sides of the rod, with tw^o
holes seven-eighths of an inch in diameter. These holes flare
out both ways 0.25 inches, allowing free passage to the fluid from
the i-ear to the front of the piston, permitting the top-carriage
to run back without strain.

Upon the top of the rear end of each rail of the chassis of jS'o.
3, is bolted a wedge or incline, having a rise of 2.5 inches in 64
inches; near the rear end of this, is attached a brass angle-
plate, to which are secured three rubber counter- hurters. A
similar angle-plate with hurters is attached to the front part of
the chassis.

Carriage N"o. 4 is likewise provided with hurters and counter-
hurters of rubber.

The top-carriage of IsTo. 3 is provided with two sets of wheels
or rollers^ those in rear having eccentric axles. In i-ecoiling.
the carriage starts on sliding friction, which becomes rollin;^ fric-
tion when it accomplishes part of tlie rise, the ascent absorbing
a considerable portion of the recoil. To prevent the carriage
running into battery after striking the counter-hurters, couplings
are attached to the bottom transom of the top-carriage and to
the sides of the chassis rails; the top-carriage is released, and
permitted to run into battery, b}-^ means of levers on the outside
of the cliassis rails.

Attached to the rear end of the chassis, in carriages N'os. 3
and 4, is a geared windlass, for the purpose of drawing the gun
from batterj^

In carriages jN'os. 1, 3, and 4 the gun is elevated and depressed
b}'" means of circular toothed arcs, to which motion is transmitted
by simple multiplied gearing and a hand-wheel on the left side
of the carriage. Carriage No. 2 has the ordinary ratchet-post.

The chassis of carriage ISTo. 3 is provided with rollers, resting
on the pintle-plate, instead of the truck-wheels, with eccentric
axle of the ordinary barbette carriage. The rollers are without
eccentric axles.

8-INCH RIFLE — SERVICE. 137

Flooring-boards are dispensed with in cari'iaoes iS'os. 3 and 4.
A step is placed across the rear notches for the accommodation
of the g^nnner when serving vent or sighting.

The carriage admits of 28° 45^ elevation and 12° 50^ depres-
sion ,

Service of 8-inch Eifle.
{Qarriage No. 1.)

3^1. Eight men are necessary: one chief-of-detachment,
one gunner, and six cannoneers.

The implements and equipments are the same, and are ar-
ranged in the same manner, as for the 10-inch smooth-bore {par.
277), omitting the wheel-chocks and elevating-bar, and adding
two small handspikes (iron), which are laid on the steps of the
chassis, one on each side ; one compressor-bar, standing against
the parapet near ]N^o. 1 ; and blocks and fall attached to crane.

The pouches are hanging on the left eccentric socket of top-
carriage.

The powder, primers, and fuses are in the service magazine.

The shells are in the tilling-room of the service magazine, and,
prepared for firing, are brought up to the piece as required.

The solid projectiles are kept piled convenient to the piece.

To distribute the implements and equipments.

3^2. Executed as in par. 278, except that IsTo. 4, instead of
mounting upon the chassis, takes hold of the handles of the
hand-wheel and, by direction of the gunner, adjusts the piece
convenientlj^ for loading, and resumes his post.

The service of the piece is executed by the following com-
mands :

1. From battery.

323. The gunner places himself two paces in rear of the
chassis, and commands: 1. In-gear, 2. Heave. IS'os. 3 and
4, at the first command, insert the small handspike in the ec-
centric sockets of the rear wheels of tlie top-carriage ; IS"©. 4
unkeys the axle, and at the second they throw the wheels in.
geai- ; l^o. 4 keys the axle ; N'os. 3 and 4 replace the handspikes
upon the steps, and, taking the truck handspikes, insert them in
the sockets of the truck-wheels ; N"©. 1, meanwhile, inserts the
compressor-bar in one of the holes of the compressor-screw, and
imclamps the friction-plates, leaving the compressor-bar in the
hole ; jN'os. 3, 4, o, and 6 seize the truck liandspikes with both
hands in the manner prescribed in par. 279, and the piece is

138 8-INCH KIFLE — SERVICE.

moved from battery by the commands and means specified in
the same paragraph, except that ^NTos. 1 and 2 do not follow np
with the chocks, but, instead, No. 1, by alternately tightening
and slacking the compressor-screw, retains the carriage in posi-
tion as it is run back.

When the muzzle of the piece is about one yard from the par-
apet, tlie gunner commands : 1. Halt, 2. Out-of-gear, 3.
Heave. At the first command, ^N'os. 3 and 4 withdraw their hand-
spikes and replace them on the hooks ; at the second, they insert
the small handspikes in the eccentric sockets ; and at the third,
throw the wheels out of gear, leaving the handspikes in the
sockets. All resume their posts.

1. By the numbers^ 2. Load.

3^4. The gunner mounts upon the chassis and closes the vent.

No. 2 takes out the tompion and places it by the parapet near
his post.

No. 1 turns to his left, steps over the sponge and rammer;
faces the pieces ; takes the sponge-staff" in both hands, the back&
down, the right hand three feet from the sponge-head, the left
eighteen inches from it; returns to the piece, raising the staff
over the crest of the parapet ; places the left foot on the rail of
the chassis, the other in the most convenient position on the
parapet, or on a step placed against it for the purpose, and in-
serts the sponge-head into the muzzle ; the staff" in prolonga-
tion of the bore, supported by the right hand, the right arm
extended, the left hand hanging naturally by the side.

No. 2 takes a position on the left of the piece corresponding
to that of No. 1 on the right, and seizes the staff" with the left
hand, back down, near to and outside of the hand of No. 1.

No. 3 faces to his rear, steps over the rammer and, facing
about, seizes the staff" with both hands, as prescribed for No. 1
with the sponge, and stands ready to exchange staves with
No. 1.

No. 4 unkeys the crane, takes the pass^box to the rear for a
cartridge, and, returning, stations himself to the right and rear
of No. 2.

No. 5, taking the shell-hooks, and No. 6 the carrying-bar, go
for the projectile; No. 5 engages the shell-hooks and steadies
them while No. 6 passes the bar through the ring. They then
carry the projectile. No. 5 in f mnt and No. 6 in rear, and place
it under the crane conveniently for hoisting.

No. 6 withdraws the bar and places it on the ground; No. 5
hooks the fall into the ring of the shell-hooks; Nos. 5 and 6,
working upon the fall, hoist the projectile.

8-INCH RIFLE — SERVICE. 139

In the meanwhile, Xos. 1 and 2 insert the sponge in the bore
by the following motions, at the commands two — three— four —
five — six :

Two. They insert the sponge as far as the hand of l^o. 1,
bodies erect, shoulders square.

Three. They slide their hands along the staff and seize it
at arm's-lengtli.

Four. They force down the sponge as prescribed for two.

Five. They repeat what is prescribed for three.

Six. They push the sponge to the bottom of the bore. 'No.
1 replaces the left hand on the stafi", back up, six inches nearer
the muzzle than the right; No. 2 places the right hand, back
up, between the hands of N^o. 1; both then change the other
hand so as to seize the staff, back up.

1. Sponge.

325. ISTos. 1 and 2, pressing the sponge firmly against the
bottom of the bore, turn it three times from right to left and
three times from left to right, replace the hands by the side, and
withdraw the sponge by similar commands, but by motions con-
trary to those for inserting it.

No. 2 quits the staff and, tm*ning to No. 4, receives from him
the cartridge, and introduces it into the bore; he then grasps
the rammer in the manner prescribed for the sponge.

in the meanwhile. No. 1, turning to his left, passes the sponge
above the rammer to No. 3, and, receiving the rammer from No.
3, presents it as prescribed for the sponge, except that, retaining
hold with his left hand, he rests the rammer-head against the
right side of the face of the piece. No. 3, as soon as the sponge
is withdrawn, passes the rammer in front of No. 1 onto the par-
apet; receives the sponge from No. 1, replaces it upon the prop,
and resumes his post.

No. 4, setting down the pass-box, takes out the cartridge and
hands it to No. 2, choke to the front ; replaces the pass-box, and
goes to the assistance of Nos. 5 and 6, who are working upon
the fall hoisting the projectile ; No. 4 steadies it ; Nos. 1 and 2
force the cartridge home by the same commands and motions as
for the sponge.

1. Ram.

326. Nos. 1 and 2 slide their hands along the staff to the
full extent of their arms, and press the cartridge firmly liome;.
No. 2 quits the staff and steps slightly to one side ; No. 1 throws
out the rammer and lays it upon the parapet; No. 4, as soon as
No. 2 steps aside, swings the crane so as to bring the projectile

140 8-INCH RIFLE — SERVICE.

ilirectly ill front of the muzzle ; ]^os. 1 and 2 insert it, base fore-
most, into the bore; N'o. 1 holds it while N'o. 2 disen^a<^es the
shell-hooks, which he hands to N.o. 5, who replaces them and
resumes his post.

JSTos. 4 and 6 overhaul the fall ; I^o. 6 replaces the bar; No. 4
secures the crane and fall, and both resume their posts ; N'os. 1
and 2 force the projectile home by commands and motions simi-
lar to those prescribed for the cartridge, pressing it firml}'' home
at the command Ram; N"o. 2 quits the staff and resumes his
post; 'No. 1 throws out the rammer, replaces it on the prop,
and resumes his post.

The gunner pricks the cartridge, leaving the priming-wire in
the vent, and directs No. 4 to give the piece an elevation of
about five degrees.

1. In battery.

32'?. The gunner commands: 1. iN-aEAR, 2. Heave. At

the first command, N'os. 3 and 4 seize the small handspikes and
No. 1 the compressor-bar; No. 4 unke3^s the axle, and, at the
second command, Nos. 3 and 4 throw the wheels in gear and
withdraw their handspikes ; No. 1, b}'^ slacking up on the com-
pressor-screw, then permits the piece to run gently into battery.
As soon as the carriage is against the hurters, the gunner com-
mands : 1. OUT-OF-GEAR, 2. Heave. Nos. 3 and 4 replace the
handspikes in the sockets, and at the command heave throw the
wheels out of gear; No. 4 keys the axle ; both replace their
handspikes on the steps; No. 1 tightens the compressor by giv-
ing the bar a moderate pull (a pull of about 20 lbs.); withdraws
the bar, returns it to its place against the parapet, and all the
cannoneers resume their posts.

1. Aim.

328. The gunner commands : 1. Chassis in- gear, 2.
Heave. At the first command, Nos. 3 and 4 embar in the
eccentric sockets of the chassis -wheels; at the second com-
mand, assisted by Nos. 1 and 2, they throw the wheels in gear,
and, leaving the handspikes in the sockets, resume their posts.
The gunner withdraws the priming- wire, adjusts the breech
sight, and gives the direction.

In the meanwhile, Nos. 5 and 6 embar in the mortises of the
rear traverse-wheels, and move the trail to the left or right at
the command Left or Right by the gunner. Nos. 1 and 2
assist Nos. 5 and 6.

The proper direction being given, the gunner commands : 1.
Chassis out -op- gear, 2. Heave. At the first command.

8-INCH RIFLE — SERVICE. 141.

Nos. 1 and 2 seize the handspikes; at the second, tliey throw
the wheels oat of gear ^ replace the handspikes upon the hooks,
and resume their posts; Xos. 5 and 6 unbar, replace their hand-
spikes upon the hooks, and resume their posts ; I^o. 3 passes the
hook of the lanyard throus^h the eye of a primer, holds the han-
dle of the lanyard with tlie ri^ht hand, the hook between the
thumb and forefinger, and stands ready to hand it to the run-
ner ; N'o. i seizes the handle of the elevatin.i^-wheel and, by
direction of the gunner, elevates or depresses the piece, turning
the wheel to the rear to elevate, and to the front to depress.
When the piece is correctly aimed, the gunner commands :
Ready, makes a signal with both hands, removes the sight,
and, receiving the primer from ^o. 3 with his right hand, in-
serts it into the vent, dismounts from the chassis, and goes
where he can best observe the effect of the shot; Nos. 1 and 2
break off sideways with the foot farthest from the parapet; N'o.
3 steps back obliquely three yards to the rear, and breaks off to-
his left and rear with the left foot, the left hand hanging natu-
rally by the side, the lanyard stretched ; Xo. 4 resumes his post.

1. Number one (or the like), 2. Fire.

329. IN'o. 3, turning his face from the piece, pulls the lanyard
quickly, but steadily, and fires. Immediately after the discharge,
Kos. 1, 2, and 3 resume the erect position ; ISTo. 3 rewinds the
lanyard and replaces it in the pouch. The gunner, having ob-
served the effect of the shot, returns to his post.

To load without the numbers, and to fire.
As explained in par. 245.

To load and Jire continuously., and to cease Jiring,
As explained in pars. 246 and 247.

To secure the piece.
As explained in par. 249.

To replace equipments.

330* As explained in par. 250, except that the gunner re-
places the pouches on the left eccentric socket of the top-carriage».
instead of on the knob of the cascable.

Service of the 8-inch Rifle.

{Carriage No. 2.)

331. Carriage !N'o. 2 differs from No. I only in having the
ordinary ratchet-post, instead of the tootlied arc and hand-wheel^

142 8-INCH RIFLE — SERVICE.

for elevating purposes. The service of the piece with it differs
from that of ^o. 1 only in the operation of elevating. For this
purpose an elevating-bar is required, and is used as explained in
pars. 278 and 284. (Service of the 10-inch smooth-bore gun.)

Service of the 8-inch Rifle.
{Carriage No. 3.)

332. Eight men are necessary: one chief -of -detachment,
one gunner, and six cannoneers.

Tlie implements and equipments are arranged as follows :

Four truck handspikes.... \ Two on the hooks, and two on the
(iron) j steps of the chassis.

Two small handspikes.... \ On the steps of chassis; one on each
(iron) j side.

One yard behind tlie cannoneers of

Sponge the right ; supported upon a prop ;

Rammer " heads turned from tlie parapet and

inclined slightly from the piece.
Pass-box One yard m rear of 'No. 4.

} Containing friction-primers and lan-
yard ; suspended upon the left ec-
centric socket of the top-carriage.
1 Containing breech sight and prim-
Gunner's Douch I i"g-wire ; suspended upon the left
i^unner s poucn y eccentric socket of the top-car-

J riage.

Vent-cover Covering the vent.

Muzzle-cover On tlie muzzle.

} Containing cartridges; at a safe
and convenient place in rear of
the piece.

Windlass-rope } "^^^^"^ "P^" *^^ ^^^^^^ ^* *^« ^"^^-

Sponge-bucket ^ear sponge.

Shell-hooks Near and in rear of No. 5.

Carrying-bar ISTear and in rear of No. 6.

Blocks and falls.. Attached to the loading crane.

When several pieces are served together, there will be one
quadrant^ one worm^ one ladle, one hammer-wrench., two vent-
punches, one gunner'' s pincers, two lanyards ( extra ), and two

8-INCH RIFLE — SERVICE. 143

vent-gimlets to each battery of not exceeding' six pieces. Tliese
are kept in the filling-room of the service magazine.

The shells are in the filling-room of the service magazine, and
are brought up to the piece, prepared for firing, as they are re-
quired. The powder is kept in the service magazine. The solid
projectiles are kept piled convenient to the piece.

To dish'ibute the equipments,

333. The instructor commands :

1. Take equipments.

The gunner mounts upon the step of the top-carriage ; takes
off the vent cover, hands it to ^NTo. 2 to place against the parapet
in rear of his post; gives the primer-pouch to N'o. 3; equips
liimself with his own pouch ; clears the vent ; directs N'o. 4 to
-adjust the piece conveniently for loading, and resumes his post.
^o. 4 adjusts the piece by means of the liand- wheel.

The service of the piece is executed hy the following commands :

1. From battery.

334. ]N"os. 5 and 6, facing to the front, seize the crank-
handles with both hands (the hand farthest from the chassis at
the end of the handle ; the other about five inches from it), and
unwind the rope; the gunner attaches the hook of the I'ope ^^
the rear of the carriage, commands: 1. In-gear, 2. Hea^v^I^'
and places himself in rear of the chassis. At tiie first command,
Kos. 3 and 4 insert the small liandspikes in the eccentric sockets
of the rear wheels of the top-carriage, and unkey the axles ; at
the second, throw the wheels in gear, key the axles, replace the
handspikes upon the steps, and, facing to the rear, grasp the
crank -handles witli both hands, the hand farthest from the
cliassis between the hands of IsTos. 5 and 6.

The gunner then commands : Heave. l!^os. 3, 4, 5, and G,
turning the crank, run the gun from battery until the couplings
catch ; N'os. 3 and 4 quit the crank-handles ; N^os. 5 and 6 slightly
unwind the rope until the gunner can unhook it. The gunner
then commands : 1. Out-of-gear, 2. Heave. ISTos. 3 and 4 in-
sert the small handspikes in the eccentric sockets and throw the
wheels out of gear, and, leaving the handspikes In the sockets,
all resume their posts.

Load — Sponge— Ram .

335. All executed identically as just explained for carriage
^o. 1.

144 8-INCH RIFLE — SERVICE.

1. In battery.

336. The gunner commands: 1. In-gear, 2. Heave. At
the first command, Nos. 3 and 4 nnkey the axles, and at the
second command throw the wheels in gear, leaving the hand-
spikes in the sockets; at the same time, Nop. 5 and 6 grasp the
coupling-levers with both hands, and at the command Uncouple,
by the gunner, let the piece run into battery.

The gunner then commands: 1. Out-of-Gear, 2. Heave;
at which N"os. 3 and 4 throw the wheels out of gear, rekey tli«
axles, replace their liandspikes on tlie steps, and all the cannon-
eers resume their posts.

1. Aim.

327. The gunner withdraws the priming-wire, adjusts the
breech-sight, and gives the direction.

l!^os. 5 and 6, assisted by I^os. 1 and 2, embarring in the mor-
tises of the rear traverse-wheels, move the trail to the left or
right at the command Left or Eight by the gunner. At the
signal from tlie gunner, ]N"os. 5 and 6 unbar, replace their hand-
spikes on the steps, and resume their posts.

No. 3 prepares the primer ; No. 4, working at the hand- wheel,
elevates the piece; the gunner commands : Ready; Nos. 1, 2,
and 3 break oft", — all as just explained for the same operation
with carriage No. 1.

1. Number one (or the like), 2. Fire. .
Executed as explained for carriage No. 1.

To load without the numbers^ and to fire.
As explained in par. 245.

To load and fire continuously., and to cease firing.
As explained \npars. 246 and 247.

To secure the piece.
As explained in par. 249.

To replace equipments.
As explained in par. 250, except that the gunner replaces
the pouches on the carriage, instead of on the knob of the cas-
cable.

Service of 8-inch Rifle.
{Carriage No. 4.)
338* The implements and equipments for this carriage are

10-INCH SIEGE MORTAR — SERVICE. 145

the same as for carriage No. 3, and are disposed of in the same
manner. The number of men is likewise the same.

1. Fbom battery.

339. !N'os. 5 and 6 apply themselves to the crank-handles ;
the gunner attaches the hook of the rope, and commands : 1.
In-gear, 2. Heave, — all as prescribed for carriage IS'o. 3.

At the first command, Nos. 3 and 4 insert the small hand-
spikes in the eccentric sockets of the rear wheels of the top-
carriage ; No. 4 unkeys the axle. At the second command, ^N'os.
3 and 4 throw the wheels in gear ; N"o. 4 keys the axle ; both
replace their handspikes on the steps of the chassis, and, facing
to the rear, grasp the crank-handles as for carriage No. 3.

The gunner then commands : Heave. N'os. 3, 4, 5, and 6,
turning the cranks, run the gun from battery until the muzzle
is one yard from the epaulment. The gunner commands : 1.
Halt, 2. Out-of-gear.

Nos. 3 and 4 insert the small handspikes as before ; No. 4 un-
keys the axle, and at the second command the wheels are thrown
out of gear ; the handspikes are left in the sockets. Nos. o and
6 then unwind the rope until the gunner can unhook it, and all
resume their posts.

All of the remaining operations are executed as prescribed
for carriage No. 1, except so much as, in No. 1, relates to the
compressor.

Remarks.

340. 1st. Owing to the fact that, in all of the foregoing car-
riages, the steps of the chassis interfere witli the handspikes when
traversing the carriage, each piece should, in addition, be pro-
vided with two pinch-bars; and, for the purpose of holding the
traverse-wheels securely in position when delicate adjustments
in pointing are required, two wheel-chocks (iron) siiould also be
furnished. This rule is general for all pieces having traversing
carriages.

2d. The projectiles, as now supplied, are not furnished with
holes for the shell-hooks. To remedy this defect, a rope strap
Is used, instead of shell-hooks.

Sebvice of a 10-inch Siege Mortar.

{Fig. 1, Plate 9.)

Description op Piece.
841. Mortar, cast-iron ; smooth-bore, without chamber.
10

146

10-INCH SIEGE MORTAR — SERVICE.
Number^ weights^ and dimensions.

Designation.

Calibre

Weight

Preponderance

Length of piece

Length of bore

Windage

Charge (maximum), mortar powder ,

Weight of shell (empty)

Charge to fill the shell (musket powder)

Charge to burst the shell (musket powder)

Charge to blow out fuse (musket powder)

Weight of carriage

Weight of mortar-wagon

Total weight of mortar, carriage, mortar-wagon,

and implements

Horses to transport

No.

Lbs. iKcn.

1900
00

1313

3185

6600

20.5
0.13

The mortar is fired from a wooden platform. {Par. 225.) The
carriage is of wrouojht-iron, and, being without chassis, rests
directly upon the platform.

Ranges.

Charge.

Elevation.

Range, Yaeds.

Time oe' Flight.
Seconds.

Lbs.

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0.5

0.75

1.0

1.25

1.5

1.75

2.0

2.25

2.5

2.75

3.0

3.25

3.5

3.75

4.0

2.5

Degrees.

45
45
45
45
45
45
45
45
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
45

Shell, 102 lbs.

217

582
1056
1366
1740
1943
2188
2235

140

237

545

789

939
1072
1189
1337
1459
1582
1667
1732
1780
1935
2085

Shell, 92 lbs.

193

554-

922
1268
1613
1846

Shell, 102 lbs.

6.92
10.88
15.00
17.2
19.2
22.33
22.00
24.00

7.16

9.5
15.0
19.0
19.0
20.0
20.4
21.6
23.5
24.4
25.4
2G.5
27.2
28.0
29.0

SheU,921b8.

6.33
10.75
14.9
16.7
18.0
not taken.

,,,,,„„

( ShVli,* w"b».

1 1530

C ShVu"oo*lb».

I 19.5

10-INCH SIEGE MORTAR — SERVICE.

147

Maximum pressure with charge of four pounds : 27,000 pounds
iper square inch.

To serve the piece.

342. Six men are necessary : one chief-of-detachment, one
rguniier, and four cannoneers.

The implements and equipments are arranged as follows :

^ Two on each side, lying on the ma-

rr T .^ r J3\ nceuveriug bolts : tlie small ends

Handspikes (wood) V ^^ ^^^ f^^j. ^^J ^^^^^ ^^^.j^ ^^^

J front of the cheeks.
\ In the basket, between the cheeks
j of carriage, in rear.

} Containing the priming-wire, fric-
tion-primers, and lanyard ; in the
basket.
1 Containing the gunner's level, chalk-
' J line, and chalk ; in the basket.

■Oartridge-pouch

Primer-pouch.

■Gunner's pouch

In the basket.

- With the basket.

Wiper

•Quadrant

Plummets (3)..,.

Sliell-hooks ..

'Sleeves(2 pair)

Tompion In the muzzle.

Sponge-bucket ,

Wiper-stake

Maul

Broom

•Elpvatino-.bar ^iron^ \ ^^^'"^ ^^ *^® carriage, over rear

±.ievaung-Dar (uon; | notclies; handle to the left.

Trestles fS") \ ^^^^' ^^^® epaulment, in front of the

To each battery of not more than six pieces there should be
one hammer-wrench^ two vent-punches^ one gunner'^s pincers, two
vent-gimlets^ and two lanyards (extra).

The powder, primers, and fuses are kept in the service mag-
azine, and the shells, wlien filled, in the flUing-room of the
magazine. To prepare the ammunition, there will be required,
at the magazine, the implements specified in par. 275.

The charge of powder is varied to suit the required distance,
and should be carefully weighed. The elevation is usually con-
stant, and 45 degrees.

148 10-INCH SIEGE MORTAR — SERVICE.

The plane of sio^ht is established by plummets : one suspended'
in front and anotlier in rear of the mortar.

A convenient method of suspending the plummets is by means
of trestles, made light and easy to handle. The one in rear of
the mortar should be about six feet high, to permit the gunner
to sight without stooping. The one in front, being on the par-
apet, need not be more than eighteen inches high. They should
have their upper edges scored with fine saw-cuts, close together,
to secure the plummets when adjusted in position.

The plummet-cord should be of fine thread or silk, and if affect-
ed by wind when suspended, the bob should swing in a bucket
of water.

A third trestle and plummet is required temporarily for plac-
ing the first two in position.

To establish the plummets in position, the instructor com-
mands :

1. Place the plummets.
{Fig. 6, Plate 16.)

343. The gunner, assisted by N'o. 2, places a trestle upon
the parapet near the interior crest, and suspends from it a plum-
met in such position that it will be approximately in the line
passing througii the centre of the platform and the object to be
fired at. 'No. 3 brings up another trestle, which' the gimner
causes him to place a few feet in advance of the first, and in line
with it and the object; sighting by the plummet first establish-
ed, he causes the second plummet to be accurately adjusted on
the line to the object; then, going to the front plummet and
sighting back, he causes J^o. 4 to place in position the trestle in
rear of the mortar, and suspend from it the plummet, being
careful to have it in exact line with the two on the parapet. The
front trestle is then removed by No. 3.

The trestle in rear of the mortar should be about three yards
from the platform.

]N'o. 1, meanwhile, taking the maul and wiper-stake, plants the
latter in the ground one yard in rear of his post, and leaves the
maul on the ground near it. All resume their posts.

Eemarks.

Should the fire from the enemy endanger the plummet on the
parapet, a priming-wire may be stuck there in its place to mark
the line.

When, owing to the interposition of an intermediate obstacle,
the object to be fired at cannot be seen from the mortar, a point
must be interpolated on the required line in such position that

10-INCH SIEGE MORTAR — SERVICE. 149

it can be seen from the mortar. This is most readily effected by
nsing Paddock's interpolator, a simple and convenient instru-
ment, consisting of two small mirrors attached to a metallic
frame. One of these, termed the upper mirror, revolves on a
horizontal axis; the other is called the lower mirror, and to it is
attached a small spirit-level, a. {Fig. 4, Plate 15.) Hair-lines
are marked on these mirrors, representing the trace of a plane
normal to the axis of the level at its centre, and also to the axis
of the upper mirror.

To use the instrument, the observer places himself approxi-
mately on the line from the mortar to the object to be fired at.
Keeping the bubble in the centre of the level, he turns the in-
strument so that the mortar will be reflected from the upper
mirror onto the hair-line of tiie lower mirror. He then revolves
the upper mirror, and, catching the reflection of the object, ob-
serves on which side of the hair-line of the lower mirror it falls.
He moves in that direction until both images — that of the mortar
and of the object — fall upon the lower hair-line, the two hair-
lines being coincident. A pin or plummet is placed in prolonga-
tion of this line to mark the required point.

To make the last part of the observation with accuracy, the
instrument should be rested on some convenient object.

When the foregoing instrument is not to be had, a point may
be interpolated by two persons, each using a light slender stake.

They place themselves as near as practicable on the required
line, one facing towards the mortar, where he can see it, and the
other towards the object, where he can see it, and both within
view of each other.

Holding their stakes vertical, they sight and move them alter-
nately, until finally tiiey have them in such position that they
range both upon the mortar and the object. The stakes or, bet-
ter, plummets are then adjusted at these points, and sighting by
them back to the mortar, a plummet is suspended in the usual
manner behind the platform. The plummets thus established
mark the desired plane of sight.

Tills operation is more conveniently performed by using a strip
of board, ten or twelve feet long, in which is set at each end
a priming-wire. The board is placed at the intermediate point
in a position approximately in the plane of sight, and where the
mortar can be seen by sigiiting past both wires back upon it, and
the object can be seen by sighting forward in the same manner.
Two persons, one at each end, by alternately sighting and mov-
ing the board, readily establish the wires in the required line.
A plummet is then suspended, at some convenient point in front
of the mortar^, in line with the two wires on the board. The

150 10-INCH SIEGE MORTAR — SERVICE.

plummet in rear of the mortar is suspended on the same line^
Tiie two phimmets thus established determine the plane of sight.-

To distribute the implements and equipments,

344. The instructor commands :

1. Take equipments.

The gunner goes to the basket ; gives to N"o. 1 the broom, the
sponge-bucket, the wiper, and a pair of sleeves ; to No. 3, the
primer pouch ; to No. 4, the cartridge-pouch ; takes himself the
gunner's pouch and a pair of sleeves, and gives to No. 2 the bas-
ket. The gunner equips himself with his pouch, and, assisted
by No. 4, puts on his sleeves.

No. 1 hangs the wiper upon the stake, places the broom and
sponge-bucket on the ground by the side of it, and, assisted by
No. 3, puts on his sleeves.

No. 2 places the basket one yard in rear of his post, and lays
the shell-hooks on the ground near it.

No. 3 equips himself with the primer-pouch, assists No. 1 in
putting on the sleeves, and clears the vent.

No. 4 equips himself with the cartridge-pouch, which he carries
slung from the left shoulder to the right side, adjusts the piece
to about 45 degrees elevation, and places the elevating-bar on
the ground, one yard in rear of his post and perpendicular to
the platform.

As soon as the gunner has put on his sleeves, he' applies his
level and marks the highest point of metal at the muzzle and
near the vent ; between these points, assisted by No. 4, he snaps
the chalk-line, thus marking the line of metal. The cannoneers
then take their handspikes, and all resume their posts. The
handspikes are held, laid down, and resumed as explained \\\
pars. 235 and 236.

The mortar being from battery^ the instructor commands :

1. In battery.

345. The gunner places himself two yards in rear of the
platform, facing the piece; Nos. 1, 2, 3, and 4, facing towards
the epaulment, embar; Nos. 1 and 2 under the front manoeuver-
ing bolts, and Nos. 3 and 4 under those in rear, engaging the
butts of their handspikes about three inches ; Nos. 1 and 3 hold
the small end of their handspikes in the left hand, Nos. 2 and 4
theirs in their right.

All being ready, the gunner commands : Heave, and repeats
it as often as ma}'^ be necessary. As soon as the piece is on the^
middle of the platform, he commands : Halt. All unbar, anc£
resume their posts.

10-INCH SIEGE MORTAR — SERVICE. 161

The mortar is moved to the rear by the command :

1. From battery.
Executed by inverse means.

1. Bi/ the numbers, 2. Load.

346. The gunner places himself one yard in front of and
facing the muzzle.

No. 2 takes out the tompion, and places it by the epaulment
in rear of his post.

N^os. 1, 3, and 4 lay down their handspikes.

No. 1, turning to his right, takes the wiper with his right hand,
turns to his left, and, placing himself in front of the piece, wipes
out the bore, sweeps, if necessary, the platform, and resumes his
post.

No. 3, as soon as the piece is wiped, clears the vent with the
priming-wire, and resumes his post and handspike.

Nos. 2 and 4 go for the cartridge and shell.

No. 2 takes with him liis handspike and the shell-hooks, and
wliile No. 4 is getting the cartridge inserts the shell-hooks into
the ears of the shell, and passes the handspike through the ring.
In carrying the shell, they hold the handspike in their right
hands. No. 4 in advance and at the small end.

Nos. 2 and 4, passing by the left side of the piece and between
the muzzle and the gunner, rest the shell on the platform against
the front transom of the carriage.

The gunner receives the cartridge from No. 4, and, stepping
up to the piece, introduces it into the bore, and carefully pours
out the powder, which he distributes evenly over the bottom of
the bore ; he returns the cartridge-bag to No. 4, who places it
in the cartridge-pouch.

Nos. 2 and 4 lift the shell into the muzzle; the gunner steps
forward, and, taking hold of the sliell-hooks, assists in lowering
it gentl}'' into its place. No. 2 then withdraws his handspike
from the ring, and Nos. 2 and 4 resume their posts. The gunner
adjusts the shell so that the fuse is in the axis of the piece, dis-
engages the shell-hooks, which he throws to their place behind
No. 2, and resumes his post.

1. Aim.

341'. The gunner places himself behind the rear plummet to
give the direction, and commands : Mortar right ; Mor-
tar left; Muzzle right; Muzzle left; Trail right;
Trail left, as may be required.

152 10-INCH SIEGE MORTAR — SERVICE.

To throw the mortar to the right.

Ko. 1 embars under the right front manoeuvering bolt, from
the front; !N"o. 2 embars under the left front notch; No. 4 em-
bars under the right rear notch, from the inside ; botli of these
numbers perpendicular to the cheelis of the carriage. Wlien all
are ready, the gunner commands : Heave; Steady. The can-
noneers remain embarred until he gives some other command,
or makes a signal to unbar.

To throw the mortar to the left.

No. 2 embars under the left front manoeuvering bolt, from the
front; No. 1 under the right front notch; No. 3 under the left
rear notch, from the inside.

To throw the muzzle to the right.

No. 1 embars under the right front manoeuvering bolt, from
the front ; No. 2 embars under the left front notch, perpendicu-
larl}'^ to the cheel<.

To throw the muzzle to the left.

No. 2 embars under the left front manoeuvering bolt, from
the front ; No. 1 under the right front notch, perpendicularly to
the clieek.

To throw the trail to the right.

No. 4 embars perpendicularly to the cheek under the right
rear notch, from the inside.

To throw the trail to the left.

No. 3 embars perpendicularly to the cheek under the left rear
notch, from the inside.

In all of these operations the cannoneers face towards the
gunner and observe his signals.

The direction having been given, No. 4 embars with the ele-
vating-bar through the ratchet-post, and raises or depresses the
breech at the command of the gunner. The gunner applies the
quadrant to the face of the piece, giving to No. 4 the command
Raise, or Lower, until the piece is at the required elevation —
usuall}'^ 45 degrees — makes a signal to No. 4, who then unbars,
replaces the elevating-bar on the ground, and resumes his post.
The gunner, giving the command Ready, makes a signal with
both hands, returns the quadrant to the basket, and goes where
he can best observe the flight of the shell.

Nos. 1, 2, and 4, taking tlieir handspikes with them, go four

10-INCH SIEGE MORTAR — SERVICE. 158

yards in rear of the platform and face to the front; No. 4 be-
tween IS'os. 1 and 2, their handspikes held erect by the right side,
the right arm extended naturally.

ISTo. 3, while the elevation is being given, pricks the vent,
makes ready a primer, inserts it in the vent, moves three j^ards
obliquelj'^ to his left and rear, holds the lanyard with the right
hand, the cord slightly stretched, back of the hand up, and
breaks to the left and rear a fnll pace with the left foot, the left
hand hanging naturally by the side.

The lanyard, to keep the primer from pulling out of the vent,
should be passed under the pipe of the carriage.

1. Number one (or the like), 2. Fire.

348. N'o. 3, turning his face from the piece, pulls the lanyard
quickly, but steadil3^ and fires.

On the discharge of the piece, all except the gunner return,
without command, to their posts. As soon as the shell strikes,
the gunner returns to his post.

Previous to firing the piece, any mortar near the one to be
fired, if loaded or partly loaded, should have the muzzle closed
with the tompion, or with a cloth laid over the face. This rule is
general.

349. When exercising for instruction only, the instructor
continues it by causing the piece to be moved toward the rear of
the platform by the command From battery. He then com-
mands :

1. Unload.

350. The gunner, receiving the shell-hooks from N'o. 2, at-
taches them to the shell, l^o. 2 passes his handspike through
the ring of the hooks and, assisted by jNTo. 4, raises the shell from
the bore of the piece and carries it to its former place ; all in the
inverse order in which it was brought up. The gunner and N"os,
3 and 4 resume their posts.

351. The instructor continues the series of exercises, begin-
ning witlj in battery.

In changing posts, No. 2 passes by the front of the piece. This
rule is general for all mortars.

To load without the numbers^ and to Jire,

To load and jire continuously,

352. Executed as in pars. 245 and 246,

To cease firing.
Executed as in par. 247.

154 10-INCH SIEGE MORTAR — SERVICE.

To secure piece and replace equipments.

353. The instructor causes the piece to be placed on the
centre of the platform, and commands:

1. EEP1.ACE EQUIPMENTS.

All replace their handspikes on the manoeuvering bolts ; !N'o.
2 puts in the tompion and replaces the basket between the
cheeks, in rear; N'o. 1 and the gunner take off their sleeves;
the gunner receives the equipments from the cannoneers and
replaces them in the basket ; Nos. 3 and 4 replace the trestles
and plummets.

Remarks.

354. The time of flight, in seconds, for siege-mortar shells,
at an elevation of 45 degrees, with ordinary charges, is approxi-
mately equal to one-fourth the square root of the range in feet.

The range in feet is approximately equal to sixteen times the
square of the time of flight. The experimental weight of charge
and length of fuse required may be obtained from these rules.

The Boulongd telemeter is used in determining the distance at
which a shell bursts ; or this distance imiy be ascertained by
multiplj'ing tlie number of seconds whicli elapse between see-
ing the flash and hearing the report of the shell by 1100; the
product will be approximately the distance in feet.

Fire and light balls, according to their size, are fired from
mortars of corresponding calibres. With a charge of one twen-
ty-fifth of its weight, the ball is thrown from six hundred to
seven hundred yards. Shells for mortars are fired without
sabots.

Siege mortars can be fired conveniently at the rate of twelve
rounds an hour, but in case of need they may be fired with,
greater rapidity.

To prepare the mortar for transportation, see par. 466.

It is preferable to weigh the powder instead of measuring it,,
as by so doing more uniform results are obtained. For thi&
purpose a pair of brass counter-scales are required at the maga-
zine, in place of the prescribed set of powder-measures. The
quantity of powder which a measure will contain is consider-
ably increased by tapping and settling it ; therefore, to obtain
uniform results when the powder is measured, all the charges
for any series of firings should be either settled or unsettled.

Ever}'' mortar should have the line of metal permanently
marked on it ; in which case all, in the foregoing and following,
that relates to marking the line of metal with chalk will be
omitted.

8-INCII SIEGE MORTAH — SERVICE.

155^

Service of an 8-inch Siege Mortar.
Description op Piece.
3*^Ti • Mortar, cast-iron ; smooth-bore, without chamber.
Number, weights, and dimensions.

Designation.

Calibr'?

Weighi. ~..

Preporc erance

Length nf piece

Length < f bore (calibres)

\Vindag(

Charge (xnaximum), mortar powder

Weight <>f shell (empty)

Charge to fill shell, musket powder

Charge to blow out fuse-plug

Weight of carriage

Weight of carriage, mortar, and implements.

(One m ortar- wagon will carry three mortars,

with th eir carriages.)
Horses rtq^uired for above

No.

Lbs. Inch.

1010
00

2.25

2.5

0.25

900

1965

0.12

Ranges.

Charge.

Elevation.

Range, Yards.

Time of Flight.
Seconds.

Ounces.

Degrees.

Shell, 52 lbs.

Shell, 46 lbs.

SheU,521bs.

Shell, 46 lbs.

399

433

9.50

9.65

717

727

12.45

12.50

955

1029

14.85

1265

1275

16.50

16.80

The piece is tired from a wooden platform. {Par. 225.)
To serve the piece.

Four men are necessary : one chief-of-detachment, one gun-
ner, and two cannoneers.

The implements and equipments — omitting two handspikes
and adding a grummet-wad — are the same as for the 10-inch
siege mortar, and are arranged in the same manner. The
grummel-wad is in the basket.

356. The service of the piece is the same as that prescribedj
for the 10-inch siege mortar, with the following modifications :

156 8-INCH SIEGE MORTAR — SERVICE.

At the command take equipments^ isTo. 1 performs the duties
oi No. 3, and No. 2 those of No. 4, in addition to their own.
No. 2 places the grnmmet-wad on the platform in front of the
carriage, near the transom, and assists No. 1 to put on his
sleeves.

At the command in battery^ Nos. 1 and 2 embar under the
front manoeuvering bolts, facing to the front.

At the command from battery^ No. 1 embars under the right
front manoeuvering bolt, and No. 2 under the left rear bolt,
both facing from the parapet. If the carriage has no rear
manoeuvering bolts. No. 2 embars under the left rear notch,
nearly perpendicular to the cheek.

In loading, No. 1, having wiped out the piece, clears the vent
and, if necessarj^ sweeps the platform.

No. 2, laying down his handspike and taking with him the
shell-hooks, goes for a cartridge and shell, returns by the left of
the piece, passes between the gunner and the muzzle, and, rest-
ing the shell upon the wad, gives the cartridge to the gunner.

The gunner, having poured in the powder, returns the car-
tridge-bag to No. 2, and distributes the powder evenly over the
bottom of the bore ; takes from No. 2 the shell-hooks, raises the
shell and lowers it into its place in the bore. All j-esume their
posts.

At the command Aim, the gunner perfonns the same duties
and gives the same commands as with the 10-inch mortar. (Par,
347.)

For mortar right : No. 1 embars perpendicularly to the cheek
under the right front notch, from within, and No. 2 similarly
under the left rear notch, from without.

Y or mortar left : No. 2 embars perpendicularly to the cheek
under the left front notch, from within, and No. 1 similarly un-
der the right rear notch, from without.

For muzzle right : The same as for the 10-inch mortar. (Par,
347.)

For muzzle left: The same as for the 10-inch mortar. (Par,
347.)

For trail right: No. 2 embars perpendicularly to the cheek
under the right rear notch, from the inside.

For trail left: No. 1 embars perpendicularly to the cheek un-
der the left rear notch, from the inside.

In all of these operations Nos. 1 and 2 face towards the gunner
and observe his signals.

The direction being given, the elevation is given as prescribed
for the 10-inch mortar {par. 347), except that No. 2 performs the
duties therein prescribed for No. 4, and No. 1 those for No. 3.

COEHORN MORTAR — SERVICE.

157

At the signal from the gunner, N"o. 1 prepares to fire as pre-
scribed for No. 3 ill the exercises for the 10-inch mortar. {Par,
347.)

Service of a Coehorn Mortar.

{Fig. 2, Plate 9.)

Description of Piece.

Sd*?. Mortar^ bronze; hore^ smooth, with chamber; calibre^
0.8 inches ; weight ofpiece^ 164 lbs. ; extreme lengthy 16.32 inches ;
maximum charge, 12 oz. '•''mortar powder'''''^ weight of shelly.
empty, 16.8 lbs. ; charge to fill the shell, 1 lb. ; to blow out fusey.
2 oz.

The carriage is simply a block of wood, weighing 132 lbs. ;:.
total weight of piece, equipments, and carriage, 311 lbs.

Ranges.

Charge.

Eleyatiok.

Projectile
weighing

17.5 LBS.

Time of
Flight.

Ounces.

Degrees.

Yards,

Seconds.

2.0

4.0

261

5.0

425

6.0

548

6.5

666

7.0

840

7.5

980

8.0

8.5

i074

9.0

9.5

10.0

1*262

10.5

11.0

1316

12.0

1385

The carriage or block upon which the Coehorn mortar i»
mounted, is provided with two handles on each side, by means-
of which the mortar is readily carried by four men from one part

158 COEHORN MORTAR — SERVICE.

of the work to another. They accompany troops in the field for
use against an enemy covered by intrenchments.

The ground, when firm, is sutBclent for the carriage to rest
upon ; if it is not firm, a platform can readily be extemporized
from such material as may be at hand. The carriage should be
level when the mortar is fired.

To serve the piece.

358. Four men are necessary : one chief-of-detachment, one
gunner, and two cannoneers.

The implements and equipments are carried in a basket, which
is near and in rear of the mortar. They are as follows : Primer-
pouch, containing priming-wire, primers, and lanyard; gunner's
pouch, containing gunner's level and a pair of small pincers ; one
quadrant, one sponge, one plummet, and one mallet. A small
wedge is used as a quoin.

The mortar should have a permanent line of metal marked
upon it ; otherwise this must be marked as for the 10-inch siege
mortar. {Par. 344.)

The shells should be strapped with tin, apd be provided with
•cord handle. They, together with the powder and fuses, are
kept in the service magazine.

The implements for preparing ammunition are the same as
prescribed in par. 275.

The service of the piece is analogous to that for the 10-inch
siege mortar. {Par. 342 and following.)

Remarks.

359. When Coehorn mortars accompany troops in cam-
paign, they may be carried on ordinary field caissons; each cais-
son carrying one mortar, together with sixty rounds of ammuni-
tion.

The mortar is carried on the caisson body, the front chest being
removed for this purpose. The piece is securely lashed with
ropes through the handles. The remaining ammunition chests
are arranged to carry thirty shells each. The powder is in cans,
and a set of measures (from one to six ounces) should be pro-
vided. The shells should be charged and the fuse-plugs driven,
ready for the insertion of the fuses.

A caisson with chests similarly arranged should accompany
each piece.

The mortars may also be carried in ordinary army transporta-
tion-wagons. Each wagon will carr}^ one Coehorn and its
equipments (weighing 311 pounds), and sixteen boxes, each
containing eight shells and weighing 168=2688 pounds — total,
2999 pounds : a fair load, on good roads, for four horses or six
mules.

13-INCH MORTAR — SERVICE.

159

Battery of Six Coehorns.

One captain, three lieutenants, six sergeants, six corporals,
•eight drivers, thirty cannoneers, and thirty-two horses.

When ordinary wagons are used instead of caissons, two one-
Jiorse carts are allowed as tenders in bringing up ammunition, &c.

An army operating in the field should be abundantly supplied
Avith this handy and useful weapon.

Service of a 13-inch Mortar (eccentric axle).
{Fig. 4, Plate 9.)
Description op Piece.
360. Mortar, cast-iron ; smooth-bore, without chamber.

Designation".

"Weight of piece -

Preponderance

Extreme length

Length of bore

Windage

Charge (maximum), mortar powder.

Weight of shell (empty)

Charge to fill shell

Charge to blow out fuse-plug

Weight of carriage

Lbs. Inch.

17,120
00

20
216

0.3

4,140

54.5
35.1
0.13

The mortar is fired from a wooden platform. {Par. 227.) The
carriage is of wrought-iron, and, being without chassis, rests' di-
rectly upon the platform.

An axle, carrying at each extremity a truck-wheel, passes
through the carriage near the front end ; this axle is eccentric,
and when thrown in gear the truck-wheels rest upon the plat-
form ; only the rear part of the shoe then rests on the platform
and moves with sliding friction. Two steps are placed on the
iront part of the carriage for convenience in loading.

Ranges.

Charge.

Lbs,

10
10
15
20
10
15
20

Elevation.

Range.

Degrees.

Yards.

2875

3187

3759

4636

2852

3378

3893

Time of
Flight.

Seconds.

25.8

31.75

32.75

38.75

39.16

160 13-INCH MORTAR — SERVICE.

To serve the piece.

361. Eight men are necessary : one chief-of-detachment, one
gunner, and six cannoneers.
The implements and equipments are arranged as follows :

Truck handspikes (iron) .. \ ^""^ ^H ^^^^ ^]^^^ hanging by hooks
'^ "^ i on the cheeks.

] One on each side, lying on plat-
Manoeuvering handspikes. I form against the cheeks, small
(wood.) r ends to the front and resting on

J the truck-wheels.

Elevating-bar (iron) \ Lying on the carriage, over rear

* ^ '' / notches, handle to the left.

Wheel-chocks (iron) \ ^"1 ^^' ^.^^^ ^'^^^' ^^^ ^^® »Pi^^^ step

^ ' J of carriage.

}0n prop, one yard in rear of No. 1 ;
sponge - head towards the epaul-
ment.

Pass-box One yard behind N"o. 4.

Quadrant 1

Plummet's 7th reeV I ^'^ basket, between the cheeks of

Sleeves (two paiio"*. Z''Z \ ^^^ carriage, in rear.

Shell-hooks J

Tompion In the muzzle.

} Containing the priming-wire, fric-
tion-primers, and lanyard ; in bas-
ket.

Gunner's pouch \ Containing gunner's level, chalk

^ J and chalk-lme ; in basket.

Sponge-bucket ^

Broom I With basket.

Carrying-bar (iron) J

Trestles (three) Kear epaulment, in front of piece.

To each battery not exceeding six pieces there will be one
hammer-wrench^ two vent -punches, one gunner'' s pincers^ two
lanyards (extra), and two vent-gimlets. These are kept in the
filling-room of the service magazine.

The powder, primers, and fuses are kept in the service maga-
zine, and the shells in the filling-room of the magazine.

The implements for preparing the ammunition are those speci-
fied in par. 275.

13-INCH MORTAR — SERVICE. 161

To establish the plummets in the plane of sight, the instructor
commands : Place the plummets. Executed as for the 10-
inch siege mortar. {Par. 343.)

To distribute the implements and equipments,

362. The instructor commands :

1. Take equipments.

The gunner goes to the basket ; gives to N^o. 1 the broom, the
fiponge-bucket, and a pair of sleeves ; to IS'o. 3, the primer-pouch,
and to ]S"o. 2 the carrying-bar and basket. N^o. 1 places the
broom and bucket on the ground in his rear, and, assisted by
l^o. 3, puts on a pair of sleeves.

The gunner equips himself with his pouch and, assisted by
N"o. 4, puts on a pair of sleeves ; then, applying his level, ascer-
tains and marks the highest points of metal at the muzzle and
near the vent. Between these points, assisted by No. 4, he
snaps the chalk-line, thus marking the line of metal ; he then
resumes his post.

JSTo. 2 places the basket one yard behind him, and lays the
carrying-bar and shell-hooks on the ground near it; No. 3
equips himself with the primer-poucli and clears the vent ; No.
4 places the elevating-bar behind him and perpendicular to the
carriage ; Nos. 5 and 6 place each a manceuvering handspike on
the ground perpendicular to the carriage, the small end resting
on the edge of the platform and on the side of them next the
epaulment.

The truck handspikes, when not in use, remain on the hooks.

The mortar being from battery.

363. The instructor commands :

1. In battery.

The gunner places himself two yards in rear of the platform,
facing to the i)iece, and commands : In-gear. Nos. 3 and 4
take the truck handspikes from the hooks and embar in the
eccentric sockets ; Nos. 5 and 6 seize the handspikes above the
hands of Nos. 3 and 4. The gunner commands : Heave and,
as soon as the wheels are in gear, Embar, when the handspikes
are placed in the most convenient rear mortises of the truck-
wheels. The mortar is moved to the front as fai- as required by
the alternate commands heave 'AxiOi embar ivom. the gunner; he
then commands : Halt and Out-of-gear, and the handspikes
are again inserted in the eccentric sockets. The gimner com-
11

162 13-INCH MORTAR; — SERVICE.

mands : Heave, the wheels are thrown oat of ^ear, and the
handspikes returned to their hooks. Nos. 3, 4, 5, and 6 then re-
sume their posts.

1. From battery.

Executed as above, except that the truck handspikes are in-
serted in the most convenient front mortises of the truck-wheels
at the command embar.

1. By the numbers^ 2. LoAD.

364. 1^0. 2 takes out the tompion and places it by the epaul-
ment in rear of his post. The gunner places himself one yard
in front of the piece, facing the muzzle.

'No. 1, facing to his right, takes the sponge-staff in his right
hand, mounts upon the step, and passes the sponge to the bottom
of the bore ; sponges with both hands, withdraws the sponge,
replaces it on the prop, and resumes his post ; No. 3 clears the
vent; No. 4, taking the pass-box, goes for a cartridge ; Nos. 2,
3, 5, and 6 go for the shell ; No. 2 takes with him the carrying-
bar and shell-hooks, engages the shell-hooks in the ears of the
shell, and passes the carrying-bar through the ring.

In carrying the shell, ISTos. 3 and 5 are in advance, and IN'os. 2
and 6 in rear ; N^os. 2 and 3 are at the ends of the bar, using
their right hands ; N"os. 5 and 6 use their left hands. The shell
is brought up by the left side of the piece, and those carrying it,
passing between the gunner and the muzzle, rest it on the step ;
No. 4 hands the cartridge to the gunner, who pours the powder
into the piece, and, using the spatula, distributes it evenly over
the bottom of the bore ; he then returns the cartridge-bag to
No. 4, who, putting it in the pass-box, resumes his post.

The shell is raised b.y the numbers at the carrying-bar, and
lowered into the bore until the bar rests against the face of the
piece. The gunner seizes the shell-hooks, and, after No. 2 with-
draws the bar, lowers the shell into its place, adjusting it so
that the fuse will be in the axis of the piece ; disengages the
shell-hooks, which he throws behind No. 2, and then resumes
his post. No. 2 replaces the carrying-bar on the ground, and
resumes his post.

When necessary, the platform will be swept by No. 1.

1. Aim.

365. The gunner places himself behind the rear plummet to
give the direction, and commands : In-gear — Heave— Em-
bar. All executed as prescribed in par. 363.

The gxinner then, sighting by the plummets, gives the direc-

13-INCH MORTAR — SERVICE. 16

■tion, commanding : Muzzle right; Muzzle left; Mortar
right; Mortar left, according as desired.

For muzzle right : ]N'os. 3 and 5 heave to the rear, and Nos. 4
and 6 to the front, at the command Heave from the gunner,
wlio repeats the alternate commands heave and embar as often
as nmy be necessary.

For muzzle left : Same as above, except that Nos. 3 and 5 heave
to the front and N'os. 4 and 6 to the rear.

Mortar right (or left) is executed by giving the muzzle the
proper direction and running the mortar in battery, or by giv-
ing the muzzle the opposite direction and running the mortar
from battery. In either case the manoeuvre is completed by
throwing the muzzle in the proper direction on its platform by
the commands alread}'' given.

The direction having been given, the gunner commands :
Halt, and the eccentrics are tin-own out of gear as described in
par. 363. To prevent the carriage from moving out of line when
the eccentrics are thrown out of geai", the wheels should be firmlj'^
chocked in front. This is done by Nos. 1 and 2 at the command
halt.

If necessary to rectify the direction of the piece after the eccen-
trics are out of gear, the gunner causes ^N'os. 5 and 6, assisted by
all the other cannoneers, to embar under the rear notclies with
the manoeuvering handspikes and move the trail to the right or
left. No. 3 pricks the vent and then prepares the lanyard and
primer ; !N'o. 4 embars with the elevating-bar through the ratchet-
post, and, assisted by IsTo. 5, raises or depresses the breech at the
command of the gunner. The gunner applies the quadrant to
tlie face of the piece, giving the commands to No. 4, Raise or
Lower, until the piece is at the required elevation, usually
forty-five degrees, makes a signal to No. 4, who then unbars,
places the elevating-bar in its place on the ground, and resumes
his post. The gunner commands : Ready, returns the quad-
rant to tlie basket, receives the primer from No. 3, and, passing
the lanyard under the pipe, inserts the primer in the vent, and
goes where he can best observe the shot.

The cannoneers, except No. 3, go at the command ready to
the rear of the platform and form detachment as in detachment
rear., leaving No. 4 uncovered; No. 3, holding the handle of the
lanyard in his right hand, back of the hand up, moves tliree
yards obliquely to his left and rear, and breaks oft* to his left and
rear a full pace with his left foot, his left hand hanging naturally
■by his side.

1. Number one (or the like), 2. Fire.
366. No. 3, turning his face from the piece, pulls the Ian-

164: 13-INCH MORTAR — SERVICE.

yard quickly, but steadilj^ and fires. On the discharge of the-
piece, all except the gunner return — without command — to their
posts; as soon as the shell strikes, the gunner returns to his
post.

When exercising for instruction only, the instructor continues
it by causing the piece to be moved toward the rear of the plat-
form by the command From battery. He then commands :

1. Unload.

36*7. The gunner, receiving the shell-hooks from No. 2,
mounts upon the step of the carriage and attaches them to the
shell ; N'o. 2 puts the carrying-bar through the ring of the hooks,
and, assisted by Nos. 3, 5, and 6, raises the shell from the bore
of the piece and carries it to its former place.

In doing this, the cannoneers apply themselves as in bringing
up tlie shell, but move in the reverse order. All then resume
their posts.

The instructor continues the series of commands, beginning
with In battery.

In changing posts, l^o. 2 passes by the front of the piece.

To load without the numbers^ and to Jire.

To load and jire continuously^ and to cease firing.

Executed as in jpars, 246 and 247.

To secure piece and replace equipments.

Tlie instructor causes the piece to be placed on the centre of
the platform, and commands :

E'eplace equipments.

368. Nos. 5 and 6 replace the handspikes on the truck-wheels ;,
N"©. 2 puts in the tompion and replaces the basket between the
cheeks, in rear; N"o. 4 assists the gunner to take off' his sleeves;
No. 3, in like manner, assists No. 1 ; the gunner receives the
equipments f i-om the cannoneers and replaces them in the basket ;
Nos. 3 and 4 replace the trestles and plummets.

Remarks.

If, in securing the mortar, the muzzle has been so far depressed
that the elevating-bar cannot be engaged in the ratcliets, a trace
chain may be doubled over the ratciict and the bar engaged in
tlie bigiit of the chain ; or the elevating-bar may be placed in the
ratchets perpendicular to the axis of the piece, and a wooden
handspike engaged over the bar and under the nuts or T-plate&
of the clieeks, and the mortar thus elevated.

10-INCH SEA-COAST MORTAR — SERVICE.

165

A bar known as Fiper^s loading bar is a far more conven-
ient implement than the shell-hooks for carrying and loading
the shell. It is simply a bar of round iron about two feet long,
fashioned into a ring at one end for a handle, and having a screw
•cut on the other end, which screws into a shallow hole tapped in
the shell at a short distance from the fuse-hole. When the shell
is lowered into the bore and adjusted, the bar is unscrewed and
removed.

To insure the ignition of the fuse of mortar shells, the end of
the fuse-plug and the shell around it should be smeared with
treacle, varnish, mucilage, or any other sticky substance, and
after the shell is in the bore a little fine-grain powder thrown
on it.

In rainy weather, great care must be observed to keep the
•charge dry during the operation of loading. This may be ef-
fected by covering the piece with a paulin, the front part of
which can be raised while the loading is going on.

Service of a 10-inch Sea -coast Mortar (eccentric

axle).

Description of Piece.
369. Mortar, cast-iron; smooth-bore, without chamber.

Designatio:n^.

Calibre

Weight

Preponderance

Lengtli of piece

Length of bore

VS^indage

Charge (maximum), mortar powder

Charge to fill shell

Charge to burst shell

Charge to blow out fuse

Weight of carriage

Lbs.

7300
00

12
5
2

0.5
2924

Inch.

47.05
32.5
0.13

The carriage is of wrought-iron, and is pi-ovided with an eccen-
tric axle and truck-wheels similar to the carriage for the 13-inch
mortar. {Par. 360.) The mortar is fired from a wooden plat-
form. (Par. 228.)

With heavy charges, the shell used in the 10-inch gun may be
used for this mortar. The 10-inch siege-mortar shell may be
♦used with moderate charges.

166

10-INCH SEA-COAST MORTAR — SERVICE.

Ranges.

With 10-iiich siege-raortar shells, filled with sand (weight 96.5^
pounds).

Ohabgb.

Elevation.

Range.

TnVTR OF

Flight.

libs. oz.

Degrees.

Yards.

Seconds.

2720

25.20

5 8

2983

26.33

3005

26.50

6 8

3254

26.75

3325

27.50

With 10-inch gun shells, filled with sand (weight 104 pounds).

Charge.

Elevation.

Range.

Time op

Flioht.

libs.

oz.

Degrees.

Yards.

Seconds.

3471

28.10

3638

29.60

3648

29.75

3677

30.75

4096

30.40

4301

31.25

4345

32.00

4458

33.50

4465

34.00

4536

not taken.

To serve the piece.

Six men are necessary: one chief-of-detachment, one gunner,,
and four cannoneers.

The implements and equipments are the same as for the 13-
inch mortar {par. 301), omitting the sponge and adding a wiper,
a wiper-stake, and a maul, and are distributed as in the service
of the 10-inch siege mortar (par. 344), except that when there
are no hooks on the cheeks for the truck handspikes, these ar(^
laid on the platform in front of ^N'os. 1 and 2, parallel to the
cheeks, small ends to the front, and are returned to this posi—
tion whenever not actually in use.

13-INCII MORTAR — CENTRE PINTLE — SERVICE. 167

The mortar is raanoeuvered on its platform as prescribed for
the 13-inch mortar, and by the same commands. {Par. 363.)

The loading and firing are executed as prescribed for the serv-
ice of the lO-inch siege mortar. {Par, 346 et seq.)

Service of a 13-inch Mortar (centre-pintle carriage).

[Fig. 3, Plate 9.)
Description of Piece.

370. This piece differs from the one described in par. 360
only in the method of mounting. Both have the same cari-iage,
but instead of the carriage resting directly on the platform, as
in the first, the carriage for the centre pintle is mounted on a
chassis itself resting on the platform.

The cliassis is attached at its centre to the platform by a pin-
tle, and traverses upon iron circles in the manner usual for this
class of carriages.

In addition to the eccentric axle at the middle of the chassis,
for throwing it in and out of gear, there is another axle, also
eccentric, carrying a traverse-wiieel which works between the
parts of a double transom on the front end of the chassis. This
wheel communicates motion to the chassis.

A crane is attached to the left cheek for hoisting the shell to
the muzzle.

The chassis has an inclination to the rear of three degrees ; it
is of wrought-iron, and weighs 5560 pounds.

The ranges are as given in par. 360.

To serve the piece.

S*?!. Eight men are necessary: one chief-of-detachment,
one gunner, and six cannoneers.
The implements and equipments are arranged as follows :

Truck handspikes (iron)...} ^'XTsis^'''''^' ^'^^' '''' ^^^ hooks of

Wlieel-chocks (iron) One on each side, on the hurters.

Blocks and fall Attached to the crane.

The other implements (omitting the wooden handspikes) are
the same, and are arranged in the same manner as in par. 3C0.

To prepare for pointing the mortar.

3'9'2. In every position of the piece, the plane of fire passes
through and includes the axis of the pintle. The position of
this axis is determined by suspending over the centre of the pin-

168 13-INCH MORTAR — CENTRE PINTLE — SERVICE.

tie a plummet ; this is most readilj'^ done by using a light trestle,
about six feet high, with legs far enough apart to reach across
the chassis, allowing it to be traversed about a foot in either
direction.

The highest point of metal at the muzzle is determined in the
usual manner. This being marked, serves the same purpose
that a front sight does on a gun — the rear sight being the plum-
met over the pintle, or one placed in rear of the platform in the
plane including the highest point of metal and the object.

If the object can be seen from the mortar, establish a plummet
ill rear of the platform, in line with the one over the pintle and
the object. The trestle over the pintle is then removed. The
aiming is accomplished by sighting on the object from the plum-
met in rear, and traversing the chassis until the highest point of
metal falls on this line.

If, as is generally the case, the object is cut off from view by
an epaulment, a point must be interpolated on the line from the
object to the plummet over the pintle. This is accomplished as
explained in par. 343. On the line thus determined, a plummet
is suspended in rear of the platform, as before, and the trestle
over the pintle removed.

The Lorain sight may be used on this mortar.

When Dyer's apparatus is used, the direction is given as ex-
plained in par, 210.

Remark,

Owing to the fact that the top-carriage has some lateral play
on the chassis, it is well to have the line of metal marked in the
usual way, and then, in aiming, bring this line in the plane of
sight.

To distribute the implements and equipments.

373. The instructor commands :

1. Take equipments.

Executed as in par. 362.

To sei^ve the piece.

3*74. The piece will, habitually, be in battery while being
loaded. It is in battery when the soles of the cheeks are against
the hurters.

3'9'5. The instructor commands :

1. IN-BATTERY.

Executed as in par. 363, adding, Nos. 1 and 2 will unchock
the wheels of the top-carriage.

13-INCH MORIAR — CENTRE PINTLE — SERVICE. 1G9

1. From battery.

376. Executed as in par. 363, except that Nos. 1 and 2 fol-
low up the movement and keep the wheel-chocks closely ap-
pHed to the wheels.

1. By the numbers^ 2. Load.

3^7. Executed as laid down in par. 364, with the following-
exceptions : When the shell is brought up it is placed under the
crane, the carrying-bar withdrawn, and the pulley attached to
the shell-hooks by No. 4; Nos. 5 and 6 run up the shell, No. 4
steadying it. When sufficiently raised, it is swung over the
muzzle, and lowered to its place in the bore as explained in par.
264; No. 4 swings back the crane and keys it to the cheek. All
resume their posts.

1. Aim.

378, The gunner places himself in rear of the chassis, and
commands :

1. Chassis in-gear, 2. Heave.

At the first command. No. 1 unlocks the eccentric of the front
wheel; No. 2 embars with his handspike in the eccentric socket
of this wheel, and is assisted b}'^ No. 1 ; Nos. 5 and 6 embar in
the eccentric sockets of the truck-wheels upon the sides of the
chassis. At the second command, the chassis is thrown in gear;
No. 1 locks the eccentric of the front wheel, and No. 2 inserts
his handspike in the uppermost mortise of this wheel, No. 1
still assisting him.

The gunner then, sighting hy the plummet, commands : Muz-
zle RIGHT, or Muzzle left. Nos. 1 and 2, applying them-
selves to the handspike in the front wheel, give the piece the
right direction. If the chassis traverses witli difflcult3% Nos. 1
and 2 embar separatelj% each with a handspike in a mortise on
his own side.

The direction being given, the gunner commands : 1. Chassis
out-of-gear^ 2. Heave.

Executed in a manner similar to that of throwing it into gear.

All the cannoneers then resume tlieir posts.

No. 3 pricks the vent, and then prepares the primer and lan-
yard. The elevation is given as explained in par. 365. The
gunner commands : Ready, receives the primer from No. 3,
inserts it in tiie vent, and goes where he can best observe the
effect of the shot.

The cannoneers go to the rear as explained mpar, 365.

170 GATLING GUN.

1. Number one {ov the like), 2. Fire.

Executed as \npar. 366.

The remaining exercises are executed as explained in pars^
367 and 368.

When Dyer's pointing apparatus is used, the gunner, after the
chassis is thrown in gear, goes to the instrument on the parapet,
sights through it upon the object, notes the degree, returns and
causes the piece to be traversed until the pointer on the chassis
is at the same degree on the arc of the platform.

G-ATLiNG Gun.

{Fig. 1, Plate 17.)

379. The Gatling is a machine gun of small calibre, throw-
ing lead projectiles. It is used for field service, and also as an
auxiliary in the armament of fortifications. For both purposes,
it is mounted on a traveling carriage.

Two calibres have been adopted, viz.: the 1-inch, which, in
addition to solid projectiles, throws also canister ; and the 0.45-
inch, which uses the same cartridge as the regulation rifle-mus-
ket.

The general features of the mechanism are the same for both,,
consisting of a number of breech-loading rifled barrels, grouped
around and revolving about a common axis, with which they
are parallel. The bore of each barrel extends entirely through
it, and the breech is chambered to receive a flange, centre-fire,,
metallic-case cartridge. The barrels are rigidly attached to a
central shaft extending to their rear, and supporting a cylindri-
cal breech -casing, which carries within it all the machinery by
which the barrels are loaded and fired. A crank upon the right
side of this casing is used for operating the machinery. The
barrels are discharged successively as they revolve with the
shaft.

Each revolution of the crank gives one discharge with the
1-inch gun; with the 0.45-inch, three discharges are made by
each revolution. The former is capable of firing 150 shots per
minute ; the latter, 500 shots.

1-INCH GATLING — SERVICE.

171

Service of the 1-inch G-atling.
Description of Piece.

Designatiox.

Extreme length of piece

Length of barrel ^

liCngth of breech-casing

Length of feed-case

Cartridges in each case

Cartridges in each ammunition chest

Total number of rounds for each gua

G-un (weight)

Total weight of gun, implements, carriage and

limber.,

Number of barrels

Number of grooves

Depth of grooves

Twist: one turn in six feet

Preponderance

Number of horses for each piece

Number of horses for each caisson •

No. Lbs. Inch

472

2592

315

1008
3263

"lio

68.15
33.
21.5
14.5

0..01

The piece is mounted on tiie 3-inch field-ojun carriage.
For field service, each piece is accompanied by one caisson.

To serve the piece.

3S0. Ten men are necessary : one chief-of-detachment, one
gunner, and eight cannoneers.

The equipments consist of three cartridge-pouches, which are
hung on the knob of the cascable.

At the command of the instructor : Take equipments, the
gunner steps to the piece and distributes them to Nos. 4, 5, and
7, who carry tliem slung from the left shoulder to the right side.
!N'os. 1 and 2, passing around in front of the axle, assist the gun-
ner in removing the cover, which is folded and placed on the
limber chest. It should never be laid on the ground, as it would
be liable to pick up sand and dirt, injurious to the working of
the parts.

When the piece is unlimbered, the end of the pole, or if with
liorses the heads of the lead horses, are six yards from the small
end of the trail handspike, the pole pointing in the direction of
the piece.

Post of cannoneers, piece unlimbered,

{Fig. 2, Plate 17.)

381. Tlie gunner is on the left of the trail handspike, nearly

172 1-INCH GATLING — SERVICE.

touching; it:, heels on a line witli the end; I^fos. 1 and 2 are ei2:ht-
-een inches outside of tl»e wheels, No. 1 on the rig-ht and jS'o.
2 on the left, in line with the rear part of the wheels; Nos. 3
and 4 arc opposite the trail handles, in line with Nos. 1 and 2,
No. 3 on the rioht. No. 4 on the left ; No. 5 is five yards to the
right of No. 4, in line with Nos. 2 and 4; No. 6 directly hehind
the limber chest, and No. 7 two feet behind the left limber-
wheel. All face toward the piece. No. 8 attends to the supply
of ammunition, and is with the caisson or at tlie ma<yazine.

382. The commands of the instructor are: 1st. Load; 2d.
CoivoiENCE FIRING ; 3d. Cease FIRING ; 4th. Secure piece.
These are repeated by the gunner.

The duties of the gunner are to direct the piece ; observe that
the shots are striking at the proper point ; see that the supply of
ammunition is kept up; throw the oscillating apparatus in and
out of gear ; remove disabled locks ; see that No. 1 is relieved b}'
No. 3 when fatigued by rapid firing; and have general super-
vision of the gun.

The duties of No. 1 are to turn the crank; see that the car-
tridges are feeding properly from the case ; and use the ejecting
rod when necessary.

Tiie duties of No. 2 are to supply the piece with ammunition
by inserting the feed-cases into the hopper, and to see that the
•cartridges are feeding properly.

The duties of No. 3 are to assist the gunner in giving the di-
rection.

The duties of No. 6 are to give out ammunition from the lim-
ber chest to Nos. 5 and 7, who alternate in bringing it up to
No. 2.

To serve the piece.

3S3. The instructor commands: Load.

The gunner, repeating the command, takes hold of the trail
handspike at the end with the right hand and at the centre with
his left ; looks over the top of the piece and gives the general
direction. He then steps to the breech and adjusts the rear
sight to the required distance; sights through the notch of the
rear sight; seizes the handles of the elevating screw and gives
the proper elevation, and, assisted by No. 3 at the trail hand-
spike, gives the exact direction. The piece being pointed, he
stations himself where he can best observe the effect of the shots.

When the shots are not striking properly, the gunner places
himself at the elevating screw as before, and, with the assistance
of No. 3 at the trail handspike, readjusts the pointing.

No. 1 places himself rapidly between the piece and the wheel.

1-INCH GATLtNG SERVICE. 173

in rear of the axle, facing to the front ; breaks to the rear with
the left foot ; frees the crank from its catch, and seizes the
crank handle with his right hand, taking care not to tnrn it nntil
the command commence firing is given. Nos. 1 and 3 exchange
dnries and numbers when so ordered bj'- the gunner.

No. 2 stations himself at the hopper in a position similar and
opposite to that of IN'o. 1, but facing to the right; receives the
full feed-cases, one at a time, from Ko. 5, and introduces them
into the hopper, the hole to the right and projectiles to the front.
He calls case as the last cartridge passes the hole ; receives a full
feed-case with his right hand from N'o. 5, and inserts it in the
hopper as the emptj' case is removed hy N'o. 4, thus keeping a
continuous stream of cartridges fed to the gun. Nos. 2 and 4
exciiange duties and numbers when ordered by the gunner, but
without interrupting tiie tiring.

Xo. 3 goes to the end of the trail handspike ; seizes it with
both hands as soon as the gunner goes to tlie elevating screw,
and prepares to move it to the right or left at a signal from the
gunner. He remains at the end of the trail handspike, and as-
sists the gunner to point the piece.

No. 4 places himself in front of the axle, between the left
wheel and piece, facing to the rear. When No. 2 calls case, he
removes the empty case from the hopper, puts on its cover which
he has received from No. 5, and deposits the emptj' case in his
poucii until called for by No. 5.

No. 5 runs to the ammunition chest; receives in his poucii
four full cases from No. 6 ; takes them to the piece, and places
himself to the right and rear of No. 2, facing to the right. He
then removes tiie cover from a case and iiands it to No. 4; the
case to No. 2. This he continues until his pouch is empty, when
he makes a signal to No. 7 to take his place; gets the empty
feed-cases from No. 4; returns them to the limber; receives full
cases from No. 6, and resumes his post; meanwhile. No. 7 as-
sumes the place and duties of No. 5 beside No. 2. When tlie
piece is limbered up, he returns all the cases to No. 6, who re-
places them in the ammunition ciiest.

Nos. 6 and 8 attend to the supply of ammunition. The empty
feeil-cases are filled at the limber or caisson, care being taken to
place the projectile to the left. To liU a feed-case, rest it on
the left fore-arm, inclining downwards towards the elbow, the
side containing the hole uppermost, tiie open end supported in
the palm of the left hand, the other end in the bend of the
elbow. The first cartridge is introduced (point to tlie left) and
gradually pushed to the bottom of the case by those succeeding.

174 1-INCH GATLING — SERVICE.

It. When not otherwise engaged, the numbers from 5 to 8, in-
delusive, are employed filling cases.

As soon as No. 5 is supplied with full cases, No. 7 gets four
full cases in his pouch and, upon the signal from No. 5, as-
sumes the place and duties of the latter beside No. 2. As
soon as he has passed all of his cases to No. 2, he signals No. 5
to take his place, gets the empty cases from No. 4, returns them
to the limber, and gets full cases in his pouch ready again to
relieve No. 5.

1. Commence firing.

384, This command is repeated by the gunner. No. 1 turns
the cranlc with a moderate uniform motion, avoiding all sudden
movements or lateral wrenching, and allowing ample time for
the cartridges to drop from the feed-case into the carrier. He
watches the hopper to see that the cartridges are feeding prop-
erly.

Should any of the shells not be thrown out after firing, or the
piece become jammed in any manner, he will at once notlf\"
the gunner, who will see that the proper means are taken to
remove the obstruction.

If the gun jams, remove the feed-case at once, open the hop-
per, and reverse the crank until all the cartridges are taken out.
This will be found to save time, unless the cause of the jamming
IS evident and in the immediate vicinity of the hopper.

When it is necessary to use the ejecting rod. No. 1 steps to
the front, unke5"S it, and, under the direction of the gunner,
removes the obstruction by forcing it backwards.

1. Cease firing.

B$5. At this command from the instructor, repeated by the
gunner. No. 1 ceases to turn the crank ; No. 4 removes the case,
^md No. 2 opens the hopper; the gunner directs No. 1 to slowh'
reverse the crank, while No. 2 removes the cartridges, passing
them to No. 4, who restores them to the feed-case, which he
gives to No. 5 to return to the chest ; No. 1 secures the crank
iby the latch, and all resume their posts.

A partiallj^-filled feed-case should not be put back into the
ammunition chest without being filled up, as the cartridges may
become inverted and jam the gun.

If, for any purpose, it is desired to temporarily arrest the fir-
ing, the instructor, or the gunner, commands : Halt. No. 1
stops turning the crank, and all remain at their positions until
the instructor, or the gunner, commands : Commence firing,
or Cease firing.

1-INCH GATLING — SERVICE.

175

1. Secure piece.

386. The gunner steps to the rear of the piece as at the
'Command load^ runs down the elevatin^^ screw, turns down
the front and lowers the rear sight, and, with the assistance of
Nos. 1 and 2, who step to the front for that purpose, places and
fastens the canvas cover upon the piece ; all then resume their
posts.

Service of piece with reduced numbers.

387. When the number of cannoneers is reduced, the respect-
ive duties are performed as indicated by the following table :

Numbers Re-
tained.

DiSTEIBUTION OF DUTIES.

Gunner.

G. 1

2 3 4 5 6 7
3 5 6 7
1
1
1
1

2 4

3 5 6 7

3 5 6

4 2

42
4

5 6
5

G- 1,2

G. 1,2,3

G. 1,2,3,4

G. 1,2,3,4,5

G. 1,2,3,4,5,6..

Nomenclature of the 1-inch Gun.

In view.

Main shaft, around which the
barrels are clustered.

Front plate, which supports
the front of the barrels.

Kear plate, which supports the
rear end of the barrels.

Barrels.

Gun frame.

Trunnions.

Gun face.

Front sight.

Rear sight.

Breech-casing.

Breech-casing screws.

Cascable plate.

Hopper.

Ejector.

Cartridge carrier.

Crank.

Elevating screw.

Elevating-screw box.

Elevating-screw bed.

Elevating-screw handle.

Wiping rod (brass).

Ejecting rod (iron).

Lock.

liOck tube.

Lock hammer.

Lock spring.

Firing-pin,

Extractor.

Lock cylinder.
Rear-guide nut.
Cocking ring.
Cocking-ring clamps.
Spiral cam.

Within the breech-casing.

Diaphragm.
Diaphragm plug.
Gear-wheel.
Pinion.
Rear-cam screw.

176 1-INCH GATLING — SERVICE.

To take the gun apart.

38S. The piece is first dismounted and placed with its casing-
restino; on bloclcs. Mounting and dismounting are best accom-
plislied by means of a gin. In case of necessity, it may be
mounted and dismounted as a field-piece, care being taken to
place blocks of wood to receive the gun frame and to prevent
injuiy to the front sight, or to the barrels.

The operations of taking apart are executed in the following,
order :

1st. Block up the frame and barrels.

2d. Remove the hopper.

3d. Eemove the cascable plate.

4th. Take out the steady-pin ; then turn the crank downwards
and remove the crank shaft in that position.

oth. Remove the rear sight, and take out the large gear-wheel.

6th. Take out the rear plug in the diaphragm, and then gen-
tly revolve the gun until a lock presents itself on a line with the
hole in the diaphragm, through which one lock after another is
taken out.

7th. Take out the breech-casing screws, and remove the cas-
ing by drawing it off" to the rear. Care is taken in this operation
to have the lock cylinder and gun supported, so as to keep
the axis of the main shaft parallel to the top of tlie frame. This
is necessary to prevent the rear end of the gun from dropping
when the casing is removed.

8th. Remove the pin from the large nut on the main shaft in
rear of the locks, and take this nut off" by turning it to the right;
then remove the lock cylinder and carrier from the main shaft.

The spiral cam need not be taken out of the casing in order
to take the gun apart.

To assemble the gun,

389. 1st. Put the main shaft in its place through the plates
which hold the barrels, and then put in their proper places the
carrier, lock cylinder, and large rear nut. The latter should be
screwed up tight and have the taper-pin put through the nut
and shaft.

2d. Place the gun within the frame, and let the front end of
the main shaft rest in the hole designed for it in the front of
the frame. When the gun is in this position, the cocking ring
should be shoved over the lock cylinder and left for the time
loosely around the carrier.

3d. Let the breech of the gun be slightlj'' raised, when the
breech-casing can be shoved over the lock cylinder to its place ;

0.45-INCH GATLING — SERVICE.

177

then screw the casing to the frame, ptitthig, in the meantime,
the cocking ring in its proper place. Revolve the gun to the
right or left so that the places for the locks will come on a line
with the hole in the diaphragm, through which one lock at a
time can be inserted in its proper position ; afterwards the screw
plug should be inserted to close the hole.

4th. Put on the cog-wheels, replace the crank shaft, pinion,
and steady-pin. Put on the rear sight, and screw on the cas-
cable plate and hopper, and the gun is ready to be mounted.
The piece is mounted on a 3-inch gun carriage widened between

the cheeks to receive it.
for twelve travs.

The ammunition chests are arranged

Service of the 0.45-inch Gtatling Gun, mounted on
a cavalry cart.

390.

{Fig, 3, Plate 17.)
Description op Piece.

Dimensions.

Extreme length of piece

Length of barrel

Length of breech-casing

Length of feed-case

Cartridges in each case

Cartridges in each chest

G-un (weight)

Total weight of gun, carriage, and implements

Number of barrels

Number of horses to draw (good roads)

" " " (bad roads)

No. Lbs.

40
960

10
1
2

144
925

Inch.

85.5
18
8.5
20.25

To serve the piece.

391. Five men are necessary : one chief-of-detachment, one
gunner, and three cannoneers.

Witii a greater number of cannoneers a more rapid and con-
tinuous fire can be sustained, (the additional men refilling feed-
cases and bringing up ammunition,) but it is not advisable to
expose more men than are absolutely necessary.

The animal being unhitched, the muzzle is pointed in the
desired direction, by the gunner and Nos. 1 and^ 2, working —
the former at the shafts and the latter two at the wheels; the
shafts and prop are then allowed to rest upon the ground.
12

178 0.45-INCH GATLING — SERVICE.

Posts of cannoneers^ piece unhitched,

393. The gunner is in rear of the piece, covering it, and at
the end of the shaft; N"o. 1 is eighteen inches outside and
opposite the rear part of the right wheel ; iNTo. 2, two feet out-
side and opposite the rear part of the left wheel ; ^o. 3, five
yards in rear of and covering N'o. 1, all facing the piece.

The cover is removed from the piece by the gunner, assisted
in front by U^o. 1, who folds and places it in the tool box, and
resumes his post.

The commands of the instructor are : 1. Load; 2. Commence
firing; 3. Cease firing; 4. Secure piece; and are repeated by
the gunner.

The duties of the gunner and No. 1 are as prescribed for the
l-iucli gun.

The duties of No. 2 are to supply the piece witli ammunition,
by taking the feed-cases from the ammuntion chest and insert-
ing them into the hopper, and to see that the cartridges are
feeding properly.

Service.

393. The instructor commands : Load. The gunner, repeat-
ing the command, steps to the rear of the piece, throws his right
leg over the sliaft, reaches forward, turns up tlie front sight, and
adjusts the rear sight for the required distance. He then gives
the piece the proper elevation by means of the elevating screw,
correcting the direction with the traversing screw; should any
considerable change be required, he loosens both clamp screws
and shifts the bed-plate, being very careful to refasten the clamp
screws. He then resumes his post.

'No. 1, as the gunner resumes his post, springs in by a side
step to his left, close to the shaft, frees the crank from its latch,
and seizes tlie handle with his right hand, being careful not to
turn it until the command commence firing is given.

No. 2, stepping to his right and over the one nearest to liim,
takes his place between the shafts in rear of the left ammunition
chest, opens it, takes a feed-case with his left hand, withdraws
it from the chest and seizes it at the middle with the right hand,
back of the hand up, turns it until the spring shall be down, the
slot to the right, and inserts it into the hopper; he then takes
another feed-case, seizing it as before, and stands ready to re-
move the empty case with his left hand, and insert the full one
into the hopper with his right.

1. Commence firing.

394. The gunner steps to the side from which he can best
observe the effect of the shot.

0.45-INCH GATLING — SERVICE. 179

No, 1 turns the crank with a moderate uniform motion, tak-
ino^ care not to clerano;e the position of the gun by sudden jerks
or lateral wrenching ; should any of tlie shells not be thrown
out after firing, or the piece become jammed in any manner, he
-will at once notify the gunner, who will see that the proper
means are taken to remove the obstruction.

No. 2, as soon as the feed-case is empty, seizes it, and, after
replacing it by a full one, returns the empty case to the chest,
taking care that the spring enters first and is on the under side^
and then proceeds as before.

The ammunition in the left chest being nearly exhausted, No.
2 notifies the gunner, who calls up No. 3, who takes his post in
rear of and opens the right chest, and stands ready to pass the
full cases to N"o. 2, in rear of No. 1. In taking the feed-case
from the chest. No. 3 seizes it first at the end, afterwai-ds just
above the middle with the left hand, and hands it to No. 2, so
that when the latter seizes it, which he does with his right hand
at the middle, the spring shall be down and the slot to his
riglit ; No. 2 passes the empty case with his left hand to No. 3,
who receives it with his right and places it in the chest.

1. Cease firing.

395. No. 1 ceases to turn the crank; No. 2 removes the case
.from the hopper; the gunner steps to the rear of the piece, opens
the hopper, and directs No. 1 to slowlj'- reverse the crank, when
he removes the cartridges which have not been fired, passing
them to No. 2, who restores them to the feed-case and replaces
it in the chest, or hands it to No. 3 if the right chest is being
used ; No. 1 secures the crank by the latch, and all resume their
posts.

1. Secure piece.

396. The gunner steps to the rear of the piece as at the com-
mand load, runs down the elevating screw, turns down the front
and lowers the rear sight, and, with the assistance of No. 1, who
steps to the front for that purpose, places and fastens the canvas
•cover upon the piece ; both then resume their posts.

Precautions to be observed.

397. (a) Never lay the cover upon the ground, as it is liable
to pick up sand and dirt, which may derange the working of the
parts.

(6) A partially-filled feed-case should not be put back into the
annnunition chest without being filled up, as the cartridges may
become inverted and jam the gun.

180

0.45-INCH GATLING — SERVICE.

(c) If the gun jams, remove the feed-case at once, open the
hopper, and reverse the crank until all the cartridges are taken
out. This will be found to save tinie, unless the cause of the jam-
mhig is evident and in the immediate vicinity of the hopper.

(d) See that all the parts are kept well oiled to prevent frio--
tion and scourino^.

39$.

^Nomenclature of the 0.45-inch Gun.

ComponeJits.

Adjustable- screw nut.

Barrels (10).

Breech-casing.

Breech-casing screws (6).

Bushings (10).

Cartridge carrier.

Cartridge-shell ejector.

Cartridge-shell ejector screws
(3).

Cartridge - shell extractor
block.

Cartridge - shell extractor-
block screws (2).

Cascable plate.

Cocking device.

Crank.

Crank latch.

Crank shaft.

Diaphragm.

Dowel-pins.

Extractor-hooks (10).

Firing-pins (10).

Front cap.

Main shaft.

Oscillating thread nut and
washer.

Rear-guide nut.

Rear plate for barrels.

Rear sisrht.

Rear-sight screws.
Front plate for barrels.
Front sight.
Front-sight screws.
Gas collar.
Gun frame.
Hopper.
Hopper hinge.
Hopper-hinge pin.
Hopper-hinge screws (2),
Hopper latch.
Hopper-latch screws.
Lock cylinder.
Lock-cylinder screws (2).
Lock extractor.
Lock-extractor screws.
Lock-extractor sleeve.
Lock-extractor sleeve screws^

(2).
Lock main-springs (10).
Lock nuts (10).
Lock tubes (10).
Spiral cam.
Spiral-cam screws (2).
Trunnions (2).
Waslier for front end of mairb

shaft.
Worm.
Worm gear.

Appendages.

Adjusting screw-wrench.
Brass wiping-rod.
Clamp for worm gear.
Feed-cases, straight (48).
Lock screw-driver.

Pin-wrench.
Rear-guide nut wrench.
Shell driver.
Small screw-driver,
T screw-driver.

0.45-INCH GATLING SERVICE. 181

The carriage.

Shafts. Ammunition chests (2).

Eye-bolts and straps (6). Chest handles (2).

Splinter- bar. Lid.

Step. Lid latch (2).

Hounds. Corner plates.

Assembling bolts. Angle irons.

Prop. Tool box.

Foot-board. Tool-box latch.

Floor. Tool-box straps and hinges.

Bed. Guard plate.

Bed-plate. Linch-pins (2).

Clamp screws (2). Washers (2).

To take the gun apart,

399. 1st. Remove the locks.

2d. Remove the screws and take off the cascable plate.

3d. Remove the screw from the end of the crank shaft and
take off the oscillating screw, drive out the steady-pin, and take
out crank shaft, worm, and sleeve.

4th. Remove screw from rear end of main shaft and take off
worm gear, using clamp for that purpose.

5th. Take off brass traversing apparatus, and block up gun
under front of rear plates.

6th. Take out screws and remove hopper and breech-casing.

7th. Unscrew screw from lock cylinder, back out steady-pin
whicli holds the rear guide nut, and remove the nut. (The nut
works on a left-hand thread.)

8th. Take off lock cylinder and carrier block.

To remove the barrels singly, stand the cluster muzzles up,
and let the rear end of the main shaft strike gently on a block;
the shaft and front plate will be forced off, after which the bar-
rels may be unscrewed witii a socket-wrench.

To talvc tlie breech-casing apart, remove the screws which
hold the double cam to the diaphragm and slide it out to the
front.

To assemble the gun.

4LOO. 1st. Put the breecli-casing together; screw the barrels
hi to the rear plate; replace the front plate and shaft; insert the
iront end of the shaft into the socket in the front of tlie frame,
-and rest the front and rear plates upon blocks.

2d. Replace the carrier blocks and lock cylinder.

3d. Put on the rear guide nut and put in steady-pin and
tscrew.

182 HOTCHKISS REVOLVING GUN.

4th. Put on breech-casing and hopper and replace the screws^

5th. Put on the brass traversing apparatus.

6th. Replace worm gear.

7th. Replace worm and sleeve and insert crank shaft, fasten-
ing the worm in its place with the stead5''-pin,

8th. Replace oscillating nut and set screw.

9th. Replace cascable plate and screws.

10th. Replace locks.

In taking the gun apart, it will be found much more conven-
ient and expeditious to first remove the cascable plate, and then
the locks by hand, and in assembling it they can be inserted in
the same manner before replacing the cascable plate.

When the lock extractor is used, the breech plug is turned
horizontally; the crank handle is turned until the mark upon
the rear barrel plate and the arrow on the hopper coincide, when
the lock is withdrawn.

HoTCHEiss Revolving Gtun.

The Hotchkiss revolving gun is a machine gun resembling
in exterior aspect the Gatling gun. It fires explosive shells,
and has a range equal to modern field artillery.

The gun consists of five barrels, grouped around a common
axis, which are revolved in front of a solid immovable breech
block. This has in one part an opening to introduce the car-
tridges, and another opening through which to extract the empty
shells. The cartridges are discharged singly as they present
themselves by the rotary motion to the blow of the firing-pin,
and while motionless in front of the solid portion of the breech.

The barrels are of steel; the breech block is of cast-iron, weigh-
ing about 385 pounds. This absorbs the greater part of the re-
coil.

The turning of a crank causes the automatic loading, firing,
and extraction of the empty cartridge-cases, all these operations
being performed continuously during the movement of the crank,
the peculiar feature being that the barrels remain stationary dur-
ing the discharge, thus insuring accuracy of fire.

The cartridges are fed through a trough similar to the case of
the Gatling. The piece can be accurately aimed and fired at the
rate of twent}'^ shots per minute ; when great i-apidity is required,
this may be increased to sixty or eighty.

The piece is served by the same number of men and in a
similar manner to the 1-inch Gatling.

The ammunition consists of a centre-fire metallic cartridge of

TARGET PRACTICE.

183

special construction, holdino: in each one the powder, the pro-
jectile, and the Inbricatini^-wad, arranged like the ammunition
generally used for small-arms. Both solid shot and shell are
used. Solid shot made of steel are capable of penetrating iron
plating of one inch thickness at a range of 1000 yards. The
shell is of cast-iron, and is generally fired with a percussion-fuse.

Calibre 1.457 inches.

Length of bore 4.2 feet.

Rifling, one turn in 4 feet.

(Twist and depth of grooves uniform.) .

Number of grooves 12

Length of shell with fuse 3.66 inches.

Weight of shell with fuse 16.05 ounces.

Charge of powder 4.3 ounces.

Weight of complete cartridge 25.04 ounces.

Length of complete cartridge 6.58 inches.

Weight of piece 1047 pounds.

Weight of carriage complete 1092 pounds.

Weight of limber 661 pounds.

Weight of 460 rounds of ammunition 720 pounds.

Total weight 3561 pounds.

The carriage, made principallj^ of steel, is of peculiar construc-
tion, and is well adapted both for traveling and as a stable sup-
port for the piece when firing.

Attached to the frame supporting the breech block and bar-
rels is a turn-table, which connects the cannon to a trunnion-
saddle, arranged in such manner that, without displacing the
carriage, a certain amount of lateral motion as well as of eleva-
tion may be given to the piece. Thus the gun is made to sweep
horizontally along a line by adjustment between each shot, or
during rapid discharge.

In addition to the great value of this gun for light field ser-
vice, it is peculiarly well adapted to field intrenchments and
permanent fortifications, and is intended, when fully introduced
into service, to replace howitzers for flank defenses.

TARGET PRACTICE.

401. Owing to the great expense attending target practice
with artillery, and consequently the veiy limited quantity of am-
munition allowed for it, every possible means should be taken to
secure the greatest amount of instruction that can be had from
such practice.

184 TARGET PRACTICE.

The purpose should be to test, from actual observation, the
effective power of the piece, and to acquire skill in utilizing this
power. The object for wliich a piece is placed in a work should
be studied, and practice with it made to conform, as far as pos-
sible, to this object.

Siege guns.

40t2. Siege artillery is generally used against fixed objects on
land ; the target should therefore be placed on land.

The range for the 4.5'^ gun should be about 2000 yards, and
for this distance a target 12 feet square would be suitable. It is
made of canvas, or of light boards nailed to uprights planted in
the ground, and is whitewashed. A circular bull's-eye 4 feet in
diameter is painted in black in the centre of the target. About
100 feet diagonally in front of the target, a pit of suitable size
for the marker is dug, the earth being thrown upon the side to-
wards the piece. It adds greatly to the security of the marker
to have splinter-proof covering for the pit. The marker is pro-
vided with a disk, about a foot in diameter, made of sheet-iron
or thin board, one side of which is painted black, the other white,
and provided with a stall" sufficiently long to enable him to point
the disk to any part of the target. The marker should be accom-
panied by a flagman skilled in signaling, and provided with a
white or red flag, such as are supplied by the Signal Bureau.
At the piece is another flagman similarly provided. Where it is
possible, a hill, situated two or three hundred yards beyond the
target, is advantageous for arresting the projectiles. Cleared
space beyond the target is preferable to woods.

Firm ground is selected for the gun platform, which is laid
with care and precision. The distance to the target is ascer-
tained either by direct measurement, with the telemeter, or by
triangulation. Previous to going out to fire, the instructor
should prepare a memorandum table of elevations for each kind
of projectile to be used, and the time to which fuses are to be cut
for shells. The time of flight is determined by means of a stop-
watch, and the distance at which shells burst by the Bouloug^
telemeter. Care and deliberation is exercised in loading and
pointing. When the piece is ready to be fired, a signal is made
by the flagman at the piece to the marker and flagman at the
target, who then screen themselves in the pit. As soon as the
projectile strikes, the flagman at the pit raises his flag and the
marker proceeds, in case it has struck the target, to cover the
hole with his disk ; when a shell has been flred, the flagman sig-
nals whether it has burst short of or beyond the target. An
observer at the piece, with a glass, or even with the naked eye,

TARGET PRACTICE. 185

can see upon which side of the target the projectile passes, and
can form an approximate estimate of the distance to the right or
left.

From the data thus obtained, errors of pointing and of cutting
the fuse may be corrected for succeeding shots. A complete rec-
ord of each fire is kept and entered on a blank form furnished
by the Ordnance Department. This record, besides giving a de-
scription of the piece, contains the kind and weight of the pro-
jectile, the kind of powder and tlie weight of charge, the eleva-
tion and the time of flight, the kind and length of fuse, and the
position of the piece, whether above or below the level of the
target. In the column of remarks is entered whether the pro-
jectile struck the target, and if so, where; or if it missed, to
which side, and how far; whether it fell short or went beyond ;
whether the shell exploded short, beyond, or did not explode.
The direction of tlie wind, with reference to the line of fire, and
its strength are noted.

Those engaged in the firing, particularly the officers, should
examine and study the ground about the target, observing the
eff'ect produced by the striking of the shot; whether they pene-
trated or ricocheted; the deptli of penetration, the character of
the craters formed by bursting shells, and of the furrows made
by glancing projectiles. This information is useful when con-
structing works of shelter against an enemy, and in the attack
upon and demolition of his works.

When the allowance of ammunition that may be expended
admits of it, firing at a horizontal target should be practiced.
The object of this kind of firing is to group the shots as closely
as possible on the ground about the target. The rectangular
space inclosed by the shots is called the polygon of fire. In
actual service, the purpose of such fire is to reach an enemy shel-
tered behind works or some intervening object, as hills or woods.
This is accomplished by the drop of projectiles fired at long
range, or at short range by reducing the cliarge and giving high
elevation. Skill in this, the most difiicult kind of firing, can be
acquired onlj'^ by practice.

At the close of the firing the piece and carriage should be
thoroughly inspected, and every crack or breakage noted on the
firing report. For the method of inspection, see subject of In-
spection. This report of target practice is general for all artil-
lery.

To obtain the centre of impact, the target, if an upright one,
is divided into four parts by a horizontal and a vertical line pass-
ing through the centre of the bull's-eye ; if the target is horizon-
tal, as for mortar firing, one line is drawn as the trace of the

186

TARGET PRACTICE.

plane of fire, and the other through the centre of the target at
right angles to it.

The distance in feet of each shot is measured from these lines
as co-ordinates, and recorded in a table ; as, above or helow the
horizontal line, and to the right or left of the vertical line.

The table is of the folio wins: form :

O
CQ

O
1

Distance feom co-ordinates.

Distance from centre op

IMPACT.

Vertical.

Horizontal.

Vertical.

Horizontal.

Above.

Below,

Right.

Left.

Above.

Below.

Right.

Left.

2
3

4
5

2
4
3

5
2

4
5

3
5

1.6
3.6
2.6

5.4
2.4

7.8

5-i-5=l

2-5-5=0.4

18 : 5—3.6

lo.6-j-5=3.12

The algebraic sum of the distances in each direction, divided
by the number of shots, gives the position of the centre of im-
pact in this direction. In the above example, the position of the
centre of impact is 1 foot below and 0.4 of a foot to the right of
the centre of the target.

To obtain the mean deviation, it is necessary to refer each shot-
hole to the centre of impact as a new origin of co-ordinates ; and
this is done by subtracting the tabular distance from tiie distance
of the centre of impact, if both be on the same side of the centre
of the target, and adding them, if on different sides. The sum
of all the distances thus obtained in one direction, divided by the
number of shots, gives the mean deviation in that direction ;
which in the present case is 3.6 feet vertically, and 3.15 feet hori-
zontally.

The foregoing affords a measure for the accuracy of fire of the

TARGET PRACTICE. 187

piece and projectile, but it does not afford so good a test of marks-
manship as the string^ or sum of the distances of the shots from
tlie point aimed at.

Wlien practicable, epaulments are constructed for siege guns,
howitzers, and mortars.

Siege howitzer.

403. Target practice with the 8-inch siege howitzer is con-
ducted in tlie same manner as for siege guns, but the distance
should not exceed 1200 yards, and the target need not be over
10 feet square.

Direct, ricochet, and rolling tire should each be practiced with
this piece. To observe the flight of canister, it is best to fire it
over smooth water, with an elevation not exceeding two degrees.

\0-incli siege mortar. '

404. The target for the 10-inch siege mortar should be about
1500 yards from tlie piece. The best form for the target is tliat
of a square, inclosing the general trace of a field-work. The
sides of the square should be about 100 yards, and tlie trace
marked by stakes driven at distances of about 10 feet apart.

A. large empty cask or box, placed upon a post in the centre
of the figure, and whitewashed, serves as a point to aim at.

At a distance of not less than 150 yards to the right or left of
the target, is constructed a strong bomb-proof for the marker
and flagman.

The marker is provided with a number of small stakes, which,
to make them more conspicuous, have attached to them a piece
of white or red stutt". When a shell strikes the ground, the
marker notes the place with a stake, marking it with a number
corresponding to the number of the shot. The rules governing
the flagman at the bomb-proof and at the piece are the same as
those already given for the siege gun.

A convenient method of notifying those at the mortar as to the
points at wdiich the shells strike, is to describe around the centre
of the target a circle with a radius of about twenty-five yards.
Divide this circle into twelve equal parts, which mark conspicu-
ously witii stakes, being careful to place one of the divisions on
the prolongation of the line passing tli rough the mortar and the
centre of the target. Call this point XII, and number the others
around to the riglit similar to the dial of a clock.

Suppose tile shell falls at the point C, {Fig. 1, Plate 15,) on
the line passing through the centre B and I, and at a distance of
say twenty yards from the centre. Tlie marker steps, or other-
wise measures this distance, and signals to the piece "■ 0?ie"— ~

188 TARGET PRACTICE.

" 20." Those at the piece, referring to a similar diagram made
upon diagram paper, ascertain at a glance tlie approximate
point at which the shell struck the ground.

Firm ground is selected for tiie platform, and the distance to
the target is determined as for siege guns, as is likewise the time
-of flight of shells and the distance at which they explode.

In order to economize shells, charges sufficient only to blow
out the fuse are used, and tiie shells are afterwards collected-
After the firing is completed, the distance from each point
where a shell fell to the centre of the target is measured, and, if
desirable, a diagram made of the target, showing the position of
each shot.

Previous to going out to fire, the instructor should prepare a
memorandum range table, so tliat the first shots may be approx-
imately accui^te. Subsequent shots should be rectified with
care ; the tendency is always to overdo the correction ; as, for
instance, when the shell falls short, tlie addition given to the
•charge will most likelj^ send it far bej'ond; or, should it fall to
one side, the correction given to the direction will probably be
so great as to cause it to fall a still greater distance to the other
side. Under the most favorable circumstances, mortar firing, as
compared with firing from other kinds of cannon, possesses, in-
herently, a considerable degree of inaccuracy, and in making
•corrections care should be observed to discriminate between this
. and faulty gunnery.

When practicable, the charges of powder should be weighed ;
if measured^ uniformity should be observed as to the manner of
doing it, so that all shall be shaken down in the measure, or all
measured loosely.

The platform should be tested frequently, to see that it does
not settle unevenly. The shells should be weighed and marked
with chalk, and in firing them care should be observed to com-
mence with the lightest and go up to the heaviest, or vice versa.
This enables the corresponding variation of the charge to be made
with a greater degree of certainty. In all cases oif target prac-
tice a complete record is kept for each shot, and a report, as
heretofore explained for siege guns, is made.

8-inch mortar.

405. Target practice with the 8-inch mortar is conducted as
.just explained for the 10-inch.

Coehorn mortar,

406. Target practice with this piece is similar to the fore-
going; but the distance to the target should not exceed 1000

TARGET PRACTICE. 18^'

yards, and the target may be smaller. As this piece can be-
moved from place to place with ease, and requires nothing more
than level and firm ground for a platform, the distance to the
target should be varied, thus affording practice such as fre-
quently occurs in war service.

Sea-coast mortars,

(i3-inch.)

40*7. These mortars are cliiefly used against shipping, in the-
defense of harbors; a floating target should therefore be used.
Any floating object, as an empty cask or a spar, anchored to-
mark the spot, sufiices.

The distance to the target should be about 3000 yards. The
practice is conducted in the same manner as for the 10-inch siege
mortar, except that for the purpose of determining tlie points of
fall, or of explosion of the shells, plane-tables are employed in
the manner hereafter explained. As the shells are not recov-
ered after being fired, bursting charges may be used.

(lO-inch.)

40§. Target practice with this piece is identical with that for
the 13-inch mortar.

Sea-coast guns.

409. As this class of guns are chiefly used against ships, and^
are fired over water, the target should be floating.

For the 15-inch smooth-bore and the 8-inch and Parrott rifles,
it should be moored at a distance of about 3000 yards; for the
10-inch smooth-bore, the distance should be about 2000 yards.

Plane-tables {Fig. 2, Plate 15) are employed for the purpose
of recording the striking points of shots, or the bursting distance
of shells. The tables are stationed, one at each extremity of a
line, the length of which is accurately determined either by act-
ual measurement or by triangulation from a base-line, the meas-
urement of which has been made with care and precision.

At every post mounting heavy artillery a base-line should be
so determined and permanently marked, to be used for the vari-
ous requirements of artillery firing. About 1000 yards is a suit-
able length for it.

The plane-tables are placed so as to have a clear view of the
target, of each other, and of the guns. They should, further-
more, be so placed that the lines joining them with the target
will intersect at as near a right angle as possible. This enables
the position of the shot to be determined and plotted with greater

190 TARGET PRACTICE.

•accuracy than would be the case did the lines intersect with a
very acute angle.

Floating Target. {Fig. 3, Plate 15.) The best and most
readily constructed target is composed of three stout boards
twelve feet long and a foot broad, forming a triangle. A fourth
board extends from one of the angles to the middle of the oppo-
site side. The whole is fastened togetlier with spikes, or, better,
with screw bolts.

At tlie centre of the triangle, a hole is cut in the last-mentioned
board; this hole is about four Inches in diameter; through it
passes a pole projecting about twelve feet above and three feet
below.

A 10-inch shot, or equivalent weight, is secured to the lower
end of the pole, and rope gu5'^s are led from the top to the angles
of the platform to keep the pole upright. To these ropes are
fastened triangular pieces of canvas. A bulPs-eye four feet in
diameter is painted on the middle of this screen, upon each side.
On each side of the pole, underneath the platform, an empty
water-tight barrel is lashed to the athwart-board, and a small
red flag is placed on the top of the pole.

This target is suitable for even the roughest water. To hold
it, under such circumstances, requires an anchor weighing not
less than 200 pounds. This is attached to tlie target by a chain
or heavy rope, secured to one angle of the base by an eye on tlie
under end of the bolt holding the planks together.

When a single anchor is used, the chain or rope is liable to
wind itself around and trip the anchor, causing it to drag. To
obviate this, it is advisable to moor the target with two anchors,
placed in the direction of the current. The distance of the
anchors apart must depend upon the depth of the water, and
should be such as to form, with the mooring-chains, about an
equilateral triangle.

Figure 4, Plate 15, shows the construction of a target fre-
quently used in smooth water.

An empty water-tight cask, painted some dark color, forms a
good target or point at which to aim. The cask is secured in
position by means of a small anchor or kedge attached to it by
a stout rope fastened to secure lashings on the cask. Instead of
an anchor, any heavy body, such as a stone or bars of iron, may
be used. If the current is swift, the weight should not be less
than the flotation of the cask. This latter is obtained by multi-
plying the number of gallons contained in the cask by ten — the
approximate weight of a gallon of water.

A spar, similar to the spar buoys to be seen about harbors,
iorms a good target and one of easy construction. When a spar

TARGET PRACTICE. 191

or cask is used, a small flag of some bright-colored stuff, attached
to the target, makes it more conspicuous and easy to aim at.

The target is moored in position at the commencement of the
season's firing, and is left out until the firing is completed. Its
distance from the two stations and from the guw is determined
by ordinary trigonometrical methods, or by plotting from plane-
table observations.

The plane-tables are the ordinary instruments described in
works on surveying.

After the table is set up at its station and adjusted, the officer
in charge marks upon it the line to the target, to the gnn, and
to the other station. These lines form the basis for the subse-
quent plotting of the shots.

The officer at each station is accompanied by a flagman to
signal to the piece whether the shots are short, or over. By this
means the error, for subsequent shots, is approximately corrected.

The officer in charge of the firing attends to the loading and
aiming, sees that the charges and projectiles are weighed, and
that the pressure plug (when used) is properly attached to the
•cartridge ; also that the fuses for the shells are of the proper
length. When everything is in readiness, he directs his signal
flag to be raised to inform the observers at the stations that he
is about to fire. The piece is then discharged. The other of-
ficers at the battery attend to the stop-watch and telemeter.

When the gun is fired, the officer at each station, sighting
through the alidade, catches the point on the water where the
shot strikes, or, in case of a shell, the point in the air where it
explodes. He tlien draws a fine line to mark the direction, and
gives it a number corresponding with the number of the shot.

The observations thus obtained are plotted. A suitable scale
is assumed, (one of one inch to 100 yards is convenient,) and the
line joining the two stations is laid off on the plotting sheet ac-
cording to the scale. From this all the other lines are laid oft',
usually by the method of chords. The intersection of the lines
to the target establishes its position, and those to the gun its
position also. Tlie distance from the gun to the target is ascer-
tained from the scale. The lines of observation to each shot
having been carefully numbered by the observers at the plane-
tables, the intersection of corresponding numbers on the plot
give the striking points of the shots, or bursting points of the
shells.

When plane-tables are not to be had, any instruments gradu-
ated for measuring angles and provided with sights through
which the sliots can be observed, may be used, and the work
Accomplished as just described. An observer at the piece takes

192 TELEMETERS.

the time of flight with a stop-watch, and another observer ob-
tains the bursting distance of shells with the Boulongd telemeter,

Tlie direction of the wind is determined by a vane at the piece.
The most convenient and reliable method of noting it is by refer-
ring it to the dial of a watch held in such a position that the line
passing through VI and XII will be parallel to the line of fire
with the XII towards the target. The direction is that from
which the wind comes. When coming directly from the front,
it is noted as '"''twelve o'' clock'''' '^ when from tiie rear, as ''''six
o^clock^^ ; when from the right, as '•''three o''clock^^ ; when from
the left, as '•'"nine o'' clock''"' ; and when from intermediate points,,
in a similar manner.

The velocity of the wind is determined by an anemometer;
but as this instrument is seldom to be found at military posts,
the best that can be done is to estimate the velocity, and record
it as explained in par. 204.

When it is practicable to establish telegraphic communication,
all of the foregoing operations, so far as signaling is concerned^
are greatly facilitated.

Galling gun.

410. The target for this gun is made of light canvas or ordi-
nary muslin, and is in four or more sections, each section being
8 feet long by 6 feet high. The canvas is nailed to a strong
light frame, the uprights of which extend about 12 inches below
the canvas, in order tliat they may be set in the ground.

Practice should commence at 200 yards and the distance be
increased up to 1000 yards, or more. At the first distance a single
section of the target is sufficient, and, as the distance increases,
other sections will be added. Smooth, level, and firm ground
should be selected for the gun to stand upon.

Telei^ieters.

411. The Boulongi telemeter is an instrument devised for as-
certaining the distance to a point by means of sound proceeding
from the point to the place of observation. The one used for
artillery purposes consists of a glass tube about six inches in
length, filled with a transparent liquid that does not freeze ex-
cept with intense cold. [Fig. 1, Plate 16.)

In the liquid is a metallic disk, which moves freely from one
end of the tube to the other. It is so adjusted that the motion
will be uniform and comparatively slow. Tlie tube is inclosed
in a brass case, to which is attached a scale, after the fashion of

TELEMETERS. 193

a thermometer. This scale is marked for each hundred yards
up to 4000.

The divisions on the scale show the distance, in yaids, throuo-h
which sound will travel in air, during the time required for the
disk to descend over the space on the scale marked by the corre-
sponding number of yards. If, for instance, the disk passes
from zero to the 500 mark, it indicates that sound would have
traveled 500 yards through the air during that time.

The instrument must be held vertically, or as nearly so as pos-
sible. To arrest the motion of the disk at any point, the instru-
ment is quickly turned to a horizontal position.

To use it for determining the time of flight of shells, it is held
in the right hand, back of the hand up, with the zero of the in-
strument to the left; a turn of the wrist to the right brings the
instrument vertical, with the zero end uppermost; the disk then
descends, and a turn of the wrist to the left arrests its motion.
The observer, holding the instrument as described, watches for
the flash of tiie shell, and upon seeing it, instantly brings the
instrument to a vertical position ; upon hearing the report from
the shell, he instantly turns it back again. The position of the
disk indicates the number of yards from the observer to where
the shell exploded.

To ascertain the distance to an enemy's battery, the instru-
ment is held and turned in the same manner. The observer
watches for the flash of a gun ; observing which, he turns the
instrument, and, when he hears the report, turns it back and
reads off the distance. Each hundred yards on the scale is sub-
divided into quarters.

412. The telemeter invented by Captain A. Gautier, of the
French army, is an instrument for measuring, with a great degree
of approximation, any difi^erence, not exceeding three degrees,
which may be exhibited in the bearing of a distant object by
viewing it from different points of a base-line transverse to its
general direction from the observer.

The instrument, in its simplicity, accurac5% and portabilitj'',
recommends itself in all cases where a knowledge of distances is
desired at any moment and with the least possible delay ; such,
for instance, as range-finding, river-crossing, reconnoitering, and
the like. A slight acquaintance with its use on sucli occasions
enables the observer to estimate, with more than ordinary
promptitude and precision, the distance which it might be all
important to obtain.

The principles of this instrument are explained mathematically
in Ordnance Memoranda No. 12.

The instrument {Fig. 2, Plate 16) resembles in shape and size
13

194 ^ TELEMETERS.

one barrel of an ordinary reconnoiterhig or field-o:lass. The case
in which it is carried is fashioned so as to answer as a handle for
liolding the instrument when making observations. {Fig. 3,
Plate 16.)

Within the barrel of the instrument are placed two mirrors at
an angle of about 45 degrees with each other; this angle can
be varied within certain limits by means of a milled-headed
screw acting on one of them. The mirrors are thus made to
operate upon the principle of the sextant. A slot on one side of
the barrel permits the rays of light from an object to fall upon
one of the mirrors, from whence they are reflected upon the other
mirror, and the image is seen through the eye-glass at the small
end of the instrument.

At the front or large end is fixed, in a ring surrounding the
barrel, a prism, whose displacement modifies the direction of an
object seen through it.

At the rear of the instrument is a small eye-glass, by means of
which the observer sees, over the mirrors and through the prism,
the object which is before him, and by double reflection in the
mirrors the object to the side of him.

The semi-revolution of the movable ring containing the prism
corresponds to a displacement of the object toward the left of
about three degrees. The ring is provided with a graduated scale
containing numbers, the use of which will be explained.

Method of using the instrument.

Suppose C {Fig. 4, Plate 16) to be the object and A the point
from which the distance A C is to be determined.

Select some distant object, as M, for a signal., the direction A
M to it making with the line A C an angle a little greater than
90 degrees. From the point A measure a base, A B, in prolon-
gation of the line to the signal.

After having adjusted the telemeter upon the case, which
serves as a vertical handle, turn the ring until the word "infin-
itj'" is brought opposite the fixed index or arrow. This brings
the prism to its initial position.

A small opening in the under part of the instrument, exhibit-
ing the mirror index, enables the observer to assure himself that
the movable mirror is at its mean position,, which is indicated by
a fixed mark.

The telemeter is then ready for operation, and the observer
places himself at A, so that the object C will be on his right.
(The right is here chosen merely for purpose of illustration.
The observation can be as easilv made with the object on the
left.)

TELEMETERS. 195

The instrument is held in the left hand, the fino^ers of whicli
'Clasp the barrel firmly to the handle (the case). The observer,
facing the sio^nal M and sighting through the eye-glass upon the
signal, turns, with the right hand, the milled screw until the
image of the object C coincides with the signal M. Leaving the
screw in this position, he retires to the other end, B, of the base-
line, where, holding the instrument as before, he sights upon
the signal, and turning the graduated ring on the front end,
makes the images again coincide. This done, there will be
found on the ring opposite the fixed index a number, which,
being multiplied by the number of units in the base-line, will
^ive the required distance A C in terms of the unit used in
measuring the base.

This is the method of B.Jixed base. Another method is by
means of a proportional hase^ which is, instead of measuring a
base as just described, a certain factor is selected on the ring
and tiie instrument set to it; then by moving back in the direc-
tion A B until the images coincide, the distance thus moved over
will be the base, which is then measured and multiplied by the
selected factor. This method has the advantage of eliminating
the errors of reading the movable ring.

A base of y^ of the distance suffices in general for obtaining
the exactness of measurement required in military operations.
It is necessary always that the object and the signal be well de-
fined and of a convenient form and size, and that the observer
be sufficiently skilled with the instrument to make with precis-
ion the necessary sightings, and to make the proper alignment
of the two stations upon the signal. In a case where a good
natural signal is found, distances up to 2000 meters can be read-
ily measured in less than two minutes. If the conditions are
less favorable, the measurements may be effected by employing
bases of -^jj or of ^^. Whatever be tlie method employed, tlie
immediate result of the operation is the knowledge of the rela-
tion between the distance sought and the base. The base may
be expressed according to any unit of measurement, and the dis-
tance will be correspondingly expressed. If the base is measured
in yards, the distance will be yards, &c.

A good natural signal is one which best satisfies the following
conditions, viz. : Perfectly visible ; form well defined and sym-
metrical, with reference to a vertical axis ; distance very great
in proportion to the length of base we wish to use ; height at
least -^^fj of its distance from us; direction, making with that of
the object, an angle a little greater than 90 degrees. . In case no
convenient natural signal can be found, its place may be arti-

196 TELEMETERS.

flcially supplied by an aid placing himself at 200 or 300 meter*
distant and holding himself immovable.

An operator who thoroughlj^ comprehends the principle of
the telemeter will in a short time acquire sufficient skill to use
it to the best advantage. He will discover that the choice of the
signal has a great influence on the accuracy of the operation ;
he will judge of the amount of care necessary in securing align-
ment of the stations ; and, in fine, he will be able to modify or
perfect, according to circumstances, the processes heretofore
indicated.

The choice of the signal is a point very important to the pre-
cision of sighting. If the object and the signal are each sym-
metrical with reference to a vertical axis, and of a height at
least ^^ of their distance from the observer, and upon nearly
level ground, the sighting can be made to within 2'^ or 3'';
while if the signal is but barely visible, or of little height, or of
vague form, errors up to 2^ may be committed. It is seen,
therefore, that of two natural signals unequally distant from
the observer, the nearest may be the more advantageous ; but
of this, experience will be the best guide of the observer.

The alignment of the two stations can be made in several
different manners, according to requirements. The operator
can take before him two natural objects, the first near and the
second suflScientlj'^ far off, very distinct, and high enough not
to be masked by the first. It is always of advantage to use a
stake at the first station not high enough to obscure the signal;
and this precaution is the more necessary if the signal is but a
short distance off.

The instrument gives a very simple means of knowing whether
the position of the second station is well chosen. After having
established the coincidence between the reflected object and the
signal at the second station, the front of the instrument should
be lowered perpendicularly, so as to take in the point of first
observation. This point should, if the second station is correct,
appear in coincidence with the reflected object.

The operation can be performed by either facing the signal or
facing the object. The first method is always preferable, as
the latter necessitates the taking of the base to the side, which
renders alignment more difficult. ^Nevertheless, if the object
be indistinct or difficult to distinguish from its surroundings, it
may be regarded by the second method, care being taken at the
second station that the instrument is turned a little on its own
axis, so as to take in the point of first observation, and that

PRESSURE PLUG. 197

point be found to lie in the same vertical plane with the natural
signal.

Pressure Plug.

413. Rodman's pressure plug {Fig. 5, Plate 16) is used when
it is desired to ascertain the pressure per square inch exerted by
the powder on the surface of the bore of a piece. To apply tliis
instrument, it is first taken apart by unscrewing the cap and
removing the piston and disk containing the knife. Tlie whole
is then thoroughly oiled with sperm oil. This done, place a cop-
per disk in tlie plug, and after it the disk containing the knife,
the latter being slid down so as not to cut the copper disk. Next
pass the piston into the liole in the stem of the cap, and screw
the cap into its place. For this operation the pkig is held liori-
zontally in a vise. A small copper gas-check is then inserted
into the hole on top of the piston ; a wooden drift is used to
set tiie gas-check firmly in its place, and a small wad of cotton-
waste is inserted over the gas-check ; the plug is now put into
the empty cartridge-bag, with its grooved end at the bottom and
centre of the bag, and the bag tied firmly to it from tlie outside,
with twine passing around the grooves on the bottom of the
plug. The powder is next put in, care being taken to distrib-
ute it evenly around the plug. The bag is tied close to the pow-
der so as to make the cartridge firm and compact.

When inserting the cartridge into the gun, care is taken that
the plug, wlien at the bottom of the bore, is, as nearly as possi-
ble, in the axis of the piece.

After the discharge, the plug is removed from the bore by a
rake made for the purpose ; the cap is unscrewed, the copper
disk removed, and, after being wiped, the cut made upon it by
the knife is measured, from end to end, with a pair of dividers.
The dividers are then applied to the scale and passed down the
two long lines until they intersect a cross line the length of
which corresponds to the width of the dividers ; the figures at
this point indicate the number of pounds pressure to the square
inch.

Pressure plugs are of three sizes : one for the 12-inch rifle
and 13-inch and 15-inch smooth-bores ; one for the 100-pounder
Parrott rifle and 8-inch and 10-inch smooth-bores ; and one for
smaller calibres.

Wnvt Sftirl

MECHANICAL MANCEUYRES.

General Directions,

414* The mechanical manoeuvres are the application of ma-
chines and of mechanical powers for mounting, dismounting,
moving, and transporting artillery.

415. The detachment for mechanical manoeuvres consists of
one chief-of-detachment, one gunner, and ten cannoneers. It is
formed as in par. 14; marched to the place of exercise as in par.
106, and tal^es post as in par. 107, except that the cannoneers are
posted two yards from the axis of the piece or carriage ; Nos. 1
and 2 opposite the muzzle or front part of the carriage, the other
numbers and the gunner dressing on Nos. 1 and 2, respectively,
at intervals of one yard, except between Nos. 3 and 5, wliere
there is an interval of two yards. All face towards the piece or
carriage.

The cannoneers change posts as in par. 112.

The chief-of-detachment is posted two yards in rear of the
breech, chassis, or trail, or on the left of the pole, two yards
from and opposite its end, according as the piece is dismounted,
unlimbered, or limbered. During tlie execution of the manoeu-
vres he goes wherever his presence maybe necessary; but, in
rendering assistance, will generally place himself opposite the
gunner, between Nos. 3 and 5.

416. The implements and machines required for the various
operations depend upon the kind and weiglit of the piece and
tlie nature of the manoeuvre to be performed. For each exer-
cise, those specially required are given.

In every case the minimum number of each is given. Wlien
much work is to be done, due allowance must be made for wear
and tear, which, with heavy material, is very considerable.
Sound discretion should be exercised not to allow the wearing
to go beyond the limit of safety.

Those now used for siege-pieces are such as can be found in
most localities; the roUei'S, chocks, and, if necessary, the hand-
Spikes being readily shaped from sections of trees.

(199)

200

MECHANICAL MANCEUVRES.

The following table contains implements used for siege-pieces

{Plate 18.)

Implements.

Hemakks.

Handspike

Long roller

Inch.

84
42
12
3.6

7
7

360

Inch.

Lb. Oz.

12
25
12

6
2 4

8 8

2 4

\ Grooved K in. deep in

J the middle.

Wedge-shape.

? Section a triangle. Top

S rounded H of an inch.

? Ends beveled oh oppo-

> site sides.

} Sometimes caUed mon-

> key-wrench.

1 Made of round iron 0.75
[in. in diameter, with a
I stout hook at each end ;
J length of links, 5 ins.

6
7
2.75
6
5

r'nd

r'nd
r'nd
3.5

2.25
1.25

Short roller

Gun-chock

"Wheel-chock

Roller-chock

Shifting-plank

Trace-rope

Rlinc-pliHin . ..

156

The machines and their uses will be described with the ma-
noeuvres for sea-coast pieces.

41 f. In every case the wooden handspike is required, and to
avoid repetition the following general directions for its use are
given. Six are the number generally used, and they are in
charge of JSTos. 1, 2, 3, 4, 5, and 6.

When men on opposite sides of a piece apply themselves to a
handspike, the handspike used is that of one of the even num-
bers ; the man to whom it belongs is at the smaller end, the
corresponding odd number at the butt end; those who assist
place themselves inside of these two numbers; the lowest num-
bers nearest the ends.

When two or more men work at the same end of a handspike,
the man to whom it belongs is at the end, and the other men in
the ascending order of their numbers from him.

When several handspikes are crossed at the muzzle in order
to raise or lower it, they are applied in the order of the numbers
of the men to whom they belong, those of the highest numbers
nearest to the trunnions.

The handspikes used in the mechanical manoeuvres are beveled
on one side, as these will enter into places or under bodies where
square handspikes could not be used.

When a handspike rests on a fulcrum, and the weight on one

GENERAL DIRECTIONS. 201

«ncl is to be raised by bearing down on the other, the weight
should never rest on the beveled side, as the handspike would
not then ,i>ive a good hold, and would be liable to split. In this
-case the beveled side should be down. But if used for lifting, as
when two handspikes are crossed under the breech or chase of a
^un to heave it upward, their ends resting on the ground or plat-
form, the beveled side should be up.

When two or more men haul together on a rope, the lowest
number is next the object of resistance, and tlie remainder next
liim in ascending order of their numbers.

418. At the completion ot each movement of a manoeuvre,
the men retain the places they are in at its conclusion, ready to
proceed to the next movement, resuming their posts only at the
command To YOUR POSTS, which is given by the instructor at
the end of each manoeuvre.

419. The front, when a piece is unlimbered or dismounted,
is the direction in which its muzzle points; when limbered, it
is the direction in which the pole points. In the execution of
the following manoeuvres, when a piece is put in motion upon
rollers, the terms back and forward are applied to the direction
of the breech and muzzle respectively.

A body moving upon a roller gains twice the distance passed
over by the roller.

The ground should be level and firm and the implements in
good oi-der.

Preparatory to manoeuvering, the implements and machines
required are taken to the place of exercise. The instructor ex-
plains to the detachment their names, uses, and mode of appli-
cation. He then commands :

1. Prepare to manoeuvre.

4dO. The men take the implements, repair to their posts,
and place them upon the ground in their rear; the handspikes
behind N'os. 1, 2, 3. 4, 5, and G perpendicularly to the axis of
the piece, on that side of the cannoneer toward the muzzle, the
small ends on a line with their toes ; the chocks equally divided,
behind and near Nos. 3 and 4; the long rollers near and behind
No. 4, and the short rollers, shifting-plank, trace-rope, sling-
<ihain, and hammer-wrench in rear of the guimer.

Whenever, in the course of a manoeuvre, an implement is not
in immediate use, it is returned by the person using it to its des-
ignated place.

421. The instructor gives the commands and has a general
supervision of the manoeuvres. He sees that each man performs
the duties assigned him ; that everything is in a proper state of

202 MECHANICAL MANOEUVRES.

readiness before giving the command of execution ; and that par-
ticular care is taken to avoid all shocks and sudden movements.

422. The chief-of-detachment attends directly to the execu-
tion of the movements, and particularly assists and directs the
gunner in all his duties.

423. The gunner gives commands when specified ; places
the shifting-plank; attaches and takes otf the trace-rope; re-
moves and replaces the elevating screw ; places and removes
chocks and the short rollers ; superintends the i-ighting of the
piece ; directs the pole of the limber, &c.

!N'os. 1, 2, 3, 4, 5, and 6 have charge of the handspikes; ISTos.
7 and 8 rig and work the windlass, IN'os. 1 and 2 holding on ta
the rope ; Nos. 3 and 4 chock and unchock the wheels, the gun,
and the long rollers ; take off and replace the cap-squares, and
place and I'emove the long rollers.

INTos. 5 and 6, with their handspikes, steady and right the
piece, haul on the ropes, &c. N"os. 7, 8, 9, and 10 assist the
others. Nos. 7 and 8 generally assist N'os, 1 and 2, or 3 and 4.
N^os. 9 and 10 assist Nos. 3 and 4, or 5 and 6 ; thej'^ assist in plac-
ing the implements preparatory to manoeuvering; haul upon the
ropes, and apply themselves by hand to move the carriage.

424. Two or more men, lifting or hauling together, must
wait for the command before exerting their strength. The gun-
ner sees that all are ready before giving the command heave.
Then all move with a prompt but steady effort, and apply their
power increasingly until the weight responds to their effort.
The gunner will repeat the command heave as often as it may
be necessary. When the movement has been sufficiently made,,
the gunner commands : Ease away. Those making the effort
will then desist ; but in doing so will be careful to avoid all sud-
den shocks or strains.

The command ease away will be omitted in the text, for the
reason that its application will, in most cases, depend upon cir-
cumstances, to be judged of by the gunner.

Every operation should be done with spirit and animation^
but without bustle or confusion. Vigilance should be constantly
exercised to have tlie piece or rollers securely chocked.

425. The limber of a siege-piece makes a powerful lever,,
and may be advantageously used in many cases. The pole ia
raised and the pintle engaged in a sling around the weight to be
raised. The pole is hauled down by a trace-rope attached to
the eye.

426. ParbucJding. {Fig. 1, Plate 19.) A rope used as a par-
buckle is the best method of rolling a gun. To do this, place
the gun on skids, and attach the rope by a bowline to one of the

GENERAL DIRECTIONS. 203-

trunnions, passing- it under and around up over the gun, and-
hauling on the end.

If the gun is to be rolled up a slope, two ropes, of size suitable
to the weight of the gun, are used. An end of each rope is made
fast to some fixed object at the upper part of the slope ; the other
ends are carried under tlie chase and body respectively, and up
over the gun ; these ends are hauled upon by means of a cap-
stan, or by attaching to them a fall and tackle. The muzzle is
slued forward by pinching with bars, or by means of a rope
and tackle attached to a roller or skid thrust into the muzzle.
The piece is lowered by inverse means.

42*7. To cross-lift a piece or other object {Fig. 2, Plate 19)
is to cross handspikes under it from opposite sides ; the butt end
of the handspike is on the ground, and the power is applied by
lifting at the other end.

42JS. To slue the trunnions is to turn the piece on its axis so
as to bring the trunnions into any required position. This is
done by first placing the piece on skids perpendicular to its axis.
A fulcrum is placed near the trunnion to be raised ; upon this a
handspike or other lever is used, the piece meanwhile being
chocked on the opposite side. Or a trunnion-loop maybe passed
around the trimnion to be raised, and a handspike or lever pass-
ed through it, with the butt end resting on the top of the piece ;
the power is applied by lifting at the other end, the piece being
chocked as before. Or, by passing the bight of a rope once or
twice around the piece, and placing the butt of a handspike or
lever through the bight, and bearing down or lifting up, using
the piece as a fulcrum, the ends of the rope being held to pre-
vent them from slipping. All three of these methods ma}^ be
used at the same time.

The skids should be well greased under the piece, as likewise
should be the chocks.

When the piece is of great weight, the hydraulic-jack or gin
is advantageously used, provided the axes of the trunnions are
not vertical. The former is placed under and the latter over the
trunnion to be raised. When the axes of the trunnions are ver-
tical, or nearly so, a rope is passed around the upper one and
hauled upon by means of tackle.

429. To pinch a gun or other object is to move it by small
heaves with a pinch-bar or handspike, without allowing it to
turn on its axis. A piece is pinched one end at a time, the other
being chocked. The bar or handspike is placed as a lever, with
the beveled side down, and the power applied at the other end
by bearing down.

430. To launch a piece or other object forward or backward!

:204 MECHANICAL MANCEUVRES.

"is to move it in the direction of its axis. If tlie weiglit is sucii as
to require levers or handspikes, they are placed, usually, on op-
posite sides, and the power applied by bearing down, at the same
time carrying the free end of the lever in a direction contrary to
that in which the object is to be moved.

To slue a piece or other object, end for end., is to turn it
round, not allowing it to revolve on its longer axis.

To cut is to move the object horizontally, without rolling, by
moving each end alternately in the required direction.

Manceuvres with the Siege Gtuns.

431. The implements required are those habitually accom-
panying each piece, viz. : Six handspikes., two trace-ropes., six
wheel-chocks., one hammer-wrench., one shoi^t roller., one sling-
chain, and four roller-chocks.

432. The following manoeuvres are arranged on the sup-
position that no other implements are available. When two or
more pieces ai-e together, or planks or skids are available, as
would generall}^ be tlie case in the field, the manceuvres may be
often simplified, as will be indicated.

The directions laid down in par. 417 and following will be
observed. This is essential for the prevention of confusion and
accidents, since directions to particular numbers are in most
cases omitted.

Ordinary manoeuvres.

1. To limber and to unlimber.

2. To move the carriage when limbered, with and without its
piece, bj^ hand to the front and rear.

3. To place the short roller under the chase and to remove it.

4. To place the short roller under the body of the gun and to
remove it.

5. To shift the gun from its traveling bed to its firing bed.

6. To shift the gun from its firing bed to its traveling bed.

7. To side-lift the carriage.

All the other manoeuvres arc exceptional, and are rarely re-
quired in actual service with the guns now mounted on travel-
ing carriages. They are, therefore, prescribed for exercise only
to such an extent as may be necessary to enable officers and men
to become familiar with the operations.

To limber.
{Fig. 3, Plate 19.)

433. When these guns are used for field service, they may

SIEGE GUNS. 205-

be limiDered to the rear, front, riglit, or left. In every case the
piece is in its firing bed.

To the rear. The instructor commands :

1. Limber up.

Xos. 3 and 4 choclc the wheels front and rear; ^o. 2 inserts
his handspike in the bore, and is assisted to bear down by No.
1; No. 6 crosses his handspike under the stock, as near the
trail as practicable, and is assisted hj Nos. 3, 4, 5, 7, and 8, all
facing in the direction of the trail. If the limber is not liorsed,
it is brought up by the chief-of-detachment, gunner, and Nos. 9
and 10. The stock is raised at the command Heave from the
gunner until the pintle can be caught under the trail and the
pole used as a lever to sustain it. The handspike is then shifted
in rear of the lunette; Nos. 9 and 10 take hold of the limber-
wheels; the gunner gives the necessary instructions to cause
the pintle to enter the lunette, and when it is in, hooks the
lashing-chain.

The instructor then commands : 1. To YOUR POSTS ; at which
all take their posts as explained in par. 415.

To the right, or to the left. The instructor first causes the trail
to be moved around to the right or to the left, so as to bring the
axis of the piece perpendicular to its former position. The lim-
ber is moved to its place corresponding to the new position of
the piece.

In moving the trail around, Nos. 1 and 3 at the right wheel,
and Nos. 2 and 4 at the left, apply themselves as in in battery^ or
from battery., but in contrary directions, as the case may require.
Nos. 5 and 6 both embar under and perpendicular to the stock
on the side opposite tiiat to which the trail is to be moved. The
gunner commands : Heave, and repeats it as often as maybe
necessary. The piece is then limbered up as before.

To the front. The instructor causes the trail to be brought
around so that the piece will point in the opposite direction.
This may be done either to the right or left, as best suited to the
ground, and is executed as in the preceding paragraph. The
limber is moved to its place corresponding to the new position
of the piece, and passes the piece either to the right or left, ac-
cording to the nature of the ground. The piece is then limbered
up as in the preceding cases.

To unlimber.
434. The instructor commands :

1. Unlimber.
The gunner unhooks the lashing-chain ; Nos. 3 and 4 chock-

206 MECHANICAL MANOEUVRES.

the wheels front and rear, and all applj^ themselves as in limber-
ing up. At the command Heave from the <^iinner, the trail is
raised to disengage it from the pintle, the limber is moved for-
ward, and the trail lowered to the ground. All resume their
posts at the command To YOUR POSTS.

When the piece is unlimbered, the habitual position of the
limber is six yards in rear of the piece, measured from its axle
to the trail, the pole pointing to the rear. In bringing it up for
limbering, it is hacked to its place at the trail. If the cari-lage is
without its piece, N"os. 1 and 2 embar through the wheels and
under the rear part of the cheeks, instead of as prescribed in
yar, 433.

In limbering and unlimbering a siege howitzer^ N'os. 1 and 2
both insert handspikes in the bore.

To move a piece^ or its carriage, to the front or rear.

435. The instructor commands :

1. Forward (or backward), 2. Mabch, 3. Halt.

The piece being limbered, iN'os. 1 and 2 embar obliquely under
the rear of the wheels of the carriage ; Xos. 6 and 6, in like
manner, under the limber-wheels; Nos. 3 and 4 through the
spokes and under the cheeks; IS'os. 7 and 8 apply themselves to
the limber- wheels by hand; ISTos. 9 and 10 at the splinter-bar,
and the gunner and chief-of-detachment at the end of the pole;
all facing to the front. The gunner commands: Heave, and
repeats it as often as may be necessary.

In moving to the rear, N'os. 1 and 2 embar through the spokes
and under the cheeks; Nos. 3 and 4 under the front of the
wheels of the carriage ; Nos. 5 and 6 under the front of the lim-
ber-wheels; Nos. 7, 8, 9, 10, and the gunner apply themselves
as in moving to the front ; all facing to the rear.

Tlie carriage being limbered, but without its piece, at the com-
mand forward the numbers apply themselves by hand as fol-
lows: N'os. 1 and 2 at the head of the cheeks; N'os. 3, 4, 5, and
6 at the wheels of the carriage ; Nos. 7 and 8 at the wheels of
the limber; N'os. 9 and 10, and the gunner, as with the piece
mounted. At the command march, the carriage is moved for-
ward.

To move to the rear, N'os. 1, 2, 3, and 4 apply themselves by
hand to the wheels of the carriage; Nos. 5 and 6 to the rear end
of the cheeks; N'os. 7, 8, 9, 10, and the gunner, as with the
piece mounted. At the command march, the carriage is moved
to the rear.

In the foregoing movements, at the command halt, all resume
their posts.

SIEGE GUNS. 207

To place the short roller under the chase,

436. The piece being limbered and in its traveling bed,
tlie instructor commands :

1. Place ROiiiiEB under the chase.

{Fig. 4, Plate 19.) At this command, the cap-squares are
removed and the wheels chocked by Xos. 3 and 4; the hand-
spike of ^NTo. 2 is placed in tlie bore ; that of ^N'o. 6 is crossed un-
der the handspike of No. 2 ; No. 1 assists No. 2, and Nos. 3, 4,
5. 7, and 8 assist No. 6. The gunner stands at the head of the
right cheek with the roller, and wlien all is in readiness gives
the command Heave. The chase being raised high enough, the
roller is rolled forward on the stock mitil its axis is within six
or eight inches of the axis of the trunnions, and chocked in rear;
the piece is then allowed to rest on it.

Note. — The roller is placed under the chase only when the
piece is in its traveling bed, and for the purpose of shifting it.

To remove the short roller from under the chase.

dB*^. The piece being limbered, the instructor commands :

1. Remove the roller.

Executed as in the foregoing paragraph, except that when the
chase is raised the short roller is rested on the head of the stock
by the gunner, to enable the men at the handspikes to take a
new hold. The chase being raised again, the roller is with-
drawn and the piece lowered into its bed.

Either of these operations can be performed, though more
time is required, by successive purchases with the handspikes
over the heads of the cheeks and under the chase.

To place the short roller under the body.

438. The piece being either limbered or unlimbered, the in-
structor commands :

1. Place roller under the body.

Nos. 3 and 4 chock the wheels and remove the cap-squares ;
No. 2 inserts his handspike in the bore, and is assisted by No. 1
to bear down ; Nos. 5 and 6 embar over the cheeks and under
the gun in rear of the trunnions, and raise the breech at the
command Heave from the gunner until he can place the short
roller under the body of the piece, as near to tlie trunnions as
can be effected readily. The gunner chocks the roller on the
side toward the muzzle when the piece is limbered, and in rear

208 MECHANICAL MANCEUVRES.

when unlimbered; removes the elevating screw and places it m
rear of his post, resting it upon its handles.

Note. — The roller is placed under the body of the piece only
when it is in its firing hed^ and for the pin-pose of dismounting^
it, or of shifting it to its traveling bed, to a mortar-wagon, or to
another carriage.

To remove the short roller from under the body of the piece.

439. The piece being either limbered or unlimbered, the
instructor commands :

1. Remove the roller.

The gunner replaces the elevating screw, and the roller is re-
moved as prescribed in the preceding paragraph.

Note. — All that is presci-ibed in the foregoing paragraphs ap-
plies likewise to the siege howitzer.

To shift the piece from its traveling to its firing bed,

{Fig. o, Plate 19.)

440. The piece being limbered, the instructor causes a roller
to be placed under the chase as explained in par. 436, and then
commands :

1. Shift the piece.

N'os. 3 and 4 remove the cap-squares ; jKTo. 2 inserts his hand-
spike in the bore, and is assisted by No. 1 ; No. 6 crosses his
handspike over that of No. 2, and is assisted by Nos. 3, 4, and 5.
The gunner attaches the trace-rope at its middle by a double
hitch to the knob of the cascable, and passes the ends over the
limber to Nos. 7, 8, 9, and 10, who take a turn with each part
around the manceuvering bolts. At the command Heave from
the gunner, the muzzle is borne down and the piece allowed to
run slowly on the roller until the trunnions are over their firing
beds, when they are borne down into place and the short roller
removed from the rear.

Before executing this or any similar manoeuvre, the manceu-
vering bolts should be set tight to the stock with the wrench, to
prevent accident from turning. The precaution should be taken,
also, of putting a chock near the head of the stock to stop the
roller, should the men at the trace-rope fail to control the piece
after the trunnions have been lifted over the chin bolts.

The gunner must observe that the lashing-chain is hooked.

To shift the piece from its firing to its traveling bed.

441. The piece being limbered, the instructor causes the

SIEGE GUNS. 209

roller to be placed under the body of the piece as explained in
par. 438, and then commands :

1. Shift the piece.

At this command, No. 2 inserts his handspike in the bore; the
handspike of N'o. 4 is crossed under that of No. 2, and manned
hy Nos. 1, 2, 3, and 4; the gunner attaches the trace-rope at its
middle to the knob of the cascable by a double hitch, and passes
its ends over the limber to Nos. 5, 6, 7, 8, 9, and 10. At the
command Heave by the gunner, the piece is pushed and hauled
until the trunnions are over their traveling beds, when the
breech is allowed to rest on the bolster. The roller is removed
from the front by raising the muzzle as described in par, 437.

443. Note. — In any of the preceding manoeuvres with the
8-inch howitzer, when the handspike of No. 2 is inserted in the
muzzle it should be chocl^ed about 18 inches in the bore, and
again at the muzzle. When the howitzer is transported on its
traveling bed, a temporary bolster should be constructed to sup-
port the breech. The short roller, resting on a piece of plank
two or three inches thick and supporting the knob of the casca-
ble, will answer for this purpose.

To side-lift a carriage.

443. For the purpose of moving a carriage a short distance to
the right or left, it being unlirabered, the instructor commands ;

1. Side-lift to the right (or left).

To the right. Nos. 2 and 4 embar under and perpendicular
to the left wheel, from the outside ; Nos. 1 and 3 under the
right wheel, from the inside, and No. 6 under and perpendicu-
lar to the trail. The gunner commands : Heave, and the car-
riage is lifted, short distances at a time, to the right.

To the left. Executed in the same manner, but by inverse
means.

Remarks.

444. The short roller is carried as explained in par. 256.
When the piece is on its traveling bed, the elevating screw is

run in on the lower side of the stock, and held in its place by a
lashing-strap.

The sponge and rammer are lashed upon the piece, their
heads projecting beyond the base of the breech. A convenient
way of transporting them is by two iron collars, containing
hooks, buckled upon the breech and chase.

The handspikes are carried as explained in par. 256.
14

210 MECHANICAL MANCEUVRES.

Two trace-ropes should accompany each piece of sie^e artil-
lery. They are useful not only in shifting the piece, but in lash-
ing and in extricating the carriage or mortar-wagon from diffi-
culties.

The sling-chain is carried wound around the stock. It may
be used for a lock-chain, the one provided with a shoe being dis-
pensed with.

The shifting-plank is carried on the stock, between the cheeks.
A hole is bored in it, through which a rope passes, securing it to
the stock.

Tlie chocks and hammer-wrench are best carried in a bag
slung to some part of the carriage.

445. To prepare a piece for traveling, the instructor causes
the implements to be placed as abov^e indicated. To do this,
after shifting the piece to its traveling bed he commands :

1. Put on the implements.

The gunner places the vent-cover, short roller, elevating screw,
and water-bucket ; if it is necessary to lash the piece to its bed,
he is assisted by Nos. 1, 2, 3, 4, 5, and 6. No. 2 secures the tom-
pion in the muzzle ; 'Nos. 1 and 2 fasten on the sponge and ram-
mer, and, assisted by IS'os. 3 and 4, put on the handspikes. The
piece is lashed as explained in par. 256.

To prepare the piece for action, the instructor, before shifting
it to its firing bed, commands :

1. Kemove the implements.

The same numbers that put on the implements remove them.

446. The object of carrying the piece in the traveling bed is
to equalize the load, by throwing more of the weight upon the
limber, and thus relieving the rear wheels. For short distances,
over smooth roads, the piece may, however, be carried in its
firing bed.

Other Manoeuvres which may be required in Service.

To mount the siege gun on its carriage,

44 f. The piece is lying on the ground, vent uppermost ; the
carriage unlimbered; the elevating screw, bolster, and cap-
squares removed ; the trail about two yards from the muzzle ;
the stock squarely in prolongation with the gun. The instruct-
or commands :

1. Raise the chase.

{Fig. 1, Plate 20.) The gunner extends the sling-chain on

SIEGE GUNS. 211

the ground perpendicularlj^ to the axis of the piece, with irs
middle under the necl^ of the cascable; ]N"o. 2 hiserts his hand-
spike in the bore, and is assisted to lift by N'o. 1 ; N'os. 3 and 4,
with their handspikes, cross-lift under that of No. 2 ; ISTos. 5
and 6 stand ready with their handspikes to thrust them under
the piece as soon as it is raised. At the command Heave from
the gunner, it is raised by l!^os. 1, 2, 3, and 4, and the gunner
places the roller under the muzzle ; Nos. 5 and 6 thrust their
handspikes under the chase, in the position for cross-lifting;
!N'os. 3 and 4 take fresh holds under the chase ; the gunner com-
mands: Heave, and the piece is raised until the gunner can
place the roller under it a short distance in rear of the trun-
nions. The carriage is then run back, as from battery {par.
237), until the muzzle catches on a roller placed on the stock.
■{Fig. 2, Plate 20.) By cross-lifting the piece as before, the
roller on the ground is removed and the piece allowed to j-est
on the roller on the stock.

The stock serves as an inclined plane, up which the piece
moves on the roller. The carriage is now worked back, as yro7w
battery., as far as the trail, under the gun, will allow it to go.

The instructor commands :

1. SiiiNa the piece.

N^os. 7, 8, 9, and 10 run back the limber until the pintle is
slightly in rear of the knob of the cascable, and the wheels are
chocked front and rear. The wheels of the gun carriage are
chocked in front.

The gunner attaches one end of a trace-rope to the eye of the
limber pole, and Nos. 7, 8, 9, and 10 stand ready and raise it at
the command heave from the gunner. {Fig. 2, Plate 20.)

!N"o. 10 holds on to the rope to prevent the pole from going
over too far. The pole having been raised, the gunner draws
the sling-chain up tightly over the pintle and hooks it. Nos. 7,
8, and 9 go to the assistance of No. 10 at the rope, and, at the
command Heave from the gunner, draw the pole down to the
ground. The pole is held down and the carriage is run back, as
jrom battery., until the trunnions nearly or quite touch the trav-
eling trunnion bolts. The roller is chocked in rear, and the
piece secured in this position by laying the middle of a trace-
rope over it just in rear of the trunnions, carrying the ends to
;the front under them and making fast to the axle-tree.

The sling-chain is then unhooked and cast off from the pintle.

The instructor commands :

1. Sling the stock.
The gunner doubles the sling-chain at the middle and, passing

212 MECHANICAL MANCEUVRES.

the bight under the stock from left to right, places it over the
right manoeuvering bolt. l^os. 7, 8, 9, and 10 back the limber
so that the end of the fork will have fall play on the left of the
stock when the pole is raised ; chock the limber-wheels, front
and rear; raise the pole as prescribed in the preceding para-
graph.

The pintle should then be over and slightly to the rear of the
left manoeuvering bolt. Bring up both ends of the sling-chain
behind the left manoeuvering bolt, pass one end around the pin-
tle, taking in all the slack, and fasten the hook in a convenient
link of the other end. The wheels of the limber are now un-
chocked, and, at the command Heave from the gunner, the
pole is hauled down to the ground as in the preceding para-
graph. The stock should now be nearly horizontal ; if it is not,
support the trail with a roller, or any other convenient method,
and, shortening the sling-chain, take a new lift.

The instructor commands :

1. Shift the roller.

{Fig. 3, Plate 20.) No. 2 places his handspike in the bore,
and is assisted by No. 1 ; No. 4 crosses his under that of No. 2,
and is assisted by Nos. 3, 5, 6, 7, and 8 ; Nos. 9 and 10 hold
down the pole. At the command Heave from the gunner, the
gun is raised and the roller is shifted to just in front of the
trunnions.

The instructor commands :

1. Shift the piece.

{Fig, 4, Plate 20.) The trace-rope is cast oflf from the piece ;
the gunner attaches it at the middle to the knob of the cascable,
and passes the ends over the axle of the carriage to Nos. 3, 4, 5,
and 6; No. 2, with his handspike in the bore, is assisted to lift
and bear down by No. 1. At the command Heave from the
gunner, the piece is hauled forward until the trunnions clear
the chin bolts, when the muzzle will at once be borne down,
causing the trunnions to drop into their firing beds. As the
muzzle approaches the ground the handspike must be shoved
into the bore. The pole is raised and the trail allowed to rest
on the ground, the sling-chain disengaged, and the roller re-
moved by the rear.

To dismount the siege gun from its carriage,
{Fig. 5, Plate 19.)
448, The piece being limbered and the wheels chocked, the
instructor causes a roller to be placed under the body of the piecfr

SIEGE GUNS. 215

^s explained in par. 438. The roller is chocked on the side to-
'wards the trail. The instructor then commands :

1. Dismount the piece.

{Fig. 5, Plate 20.) The gunner attaches the trace-rope by
its middle with a double hitch to the knob of the cascable, and
passes the ends to Islos. 9 and 10, who take two turns with them
around the manoeuvering bolts and, hauling taut, stand ready to
ease off when directed ; ;N"os. 3 and 4 remove the cap-squares ;
IsTo. 2 places his handspike in the bore, and is assisted to lift by
No. 1 ; No. 4 crosses his handspike under that of No. 2, and is
assisted to lift by Nos. 3, 5, 6, 7, and 8.

At the command Heave from the gunner, the muzzle is raised ;
the rope is carefully slacked off; the trunnions are eased over
the eye-bolts and allowed to rest on the cheeks ; Nos. 9 and 10
ease off" the rope, and allow the piece to run forward until the
•trunnions clear the cheeks, when the muzzle is depressed and
allowed to rest on the ground. No. 2 pushing his handspike up
the bore for this purpose. The rope is cast oft' and the wheels
unchecked.

The carriage is then run forward as explained mpar. 435, and
the piece allowed to drop to the ground.

In performing this manoeuvre with a single roller, the breech
is sometimes jammed between the cheeks, or the head of the
stock bruised by the knob of the cascable. Both of these diffi-
culties are obviated by using two short rollers, the second one
being rolled down the stock against the first before running the
carriage out.

If the piece is dismounted in this manner on hard, stony soil,
some material, as hay, brush, &c., should be placed to receive it
in its fall.

Note. — In the above or other similar manoeuvres, should no
limber be available, the stock may be temporarily supported in
a horizontal position by any means most convenient.

To shift the siege gun from one carriage to another,
{Fig. 1, Plate 21.)

449. The piece is unlimbered ; the spare carriage, limbered,
with cap-squares and elevating screw removed, is placed with its
pole pointing in the same direction as the trail of the piece, and
two or three yards distant therefrom.

The roller is placed under the body of the piece as in par.
•438.

The instructor commands: 1. Raise the chase. At this

214 MECHANICAL MAN(EUVRES.

command, N'o. 2 inserts his iiandspike in the bore, and is assisted
by ;N'o. 1 ; jS'o. 4 crosses his under that of N'o. 2, and is assisted'
by ]S"os. 3, 5, and 6; the ofunner gives the command Heave, and
tiie chase is raised nntil a wheel-chock, base up, or the butt end'
of a handspike, can be placed by !N"os. 7 and 8 under each trun-
nion.

The instructor causes the trace-rope to be attached by its mid-
dle, with a double hitch, to the knob of the cascable ; the spare
carriage is then backed accurately, wheel to wheel, against the
carriage of the piece, and the wheels chocked ; the ends of the
trace-ropes are passed over the spare carriage to ]N"os. 9 and 10.
The gunner then places the shifting-plank, witli one end on the
head of the stock of the spare carriage, and the other end, beveled
side down, on the stock under the gun. The gunner commands :
Bear down the muzzle, which is done by Nos. 1, 2, 3, and 4,
while the gunner places the roller on the plank about eight inches
in rear of the trunnions. The instructor commands : 1. Shift
THE piece. Nos. 5, 6, 7, and 8 go to the ropes to haul with
Nos. 9 and 10. Those at the muzzle prepare to lift. The gun-
ner commands : Heave, and the piece is moved back until the
trunnions are over the beds on the spare carriage ; another roll-
er is then placed on the stock of the carriage, under the body of
the gun.

The instructor commands : 1. Remove the plank. Nos. 1
and 2 embar with their handspikes over the cheeks of the now
free carriage and under the chase, and are assisted to bear down
by Nos. 3 and 4. The gunner commands : Heave; the chase
is raised ; tlie plank and roller are removed ; the roller is placed
on the head of the stock of the free carriage, and the muzzle
rested on it.

The instructor commands : RuN OUT THE CARRIAGE. Ex-
ecuted as in in battery. {Par. 242.) The piece drops into the trun-
nion beds, after which the roller under the body is removed by
the rear as in par. 439. The cap-squares and elevating screw
are replaced.

To mount the siege gun on the mortar-wagon,
{Fig. 2, Plate 21.)

450. The gun is lying on the ground; the mortar-wagon,
unlimbered, its stakes and bolster removed, is in the prolon-
gation of the piece ; its trail on the ground about two yards f roim
the breech.

The instructor commands ;

SIEGE GUNS. 215

1. Kaise the chase.

Executed as in par. 44:7, except that the sling-chaui is not
placed under the neck of the cascable. After the roller is placed
under the trunnions, tip the muzzle down, and back the mortar-
wagon until the breech catches on another roller placed on the
stock; the wheels are then chocked.

Note. — A limber may be used to sling tlie piece until the
breech rests on the roller placed on the stock, and subsequently
to sling the muzzle clear of the ground to prevent its dragging.

The instructor commands :

1. Rig the windlass.

{Fig. 3, Plate 21.) The gunner lays the middle of the trace-
rope over the piece in rear of the trunnions ; brings the ends
under and around overthe trunnions ; takes two turns with each
end around the middle of the windlass, the standing parts to-
ward the ends ; ISTos. 1 and 2 take hold of the ends of the rope
to hold on and take up the slack ; Nos. 7 and 8 insert the hand-
spikes into the ratchet-sockets, and are assisted by Nos. 9 and
10 ; Nos. 3, 4, 5, and 6, with their handspikes, steady the piece.
At the command Heave from the gunner, the piece is drawn
up the stock. When the roller under the chase becomes free, it
is placed under the breech.

Draw the piece back on the wagon until the trunnions are
about eighteen inches in front of the axle-tree; the gunner re-
places the bolster, and Nos. 3 and 4 chock the rollers front and
rear, and likewise the wheels of the wagon.

Note. — If the wheels are unchocked, the stock will work itself
under the piece and considerably relieve the strain on the ropes.

The instructor commands :

1. Limber up.

Executed as in par. 433, except that Nos. 1 and 2 hold on to
the ropes and prevent them from slipping on the windlass.
The instructor commands :

1. Stow the piece.

{Fig. 4, Plate 21.) ;N"os. 1 and 2 cast off the rope from the
windlass and carry the ends to the front. The gunner changes
the middle of it so that it will cross the gun in front of tlie trun-
nions, ^os. 7, 8, 9, and 10 assist ^os. 1 and 2 to haul upon the
ropes; Nos; 3, 4, 5, and G, with their handspikes, steady the
piece; the rollers are unchocked. At the command Heave
from the gunner, the piece is hauled forward until the breech is

216 MECHANICAL MANCEUVRES.

over its seat in the wagon ; the front roller is chocked and the
nauzzle borne down until the rear roller can be removed; the
breech is then allowed to rest in its seat. The front roller is
removed by raising the chase as explained in par. 436, and the
chase is allowed to rest on the bolster. The stakes of the wagon
are replaced in their sockets.

To dismount the siege gun from the mortar-wagon,

451. The wagon being limbered and the stakes removed, the
instructor commands :

1. Place the roller under the chase.

Executed in a manner similar to that explained in par. 436.
The roller is chocked front and rear. The numbers who lifted
at the muzzle now bear it down, and another roller is placed
under the body of the piece, about eighteen inches in rear of the
trunnions. The bolster is removed, and the instructor com-
mands: Rig THE WINDLASS. Executed as in ^ar. 450. At
the command Heave from the gunner, the piece is hauled back
until the trunnions are about eighteen inches in front of the
axle-tree; both rollers are chocked front and rear.

The instructor commands :

1. Unlimber.

Executed as in par. 434, except that Nos. 1 and 2 hold on to
the ends of the ropes and prevent them from slipping on the
windlass.

Note. — In this operation care must be taken that the gun is
not too far to the rear, thus endangering the tipping over back-
wards of the wagon.

The instructor commands :

1. Lower the piece.

Nos. 1 and 2 ease off the ropes and allow the piece to descend
on the stock. As the rollers become disengaged in rear they are
placed under the piece in front. When the muzzle strikes the
ground, the wheels may be unchocked and the carriage moved
to the i-ear, thus permitting the piece to descend to the ground.

To shift the siege gun from its carriage to the mortar-wagon.

453. The piece and mortar-wagon are both limbered; the
latter is placed in rear of the former, but faced in the oppo-
site direction ; the windlass two or three yards from the muzzle
of the piece. The instructor causes the roller to be placed under
the body of the piece as explained in par. 438.

SIEGE GUNS. 217

He then commands :

1. Haul back the piece.

The gunner attaches the trace-rope, by its midtlle, to the knob
of the cascable, and passes the ends to l^os. 5, 6, 7, 8, 9, and 10.
Nos. 1, 2, 3, and 4 apply themselves as in par. 441. The gunner
•commands HEAVE, and the piece is moved back until the trun-
nions rest on the cheeks just behind the chin bolts.

The roller is removed by the rear as explained in par. 439,
and the wagon is backed up to the carriage, wheel to wheel, and
chocked.

The instructor commands :

1. Shift the piece.

The gunner places the shifting-plank from the head of the
stock to the mortar-wagon, and places the roller on it under the
chase, working it back as far toward the trunnions as practica-
ble, the piece being raised by successive purchases over the
cheeks and under the cliase. Kemove the bolster (which is use-
ful as a fulcrum); a turn is taken around. each manoeuvering
bolt with the trace-rope, which is held by N'os. 5, 6, 7, 8, 9, and
10. At the command HEAVE from the gunner, N'os. 1, 2, 3,
.and 4 bear down on the muzzle and permit the piece to run
forward onto the wagon, wliere the chase is received on a roller.

The roller is removed and the piece stowed as explained in
par. 450.

Note. — The gun may be shifted to the mortar-wagon, (the
piece being limbei-ed,) without a shifting-plank, by the use of a
second roller to receive the body of the gun on the mortar-wagon.
The preliminaries are the same as before; the trunnions being
lield on the cheeks, the roller is placed well up, just in rear
•of them; the trace-rope taut and around the manoeuvering
bolts ; the muzzle is raised, the wagon backed wheel to wheel,
^nd the chase rested on a roller ^vhich is placed on the rear
cross-bar plate, and receives the body of the gun as the first
roller runs off the head of the stock.

To shift the siege gun from the mortar-wagon to its carriage.

453. This operation is executed by means the inverse of
those explained in the preceding paragraphs.

When the trunnions are over their beds, the shifting-plank
and roller are extricated by cross-lifts under the chase, and
the chase allowed to rest on a roller so placed that when the
mortar-wagon is run to the fi-ont the muzzle will clear the wagon
as it drops from the roller; thus permitting the trunnions to fall

218 MECHANICAL MANCEUVRES.

into their beds. Meanwhile the piece is held fast by taking on&
or two turns of the trace-rope round the manoeuvering bolts.

To stand the siege howitzer on its muzzle.

454. The piece is lying on the ground. The instructor
commands :

1. Eaise the chase.

N'os. 1 and 2 insert their handspikes in the muzzle and chock
them on top ; No. 4 crosses his handspike under those in the
muzzle, and is assisted to lift by Nos. 3, 5, and 6; Nos. 7 and 8
assist Nos. 1 and 2. At tlie command HeAVE from the gunner,
the piece is raised and a shifting-plank run under it parallel to-
the axis; a short roller is placed on the plank under the trun-
nions perpendicular to the axis of the piece. The roller is chocked
front and rear.

Tlie instructor commands :

1. Raise the breech.

{Fig. 1, Plate 22.) Nos. 1 and 2 withdraw their handspikes;
No. 2 crosses liis over the muzzle, and is assisted to bear down
by Nos. 1, 3, and 4; No. 6 crosses his under the neck of the
cascable, and is assisted to lift by Nos. 5, 7, 8, 9, and 10. At.
the command Heave by the gunner, the breech is raised until:
tlie muzzle rests upon the ground. The men at the muzzle
hold it in this position wiiile the gunner attaches the middle of
a trace-rope by two half hitches to the middle of a handspike,
and places it under the neck of the cascable ; tfie ends of the rope
are brought up, one on each side of the cascable, and crossed on
the breech ; Nos. 7, 8, 9, 10, the gunner, and chief-of-detachment
man the ropes and hold taut, while Nos. 1, 2, 3, 4, 5, and 6 man
the handspike.

The gunner then commands : Heave ; and all lift and haul
until the piece stands on the muzzle.

To dismount the siege howitzer.

{Fig. 2, Plate 22.)

455. The piece being unlimbered, the instructor commands t

1. Dismount the piece.

The gunner attaclies one end of a trace-rope to one of the
manoeuvering bolts; Nos. 3 and 4 chock the wheels front and
rear ; Nos. 1 and 2 lay their handspikes on tlie ground parallel
to the axis of the piece, in such position that the muzzle, when
it comes over, will rest squarely on their largest part,— or if &

SIEGE HOWITZERS. 219'^

sliifting-plank is used, they place it instead of the handspikes ;
N"o. 10 liolds on to the rope; all the other numbers lift by hand
at the stock ; Xos. 1 and 2 bein<^ nearest tlie axle-tree, and the
other numbers arranoed in their order towards the trail. At the
command Heave from the gunner, the trail is raised until a.
handspike, butt end on the ground, can be placed under it by
iNTo. 9, who, following up the movement, supports the stock. The
gunner repeats the command Heave until the muzzle rests
squarely on the handspikes or shifting-plank ; the numbers at
the stock quit it as the weight passes to the front, and go to the
assistance of No. 10 at the rope.

As soon as the piece rests on the muzzle, N'os. 3 and 4 remove
the cap-squares.

The gunner cautions those at the rope to keep a sliglit strain
on it, and directs Nos. 3 and 4 to move the wheel-chocks to the
rear, an inch or two at a time ; 'Nos. 5 and 6, at the wheels,
move the carriage back ; Nos. 1 and 2 steady the piece; ]N"os. 3
and 4 follow up the movement of the wheels with the front
chocks. The movement is repeated, under tlie direction of the
gunner, until the carriage is backed sufficiently far for the cheeks
to clear the trunnions; No. 9, regulating the position of the
handspike, supporting it at each movement of the wheels, so as
to keep its preponderance to the rear without lowering it so
much as to cause the key bolts to interfere with the piece. The
trail is then lowered by means similar to those for raising it.

A turn with the rope around some secure object will prevent
the danger of the trail falling over.

To mount a siege howitzer,

456. The piece is standing with its muzzle on a shifting-
plank, or on handspikes ; the carriage, unlimbered, is as close to
the piece as practicable and have the heads of the cheeks clear
the trunnions when the trail is raised; the wheels are chocked
front and rear.

The instructor commands ;

1. Mount the piece.

The gunner attaches the trace-rope to one of the manoeuver-
ing bolts ; Nos. 3 and 4 remove the cap-squares. Tiie trail is
raised as explained in the preceding paragraph until it is nearly
vertical, Nos. 7 and 8 passing to the rope after the trail is sup-
ported by the handspike. The trail is raised slowly, No. 10-
being careful that it does not pass the perpendicular, and No. 9-
that the supporting handspike is properly placed. Nos. 3 audi
4, at the direction of the gunner, move the wheel-chocks to the-

^20 MECHANICAL MANCEUVRES.

iront, an inch or two at a time, and ^N'os. 1, 2, 5, and 6, at tiie
wheels, move forward the carriage, Nos. 3 and 4 following up
the wheels with the rear chocks. The trail is kept nearly per-
pendicular, and the handspike adjusted by No. 9. Tiiese move-
-ments are repeated until the trunnions rest in their beds, when
the cap-squares are secured by N"os. 3 and 4 and the trail lower-
ed to the ground. Nos. 1 and 2 assist by lifting with their
handspikes under the heads of the cheeks until they can embar
under the muzzle. All the remaining numbers, except 'No. 9,
haul on the rope. As the weight comes on the stock, the men,
in succession, leave the trace-rope and take hold of the stock,
and lower it by hand to the ground.

Note. — If the piece is standing on the ground, instead of on a
plank or handspikes, raise the trail as before until the trun-
nions rest against the cheeks, near and, if possible, above the
ke3" bolts; put the sling-chain {Fig. 3, Plate 22) around the
piece from behind, the ends brought to the front under the
trunnions; thence up around tiiem and through the trunnion
beds, where they are hooked together ; or, if the links are large
enough, catch two of them on the chin bolts, the chain being in
either case hauled taut. Lower the trail to the ground in the
inverse manner of raising it, as just explained.

If the piece has been well slung the trunnions will rest on the
cheeks, in front of their beds. To get them into their beds, lim-
ber up ; place the roller under the body ; attach the trace-rope by
its middle to the neck of the cascable, and take a turn with the
ends around the axle-tree ; raise the muzzle and slacken care-
fully on the rope until the trunnions are in place ; after which
the roller is removed.

To mount the siege howitzer on its carriage as a mortar,

45 T. The piece is lying on the ground, vent up; the car-
triage, pointing in the opposite direction, is placed so that the
heads of the cheeks are about two yards from the face of the
piece, and then dismounted.

The instructor commands :

1. Mount the piece as a mortar.

The muzzle is raised and a roller placed under the piece, as
explained in par. 4:54:. On soft ground, it will be necessary to
place a shifting-plank under the roller.

The body of the carriage is then moved up by embarring with
handspikes under the manoeuvering bolts and axle, and cross-
difting under the heads of the cheeks, until a shifting-plank can
be placed, (by lifting at the muzzle,) one end on the head of the

SIEGE HOWITZERS. 221

stock, beveled side up, and the other about six inches in rear of
the trunnions. At the time of placing the plank, the roller is
shifted to a point about sixteen inches in front of the trunnions
and chocked. The plank is shored up with the butt end of a
handspike. The gunner lays the middle of the trace-rope over
the piece and takes a round turn from the rear upon each trun-
nion with the ends of it. {Fig. 4, Plate 22.) Through tlie loop-
of these turns, 2^o. 2 passes a handspike, and is assisted at tlie
other end by N^o. 1 in keeping the piece from rolling while it is
being hauled up the plank. The ends of the rope are drawn
taut, crossed over the chase, and manned by ;N"os. 5 to 10 upon
their respective sides. N"os. 3 and 4 embar with handspikes
under the trunnions until the piece is started, and then shift, as
the piece ascends, to a handspike placed crosswise under the
cascable.

The gunner commands : Heave, and the piece is hauled and
pushed until its trunnions rest over their beds, when the roller
is chocked and the rope removed ; the breech is raised, the
roller and plank removed, and the trunnions lowered into their
beds ; the cap-squares are replaced. By raising the trail and
sustaining it in that position with blocking or b}" a bank of earth,
an elevation of about 40 degrees can be obtained, and by exca-
vating under the breech a still higher degree. The trail may
be used as a lever in pointing.

The service of the piece is almost the same as when it is^
mounted in the usual maimer. It is found in practice that the
recoil is very slight, the centre of gravity being nearly over the
axle.

To dismount the howitzer.

45$. Let down the trail and raise the muzzle until a wheel-
chock, base up, can be placed in each trunnion bed ; raise the
breech and place the shifting-plank and roller on the head of
the stock ; the i-oller should be just within the cheeks and chocked
in rear ; raise the trail by cross-lifting until the trunnions are
free from the key bolts. The chock of the roller is then knocked
out by the gunner, and the piece allowed to run dow^n the plank
upon the ground. The plank should be shored up as before, and'
those near the piece must stand clear.

:222 MECHANICAL MANCEUVRES.

Ranges of iJie S-inch howitzer mounted as a mortar.

Charge.

Projectile.

Elevation.

Range.

Time of
Flight.

Ounces.

Shell— Lbs.

Degrees.

Yards.

Seconds.

330

620

1080

14.75

1135

15.37

1440

16.42

1925

Spherical case can be used with great effect against troops in
trenches if made to burst fifty or one hundred feet before reach-
ing the ground.

The charge should not exceed one-half of the service charge
of the piece.

To dismount a siege carriage and its limber.

459. The carriage being without its piece, and unlimbered,
the wheels are removed in succession.
To remove the right wheel, the instructor commands :

1. Dismount the right wheel.

No. 1 crosses his handspike from the front, under the axle-
tree, as near the wheel as possible, and is assisted to lift by N"os.
2, 3, and 4; Kos. 5, 6, 7, and 8 lift at the other end; Nos. 9
and 10 remove the linch-pins, and apply themselves to the wheel.
The gunner commands : Heave; the wheel is removed and the
axle-tree lowered to the ground, or on a block.

The left wheel Is taken off in a corresponding manner.

The carriage may be mounted in a similar manner.

It may sometimes be advantageous to raise the carriage to tlu-
necessary height by successive purchases, with handspikes as
levers, and support it on props. The limber may also be used
to lift the carriage, but it will generally be found more expedi-
tious to mount it as above described.

The limber is readily dismounted and mounted by passing the
long handspikes between the sweep-bar and axle-tree, the butt
ends resting on the splinter-bar ; six men lift on the handspikes
and two at each wheel.

The mortar-wagon may be dismounted in like manner, the

SIEGE MORTARS. 223

-meii taking hold of the rails and handspikes passed under the
windlass and over the axle-tree.

To change or grease a wheel. The lifting-jack is applied under
the axle-tree near the wheel to be removed, or the wheel may
be removed by using handspikes as levers and blocks as f iil-
crums, under the axle-tree ; tlie axle may be temporarily sup-
ported by a prop.

By using the trail as a lever, a wheel may be changed, when
the piece is unlimbered, as follows : Raise the trail as in limber-
ing, and place a prop, about thirtj'^ inches in length, under the
cheek close in the rear of the axle-tree on the side on which the
wheel is to be changed. Bear down on the trail and the wheel
will clear the ground.

Mechanical Manceuvres with 10-inch Siege Mortar.

460. The implements required are those habitually accom-
panying each piece and the mortar-wagon, viz.: Four hand-
spikes (mortar), two 7ianc^5piA:e5 (manoeuvering), one trace-rope^
one hammer - wrench, two lo7ig rollers, foitr roller-chocks, six
wheel-chocks, two handspikes (windlass).

To stand the mortar on one of its trunnions,

{Fig, 5, Plate 22.)

461. The mortar iis lying on the ground or on its platform.
The instructor commands :

1 . Stand the mortar on the right (or left) trunnion.

The gunner passes the middle of the trace-rope around one of
the trunnions from underneath ; the ends are carried over the
mortar and manned by all the cannoneers. The gunner then
commands : Heave, and the piece is pulled over on its trun-
nion.

To stand the mortar on its muzzle,

(Fig. 6, Plate 22.)

462. The piece is standing on one of its trunnions. The
instructor commands :

1. Stand the mortar on its muzzle.

The gunner passes the middle of the trace-rope under the
mortar in front of the trunnion ; carries the ends back, crosses
them over the breech and passes them to the front, one on eacli
side of the upper trunnion. He then commands : Heave, and

224 MECnANICAL MANCEUVRES.

the piece is hauled over on its muzzle by the rest of the detach-
ment at the trace-rope.

To slue the mortar,

463. The mortar being on its muzzle, the iiistructor indi-
cates the direction in which it is to be slued, and commands :

1. Slue the mortak.

ISTos. 5 and 6 embar against the trunnions on opposite sides,
and, at the command Heave by the gunner, turn the piece about
its axis. To shift the piece when in this position, N'os. 5 and &
embar on the same side.

To dismount the mortar.

464. The mortar is on its carriage, which is on the platform
or on the ground. The instructor commands :

1. Dismount the mortar.

The gunner, assisted by ]S"o. 4, gives the mortar an elevation
of twenty-one degrees, or, if no quadrant is at hand, brings the
plane of the face of the piece tangent to the front ends of the
cheeks; he then throws the bight of the trace-rope over the
middle of the pipe, and, drawing the ends through the loop,
passes them to the rear to Nos. 7, 8, 9, and 10, who haul on them
with sufficient force, when the carriage has been raised, to keep
it from falling to the front ; N'o. 2 passes a handspike under the
rear notches and over the rope ; the cannoneers man the hand-
spike in the following order from right to left : N^os. 1, 3, 5, 6,
4, 2, all facing to the front. The gunner commands : Heave ;
the cannoneers at the handspike lift on it until the face of the
piece rests upon the platform or ground. {Fig. 7, Plate 22 .>
The cap-squares are removed by Nos. 3 and 4, assisted by Nos.
1 and 2, and placed in rear of their posts, the nuts ou the cap-
squares.

The instructor commands :

1. Lower the carriage.

The cannoneers man the handspike and rope as before. The
gunner commands : Heave. The cannoneers haul upon the
rope, and the four nearest the mortar leave it in succession, ap-
plying themselves to the handspikes as the weight comes upon
it, to prevent any unnecessary shock. The cap-squares are re-
placed by Nos. 3 and 4 ; N'o. 2 removes the handspike, and the
gunner the trace-rope.

SIEGE MORTARS. 225

To mount the mortar.

465. The mortar is standing upon its muzzle ; the front of
the carriage eighteen inches from it, on the side opposite the
vent.

The instructor commands :

1. Mount the mortar.

The cap-squares are removed by Nos. 3 and 4 and placed, with
their nuts, in rear of their posts. The gunner attaches tlie trace-
rope to the pipe, and the cannoneers apply themselves to the
rope and handspike as described in the preceding paragraph.
The gunner commands : Heave; and when tlie weight of the
carriage is fairly supported by the rope, Nos. 3 and 4 take their
handspikes and, embarring against the manoeuvering bolts, move
the bed as may be necessary until the trunnions are in their beds.
Assisted by Nos. 1 and 2, they put on the cap-squares.

The instructor then commands :

1. Lower the mortar.

Nos. 3 and 4, facing to the rear, embar with their handspikes
under the cap-squares, and subsequently under the front notches ;
the other cannoneers apply themselves at the rope and hand-
spike, and the mortar is lowered as described in par. 464.

To mount the mortar upon the mortar-wagon.

466. The mortar is on its carriage ; the carriage, on the plat-
form or on the giound ; the trail of the mortar-wagon, its stakes
and bolster removed, is about two yards from the pipe and per-
pendicular thereto.

The instructor commands :

1. Eaise the mortar.
Executed as prescribed in par. 464, except that the mortar
need not be given any particular elevation, and, instead of
allowing it to go over until the muzzle strikes the ground, the
carriage is poised in nearly a vertical position by N'os. 1, 2, 3, 4,
6, and 6, while Nos. 7 and 8, embarring with handspikes under
the stock of the wagon, guide it under the mortar carriage mid-
way between and parallel to the cheeks ; Nos. 9 and 10 working
at the wheels. The stock is run under the carriage as far as
practicable and the wheels chocked front and rear; the long
roller is placed on it by the gunner in such position that when
the carriage is lowered its point of contact with the roller will
be twenty inches from the toes of the shoes ; the moitar is then
lowered upon the roller.

226 MECHANICAL MANCEUVRES.

The instructor commands :

1. KiG THE WINDLASS.

The gunner lays the middle of the trace-rope across the rear
notches ; ISTos. 1 and 2 pass the ends underneath and around the
rear manceuveriiig bolts, and, carrying them to tiie rear, take two
turns with them around the windlass. The windlass is manned
as explained in par. 450, and is worked at the command Heave
from the gunner.

As soon as the mortar is in motion, the second long roller is
engaged undei* the shoe, by N"os. 3 and 4, twenty inches from
the lower roller, measuring from axis to axis. The lower roller
will then disengage just as the mortar is balanced on the upper
roller. iNTos. 5 and 6 steady the mortar with handspikes.

As soon as the lower roller is disengaged, it is taken out by
Nos. 3 and 4, who again engage it twenty inches above the other
roller. The mortar is drawn back on the last roller until the
heels of the shoes abut against the hurters on the rear cross-bar
plate. The roller is now chocked in front, and particularly in
rear., by Nos. 3 and 4.

The instructor commands :

1. LEMffiER UP.

Executed as in par. 450.

The gunner then secures the lashing-chain.

In raising the stock, in limbering and unlimbering, great care
must be taken not to raise it so high as to endanger the over-
tmniing of the wagon to the rear.

The instructor commands :

1. Stow the mortar.

No. 4 removes the front roller-chock, and satisfies himself that
the rear roller-chock is in place ; iN'os. 5 and 6 embar over the
side rails and under the shoes, near the rear notches, to cant
the carriage to the front ; Nos. 1 and 2 ease away gently, and
permit the carriage to move forward on the roller until the
front notches are over the front cross-bar plate. If the car-
riage does not move far enough forward on the roller after
canting, N"os. 5 and 6 embar over the side rails and under the
front notches, and pinch the carriage forward to its place. The
roller is then removed from the rear, and the carriage lowered
onto the wagon by repeated purchases, the disengaged roller-
chocks and bolster being placed by the gunner as f ulcruras on
the rear of the wagon. If the mortar is to travel, its carriage is
securely lashed to the wagon.

SIEGE MORTARS. 227

467. The most convenient way of carrying tlie implement?,
is to fit a bed to the mortar-wagon. The bed is made of stout
boards about a foot wide ; those for tlie sides are lield in place
bj'' rope beckets passed through auger holes in the boards and
around the stakes of the wagon ; the end boards fit between
cleats nailed to the ends of the side boards; the whole forming
a box about seven feet long, with a width equal to the widtli of
the wagon. Slots are cut in the side boards for the manoeuver-
ing bolts, which project slightly beyond the side rails of the
wagon.

To dismount the mortar from the wagon,

468. The mortar is unlashed ; the implements, bolster, and
stakes of the wagon are removed.

The instructor commands :

1. Dismount the mortar.

Nos. 5 and 6 embar over the side rails and under the rear
notches, using chocks and bolster as fulcrums, and by repeated
purchases raise the mortar carriage until a long roller can be
placed under it with the points of contact two feet from the toes
of the shoes.

The instructor then commands :

1. Rig the windlass.

The gunner attaches the trace-rope, and the windlass is rigged
as explained in par. 450. At the command Heave from the
guimer, the mortar is drawn back against the hurters, Nos. 5
and 6 embarring under the shoes and over the side rails, to ease
the carriage when it cants to the rear; Nos. 3 and 4 chock the
roller front and {especially) rear.

The instructor commands :

1. Unlimber.

Executed as explained in par. 451.
The instructor commands :

1. Lower the mortar.

Nos. 1 and 2 slack off" on the rope, and the mortar is eased
down the stock. The second long roller is engaged under the
front of the carriage as soon as tlie mortar cants to the front,
so tliat the distance between the rollers, measuring from axis to
axis, shall be twenty inches; the rollers are shifted in this man-
.n<n- by Nos. 3 and 4 until the carriage rests on the ground ;
^05. 5 and G, with their handspikes, steady the mortar while

228 MECHANICAL MANCEUVRES.

being eased down the stock; N'os. 3 and 4 unchock the wheels,,
and the wagon is run back b3'' ^N'os. 5 and 6 at the stock, and-
Nos. 7, 8, 9, and 10 at the wheels. The rope is removed b^' IN'os.
1 and 2 and the gunner. The long roller is removed as it was
placed under the carriage. {Par. 466.)

To mount and dismount the 8-inch mortar on mortar-wagon.

Executed in a manner similar to that explained for the 10-
inch mortar.

For transportation, three 8-inch mortars can be carried on the
mortar-wagon. They are stowed transversely to the wagon, one
poMiting to the right and two to the left, or vice versa^ and
securely laslied in this position.

To dismount the IS-inch mortar., and to mount it.

469. Implements : Eight whole blocks^ eight half blocks., four
quarter blocks., four handspikes (manoeuvering), one sledge-ham-
mer., four chocks (roller), one quadrant., one hammer-wrench., one
nut-wrench (large), two nut-wrenches (small), one two-foot rule.

The instructor commands :

1. PrEPABE to dismount the MORTAR.

Remove all implements, and place them outside the platform ;
take off the steps, diagonal braces, eccentric sockets, wheels, axle,
and cap-squares ; give the mortar an elevation of five degrees,
in order that it will rest level when on the blocks.

1. Dismount the mortar.

{Figs. 1 and 2, Plate 23.) Embar with the long handspikes
under the rear notches, using blocks as fulcmms, and b}'- succes-
sive purchases raise the carriage until a whole block can be
placed under the shoes, its front directly beneath the rear tran-
som ; place two wliole and one quarter block under tlie mortar,
in rear, and the same in front of the trunnions; lower the car-
riage gently onto the platform, being careful to chock the mor-
tar as soon as it touches the blocks; remove the rear transom
and pipe, and lay the cheeks down upon the ground.

1. Prepare to mount the mortar.

Raise the cheeks and place them with the trunnion beds under
the trunnions ; put in the rear transom and pipe.

1. Mount the mortar.

Embar as before under the rear notches, raising the carriage
until the mortar is lifted clear of the blocks ; remove the blocks.

13-INCH MORTAR. 229

and lower the carriao^e gently to the platform. Give the mortar
an elevation of 45 degrees, and replace the cross-braces, axle,
wheels, eccentric sockets, steps, cap-squares, and implements.

In this manoeuvre care must be taken to raise the rear part of
the cheeks equally, so that the great weight of the mortar may
not sway the cheeks sideways and warp the carriage out of true
shape.

41'0. When a garrison gin is available, the best method is
to make use of it. The block is hooked into a clevis attached to
the clevis lug. When there is no clevis lug a bail must be used.
It is necessary to remove the upper step or transom of the car-
riage, and level the mortar, before hoisting.

In the absence of a gin, the mortars may be dismounted with
the hydraulic-jack and blocks. The steps, diagonal braces, and
transoms, excepting the pipe, are removed, and the muzzle de-
pressed two degrees, the breech resting on the scaffolding and
chocked on each side. The Jack is placed under the muzzle, and
the mortar is raised until its weight is off the trunnion beds. A
scaffolding under the muzzle sustains the mortar in this position,
and the cheeks are taken apart and removed.

To place the 13-inch mortar and carriage on rollers.

471. The following implements are necessary : Four rollers
(78 inches long), four whole blocks^ four half blocks^ two quarter
blocks^ and four chocks (rollei*).

Embar under the rear notches perpendicular to the cheeks,
and raise the rear of the carriage until a quarter block can be
inserted under each shoe. These quarter blocks are worked to
the front by successive purchases until half blocks can be in-
serted in place of the quarter blocks. The half blocks are worked
to the front as before until a roller can be inserted under the
shoes.

This roller is worked to the front until it is nearly under the
eccentric axle, and another roller is placed behind it near the
heels of the shoes. The rollers are chocked front and rear.
Embar under the front notches and cant the mortar to the rear
on both rollers.

The mortar may then be moved short distances by attaching
blocks and tackle to it. Wa3^-planks are placed on the ground
for the rollers to run on.

To raise a Id-inch mortar from the ground and place it on blocks,

{Fig. 3, Plate 23.)
4*72. Build a scaffolding of blocks, about a yard from the
jipiece, on each side of it ; lay a stout skid across the mortar on

230 MACHINES AND APPLIANCES

these scaffolds, and lash the mortar, by means of sling-chains^
to this skid. If there is no clevis lug on the mortar, trunnion
rings or a bail mnst be used. Apply the jack alternately under
the ends of the skid, and raise them a few inches at a time, each
time blocking up on the scaffolds.

By this means the mortar can be raised and blocks placed
under it. If a jack is not available, a stout lever will answer to
raise the ends of the skid.

To transport a \^~inch mortar on sling-carts.
(Fig. 4, Plate 23.)

4*73. The piece is raised, as just explained, on blocks about
fifteen inches from the ground. Two sling -carts (large) are
placed, one in front and the other in rear, with their poles point-
ing in opposite directions and their wheels about eighteen inches
apart. Upon the sling-carts place two heavy skids, with a space
of about six inches between them. Across the skids place a
stout beam, around which suspend the mortar by means of sling-
chains passing down between the skids to tlie clevis lug, bail, or
trunnion-chains. The blocks underneath the mortar are re-
moved either with a jack or by means of a lever.

The pole of one of the carts is attached to a field limber, to
which horses are hitched. When the ground is soft, way-planks
should be placed under the cart-wheels.

To obtain greater freedom of motion for turning, a temporary
bolster should be placed on the front cart. A liole is made
through the bolster for the screw of the cart to pass through,
and to hold the bolster to the axle-tree. Notches should be
made in the skids to fit the bolsters of the carts, to keep them
from slipping.

MACHINES AND APPLIANCES FOR MOVINa
HEAVY ARTILLERY.

41'4. The machines and appliances usually employed for
moving heavy artillery are :

Ropes, blocks, and Railway truck. Hand-cart.

tackle. Cradle. Blocks (whole, half,.

Gins. Gun-lift. and quarter).

Hydraulic-jacks. Capstan. Waj-planks.

Sling-carts. Derrick. Pinch-bars.

Casemate truck. Shears. Mortar-wagon.

Truck- waffon. Blocks and skids. Collar.

FOR MOVING HEAVY ARTILLERY. 231

Tliese, with the implements used in the mechanical manoeu-
vres witli siege pieces, are sufficient to mana<ye the heaviest pieces
of artillery in all cases vvhicli ordinarily present themselves in
service.

4:75. All implements and machines, before being used, should
be most carefully examined in every detail, to see that they are
serviceable and suitable for the operation to be performed.
None should be put to uses for which tlie}'' are not intended,
nor subjected to strains they are not constructed to bear.

It must be borne in mind that the giving way of one part
breaks and destro3^s other parts, frequently to an extent not
readily repaired, and, furthermore, endangers those working
at the manoeuvre. Heavy weights must never be allowed to
drop^ even for the sliortest distances ; they must be lowered to
rest with a gentle motion, and at the same time chocked to pre-
vent rolling or sliding. In hoisting, the}'' must, when practica-
ble, be closely followed up with blocks and chocks to guard
against any possible giving way. All motions with heavy bodies
must be slow, so as not to generate momentum.

Supports must have a firm base, and scaffolding a level foun-
dation, and be built up vertically. All holdfasts must be secure
beyond possibility of giving way.

Cordage.
{Plates 24, 25, 26, 27, 28.)

4:'Y6. A rope is composed of threads of hemp or other fibrous
material. These threads are called yarns. A number of these
yarns twisted together form a strand, and three or more strands
twisted together form a rope.

The ropes in ordinary use are composed of three sti-ands laid
right-handed, or, as it is called, with the sun. Occasionally a
large rope will be found laid up in four strands, also with the sun.
This is generally used for stationarj' rigging, such as shrouds,
guys, heavy gun-slings, &c., and is sometimes called shroud laid.
Small halyards are sometimes laid with four strands and a core;
this kind of rope runs more smoothly and wears longer.

Cable-laid rope is composed of nine strands, and is made by
first laying up three ropes of three strands each, with the sun,
and then laying the three ropes up together into one, against
the sun.

Right-hand rope must be coiled with the sun, and cable-laid
rope against the sun.

The size of rope is always given in inches and fractions, and
is measured on the circumference, for the reason that it is seldom

232 MACHINES AND APPLIANCES.

possible to ^et a squarely-cut end in order to measure the diam-
eter. In making requisitions for rope, it sliould be clearly indi-
cated tiiat this measure is the one considered.

Spun-yarn is made by twisting together ver}'' loosely two or
more well-tarred yarns, and is designated by the njunber of
yarns ; as, two-yarn, three-yarn, &c. It is used for serving, seiz-
ings, stops, &c., and is very pliable.

Marline is also made of tarred yarns, but is tightly twisted,
and is much harder and smoother than spun-yarn. It is not fit
for serving when the rope served is to be bent up, as it is not
pliable enough to cover the rope in such cases.

4'Yf . The bight of a rope is any part not an end.

A bight is formed by bending or doubling the rope so as to
form a loop.

This distinction should be particularly noted, and the two
terms should not be confounded.

The interstices between the strands of a rope are called thejaio^
and rope is called long or short jawxd as it is loosely or tightly
laid up togethei".

Those ropes which are stationary are called standing rigging ;
as, guys for a gin, gun-slings, &c. Those which run through
blocks or pulleys, such as gin-falls, trace-ropes, &c., are running
rigging.

418. Worming a rope is filling up the divisions between the
strands by passing spun-yarn along them, to render the surface
smooth for parceling and serving.

Parceling a rope is wrapping narrow strips of canvas about it,
well tarred, in order to secure it from being injured by rain
water lodging between the parts of the service when worn. The
parceling is put on with the lay of the rope. Parceling is also
used to prevent chafing or cutting of a rope when a strain is
brought against a rough surface or sharp edge. For this pur-
pose old rope or canvas wound around is sufiicient.

Serving is the laying on of spun-j'arn or other small stuflFin turns
round the rope, close together, and hove taut by the use of a
serving board for small rope and serving mallet for large rope.
Small ropes are sometimes served without being wormed, as the
crevices between the strands are not large enough to make llu;
surface very uneven; but a large rope is always wormed and
parceled before being served. The service is put on against the
lay of the rope.

Whipping is securing the end of a rope with twine to prevent
it from fraying out. For temporary use it may be done by wind-
ing twine about the end of the rope and securing the end of the
twine by passing it under two or more turns of the twine and

CORDAGE. 233

pnllino^ it tight. It is better, however, to secure the ends by sevv-
iiii>- tliem through the rope, so that each stitch lies in the division
between two strands. This is called a sewed whipping.

4f 9, Splicing is putting the ends of ropes togetlier by open-
ing tlie strands and placing them into one anotiier, or by putting
the strands of the ends of a rope between those of the bight.

A short splice. Unlay the strands for a convenient length ;
then take an end in each hand, place them one within the other,
;and draw them close. Hold the end of one rope and the tliree
strands which come from the opposite rope fast in the left hand,
or if the rope be large, stop them down to it with a rope-yarn.
Take the middle strand, which is free, pass it over the strand
which is first next to it, then through under the second and out
between the second and third from it, then haul it taut. Pass
each of the six strands in the same manner; first those of one
end and then tliose of the otiier. The same operation may be
repeated with each strand, passing each over tiie third strand
from it, under the fourth, and through ; or, as is more usual,
after the ends have been stuck once, untwist each strand, di-
vide the yarns, pass one-half as above described, and cut off the
other half. Tliis tapers the splice.

A long splice. Unlay the ends of two ropes to a distance three
or four times greater than for a short splice, and place them
within one another as for a short splice. Unlay one strand for
& considerable distance and fill up the interval which it leaves
with the opposite strand from the other rope. Twist the ends
of these two together, then do the same with two more strands.
The two remaining strands are twisted together in the place
where they were first crossed. Open the two last-named sti-ands,
divide in two, take an overhand knot with the opposite halves,
and lead the ends over the next strand and through the second
as the whole strands were passed for the short splice. Cut off
the other two Imlves. Do the same with the others that are
placed together, dividing, knotting, and passing them in the
same manner. Before cutting off any of the half strands., the
rope should be got well upon a stretch. Sometimes the whole
strands are knotted, then divided, and the half strands passed
as above described. This splice does not increase the diameter
of the rope, and is used for splicing a fall or other rope that runs
through blocks or pulle3''S.

An eye-splice. Unlay the end of a rope for a short distance
and la}'^ the three strands upon the standing part, so as to form
an ej^e. Put the first end through the strand next to it. Put
the second end over that strand and through the second, and put
Ihe remaining end through the third strand on the other side of

234 MACHINES AND APPLIANCES.

the rope. Taper them, as in the short splice, by dividing the-
strands and sticlving them again. This is used to form a perma-
nent loop in the end of a rope.

A grommet. Talce a strand Just unlaid from a rope, with all
its turns in it, and form a ring of the size j^ou wish by putting
the end over the standing part. Then take the long end and
carry it twice round the ring in the crevices, following the lay
until the ring is complete ; then take an overhand knot with the
two ends, divide the yarns, and stick them as in a long splice.
Used for a trunnion loop for rolling or sluing a gun.

4 SO. Two half hitches. Pass the end of a rope round the
standing part and bring it up through the bight. This is a half
hitch. Take it round again in the same manner for two half
hitches.

A clove hitch is made by passing the end of a rope round a spar,,
over, and bringing it under and round behind its standing part,
over the spar again and up through its own part. It may then,
if necessary, be stopped or hitched to its own part; the only
difference between two half hitches and a clove hitch being
that one is hitched round its own standing part and the other
is hitched round a spar or another rope.

Round turn and two half hitches. Take a round turn around
the stakes or posts, and secure the end by two half hitches
around the standing part. This is very useful in securing the
guys of the gin to the stakes.

A bowline knot. Take the end of a rope in your right hand
and the standing part in your left ; lay the end over the stand-
ing part, and with the left hand make a bight of the standing
part over it; take the end under the lower standing part up
over the cross, and down through the bight. This is very useful
in forming a temporary ej^e at the end of a rope.

Square knot. Take an overhand knot round a spar; take an
end in each hand and cross them on the same side of the stand-
ing part upon which they came up; pass one end round the
other, and bring it up through the bight. This is sometimes
called a reef knot. If the ends are crossed the wrong way,
sailors call it a granny knot.

A timber hitch. Take the end of a rope lound a spar, lead it
under and over the standing part, and pass two or more round
turns around its own part ; pass the first turn over the end part
instead of thiough the bight, as in a half hitch. Used in secur-
ing the ends of the trace-ropes to the manoeuvering bolts.

A rolling hitch. Pass the end of a rope round a spar ; take it
round the second time, nearer to the standing part; then carry
it across the standing part, over and round the spar and up

CORDAGE. 235-

throiii^h the bight. A strap or a tail block is fastened to a rope
by this hitch. Used in sbiftin,i>- the fall from one end of the
windlass to the other. (See nipper and screw.)

A hlackwall hitch. Form a bight by putting the end of a rope
across and under the standing part ; put the hook of a tackle
through it, the centre of the bight resting against the back of
the hook, and the end jammed in the bight of the hook by the
standing part of the rope.

A cafs-paw. Make a large bioht in a rope, and spread it open,
putting one hand at one part of the bight and the other at the
other, and letting the standing part and end come together;
turn the bight over from you three times, and a small bight will
be formed in each hand ; bring the two small bights together,
and put the hook of a tackle through them both. This is very
useful in applying a purchase or taclde to the fall of another.

A sheet bend (weaver's knot). Pass the end of a rope up
through the bight of another, round both parts of the othei-, and
under its own part. Tliis does not jam, and is useful in tying
two ropes together.

Carrick bend. Form a bight in a rope and lay the end across
the standing part ; stick the bight of another rope up through
the loop thus formed, and carry the end over the end of the
first rope, under the standing part, and through the loop formed
by its own bight ; stop each end to its own standing part.

Fishermari's bend (anchor knot). Take two turns around the
gun-slinir or spar with the end of the rope ; hitch the end around
the standing part and through both turns, and then pass the
end over the second and under the first turn.

A sheep shank. Make two long bights in a rope which shall
overlay one another; take a half hitch over the end of each
bight with the standing part which is next to it. Used to shorten
a rope temporarily.

A marlinspike hitch. Lay the marlinspike upon the seizing
stuff, and bring the end over the standing part so as to form
a bight; lay this bight back over the standing part, putting the
marlinspike down through the bight, under the standing part,
and up through the bight again. Very useful in putting on
lashings, &c.

Stopping is fastening two parts of a rope together, as for a
round seizing, without a crossing or riding.

Nipperinq is fastening them by taking turns crosswise between
the parts to jam them, and sometimes with a round turn before
each cross. These are called racking turns. Pass riders over
these and fasten the end. This is a convenient way to secure a.
fall while it is being shifted on the windlass.

236 MACHINES AND APPLIANCES.

A screw is applied by weaving a light strap through the differ-
ent parts of a fall, bringing the two ends together, and screwing
the whole up tight by means of a stick or bar passed through
the bights.

A strap^ or sling^ is formed by knotting or splicing together the
ends of a short strand or rope. It is used for hooking tackles
into.

Pointing. Unlay the end of a rope and stop it ; take out as
many yarns as are necessary, and split each yarn in two, and
take two parts of different yarns and twist them up taut into
nettles; the rest of the yarns are combed down with a knife ;
lay half the nettles down on the scraped part, the rest back upou
the rope, and pass three turns of twine taut round the part
where the nettles separate, and hitch the twine, which is called
the warp; lay the nettles backwards and forwards as before,
passing the warp each time. The ends may be whipped and
snaked with twine, or the nettles hitched over the warp and
hauled taut. The upper seizing must be snaked. If the upper
part is too weak for pointing, put in a piece of stick. This is an
elaborate way of whipping ropes, and requires considerable prac-
tice.

Frap. To pass a rope around a lashing to keep the turns
together.

Seizing a rope is connecting the two parts with smaller rope,
or spun-yarn. Take a piece of spun-yarn and double it ; pass the
bight under the two parts of the rope to be seized ; put both
ends through it and haul taut, using a lever applied with the
marlinspike hitch ; separate the ends, pass them around the rope
in opposite directions until enough turns are taken, hauling
each turn taut, and seeing that they lay close and smooth.
Cross the seizing by passing the ends in opposite directions be-
tween the ropes and around the seizing, and finish with a square
knot.

A lashing is applied on the same principles. After sufficient
turns have been taken, the lashing is /rapped by taking the ends
around the turns, hauling them close together, and making the
lashing tighter, of course.

To pass a shear lashing. Middle the lashing and take a turn
round both legs at the cross; pass one end up and the other
down, around, and over the cross, until half of the lashing is
expended ; then ride both ends back again on their own parts
and knot them in the middle ; frap the first and riding turns
together on each side with sennit. This will be useful in rigging
shears for hoisting guns, when a gin is not available. Any two
spars that will support the weight can be used.

CORDAGE.

237

To sling a barrel with both heads in, or a box. Lay it on its
side; lay a lono: strap under it, spreading the parts; pass one
bi;^ht through tlie other, on top of the barrel, and hoolv on to it.

If one head of the barrel is out. Stand the barrel up; put
one part of a strap under the middle of the bottom; take a half~
hitch over the top with each part, the hitclies exactly opposite
to each other and just above tlie upper bilge hoops. Hook on
to the bight as before. Tliose hoops applied near the ends of a
barrel are the ''c/ime," and those near the centre the "'bilge '*
hoops.

Table showing the weight which Manila rope in daily use will
sustain^ singly and when rove in tackles.

481. Sismj? rope is about one-third stronger. Due allowance
has been made for loss of strength by wear and tear.

Look for the weight to be raised, or the next larger, in the
column lieaded with the number of sheaves in the purchase or
tackle. The circumference of the rope required will be found
on the same line in tlie left-hand column.

CiRCUlkrFEEENCE
IN IXCHES.

1....

1%.

2....

2h.

2%.
3...

3%.
354.
4....
4^.
4H-
454.
5....
5M.
5%.
5?4.
6....

Single.

6^.
6?4.
7....

540

844

],215

1,654

2,160

2,734

3,375

4,084

4,860

5,704

6,415

7,594

8,640

9,753

10,935

12,184

13,500

14,884

16,335

17,954

18,252

19,805

21,421

23,100

24,843

32,448

Number of Sheaves in Pukchasb.

1,080

1,688

2.430

3,308

4,320

5,468

6,750

8,168

9,720

11,408

12,830

15,188

17,280

19,516

21,870

24,368

27,000

29,768

32,670

35,908

36,504

39,610

42,842

46,200

49,786

64,896

1,350

2,110

3,038

4,185

5,400

5,835

8,438

10.210

12,150

14,260

16,048

18,985

21,600

24,393

27,338

30,460

33,750

37,210

41.838

44,885

45,630

49,513

53,553

57,750

62,208

81,120

1,485

2,321

3,342

4,549

5,940

6,519

9,282

11,231

13,365

15,686

17,657

20,884

23,760

26,831

30,072

33,506

37,125

40,931

45,922

49,873

50,193

54,465

58,908

63,525

68,418

89,232

1,620
2,582
3,645
4,962
6,480
8,202
10,125
12,252
14,580
17,112
19,245
22,782
25,920
29,259
32,705
36,552
40,500
44,652
49,005
53,862
55,756
59,415
64,263
69,300
74,529
97,344

1,755

2,743

3,949

5,376

7,020

8,886

10,969

13,273

15,795

18,538

20,854

24,681

28,080

31,697

35,529

39,598

43,875

48,373

53,089

58,350

60,319

64,367

6.1,618

75,075

80,740

105,456

.238

MACHINES AND APPLIANCES.

To ascertain the strain in pounds which a rope will bear witli-
out breaking, multiply the square of the circurriference by the tab-
ular number.

Dbscbiption.

Hemp MM. M^

Manila

Inches.

2.5 to 6
6 to 8
2.5 to 6
6 to 12

"White.

3-strand. 4-strand.

1140

1090

810

760

1330

1260

950

835

Tarbbd.

3-strand. 4-strand

850
825

1000
940

For ropes in daily use^ the unit should be diminished one-third
to meet the reduction in strength by wear and exposure.

A safe general rule for all ropes is this : One-fourth the square
of the circumference gives the breaking weight in tons of 2000
pounds.

When using tackles, multiply the weight thus found by one-
half the number of sheaves in the blocks.

Straps are applied by passing them around the object, putting
one bight through the other, and hooking to this ; or, after put-
ting it through, winding all the strap around the rope or spar,
and hooking to both bights.

Preservation in store. Ropes should be placed in the upper
stories of buildings, coiled up and labeled ; large ropes on skids,
allowing free circulation of air; small ropes hung up to the
joists, on pins or hooks. Ropes should not be coiled until per-
fectly dry ; they should be uncoiled evei-y year, and stretched
out for several days in the dry season. Ropes long in store lose
their strength.

Blocks, Tackles, &c.

{Plates 29 and 30.)

482. Blocks are of two kinds, made and mortised, A made
block consists of four parts : the shell, or outside ; the sheave, or
wheel on which the rope turns ; the pin, or axle on which the
wheel turns; and the strap, either of rope or iron, which encir-
cles the whole and keeps it in its place. The sheave is generally
strengthened by letting in a piece of iron or brass at the centre,

BLOCKS, TACKLES, ETC. 239

called a hush. IN'earl}'^ all heav}'' blocks for ordnance purposes
are made with iron shells and brass sHeaves.

A mortised block is made of a single block of wood, mortised
out to receive a sheave.

All blocks are single, double, or threefold, according to the
number of sheaves in them.

There are blocks that have no sheaves, to wit : a hulVs-eye^
which is a wooden thimble without a sheave, having a hole
through the centre and a groove around it; and a dead-eye^
which is a solid block of wood made in a circular form, with a
groove round it, and three holes bored through it, for the lan-
yards to reeve through.

Snatch blocks are single blocks, with a notch cut in one cheek,
.just below the sheave, so as to receive the bight of a fall with-
out the trouble of reeving and unreeving the whole. They are
generally iron-bound, and have a hook at one end.

A tail block is a single block, strapped with an eye-splice, and
having a long end left by which to make the block fast tempo-
rarily to the rigging. This tail is usually selvaged, or else the
strands are opened and laid up into sennit, as for a gasket.

483. A tackle is a purchase formed by reeving a rope through
two or more blocks, for the purpose of hoisting.

A whip is the smallest purchase, and is made by a rope rove
through one single block.

A gun-tackle purchase is a rope rove through two single blocks
.and made fast to the strap of the upper block. The parts of all
tackles between the fasts and sheave are called the standing
parts; the parts between sheaves are called running parts; and
the part which is taken hold of in hoisting is called the fall.

A whip upon whip is where the block of one whip is made fast
to the fall of another.

A luff-tackle purchase is a single and a double block ; the end
of the rope being fast to the upper part of the single block, and
the fall coming from the double block. A luff tackle upon the
fall of another luff tackle is called luff upon luff

A watch tackle, or tail tackle, is a luff-tackle purchase, with a
hook in the end of the shigle block and a tail to the upper end
of the double block. One of these purchases with a short fall is
kept on deck, at hand, in merchant vessels, and is used to clap
upon standing and running rigging, and to get a strain upon
ropes.

A runner tackle is a luff applied to a runner, which is a single
rope rove through a single block, hooked to a thimble in the eye
of a pennant,

A single Burton is composed of two single blocks, with a hook
in the bight of the running part. Reeve the end of your ropo

240 MACHINES AND APPLIANCES.

throug'h the upper block, and make it fast to the strap of the fLy
block ; then make fast your hook to the bi_2^ht of the rope, and
reeve the other end through the fly block for a fall. The hook
is made fast by passing- the bight of the rope through the eye of
the hook and over the whole. This is a very qnick-vvorking
tackle and a strong purciiase. Used for hoisting entirely.

When a very heavy weight is to be raised, the standing parts
should be attached to the slings by a fisherman's bend, instead
of to the block.

The size of blocks is expressed by the length of the shell in
inches ; if ropes of unusual size are to be used, it should be spe-
cified in making requisitions for blocks.

Tackles are also designated by the number of sheaves em-
ployed; as, twofold (two single blocks), threefold (double and
single block), &c.

A mousing is a seizing placed around a hook to prevent it from
spreading or unhooking, and should always be applied as fol-
lows: Take several turns of yarn or spun-yarn around the point
and back of the hook, and frap the ends around all the turns.

The bight of a hook is the middle of the bend of the hook part*

Useful suggestions.

484. A tackle is said to be *' two blocks " when the entire
fall is hauled through, so that the blocks are in contact.

To overhaul a tackle is to separate the blocks. This is best
done as follows : Hook the upper block firmly, or let one or two
men hold it; let one or more men take hold of the lower block
and haul, wliile one man lights the fall through the upper block
bj' hauling the running part through it. If necessary, let an-
other hand light the second part through.

Rope should always be stopped up, either with the end or with
rope-yarn stops, to prevent it getting into a snarl. When using
ropes for hauling, they sliould never be di-agged upon the ground.

To stop up a coil of rope with the end. Lay off two or three
turns of tiie coil and take a clove hitch around all parts of one
side of the coil. Do the same on the other side. If the rope
should be rove in a tackle, run' it ^'two blocks" and make the
first liitch around the fall between the blocks.

Before reeving a rope in a block, the turns should be carefully
taken out to prevent twisting when the weight is lifted. This
is done by stretching the rope out to its full length and turning
it in the opposite direction to that in which it is laid up, until
all the stiftness disappears.

Blocks should be overhauled very often to see that the sheaves
are working properly on the pin and that they work smoothly.
If they do not, turn the pin end for end, and rub a little black-

BLOCKS, TACKLES, ETC.

241

lead (graphite) on them to lubricate them, also on the sides of
the sheaves where they rub a^^ainst the shell.

When hoisting with tackles they should never be allowed to
twist. If they show a tendency to do so, insert a bar in the
block or sling, and use it as a lever to hold it straight.

It frequently happens that the men cannot apply their full
strength in the direction in wiiich it w^ould be most effective.
In such cases hook a single block to some object about two feet
above ground and reeve the end of the fall through it, so that
the men can add their strength to their weight and more men
-can apply themselves.

Kever trust the suspension of a weight to holding it by the
unaided strength of men. If it is possible to get a turn around
any fixed object, even in raising or hauling a weight, it is best
to take a turn, as all that is gained is then saved.

Always select such blocks that the fall will run freely through
them and not ride upon the edges of the y»heaves. If it does, it
will be certain to cut. The rope should not quite fill the score
or groove on the sheave. In this way excessive friction is avoid-
ed. The sailor's maxim is, *' Small ropes and big blocks."

The power gained by using tackles is as follows :

Two single blocks, or gun tackle — nearly doubled.

Luft' tackle (double and single block) — doubled. If the double
block is movable — trebled.

Two double blocks — power X 3|-.

Double and treble blocks — power X 4.

Two treble blocks — power X 4J.

Whip upon whip, single Burton — trebled.

When one tackle is applied to the fall of another, the power
obtained is found by multiplying their respective values together,

No advantage is gained by using a greater number of sheaves
than two treble blocks in one fall.

Weight and strength of '

iron chains.

m'r of
n for

ks.

ghtof
e foot
chain.

OA
O fcX)

m'r of
n lor
ks.

ghtof

3 foot

chain.

.sg.a

^ o o

Dia
iro
lin

o den

0) o

£^

Inch.

Lbs.

Inch.

Lbs.

0.1875

0.325

2,240

948

0.625

4.217

26,880

10,304

0.25

0.65

4,256

1,680

0.6875

4.833

32,704

12,544

0.3125

0.967

G,720

2,464

0.75

5.75

38,752

15,232

0.375

1.383

9,634

3,584

0.8125

6.687

45,696

17,696

0.4375

1.767

13,216

5.152

0.875

7.5

51,744

20,384

0.5

2.633

17,248

6,720

0.9375

9.333

58,464

23,520

0.5625

3.833

21,728

8,512

10.817

65,632

26,880

242 MACHINES AND APPLIANCES.

The Gin.

{Plate 31.)

485. A gill is a tripod formed of three poles. Two of these
poles, called legs, are joined togetlier by braces of wood or iron,
and contain between them the windlass. The third pole is called
the pry-pole, and is joined to the legs, at the top, by a bolt.
This bolt supports a clevis, to which the upper block of the tackle
is hooked.

The windlass is worked by two handspikes fitting into brass
sockets, one at each extremity of the windlass ; the operation of
the handspike is made continuous by the action of a pawl at-
tached to the socket on the ratchet of the windlass.

To prevent the legs and pry-pole from sinking into the ground,
or injuring the pavement of casemates, stout pieces of wood,
called shoes, are placed under them. The hoisting apparatus
consists of two blocks, through which the fall is rove. The fall
is wound two or more times around the windlass.

There are three kinds of gins used for artillery purposes : the
siege, the garrison, and the casemate.

The last two differ from each other only in height ; the first
differs from the others in construction and size. Piper's gin is
an improved modification of the siege gin.

When the gin is put together and raised, that part included
between the legs and pry-pole is called the inside, the outside
being the part without the legs; the right corresponding to the
right hand of a man standing at the middle and outside of the
windlass, facing towards it, the left corresponding to his left
hand.

4:$6. The detachment is composed of one chief, one gunner,
and ten cannoneers. The odd numbers are placed on the right
and the even numbers on the left side of the gin, all facing in-
wards ; N"os. 1 and 2 opposite and one yard outside of the foot of
the pry-pole ; l^o. 9 outside of and near the foot of the right leg ;
'No. 10 outside of and near the foot of the left leg; ISTos. 3, 5,
and 7 are between N"os. 1 and 9, dressing on them and dividing
the intervening space into equal distances; Nos. 4, 6, and 8 oc-
cupy similar positions with respect to ITos. 2 and 10. In assem-
bling the gin, the gunner and Nos. 1 and 2 bring up the pry-pole ;
Xos. 3, 5, and 7 the right leg, and Nos. 4, 6, and 8 the left leg;
]!^os. 9 and 10, the windlass. The gunner superintends putting
together the head, and the chief-of-detachment the placing of
the windlass. The braces are brought up and adjusted to their
places by N'os. 5, 6, 7, and 8.

The gunner, assisted by the most expert cannoneers, reeves

THE GIN. 243

the fall, slings the piece, and attends to all knottings and lash-
in,ij:s.

In working the windlass, Nos. 1 and 2 hold on to the fall and
take up the slack ; Xos. 7 and 9 work at the right, and Nos. 8
and 10 at the left handspike, i^os. 7 and 8 being next the wind-
lass. All, except the old-pattern siege gin, are put together and
hoisted by raising the head and bringing up the foot of the pry-
pole towards the feet of the legs.

487. The siege gin (old pattern) is put together with the out-
side of the legs and windlass downwards and the pry-pole rest-
ing on the top. {Fig. 1, Plate 32.) It has no clevis, as other
gins, and, instead of an upper block, two sheaves are inserted
•between the legs and secured by the bolt holding together the
legs. The head of the pry-pole is terminated by a flat piece of
iron, which fits between the heads of the legs above the sheaves,

-and is secured by another bolt.

This gin further differs from others in having three wooden
braces instead of two of iron. It has the disadvantage of being
exceedingly ill-contrived and unhandy.

To put the siege gin {old pattern) together,

488. The different parts of the gin having been brought to
the place designated, the instructor commands :

1. Assemble the gin.

This is executed as indicated in pars. 486 and 487.

The gin being together and lying on the ground, the instruct-
or commands:

1. Keeve the fall.

iSTos. 1 and 2 raise the pry-pole until it clears the sheaves. The
gunner, receiving from Nos. 3 and 4 one end of the faU, passes
it through the left sheave from beloW and hands it back' to them.
They pass it through the sheave of the single pulley, (hooked for
convenience on the middle brace,) and return it to the gunner,
who passes it through the right sheave from below, and gives it
to '^o. 3, by whom it is secured by wrapping it around the middle
brace. If the gin has been raised, the instructor gives the same
-command, when the gunner, mounting upon the upper brace,
receives from Nos. 3 and 4 one end of the fall, which he passes
over the left sheave from without to within. The fall is then
j-eeved in the manner prescribed.

To raise the gin.
The instructor commands :

1. Kaise the aiN.
Nos. 1 and 2 take hold of the handle of the pry-pole ; Nos. 9

244

MACHINES AND APPLIANCES.

and 10 each hold down the foot of a le^ to prevent it from slip-
pin^^ ; IS^os. 3 and 4 lift at the head, and Nos. 5, 6, 7, and 8 ap-
ply themselves at the legs on their respective sides. The gunner
commands: Heave; tlie gin is raised ; Nos. 1 and 2 caVry out
the foot of the pry-pole about twelve feet from the windlass and
place under it a shoe. A shoe is likewise placed under each leg^

To move the gin when raised.

The instructor wishing to move the gin a short distance, indi-
cates the direction and commands :

1. Move the gin^ 2. Mabch^

!N"os. 1 and 2 apply themselves at the handle of the pry-pole;.
iJ^os. 9 and 10 each place a handspike under the windlass fi-ora
without, and near the legs; Nos. 7 and 8 assist to lift at these
handspikes from within ; at the command MARCH, all move in
the direction indicated.

To lower the gin.

The gin is lowered in a similar manner, but by inverse means
to that prescribed for raising it. Nos. 1 and 2 raise the pry-pole
and assist in easing the gin to the ground, the outside down-
wards.

489. The following are the kinds, dimensions, weights, and
strengths of ropes usually required for the ditterent kinds of
gins :

Designation.

Weight.

Remarks.

o
o

ft
® o

Gin fall (siege.)

G-in fall (garrison
and casemate.)

Gun-sling (siege.)....

Trace-rope

Lashing-line

Inch.
4.25

3.25
1.75

Feet.
75

120

100

Lb. Oz.
5 4

10 6

3 1
11

Lb. Oz.

67 8

208

44 9

15 5

1 2

Lbs.
8,064

16,128

4,760
1,371

Hemp.

Hemp.
An eye at one
end, served
with leath-
er. Hemp.

Manila.

Hemp.

Marline

THE GIN. 245

To mount a siege gun.

490. It is imnQaterial upon which side of the piece the le.a:s
ot the gill are placed, but, for uniformity, they are generally
placed on the right. The gun is suspended either by a sling or
by a bail ; the latter is preferable. It consists of a stout piece
of iron {Fig. 2, Plate 32), passing like a handle over the piece
and fitting against the ends of tiie trunnions, to which it is fast-
ened by iron bolts passing through the ends of the bail into holes
bored for the purpose; one in the end of each trunnion.

A clevis, attached to tiie middle of the bail, gives a place for
hooking the lower block of the tackle.

The gin being raised and placed with its tackle directly over
the trunnions, and the foot of the pry-pole about twelve feet
from the lower brace, the instructor commands :

1. Sling the piece.

No. 1 puts a handspike in the bore, small end foremost; I^o.
2 passes the eye or loop end of the sling around the knob of the
cascable ; No. 1 passes the other end under the handspike in tlie
bore, and hands it to No. 2, who draws it through the loop; the
gunner fastens it either by a knot or with a lashing-rope, and
tiien hooks the single pulley to the sling just in rear of the trun-
nions, fastening the standing end of the fall to the sling near the
same place ; Nos. 1 and 2 pass the running end of the fall from
the outside under the windlass, and take three turns with it
around the left of the windlass, and hold on by the running end
or slack. No. 1 being nearest the windlass; the gunner applies
himself to the handspike in the bore to steady the piece ; Nos.
7, 8, 9, and 10 apply themselves at the windlass handspikes. All
' being in readiness, the instructor commands :

1. Hoist away.

The windlass is worked until the piece is high enough to admit
the carriage under it. The instructor then commands :

1. Halt, 2. Eun up the carriage.

All the men, except Nos. 1 and 2, bring up the carriage, as
explained in par, 435, placing the trunnion beds directly under
the trunnions.

The instructor then commands :

1. Slack off.

Nos. 1 and 2 slack of the fall slowly ; the gunner steadies the
;jpiece by means of the handspike in the bore, and the piece is

246 MACHINES AND APPLIANCES.

lowered into its position in tlie trunnion or traveling beds; ]N"os-
3 and 4 put on tiie cap-squares and key them.

Note. — ^Wiien the bail is used, it is attached by the same num-
bers as for the sling. If it is noc convenient to sling tlie piece in
the manner prescribed, it may be slung by a rope passed around
each trunnion, and the ends fastened together on top of the
piece ; or trunnion rings may be used. Hook the pulley to this
sling or to the trunnion rings; bear down with one or two men
on the handspike in the bore to balance the piece, and when it is
raised sufficiently high run the carriage under it, and place a
handspike in the trunnion beds and a block on the stock. (For
casemate or barbette carriages, upon scaffolds built of blocks
under the breech and chase.) Lower the gun, the trunnions di-
rectly over the trunnion beds, until the piece rests on the block
and on the liandspike. Remove the sling or rings from the
trunnions and rim the carriage, with the gun on it, back until
the head of the cheeks are in rear of a perpendicular let-fall from
the head of the gin. Pass the sling around the chase, hook the
pulley to it, and work the gin until the weight no longer bears
on the handspike in the trunnion beds; remove the handspilce,
and lower the trunnions to their places; bear down on the muz-
zle, and remove the block from under the breech.

To dismount a siege gun.

491. The gin is placed in the same position with reference
to the piece as prescribed for mounting it. The instructor com-
mands :

1. Sling the piece.

The cap-squares are removed, the piece is slung, and the run-
ning end of the fall passed around the windlass as prescribed for
mounting it.

The commands Hoist away^ Halt, Bun out the carriage^ and
Slack off are then given and executed in the manner already
prescribed.

To sling and hoist a siege mortar mounted on its carriage.

492. A gun-sling or a sling-chain is used. In either case,
the middle of it is passed under the front notches; the ends car-
ried up, and, crossing over tiie top of the mortar, are passed un-
der the rear notches. The gin is erected over the mortar and
the lower block of the tackle hooked into the sling where it
crosses the top of the mortar. The mortar is raised and lowered
upon a wagon in the manner prescribed for a gun.

THE GIN. 247

To sliift the fall.

493. As the turas gain once the diameter of the fall at each
revolution of the windlass, they will, when the weight has been
raised a considerable height, come against the opposite leg.
The instructor then commands : 1. Halt, 2. Shift the fall.
The gunner mounts to a position where he can reach the run-
ning part of the fall, and firmly applies a nipper to two of the
parts as explained in par. 480. The instructor then commands :
Ease away. N'os. 1 and 2 slack off and shift the turns on the
windlass to the opposite end ; they then tighten up the fall,
the nipping is removed by the gunner, and the manoeuvre is re-
sumed.

Piper's gin,

494. In this gin, the windlass is attached by placing it in
windlass seats of peculiar construction, and is secured in posi-
tion by keepers attach(^d to the legs. The keepers are placed
under the axles of the windlass. Two stay-chains connect the
prj^-pole and legs at the upper brace-bands, and prevent them
from spreading. They also serve to connect the parts for trans-
portation. Two braces (upper and lower) connect and secure
the legs when the gin is put together, and serve to distinguish
the right from the left leg — the long brace being permanently
attached to the right and the short brace to the left les:. The
clevis and clevis bolt are attached to the head of the pry-pole
with keys which secui-e the clevis bolt when the gin is assem-
bled ; double and single blocks, with fall, are used. This gin
was designed by the late Captain J. W. Piper, fifth artillery.

Length of legs , 13 feet 8 inches.

Length of pry-pole 13 feet 8 inches.

"Weight of gin.,..., 365 pounds.

Weight of windlass 88 pounds.

Weight of block and fall 100 pounds.

Weight of ball and dowels.. 41 pounds.

The parts are estimated to be sufficiently strong to bear a
weight of 5000 pounds. The advantages of this gin are, its
superior ligiitness and portabilit}', and its great facility of being
assembled, taken apart, packed up, and transported.

The different parts having been brought to the place designa-
ted, the gin is put together, raised, lowered, and taken apart by^^
the following commands from the instructor: ASSEMBLE THE
GIN. Nos. 1 and 2 place in position the pr3-pole ; iSTos. 3 and 5
place in position the right, and IsTos. 4 and 6 tlie left leg ; the
gunner, assisted b}'^ Nos. 3 and 4, attaches the clevis and clevis

248 MACHINES AND APPLIANCES.

bolt, assembles the head of the ghi, and hooks on the block and
fall ; ISTos. 5 and 6 attach the braces.

The gin, hi this position, is lying extended upon the ground,
with the inside downwards.

The instructor commands :

Eaisb the gin.

N"os. 9 and 10 hold down the feet of the legs to prevent them
from slipping ; ^os. 1 and 2 push up, applying themselves at
the handle of the pry-pole. The other numbers apply them-
selves as in par. 488.

The gunner commands : Heave.

The gin is raised and the pr3^-pole brought up to within about
twelve feet from the legs; N'os. 3 and 4 attach the stay-chains
on their respective sides, and ISTos. 9 and 10 put in the windlass.

To move the gin when raised.

Executed as explained in par. 488.

To lower the gin.

The gin is lowered in a similar manner, but by inverse means
to that prescribed for raising it.

The stay-chains are unhooked and windlass removed before
lowering.

To take the gin apart.

The gin is taken apart in a similar manner, but by inverse
means to that prescribed for putting it together, and is stowed
for transportation by lashing together the legs, pry-pole, and
windlass vyith tiie stay-chains.

The application of this gin to the mechanical manoeuvres of
siege ordnance is similar to that prescribed for the siege gin (old
pattern).

GrARKISON AND CaSEMATE GiNS.

495. The garrison and casemate gins differ from the siege
gin in iiaving two cross-bars of iron instead of the three wooden
cross-bars, and in having the pry-pole inserted between the legs,
which are kept together by the clevis bolt. The upper block
(generally treble) is hooked to the clevis.

The casemate gin is made shorter than the garrison gin, so
that it may be hoisted in casemates. With the guns now usually
mounted in casemates, it is essential to use a bail for slinging, in

GARRISON AND CASEMATE GINS. 249

order to sain the necessary distance from the head of the gin for
the working of the tackle.

The gin is put together across the piece, or on the ground near
it, and raised by moving up tiie legs and pr57--pole towards each
other as explained in preceding paragraph. The pry-pole has
<ileats nailed to it to enable a man to mount to the head of the
gin to hook on the block and to reeve the fall.

In raising it, ^N'os. 9 and 10, each with a handspilve, brace
^ijainst the lower cross-bar neai' the legs to prevent them from
slipping; N'os. 1 and 2 hold down the foot of the pry-pole, and
at the same time push up by the handle. The remaining num-
bei-s take hold to lift by hand near the head.

The gunner commands : Heave; the head of the gin is raised
as high as the men can lift, and the pry-pole pushed up ; jSTos. 3
and 4 go to the assistance of N'os. 1 and 2 at the handle of the
pry-pole ; Nos. 5, 6, 7, and 8 lift at the legs on their respective
sides. The gunner repeats heave until, by successive efforts,
the gun is raised. The pry-pole should be, for the garrison gin,
about seventeen feet from the legs ; for the casement gin, about
•thirteen feet.

The gin is next placed over the piece by moving the legs and
the pry-pole each a short distance at a time. To prevent thera
from spreading too much, a lashing is passed from the pry-pole
to the upper cross-bar.

To reeve the fall.

Fasten one end of a trace-rope to the upper block by passing
It through the shell of the block. An expert man ascends the
pry-pole to the head, and passes the free end of the rope through
the clevis, from whence it is carried down to the windlass, where
a couple of turns are taken. By heaving on the w^indlass, the
block is raised and the hook passed through the clevis, with its
point towards the pole. The fall is rove as explained in par.
488. The upper block may be hooked to the clevis and raised
with the gin ; the fall may also be rove and the whole raised to-
gether. The extra weight thus given makes the gin more diffi-
cult to lift.

The gin is lowered by gradually drawing out the pr^'^-pole un-
til the men can get near enough towards the head to support it ;
it is then lowered upon the piece or on the ground, as the case
111 ay be.

To mount a casemate gun.

496. The carriage is traversed to one side, and the gun — on
blocks, or on the truck — is near the middle of the casemate, the

250 MACHINES AND APPLIANCES.

muzzle towards the embrasure ; the gin is over the ^nii and
carriai^e; tlie latter on the side of the pry-pole ; the axis of the
trunnions is horizontal and directly under the head of the ^in.

The gun is slung by means of a bail or trunnion rings. The
gin is worked until the gun is raised sufSciently high, when th&
chassis is traversed under it, and the gun carriage so placed that
the trunnion beds come exactly under the trunnions. The gun
is then lowered to its place, the sling removed, and the gin car-
ried to the next casemate.

To prevent the pavement from being injured by the points, a
shoe is placed under each foot.

To dismount the gun.

Executed in the inverse manner to that prescribed for mount-^
ing. The gun is placed on the truck, or on blocks.

The windlasses of gins should never be painted, as paint is
liable to cause surging when easing off the fall, and surging is
certain to cause breaking of parts.

To dismount a barbette gun.

49*^. The safest and best method of dismounting the 15-inch
gun is by means of blocks, as hereafter explained, or with the
gun-lift. It may, however, be dismounted by using two garri-
son gins, one of w^hich is erected over the cascable and the other
over the chase, midway between the trunnions and the muz-
zle.

The piece is slung by means of chains similar to those used
with the gun-lift. The blocks and fall are those usually furnished
with the gin. Everything should be perfectly sound and in good
condition ; for it must be borne in mind that the weight upon
each gin is one-third more than it was originally intended to
bear.

Ten-inch guns, and all below, are mounted and dismounted
hy means of one garrison gin. To dismount a 10-inch gun, run
it from battery as in loading; erect the gin over the piece so-
that the head will be directly over the trunnions; the sling,
which is made of 9-inch rope, is attached by passing the bight
of it around the neck of the cascable, carrying the end forward
over the piece and under the end of a roller thrust in the muz-
zle ; thence back, passing it through the eye of the sling, draw-
ing it tight, bending it into a knot, and securing it with marline.
In all cases, gun-slings should be drawn as tightly as possible;
otherwise the tackle will be block and block before the trunnions
are free from the carriage. It may be necessary, especially with
a new sling, to take several lifts upon it in order to take the

GARRISON AND CASEMATE GINS. 251

stretch out of it ; after each lift the slaclv is taken up. A trace-
rope is attached to the muzzle as a gu}" ; the tackle is hooked
to the slin,:^ immediately over tlie axis of the trunnions; the
gin is worked as explained in par. 490 until the trunnions are
sufficiently above their beds to permit the top-carriage being
shoved forward from under the piece. This done, the chassis is
traversed, towards the pry-pole, from under the gun ; the latter
is then lowered upon blocks and the gin removed. When,
hoisting the piece, the traverse-wheels should not be chocked.

To dismount the top-carriage from the chassis.

49$. Back the limber of a field-piece against the rear ends
of the chassis rails. The ammunition chest being removed, a
couple of large blocks are placed on the limber; the counter-
hurters are removed, and the top-carriage pulled and shoved
back, off the chassis, onto the blocks upon the limber. If there
is no limber or similar carriage available, a scaffolding of blocks
is built at the rear end of the chassis, and the carriage moved
back upon it ; from this it is easily lowered to the ground.

To remove the chassis from the platform.

499. Take out the pintle key ; pry and block up the front
end of the chassis until it is clear of the pintle; the chassis is
then overturned by attaching a trace-rope to the far side of it,
chocking the near traverse-wheel, and hauling on the rope until
the chassis is on its side ; the rope is then carried around to the
other side and the chassis eased down upon blocks placed for its
reception. From this position it may be moved, if for a short
distance only, by placing way-planks and cradle rollers under
it ; if for a considerable distance, by backing the hand sling-cart
over it and slinging it with a chain. The cart is passed over the
traverse-wheels by raising its wheels on way-planks placed on
each side of the chassis rails.

In dismounting the top-carriage of the 8-inch rifle (converted),
it is best to use the gin. The carriage is slung by the front and
rear transoms with chains, the guides are removed, and it is
hoisted and lowered in a manner similar to that just described
for the gun. The latter should previously be removed from the
platform to make room for the carriage when lowered.

With carriages Nos. 1 and 2, the top-carriage is first discon-
nected from the friction-bar; in Nos. 3 and 4, the piston of the
cylinder is disconnected from the top-carriage. The geared
elevating apparatus should be removed, or if not, great care ex-
ercised to prevent injurj'- to it.

The chassis and top-carriage of a barbette gun are placed m^

252

MACHINES AND APPLIANCES.

position OQ the platform, and the piece mounted by operations
the reverse of those just explained.

To prevent spreading or breaking, the hooks of the gin tackle
should be securely moused.

Dimensions and

weight of

gins.

Dimensions.

Siege.

Garrison.

Casemate.

Length of legs and pry-pole........

Inches.
175.5

Inches.
256.5

1
Inches.
172.5

"Weights.

Lbs.

Of windlass

Of ■DTV-DOle •

310

293

280

1316

264
208
213
947

Of leg

Of gin complete (without blocks)

f Single

455
43
57

Of pulley-blocks (iron). \ '^^'^^llZ'.Z
tQ,uadruple.

165

205

165

205

Bemarks.

The garrison gin of the regulation pattern, if perfectly sound,
is capable of sustaining a weight of 17,000 pounds. It is, how-
ever, recommended that a heavier one be used for such weights
when it can be procured.

Use of the gin as shears.

500. By removing the prj'^-pole, the legs of the gin may be
used as shears. When the garrison or casemate gin is to be thus
used, a block of wood of the same dimensions as the head of the
pry-pole, with a hole in it to receive the clevis bolt, must be
inserted in place of the pry-pole. The shears are raised and
guyed as explained in par, 546. The fall and windlass are

-operated as for the gin.

The GrARRisoN Gin-derrick: (narrow).
{Plate 33.)

501. The derrick consists of two legs framed together, one
■pry-pole, two drums or windlasses with geared wheels, and two

wagon-wheels, serving the double purpose of moving the derrick

SLING-CARTS. 253*

from point to point and for working the windlass. The axle-
passes through one of the windlasses, and can at pleasure be
geared into a wheel on the other windlass. Lengtli of legs, 254
inches; greatest width of legs, 86 inches; weight, 1725 pounds.
It is hoisted by being pulled over to the front ; the feet of the
legs then rest on the ground, and the pry-pole is carried out
over the object to be raised. The wheels are now free, and the
method of operating the gin is similar to that for other gins, the
power being applied to the wheels instead of to handspikes.

Sling-cart.

502. The sling-cart is used for moving pieces of heavy artil-
lery, or other objects, short distances.

They are of two kinds: one, the garrison sling-cart, {Fig. 1,
Plate 34,) for heaviest weights, is attached by its pole to a siege
or field limber, and ma}^ be drawn by horses; the other, the
hand sling-cart, {Fig. 3, Plate 32,) is designed for moving light-
er weights and siege-pieces in the trenches by hand. The siege
limber may also, in case of necessity, be used as a sling-cart.
With tlie hand sling-cart, the weight is raised by first attaching
to it a sling, and then applying to the sling the hook upon the
rear of the axle, by raising the pole of the cart. Tlie pole is used
as a level-, the axle and wheels being the fulcrum. It maj^ be
used for anj^ weights not exceeding 6000 pounds.

With the garrison sling-cart, the weight is raised by first at-
taching to it a sling, and then applying to the sling the hooks
forming the lower part of a powerful screw passing up through
the axle of the cart. Above the axle is the nut of the screw,
provided with long handles. Power is applied to these handles
and the screw is run up, thus raising the weight.

This sling-cart is capable of carrying 20,000 ponnds; but with
sucli heavy weights the handles of the screw are difficult to turn.
To overcome tliis difficulty, a modification has been made in the
cart by substituting for the screw a hydraulic-jack. {Fig. 2,
Plate 34.)

Through the axle-body two vertical mortises are cut, each at
a distance of twenty inches from tlie middle of the axle-body.
Tlu-ongh these mortises slide two stout bars of iron, with hooks
below for the sling-chain, and holes above for pins to support
them as they are raised; the pins pass through the bars above
the axle-bod5^ A strong cross-bar connects the upright bars near
their tops; under this the head of the jack is applied, the jack_
resting on the axle-body.

i54 MACHINES AND APPLIANCES.

To use the hand sling-cart.

503. The implements necessary are : Two blocks^ two half
blocks, four wheel-chocks, one sling-chain, and one trace-rope.
One sling-chain additional for a siege mortar mounted on its
carriage.

To sling a siege gun, howitzer, or mortar.

The instructor commands :

Back the cart over the piece.

Kos. 9 and 10 go to the end of the pole ; N"os. 5, 6, 7, and 8
apply themselves at the wheels ; the cart is then backed over the
piece, the pole being in the direction of the breech and the axle
directly over the trunnions ; ^N'os. 3 and 4 chock the wheels front
and rear.

To sling the piece.

The gunner fastens the middle of the trace-rope to the eye of
the pole; Kos. 7 and 8 carry one end of the rope to the rear of
the cart; jN'os. 9 and 10 raise the pole by hand, Nos. 7 and 8
applying themselves at the same time to the rope.

When the pole is nearly vertical, N'os. 9 and 10 seize the other
end of the trace-rope to steady the pole. The gunner lays the
middle of the sling-chain over the piece in rear of the trunnions,
carries each end around the trunnions from the rear to the front,
and hooks them around the axle-hooks, being careful to take up
all the slack; IsTos. 9 and 10, assisted by Nos. 5 and 6, haul upon
the trace-rope until the end of the pole can be reached by hand,
when they seize and bear it to the ground ; Kos. 3 and 4 hook
the cascable-chain around the knob of the cascable in such a
manner that the piece will swing level when the pole is hori-
zontal; N'os. 9 and 10 raise the pole until it rests on the pole-
prop.

The piece is thus raised about eight inches from the ground.

For transportation it should be ordinarily raised higher, which
can readily be done by blocking up the piece and raising it again
in the manner above prescribed.

To unsling the piece.

The piece is lowered to the ground in the same manner, but
by inverse means to those just prescribed.

!N'os. 9 and 10 bear the end of the pole to the ground ; Nos. 3
^nd 4 unhook the cascable-chain ; Nos. 9 and 10 allow the pole
to rise gently until it is nearly vertical. If the piece does not

SLING-CARTS. 255

then rest upon the ground, it is blocked up and unslung, when,
by repeating the manceuvre, it may be lowered to the ground.

After the piece has been unslung, ISTos. 7 and 8 ease tlie pole
down carefull.y, b}'^ means of the trace-rope, until N'os. 9 and 10
can reach it witii their liands.

To sling a siege mortar mounted on its carriage.

The instructor gives the same commands, and the duties are
performed by the same numbers as prescribed for a siege-piece.

The sling-cart is backed over the mortar, the pole being in the
•direction of the breech and the axle directly over the trunnions.

If the carriage is resting on the ground, it maybe slung by first
raising the pole nearly vertical, passing the sling-chain around
the front mancBuvering bolts, hooking it over the axle-hooks, and
hauling down the pole.

The carriage is then blocked up and the sling taken off' the
bolts and passed under the carriage just in front of the cap-square
bolts; this brings the sling a little in front of the centre of grav-
ity of the mortar and carriage.

The pole is again raised and the hook attached to the sling ;
N'os. 9 and 10 bear down upon it until the end rests upon the
ground; Nos. 3 and 4 remove the blocks; the gunner passes
the other sling-chain around the rear manoeuvering bolts and over
the pole, and then hooks it in such manner that the carriage will
be level; Nos. 9 and 10 then raise the pole until it rests on the
pole-prop.

The carriage is thus raised about twelve inches from the
ground. If necessary, it may be blocked up and raised higher
hj a similar manoeuvre.

The breecli should always slightly preponderate, in order to
prevent the pole from flying up.

Sea-coast mortars and their beds are slung separately and
carried on the garrison sling-cart. The trunnion-chains are
passed over the trunnions and hooked to the hoisting screw.

To transport a siege-piece sJioH distances with a limber.

504. The piece is raised upon two blocks — one under the
breech, the other under the chase — and a sling-chain is attached
as explained in par. 503.

The limber, its pole being in the direction of the breech, is
run np until the pintle is over the chain, when the pole is slightly
raised and the chain passed around the pintle and fastened.
Tiie pole is borne to the ground, the block under the chase re-
moved, and a trace-rope fastened over the pole and around the

256

MACHINES AND APPLIANCES.

knob of the cascable.
block removed.

Tlie pole is then raised and the other

To raise a piece upon blocks by a Umber,

The trunnion loop, or an ordinary chain, is passed over the
knob of the cascable and the pintle, and made fast while the
pole is raised. The piece is then raised by bearing down the
pole, and the breech blocked up. The muzzle is raised in the
same manner.

The wheels should not be chocked, as they will soon find their
proper bearing.

To sling a piece on two limbers for transportation with horses^

The pole of one of the limbers is removed, a block is placed
under the body of the gun, and the limber run forward, with its
fork over the piece, the pintle over the knob of the cascable, to
which it is attached by a sling-chain ; the fork is borne down to
the piece and lashed with rope. The muzzle is then raised and
supported on blocks ; the other limber is backed over the piece
until the wheels are witliin about a foot of the wheels of the
rear limber ; a sling-chain is passed under the piece and up over
the pintle, tlie pole having been raised for this purpose ; the pole
is lowered to the ground, the blocks removed from under the
muzzle, and the chase lashed to the forks in front of the axle-
tree, so that the weight will balance the pole. To pi-event the
front limber from pulling away from the piece, a sling-chain is
attached to the two pintles.

505. Dimensions and weight of sling-cart.

DlMENSIOXS.

I^ength from rear of wheels to front end of pole

Length of axle-trees

Height of wheels

Distance between the wheels on the ground

"Weights.

One wheel

Whole weight (without shng-chains)

Trunnion-chain and rings

Sling -chain

Garrison.

Hand.

Inches.

242.4
92
96
62.75

Inches.

160.75
75.50
72
60.4

Lbs.

701

2302

114

1115
27

casemate trucks. 257

The Casemate Truck.
{Fig. 4, Plate 32.)
506. This machine is intended for moving pieces and their
carriages in the galleries of casemate batteries, or throngh pos-
terns. It consists — old pattern, of a stout frame of wood ; new
pattern, of wrought-iron, mounted on three low wheels. Two
of the wheels are placed at the sides, lil^e those of a cart; the
third is placed in a fork at the middle of the front end ; the fork
turns around its vertical axis as the direction of the truck
changes. The fork and wheel are removed by raising the end
of the truck and allowing the fork to drop from its socket. A
tongue, likewise removable, is attached for the purpose of guid-
ing the truck.

To place a casemate chassis on the truck.

The chassis is on the ground, the truck near it, with its front
wheel and tongue removed. The chassis, either side down, is
raised, by successive purchases, with handspikes, and blocked up
to a height sufficient to allow the truck to go under it. The
truck is then run under the chassis and turned so tliat its axis
is parallel to that of the chassis, and is so placed that the centre
of gravit}'^ of the chassis is, as near as possible, over the axle
of the truck. The blocking is then removed and the chassis
allowed to rest on the truck. The tongue of the truck is re-
placed. The truck is moved to the designated casemate, and
the chassis lowered from the truck as it was placed thereon.
If it is upside down, it is turned over as explained in par. 499,
and placed properly on the traverse circles. The tongue of the
chassis is then bolted to the front transom and secured by the
pintle in the throat of the embrasure.

The chassis may be lowered from the truck by means of the gin.

To remove the chassis from the casemate.

The tongue of the chassis is unbolted from the front transom
and the chassis raised, either by prying and blocking or with the
gin ; the truck is then placed under it as before.

It is generally preferable to remove the front wheel from the
truck and to pry up but one end of the chassis ; the truck is
then worked under it from the side, and, after the chassis is
lowered upon the truck, the raised end is borne down until the
front wheel of the truck can be replaced.

EemarJc.
To prevent injury to the pavement, way-planks must be laid
for the wheels of the truck to run on.
17

258 MACHINES AND APPLIANCES.

To place a top-carriage on the truck.

The carriage is on the ground, standing on the head of its
cheeks ; the truck near it, with its front wheel and tongue re-
moved.

The truck is run up to the carriage, the end on the ground
under the axle, and its wheels chocked; the carriage is then
pulled over on it by means of a trace-rope. The trail is borne
down and the head of the carriage raised sufficiently high for the
gunner and assistants to replace the truck-wheels and tongue.
The carriage is then moved on the truck to its place.

To lower the carriage to the ground.

The front wheel of the truck is removed and its front transom
rested on the ground. The carriage is then pulled over on the
head of its cheeks.

To shift the carriage from the truck to its chassis.

The truck is run up to the rear of the chassis rails on way-
planks, raised on blocks to a height sufficient to allow the car-
riage to be launched forward upon the rails. The front of the
carriage is towards the front of the chassis; the counter-hurters
are removed, and in launching the carriage forward it is so di-
rected that the guides will take their proper places under the
inner edges of the chassis rails.

The carriage may likewise be put on the chassis from the side.
To do this, bring it up on the truck by the side of the chassis, so
that its front end will be in tlie same direction with that of the
chassis; remove the guide from the cheek farthest from the
chassis (or, preferably, both guides); pry up the carriage and
place under it, and across the chassis rails, two shifting-planks ;
heave the carriage sideways with liandspikes until it is in proper
position over the rails; then remove the planks and let the car-
riage rest on the chassis. Replace the guides.

To shift the carnage from its chassis to the truck.

This operation is similar to that described in the preceding
paragraph.

To place a heavy gun on the truck.

The gun is raised, by means of a jack, upon blocks placed
under the chase and body, until it is sufficiently high to admit
the truck under it; the truck is placed so that the trunnions
will be slightly in front of the axle ; the gun is then lowered
upon it.

A gin may be used for raising and placing the gun on the

HAND-CART, ETC. 259

•truck. The gun is removed from the truck by means similar to
those employed for putting it on.

BemarJc.

A 10-inch gun can be carried on the truck now furnished, but,
-except in very crooked galleries, the cradle is much the best
means for moving such guns.

Hand-cart.

^OK. This is used for the transportation of light stores from
•one part of a work to another. That for carrying powder, fuses,
and such like articles has an arched lid-cover to keep oflf rain
and prevent accidents from fire.

Trunnion-chains.
(Fig. 3, Plate 34.)

50S. The trunnion-chains are three in number, for light or
Tieavy weights. They are made of a patent looped-link chain.
A pair is required to carry a gun. One is passed under each
trunnion and hooked on the head of the screw of the sling-cart.

No. 1, composed of one chain, 59 inches long, the ends joined
by a ring; weight, 27 pounds.

Xo. 2, composed of two chains, each 59 inches long, the ends
joined by a ring ; weight, 53 pounds.

No. 3, composed of two chains, each 47 inches long, the ends
joined by a ring having three branches; two for the ends of the
chains composing the pair, and the third for the hook of the
screw; weight, 61 pounds. Thickness of the iron composing
the link, .5 inches. Length of iron for the connecting ring, 23
inches for No. 1 ; 24 inches for Nos. 2 and 3. Size of iron for
<jonnecting ring, 1.375 inches, round.

Store-truck.

509. This truck is used for moving boxes, &c., in store-
houses and in embarking and disembarking stores.

Lifting-jack.
{Fig. 5, Plate 32.)

510. The lifting-jack is a geared screw, with a projecting
foot at its lower end, for lifting heavy weights. This jack is
sometimes to be found at military posts, but is becoming super-

260 MACHINES AND APPLIANCES.

seeled by the hydraulic-jack. The jack represented in Fig. 5 is^
the one carried with siege guns. It is very simple, compact^,
and powerful.

Lever-jack.

511. The lever-jack is an adjustable fulcrum with a long^
lever, used chiefly for greasing the axles of traveling carriages.

Hand-barrow.

512. Wood ; two side rails; the ends are rounded and form
handles. Rope netting joins the side rails, passing through holes
in the side rails.

MAtrii.

513. This is used for driving stakes, and such like purposes.
That furnished from arsenals has a cylindrical head of wood, 6
inches in diameter and 8 inches long, with an iron band around
each end. The handle is 24 inches long and 1.5 inch in diameter.
Weight, 10 lbs. This maul, as issued, owing to poor material
and faulty construction, is of but little value. Where much ser-
vice is required, it is better to make the head of tough, hard
wood, with a handle considerably larger than the one of regula-
tion pattern.

Trtjck-wagon.

{Plate 35.)

514. This is a powerfully-constructed four-wheel wagon, in-
tended for the transportation of iron gun carriages, sea-coast
mortars and their carriages, and other similar heavy weights.
The wheels have a diameter of 42 inches ; the axles are of iron
and the bolsters of heavy pieces of timber, having their upper
surfaces flush with the tops of the wheels. Heavj^ plates of iron
cover the tops of the bolsters and project slightl}'^ over the wheels.
The ends of these plates are turned up, forming a projection
about two inches high, to prevent the body transported from
slipping off sideways. The width between these projections is
just sufficient to admit the chassis of the 15-inch gun.

The wagon is capable of being coupled long or short, to suit
the length of the object to be transported. The pole, like that
of an ordinary road-wagon, is furnished with double-trees for
attaching horses.

MORTAR-WAGON, ETC. 261

The method of using this wagon in the transportation of the
t5-inch carriage and chassis, is explained in par, 636, and for
^transporting the 13-inch mortar, in par. 537.

Wiien a 13-inch mortar without its bed is to be carried, two
«tout skids, about 12 feet long and 12 by 12 inches thick, are
placed on tlie wagon. The skids are notched to fit the bolsters,
to prevent them from sliding to the front or rear, and a shallow
recess is cut in them to form a seat for the mortar. The mortar
is placed on the skids with its axis parallel to the axis of the
wagon ; it is hoisted into this postition by means of the gun-lift
or the gin.

MORTAR-WAGON.
{Plate, 36.)

515. This wagon is used for the transportation of siege mor-
tars, siege guns, and heavy projectiles. The limber and wheels
are the same as those for the siege-gun carriage. The body con-
sists of a platform of rails and transoms, resting on the rear axle-
tree, the two middle rails being prolonged to the front to form
the stock. The side rails are prolonged to the rear, and furnish
supports for the roller of a windlass, which is used for loading
the wagon, the guns, mortars, &c., being drawn up the stock,
which rests on the ground, forming an inclined plane. Each
end of the roller is provided with pawl and ratchet, operated by
a handspike, fitting into a socket after the manner of the wind-
lass of a gin.

Over good and firm roads the mortar-wagon is capable of car-
rying the 100-pounder Parrott, or anj'^ other piece not exceeding
in weight 10,000 pounds.

The Cradle.
{Plate 37.)

516. This is a machine used for transporting heavy guns
short distances. It is made of oak, and consists essentially of
two parallel rails 13 feet 6 inches long and 10 by 12 inches thick.
These rails are united by a transom near each end and one in
•the middle ; these ti-ansoms have such length as to make the
•entire width of the cradle 60 inches. A bolster is placed over
^each end transom ; the ends of these bolsters are fl.ush with the
exterior sides of the rails. The bolsters for the support of the
breech are 6 inches high and 8 inches thick; that for the chase
15 inches high and 6 inches thick ; the middle part of the top

262 MACHINES AND APPLIANCES.

of each is slightly hollowed out to form seats for the piece. A
movable bolster, liavins: notches at each end to lit upon the rails,,
is intended to be placed tight up against the middle part of ther
gun after it has been placed on the cradle.

Diagonal braces are fitted inside between the rails and tran-
soms. The under part of the ends of the rails, both front and
rear, are beveled off, so that, in moving in either direction, the-
rollers can be caught under the cradle with facility. The under
surfaces of the rails are shod with iron to prevent them from
splintering out. A ring is attached by a link and eye-bolt to
each end transom for the purpose of attaching blocks and tackle
when moving the cradle and piece.

The cradle moves on wooden rollers; each roller is 78 inches
long and 7 inches in diameter. From six to ten rollers are re-
quired ; they rest and move on way-planks laid on the ground.

The method of using the cradle is explained in par, 535.

The Capstan.
{Fig. 1, Plate 38.)

Sl"^. This machine is used as a strong purchase in heaving
or hoisting. When so employed, it is held in position by stout
chains attached to holdfasts. The rope is passed two or three
times around the barrel of the capstan, the free end coming off
above the turns; the standing part is attached to the weight to
be moved. The rope is drawn taut by hand, the bars inserted
into the mortises, and the free end of the rope held and taken
in by two men seated on the ground.

Twelve men — three at each bar — are all that can be advan-
tageously employed. When additional power is required, the
bars are swifted ; that is, the ends of the bars are lashed together
witli ropes, by wliich additional men to take hold.

The method of using the capstan in iioisting a 15-inch gun by
means of the derrick, is explained in par. 549, and for moving^
it on the cradle up or down a ramp, in par. 535.

Gin as a Capstan.

518. Put the gin together on the ground in the usual man-
ner; place the feet of tlie legs toward the weight, and secure
them well with stakes against tlie cross-bars, feet, and head of
the gin ; rig the fall as usual, and attach the hook of the lower
block to a rope of suitable strength running to the weight to be
moved; the windlass is worked in the same manner as when

HOLDFASTS. 263

the ^in is standing. Or the o^hi, with its pry-pole in the direc-
tion of the weight to be moved, may be raised almost to its usual
position for hoisting. A block is hooked to the clevis, and through
it the rope is passed from the weight to the windlass ; the latter
is worked as usual.

Holdfasts.

519. Pickets. These are stout wooden stakes to be driven
into the ground, and used for securing purposes and in the con-
struction of holdfasts. The ordinary stakes for siege-gun plat-
forms answer for most cases. When very heavy strains are to
be borne, posts from five to eight feet long are required, and
are set into the ground by digging holes, or with a pile-driver.
When the latter is used, the post should be shod with an iron
point, and have a ring upon tiie head to prevent splitting.

5!20. Pile-driver. A good form for this is an iron tube {Fig,
2, Plate 38) about ten feet long, with a calibre of about five
inches. One end of the tube is set into a broad block of wood,
forming a base. Upon each side of the top is attached a sheave,
over whicli works a rope ; tliese ropes are attached to tiie ham-
mer, and are hauled on by hand until the hammer is at the
top of the tube, when they are suddenl}?- let go and the hammer
allowed to drop upon the head of the pile. The hammei" is an
elongated bolt of iron, weighing from fifty to eighty pounds, and
of a diameter to work freel.y in the tube.

To use the pile-driver, it is hiid on the ground and the pile or
stake introduced, head foremost, into the tube. Tiie machine is
then set up over the point where tlie pile is to be driven, held
steady, and tlie ropes worked as just explained.

In the absence of an iron tube, a box of liard wood may be
used in its stead.

To draw heavy pickets, a gin, a sling-cart, or a limber may be
used. They may also be drawn by the application of a lever,
the point being passed thi-ough a rope or chain around the picket.

In drawing pickets, care should be taken that they are drawn
out in the same line as that in wliich tliey were driven.

521. The most essential points to be considered before any
heavy weight is moved or suspended, are the nature and condi-
tion of the securing points, together with tiie strain that will be
brought on them. JSTatural holdfasts — such as the piers of case-
mates, pintles for guns of position, trees, &c. — may frequently
be found, around whicli straps may be placed. In such cases all
corners should be protected by wood, or the rope itself parceled
to prevent cliafing.

264 MACHINES AND APPLIANCES.

In places where holdfasts can be driven or sunk, the ordinary-
picket post can be made use of, but only when light weights
have to be dealt with.

In securing to a holdfast from which it may become necessary
to ease off, at least one complete turn must be taken before mak-
ing fast ; otherwise, when the strain is on it, it is difficult to cast
off.

Precise rules cannot be laid down as to the description of hold-
fast best suited for particular operations, but it should be borne
in mind that it will save much time and trouble to make it in
the first instance considerably more secure than seems to be ab-
solutely necessary, as when a holdfast once begins to give, it is
difficult to strengthen it. Whatever holdfast may be used, the
strain should be taken by the entire structure at once ; otherwise
it might give way in del ail when it would not do so as a whole.

Figs. 1, 2, 3, 4, 5, Plate 39, represent some of the methods of
constructing holdfasts.

When the strain to be sustained is very great, the one shown
in Fig. 5 is used ; a, 6, c, d is a trench from ten to fifteen feet
long and two to four feet in width and depth. It is dug in a
direction perpendicular to the strain. Several heavy stakes are
driven in the trench far enougli from the side to admit planks
being placed between them and the earth. A heavy beam, with
the bight of a chain around it, is then laid on the bottom of the
trench against the stakes, the ends of the chain being brought
up between the planks along a trench, rising gradually to the
surface so that there will be no tendency to lift the beam up
when the strain is on it. The whole trench is then filled in and
rammed.

Anchors or heavy cannon may be buried and used as hold-
fasts.

Hydraulic-jack.
{Figs. 1 to 12, Plates 40, 41.)

52!2. Owing to their efficiency and simplicity, these handy
and powerful machines are much used wherever ponderous
weights are to be moved, and are an invaluable recourse for
artillery purposes of this nature.

Fig. 1 shows the constructive points of one form of the jack,
whereof Fig. 2 is a general view. When the jack is depressed,
its external appearance is that of a cylinder or pillar, but while
being elevated it seems only one cj^linder sliding outside another.
The outer cylinder (a) is, however, simply a tube aflSxed to the
head as a ground attachment, and carries a claw [g) to support

HYDRAULIC- JACK. 265

the weight to be raised ; the head iji) is also applicable to this
purpose. The inner cylinder (6) is the true cylinder, within
which aj^ain is another or inmost c.ylinder (c), which is the true
ram. This last cylinder is hollow, and in the enlarged head car-
ries the pivot {p) of the socket (s) and lever-arm (Z), whereby the
force pump is worked. The internal capacity of the ram and
head is the equivalent of the fluid contents of the cylinder (6)
Avhen the ram is raised; it is, therefore, in fact the reservoir or
source of the hydraulic power. Fitting? nicelj'^ into the lower
part of the hollow of the ram is the piston-head with a suitable
valve, and a siraihir valve — both of which will be given in detail
further on — is fitted below it into the bottom of the ram. The
necessary reciprocating motion is communicated to the piston-
head by a piston-rod (e) passing within the ram, suitably con-
nected with and moved by the lever handle. There are three
leather packings : one {d) to the ram in the cylinder (c), one to
the piston-head, and one to the pivot of the lever. By the action
of the lever-arm the fluid is forced into the cylinder (6) beneath
the ram, and simultaneously the ram and its load are raised.
When the jack is lowered, the fluid simply passes back into the
ram and head.

Fig. 3 is another form, having a broad base ; it is the same in
principle as Fig. 1, but does not carry the outer cylinder and
■claw.

The larger jacks, and in fact those most used for artillery, are
shown in Figs. 4, 5, 6, and 7, which give the details of construc-
tion, of which Fig. 8 is a general view. This jack differs some-
what from those mentioned, in that the ram («) is a solid plunger,
sliding in a simple cylinder (6), which is fixed to the base of the
cast-iron reservoir (k). The force pump is contained in a simi-
lar cylinder (c), and the two are connected through their lower
extremities by a channel not more than one-eighth of an inch in
diameter, contained in the reservoir base. The course of this
•channel is shown in Figs. 6 and 7, which are views of the base,
into which is let a movable brass stopper (rf), which is the bot-
tom of the channel and allows access to it. Screwed into the
top of the reservoir, and directly above the force-pump cylinder,
is a cap (e) carrying a ring encircling the ram, serving as a han-
dle for moving and carrying the jack. This cap receives the pis-
ton-rod (/) and holds it in a vertical position, maintaining its
•connection with the spindle {g)., from which a tongue {%) enters
the squai-e eye (h) formed in the rod to receive it. The spindle
is suitably connected with the socket and lever-arm, from which
it receives motion and actuates the piston pump, whereby the
fluid is forced through the pump and channel into the cylinder

266 MACHINES AND APPLIANCES.

and beneath the ram, thus raishig the load. When the ram is
lowered, the fluid passes back into the reservoir through the
same connections. There are three packings, viz. : one to the
lower end of tlie piston-rod, one to the ram, and one to the spin-
dle. The ram carries a movable claw as a ground attachment.
(«, Fig. 8.)

The valves. The valves of the larger jack and their various
functions and constructive details are shown in Figs. 9, 10, and
11. The piston-rod {f) differs from that of other forms already-
mentioned by its lower half being hollow, to admit of its carry-
ing a small steel rod (r), which backs up the valve-plunger {p)r
and by having cut in its exterior surface two channels (x) in the
same plane containing the square eye, and converging at the
lower extremity. These channels admit the passage of the fluid
into the pump-cylinder, which is usually submerged in the fluid
during the ascent of the piston-rod. The upper valve is simply a
plunger and cap {v) of brass; the latter is bored with three holes
for the fluid, and is screwed into the bottom of the piston-rod ;
the former is solid, and has a slight play in the space formed by"
the convergence of the two channels and the brass cap. At the
upward stroke this valve is open from the pressure of the fluid
passing the channels, the plunger resting in the cap. At the
downward stroke it is closed., the plunger stopping the channels
at their convergence from the fluid pressure below. The lower
valve is simply a plunger {z) of brass working in a chamber at
the bottom of the pump-cylinder, and rests on a spiral spring {s).,
which is fixed to a screw passing through the base of the jaclc
from the outside. At the upward stroke this valve is closed by
the spring ; at the downward it is opened by the pressure of the
fluid, but closes, by the action of the spring, immediately upon
a cessation of this pressure. It admits the passage of the fluid
into the channel {w) connecting the ram-cylinder, thence under
the ram.

A stop on the under side of the lever handle near the socket
prevents the two valves from meeting at the downward stroke ;
by reversing this stop and pressing the handle downward gently
the cap of the upper is brought in contact with the plunger of
the lower valve, which it opens to an extent according to the
stroke ; the fluid immediately passes through, opening the upper
valve, and the ram descends proportionally. This is called trip-
ping. A cessation of the pressure upon the handle arrests all
motion.

The valves of the other forms are essentially on the same prin-
ciple, the chief difference being that the lower valve is screwed

HYDRAULIC- JACK. 267^

into the bottom of the hollow ram, while the upper works in the
piston-head.

Thus it is seen that one, and only one, pair of valves is effective-
in the various finictions, viz., to raise, lower, and stop at any
given point, and to miss a stroke if required ; these different
effects being simply realized by a mere reversal of the lever lian-
dle in its socket. In all other respects the sole secret involved
is good work and fitting and proper adaptation of wearing sur-
faces by case-hardening metal, with care in an occasional renewal:
of the leather packing.

These jacks are made in sizes to rise, varying from 7 inches to
2 feet, to lift or press from 4 to 120 tons, and from 2 inches and
upwards in diameter, according to power. The form first men-
tioned is usually employed standing or obliquely ; the last named
ma}'' be used in any position. They maj'' be worked by one man
only, being thus capable of raising 10 tons one foot in one and a
half minutes, or in that proportion.

Fig. 12 is a hydraulic puUing-jack applicable for setting up
rigging, testing chains and rope, pile-drav^'ing, slinging heavy
weights in confined spaces, &c. It differs from the lifting-jack
in being extended when commencing to work, and then being
contracted by fluid force.

To Jill the lifting-jack,

533. Remove the small screw in the head, having the piston
or ram quite down ; fill the jack through the screw hole in the
head with winter-strained sperm oil, alcohol, or whiskey, adding
to the latter (if liable to freeze) a tablespoonful of sperm oil;
work the lever while pouring in the liquid until the ram or piston
is up to its full stroke ; when this occurs the jack is sufficiently
full. Then reverse the lever and push the ram or piston back
to the bottom of the cylinder, and replace the screw in the screw
hole in the head of the jack. This screw is not intended to fit
tightly, and must not be screwed tight home after filling. Be
careful that no dirt gets into the head of the jack while filling.

The liquid may consist of equal parts of alcoliol and water, or
equal parts of whiskey and water; but these liquids should not
be used when the temperature is at, or likel}'" to be at, freezing
point. N"either kerosene oil nor spirits of turpentine, nor any
other liquid liable to corrode the packing, is suitable for use in the
jack.

To Jill the hydraulic pulling-jacTc.

534. With the iron key unscrew and remove the screw at
each end of the cylinder; if the piston is not down, push it home ;,

:268 MACHINES AND APPLIANCES.

fill through the two screw holes with the same liquid as is used
■in the lifting-jack, and replace the screws, screwing them home,
but not too tight.

To use the lifting-jack.

525. To lift. Place the head of the jack under the object
to be lifted. If the object is too near the ground to admit of
this, use the iron claw, placing one of its hooks under the object
and the other (which has a dowel) over the head of the jack. In-
sert that end of the lever which is squared (or made with a jour-
nal) and has a projecting shoulder into the mortise or slot of
the jack, the projection of the shoulder downward (or under-
neath), and pump until the object is raised to the required
height. If this height is greater than the full stroke of the pis-
ton or ram, block up the object lifted, reverse the lever so that
the projection of the shoulder is upward (or above), press upon
it until it is at the bottom of its stroke, and then push the piston
or ram down to the bottom of the cylinder; block the jack up
higher ; then reverse the lever, and proceed to raise the object
as in the first instance.

It sometimes happens that the piston or ram cannot be pushed
down after it has been run up to its full height or stroke. This
difficulty can be overcome by slacking, with a few turns, the
small screw in the head of the jack, and thus allowing the air
with which the jack is filled to escape.

Sometimes the jack fails to work in consequence of the valve
sticking in its seat. This difficulty can be overcome b}'" striking
the lever a few sharp blows up and down with a wooden mallet
or stick, which will jar the valve and cause it to resume its
action.

The lifting-jack can be used standing at any angle between 10
and 90 degrees above the horizontal; but great care must, at all
times, be exercised that the support for its base is secure, and that
its head is not permitted to slip from under the object to be raised.

5126. To lower. Place the head of the jack securely under
the object to be lowered, with the piston or ram run up to tlie
distance to which the object is required to be lowered; pump
until the object is raised sufficiently to remove tiie supports from
under it; take out the lever, and reverse it so that when put back
in the slot or mortise the projection of the shoulder of tlie lever
is upward (or above); then, with a slight pressure of the hand,
push the lever downward as far as it will go, when the piston
will commence to descend, and will continue to lower as slowly
as desired. By raising the lever slightly, the lowering can be
arrested at any point. The object must not be lowered too fast,

HYDRAULIC-JACK.

269*

nor the lowering checked too suddenly, or the jack will cease to
work.

To use the pulling-jack.

52 Y. Screw one end of the jack to some fixed object (the end
nearest the pump is preferable); unscrew the valve in the pump
by two or three turns with the key, and stretch the jack apart ;
attacli the free end of it to the object to be moved ; shut the
valve by screwing back the two or three turns that were un-
screwed ; attach the long lever and pump away at it until the
object is moved as desired. When there is not room for the long
lever, the pump can be worked by the short lever. If the jack
does not start at once, slack the screw in the cylinder close to
the pump (which the same key fits) until a drop or two of the
fluid comes out ; as soon as this occurs, turn the screw imme-
diately back. If the piston or ram will not run out to its entire
length or stroke, place the jack in a horizontal position, take out
the screw at each end of the cylinder, and fill through both holes
with the usual liquid.

The pulling-jack can be used to pull or lift at any angle be-
tween the horizontal and the perpendicular, but the direction
of its force must be in a straight line, and the force pump always
at the lowest end when the jack is used in any other way than hor-
izontally. When the pulling-jack is in use, the lever joints must
be well oiled and kept free from dirt ; when not in use, the
piston-rod must be kept in ; and when hung up, the end where
the pump is must always be downward.

^o greater force than that of one man (provided he applies a
power of about 150 pounds) need ever be applied to the lever
of either the lifting or the pulling jack, since that force is amply
sufficient to work the jack to its full capacity.

The hydraulic-jacks usually employed for artillery purposes-
have 15-ton or 30-ton lifting capacity.

Weiglit and dimensions of hydraulic-jacks.

Kind of Jack.

Height.

Height

Lift.

Weight
(filled).

Weight

Claw.

30-ton lifting

30-ton pulling

15- ton lifting

Inches.

20
62
20

Inches.

12
18
12

Pounds.

230
310
140

Pounds.
90

1270 MACHINES AND APPLIANCES.

Blocks and Skids.

528. Blocks are rectangular prisms of wood employed ex-
tensivelj'' in all operations connected with the movements of
heavy artillery. Skids are rectangular beams of wood used for
^similar purposes. The dimensions of those used in the lighter
mechanical manoeuvres are given in par. 416; those for heavier
op^ations. in par. 534.

All blocks and skids should be sound, free from knots, and
perfectly true in dimensions. When the edges become splintered
and rounded by wear, they should be discarded, as with such it
is impossible to erect safe and stable scaffolding and supports.
They should not be painted ; the thickness of each should be
marked upon both ends. In erecting a scaffold or other sup-
port, a level foundation is of the first consideration ; the blocks
should then be laid crossing each other in alternate tiers, and the
weight supported should be made to bear equally upon all sides
of the base.

529. The way-plank is an oak plank 15 feet long, 12 inches
wide, and 3 inches thick. Each end is beveled for a distance of
six inches, the bevel on one end being on the side opposite the
bevel of the other end. These planks are used chiefly for form-
ing temporary tramways for roller, or for the wheels of car-
riages bearing heavy weights.

530. The pinch-bar (Fig. 3, Flate 38) is simply a stout hand-
spike, of iron, with a round-beveled butt, turned up into a blunt
edge for the purpose of catching under a gun or other similar
object. It is used as a lever, by pressing down, thus jumping
the gun forward a very short distance at a time. The butt
end is of steel. The length of the bar is from five to seven feet.
Those used with the 15-inch gun are of the largest size, and
weigh 53 pounds ; the shorter size weigh 26 pounds.

531. The collar {Fig. 4, Flate 38) is a device placed upon
the chase of a gun to make its diameter equal to that of the
body of the piece. This enables the gun to be rolled with facil-
ity. It is made of pieces of scantling jointed together after the
manner of the staves of a cask, and hooped with stout bands of
iron. It is shoved over the muzzle onto the chase, and secured
with wedges of wood.

532. Chocks (Fig. 11, Flate 18) for the 15-inch gun are made
of solid oak wood, of the shape and dimensions represented in
the figure. The grain of the wood runs lengthwise with the
chock.

When the piece is to be slued, a chock is used having the bev-
eled side cut out slightly concave ; the opposite, or flat side, is

FLANK-CASEMATE HOWITZER. 271

shod with spikes, for the purpose of keeping it from slipping.
The concave side is placed against the piece, and well greased,
to allow the piece to turn easily upon it.

To MOUNT AND DISMOUNT THE FlANK - CASEMATE

Howitzer.

The implements necessary are : One JiaJ^f roller, two hal/i
-blocks^ two skids, four blocks, four gun-chocks, one hammer-
wrench.

The piece being from battery.

533. The instructor commands :

1. Dismount the carriage.

I^os. 1, 2, and the gunner remove the pintle and run the car-
riage into battery; the gunner, assisted by N'os. 3 and 4, takes
oft" the three nuts that hold the fork ; a handspike, manned by
IS'os. 1, 2, 5, and 6, is passed under the chassis immediately in
rear of tlie fork, and at the command Heave from the gunner,
the chassis is raised, the fork removed, and the trail carefully
lowered to the ground; Nos. 3, 4, 5, and 6 then lay tlie skids in
rear and in prolongation of the chassis, tiieir outer edges in line
witli those of the chassis; ISTos. 1, 2, and the gunner then run
back the carriage, applying themselves as in from battery, until
the rear end of tiie cheeks touch the counter-hurters.

The gunner bears down on the roller handspike to raise the
-trail as much as possible, and, assisted by Nos. 3 and 4, who
place the ends of their handspikes under the outer edges of the
trail, lifts it over the counter-hurters onto the skids.

When the front rollers touch the counter-hurters, No. 2 puts
his handspike into the bore and chocks it ; Nos. 1 and 2, assisted
by ISTo. 5, raise the muzzle ; Nos. 3 and 4 lift at the manoeuvering
rings, and run back the carriage until the front rollers rest on
the skids; N^os. 1, 2, 3, 4, and the gunner (tlie latter embarring
in the left mortise, and pressing the roller under the rear tran-
som, and Nos. 1, 2, 3, and 4 laying hold of the manoeuvering
rings and handles) run the carriage back on the skids until the
muzzle is over their front ends.

The instructor commands :

1. Dismount the howitzer.

Nos. 3 and 4 remove the cap-squares, and lay a block and a
lialf block across the skids, touching tlie head of the cheeks; N'o.
2 inserts his handspike in the bore, chocks it, and, assisted by

272 MACHINES AND APPLIANCES.

iN'os. 1 and 5, raises the muzzle high enough for N'o. 4 to place
a half roller on top of the blocks. The chase is rested on this
half roller and chocked on each side ; No. 6 crosses his handspike
under the knob of the cascable, No. 5 taking hold of the other
end; Nos. 1 and 2 bear down on the handspike in the bore;
Nos. 5 and 6 lift on that at the cascable ; the gunner and Nos.

3 and 4 back the carriage until the front rollers rest on the rear
eifds of the skids and the trail is on the ground ; Nos. 3 and 4
then place a block and a half block across the skids under the
breech.

Nos. 5 and 6, bearing down on their handspikes at the casca-
ble, and Nos. 1 and 2 lifting on theirs, raise tiie muzzle, and
Nos. 3 and 4 remove the half block from under the half roller.
The muzzle is in like manner lowered, and the half block re-
moved by Nos. 3 and 4 from under the breech. The muzzle is
again raised, and Nos. 3 and 4 remove the block from under the
half roller and place the half roller under the trunnions. The
muzzle is borne down, and Nos. 3 and 4 remove the block from;
under the breech and replace it by a half block. The piece may
now be slued in any direction, rolled upon blocks, or placed in
any required position.

To mount the howitzer when on the skids and resting on the
half block and half roller.

The instructor commands :

1. Mount the howitzer.

No. 2 inserts his handspike in the bore, and, assisted by No.
1, prepares to bear down on the muzzle ; No. 6 crosses his hand-
spike under the knob of the cascable, and, assisted by No. 5,
prepares to lift at the breech. At the command Heave from
the gunner, they lower the muzzle, and Nos. 3 and 4 replace
the half block under the breech by a block. The breech is low-
ered on the block and chocked. The muzzle is next raised by the
same numbers at the handspikes, and Nos. 3 and 4 insert a half
block under the half roller, so that the front scaffold thus formed
is 3 or 4 inches in front of the junction of the chase and rein-
force. The muzzle is now lowered, and a half block placed by
Nos. 3 and 4 on top of the block under the breech.

The muzzle is next raised, and a block placed by Nos. 3 and

4 under the half block, thus forming under the chase a scaffold
consisting of a half roller, a half block, and a block; Nos. 3 and
4 now remove the cap-squares, and the gunner, assisted by these
numbers, places the front of the carriage on the skids, as near
the gun as convenient, the trail resting on the ground ; Nos. 1

TO DISMOUNT A 15-INCH GUN. 273

and 2 bear down on the handspike in the bore, and !N"os. 5 and
6 hft at that under the knob of the cascable ; ISTos. 3 and 4 re-
move the rear scaftbld, and, with the gunner, run up the carriage
until tiie trunnion beds are under the trunnions; IS'os. 1 and 2
raise on their iiandspike ; Kos. 3 and 4 remove the front scaf-
fold, and the trunnions are lowered into their beds; Nos. 3 and
4 put on the cap-squares. All then run the carriage forward
until the front rollers touch the counter-hurters.
The instructor commands :

1. Mount the carriage.

No. 2 inserts his handspike in the bore, and, assisted by Nos.

1 and 5 (the gunner bearing down on the roller handspike),
raises the front of the carriage ; JSTos. 3, 4, and 6 at the same
time push the carriage forward until the front rollers pass over
the counter-hurters and the guide of the front transom enters
into the guide space ; N'o. 6, with a handspike at the trail,
assisting to pass it over the counter-hurters and guiding the
flanges of tlie roller into the guide space.

No. 6 then crosses his handspike under the knob of the casca-
ble, and, assisted by No. 5, lifts against the base of the breech ;
Nos. 3 and 4 seize the trail handles, and Nos. 1 and 2 the man-
ceuvering rings; the gunner bears down on the roller hand-
spike. AH act together and run the piece up the cliassis into
battery.

Nos. 1, 2, 5, and 6 now apply themselves to a handspike crossed
under the rear end of the chassis, which they raise and hold up
while the gunner, assisted by Nos. 3 and 4, replaces the fork and
nuts. The piece is then run from battery, and the gunner,
assisted by Nos. 1 and 2, puts in the pintle.

To DISMOUNT A 15 -INCH GrUN FROM ITS CARRIAGE BY
MEANS OF BLOCKS.

534. The implements required are : Two hydraulic-Jacks
(thirtj'-ton), four pinch-bars (hirge), six handspikes (manoeuver-
ino), eight wheel-chocks^ four gun-chocks (large), one trace-rope,
six way-planks, four shifting-planks^ two wrenches (nut), one
sledge-hammer, two long rollers (cradle), four small rollers (15
inches long, l.o inch diameter), one ten-foot pole, one carpen-
ter''s rule, one screw-driver; fifty blocks^ 12 by 12 by 44 inches
(hard pine); twelve blocks, 12 by 6 by 44 inches (hard pine);
eight blocks, 12 by 4 by 44 inches (hard pine); ten blocks, 12 by

2 by 44 inclu-s (oak); ten blocks, 12 by 1 by 44 inches (oak); six
whole blocks, 8 by 8 by 20 inches (oak) ; four half' blocks, 8 by

274 MACHINES AND APPLIANCES.

4 by 20 inches (oak) ; four quaHer blocks^ 8 by 2 by 20 inches
(oak) ; two skids^ 12 by 15 bj" 204 inches (hard pine or oak) ; six
skids^ 8 by 8 by 72 inches (oak).

A four-wheel truck-wagon is convenient for removing the top-
carriage and chassis.

U'he following nnethod is for a gun mounted on a centre-pintle
carriage. Only slight changes are necessary to adapt it to a
front-pintle carriage, and these will readily suggest themselves
to any one performing the manoeuvre.

To dismount the gun.

535. Twleve men are necessary: one chief-of-detachment,
one gunner, and ten cannoneers.

Tlie manoeuvre is executed in the following order:

1st. Run the gun into battery and give it an elevation of zero.

2d. Remove the flooring-planks.

3d. Remove from the chassis all transoms and braces in rear
of tlie pintle transom. This makes a clear space under the body
of the gun for a ""crib" to be built, as shown In Fig. 2, Plate 42.

4th. Remove the fulcrum post, crane, and steps of the chassis.

oth. Remove the large nuts from the rear end of the piston
rods.

6th. Run the gun from battery until the top-carriage is within
two or three inches of the counter-hurters.

7th. Remove the truck-wheels of the top-carriage and take
out the axles of the same.

8th. Remove the counter-hurters from the chassis and the
guides from the top-carriage.

9th. Place a half block crosswise on each rail against the hurt-
ers ; upon each of these place one of the six-foot skids, its rear
end resting on the chassis rail. This gives a horizontal foun-
dation for the front scaffold to be built under the chase of the
gun, and a seat for the jack, under the muzzle, to rest upon.
(Fig. 1, Plate 42.)

10th. Build up a scaffold from the gun platform between the
rails of the chassis. (Fig. 2, Plate 42.) This supports the body
of the gun, while the front scaffold supports the chase. Both
should be built crib-fashion, and of the 44-inch blocks. Great
care should be taken that these scaffolds are firm and true.

11th. Place a 44 by 12 by 12 inch block on end, resting on
the platform and under the fulcrum-post transom to support it.
On top of this transom place blocks to support the jack when
raising the breech of the gun. {Fig. 1, Plate 43.)

12th. Place the jacks, one under the breech and the other un-
der the muzzle ; raise until the trunnions are clear of the car-

TO DISMOUNT A 15-INCH GUN. 275

Tiage, and block up the front and rear scaffolds securelj'^ under
the ^un. The greatest care should be observed in this operation
to place the jacks squarely under the breech and muzzle^ so that
the gun may not roll and thus raise one trunnion higher than
the other. The jacks should be worked alternately, commenc-
ing always with the one under the breech, and onh'^ two or three
inches should be gained at each lift. {Fig. 2, Plate 42.)

13th. Remove the front transom from the carriage, so as to
admit of the latter being run back clear of the rear scaffold.

14th. Place a trace-rope tlirough the rear axle-holes of the
Xiarriage ; pr}'' up the rear of the carriage, and insert under each
shoe a small (ly^^inch) roller.

15th. Back up the truck- wagon against the rear end of the
chassis rails. The wheels of tlie wagon should rest on way-
planks.

16th. Haul on the trace-rope and draw back the carriage,
catching it on long rollers placed on two way-planks on the
wagon. {Fig. 2, Plate 42.) The carriage can be drawn back
over the counter-hurters in case the latter are not removed.
When a truck-wagon carmot be used, the carriage can, in like
manner, be hauled back upon a crib of blocks built in rear of the
chassis, from which it may be readily lowered to the ground by
means of jacks or handspikes. {Fig. 2, Plate 43.)

17th. The gun now being free from its carriage and resting on
the scaffblds, built up as before described, is lowered, by means
of jacks, until it rests on two long skids, one end of each rest-
ing on the chassis rails, while the other end rests on a crib of
blocks built up on the side of the chassis to which the gun is to
be moved. The skids must be horizontal and on the same level.
To this end the front one should rest across and on the two six-
foot skids placed as in "9th." A bar of railroad iron placed on
the front skid will greatly facilitate the next operation.

18th. Roll the gun over on the skids until it rests above the
cribs. The muzzle is cut forward, either by pincinng or by
hauling on a trace-rope attached to a block or roller in tiie muz-
zle. The gun may now be lowered to the ground by means of
the jacks, or, should it be desired to move it to some other part
of the works, it may be placed on a cradle. {Fig. 1, Plate 44.)

To do this, the cradle is placed parallel to the gun and about
three feet from the cribs. Tlie cradle rests upon five or more
long cradle rollers resting on two way-planks laid on the ground
directly under the rails of the cradle. (It is best to double the
"way-phmks by laying them on each other in such manner as to
break joints.) The rollers are securely chocked. The gun is
now lowered, by means of the jacks, until it rests upon the two

276 MACHINES AND APPLIANCES.

long skids placed across the cradle, the ends under the g^un rest-
ing on the cribs — now reduced in height to two blocks — while
the other ends are supported by blocks on tlie other side of the
cradle. {Fig. 2, Plate 44.)

The gun is next rolled until it rests squarely over the cradle,
w^hen it is again jacked up until the skids are removed, after
which it is carefully lowered into its place on the bolsters of the
cradle. {Fig. 1, Plate 45.)

The gun may be rolled over by means of pincli-bars, but more
easily by parbuckling. A parbuckle-rope is used for this purpose,
and is hauled upon by hand, or, better, by attaching to it a tackle
secured to a holdfast or some other fixed object.

The same rope and tackle may be advantageously used for
cutting forward the muzzle ; attaching the rope for this purpose
to a block or roller placed in the bore of the gun. {Fig. 2,
Plate 45.)

The gun upon its cradle is moved by attaching to the front
ring of the cradle a heavy rope (6 to 8 inches circumference) and
hauling on it b}'^ means of a capstan, or a tackle may be used
instead of a capstan, in which case a single-sheave block is
hooked into the ring, and through it a rope is rove, one end of
which is secured to a strong holdfast to the front, and the other
hauled upon by tackle in the manner represented in Figs. 1, 2,
Plate 46.

Way-planks are placed successively as the cradle moves for-
ward, and as the rollers become disengaged at the rear they are
placed in front, care being taken to preserve an equal bearing
upon all.

In passing around curves, the rollers are kept in the position
of radii of the curve. This is accomplished by placing each roller
in the required position and by driving the ends backward or
forward, as the case ma}'^ require. By observing this, all un-
necessary jerking will be avoided. The cradle should, if possi-
ble, be moved with the muzzle of the gun foremost; it then
engages the rollers in front more freely, glides over inequalities
with greater ease, and is more readily directed in its course, —
results following from the smallest weight being in fi'ont. In
going up or down inclines, the rope should be attached to the
gun, by the trunnions, instead of to the cradle. This will obvi-
ate any danger of its slipping on the cradle.

When the inclination is great — as upon a ramp — tackling
should be used as illustrated in Figs. 3, 4, 5, 6, Plate 46.

Should the railway truck be used instead of the cradle, the
gun is placed on it by operations similar to those for the cradle,.
except that the skids must be supported entirely by the cribs at

TO DISMOUNT A 15-INCH GUN. 277

fthe sides, and not allowed to rest on the truck ; observing, also,
that the front end of the trucli must always be in the direction
towards wliich the gun is to be moved.

Unless the ground is very firm and the manceuvering detach-
ment skillful, the cradle is the safest and surest method.

To remove the chassis from its platform.

536. This may be done by jacking and blocking it up, and
placing under it tiie cradle and rollers. A better way, however,
is to use the garrison gin instead of Jacks, and the four-wheel
truck-wagon instead of the cradle.

The gin is placed over the chassis ; a sling-chain, doubled, is
passed around the latter directly in front of the pintle bolster ;
to this the hook of the tackle is attached.

The sling-chain should be of iron, at least seven-eighths of an
inch in diameter. It is better, however, to use heavy rope for
slinging. A gun-sling made of not less than 9-inch rope is most
■convenient, and to use it a cradle roller, or a beam of wood of like
dimensions, is placed under the chassis, directly in front of the
pintle bolster, its ends projecting equall}'^ on the sides. Lay the
gun-sling across and over the chassis; bring both ends of it
under the ends of the roller and up together on top of the chas-
sis, where the free end is drawn through the eye, bent into a
knot, and stoppered. The hook is attached to the sling by lash-
ing with a trace-rope, not less than six turns being taken for
this purpose.

Blocks of wood, with rounded edges, are placed against the
sides of the chassis rails, under the sling, to prevent the sharp
edges of the chassis from cutting the rope.

The chassis is then raised until the truck can be backed under
it. The wheels of the truck rest on waj-planks, and the truck
coupled to such length that when the chassis is lowered the rear
traverse-wheels will be in h'ont of the front bolster, and the
front traverse-wheels in rear of the rear bolster of the truck.
(Plate 47.) The chassis is lowered so that the rails will rest on
the bolsters between the iron projections at their ends. The
truck, with the chassis, can now be moved wherever desired.

The chassis is replaced and the gun remounted by operations
the reverse of the foregoing.

The precautions necessary to be observed in all mechanical
manoeuvres with artillery, multiply rapidly with the weight of
the piece.

With the 15-inch gun, all implements and material should be
of the most perfect kind, and no doubt should be allowed as to
-Strength of parts to sustain the weight or pressure required of

278 MACHINES AND APPLIANCES.

them. The utmost care should be taken to avoid all sudden shocks^^
and jerking niovemeyits.

53*7. Another method of mounting guns on iron carriages, is-
to block up the pi(^ce to tiie proper height, and then assemble
the chassis and carriage under it.

To do this, place the piece on the platform in such position as
to bring the chassis in its proper place with reference to the
pintle and traverse circles ; raise the muzzle and breech alter-
nately by means of the jack, supporting the gun on two scaf-
folds of blocks placed in front and in rear of the trunnions ;
assemble the chassis in position ; place one cheek of the top-
carriage on the chassis rail, with the trunnion bed directly under
the trunnion, and bolt the transoms to it; place the other cheek,
in position, and bolt it to the transoms; lower the trunnions
into their holes and remove the block.

To dismount a gun, proceed in the inverse manner.

Another method, when the top-carriage has not been taken,
apart, is as follows : Mount the chassis on the platform and the
top-carriage on the chassis, and then run the top-carriage intO'
battery; bring the gun upon the cradle or skidding until it
is parallel to a convenient portion of the chassis; roll the
gun over the chassis, having the breech projecting beyond the
rear end of the chassis ; raise it by blocking under the breech
bej^ond the rails and under the muzzle by a pier of blocks be-
tween the rails, or by a pier of blocks outside of each rail with
a skid laid across. The piece is raised until the trunnions are
high enough to permit the top-carriage being moved back under
them, when the piece is lowered into the trunnion beds and the
scaffolding removed.

^"^hen a pier of blocks is placed between the chassis rails, a gin
is used for suspending the muzzle until the pier is removed and
the carriage moved back under the trunnions.

A gin may be advantageously used for raising heavy gun&
upon blocks. To do this, supposing the piece to be lying on the
ground, insert a skid or similar piece of timber into the muzzle ;
erect the gin over the muzzle and attach the tackle to the skid ;
raise the muzzle and place a block under the piece just in rear
of the centre of gravity ; lower the muzzle and block up under
the breech ; again raise the muzzle and block up on the fulcrum;
lower the muzzle and block up under the breech ; and continue^
this operation until the piece is at the required height.

DESCRIPTION OF THE GUN-LIFT. 278

To PLACE A 13-INCH MORTAR, MOUNTED ON ITS CAR-
RIAGE, ON A TRUCK-WAGON.

538. Implements specially required : One gin^ of size larger
than garrison o;in ; one fall^ of large size (5 to 7 inches) ; one
quadruple blocks one triple blocks four sling-chains (linlcs not
less than 0.75 inch in diameter), one four-wheel truck-wagon^
one clevis for mortar lug. Instead of the sling-chains, two gun-
slings may be used. These should be of rope not less than nine
inches in circumference.

Twelve men are necessar}' : one chief-of-detachment, one gun-
ner, and ten cannoneers.

Remove the upper step from the bed and depress the mortar
until its axis is horizontal ; raise the gin over the mortar and
rig the tackle ; attach the clevis to the clevis lug and hook the
lower block to it ; pass a sling-chain under the rear notches of
the bed and up over the mortar, in front of the clevis lug,— this
is to prevent the rear end of the carriage from sagging when the
mortar is raised ; work the windlass until tiie carriage is high
enough to pass the wagon under it ; the wagon, having been
coupled short enough to receive the mortar bed on both bol-
sters, is run under and the mortar lowered upon it.

Should there be no clevis lug on the mortar, two sling-chains
are used, passing under tlie front and rear notches of the bed
and crossing each other on top of the mortar. The lower block
of the gin tackle is hooked at the crossing, and the operation of
raising is as before described.

The mortar thus mounted on a wagon can be moved by hand
short distances, and with eight horses may be transported over
level and fii-m roads.

Instead of the gin, one trestle of the gun-lift may be used for
the foregoing operation. It is set over the mortar, and the ma-
noeuvre is proceeded with as with the gin. {Fig. 1, Plate 48.)

Description of the Gun-lift.

{Plates 48, 49.)

539. A. SHU with mortises to receive the legs of the trestles.

B. Brace sill, notched to fit on sill, with a bolt and key to
secure it in its place and a cast-iron seat for end of adjusting
screw of brace to rest in.

C. Legs of trestle^ bolted and keyed together at top.

D. Brace, with adjusting screws attached to foot. One brace
on each trestle has cleats to form a ladder.

280 MACHINES AND APPLIANCES.

E. Cap^ with a shallow mortise near each end to receive ends
of legs and braces, and a hole to receive larsje bolt for securing
it to legs. These bolts are keyed below, and their heads project
above the cap about three inches, and serve as dowels to secure
the bolsters.

F. Bolsters^ resting on cap, having a clevis at centre of gravity
for hoisting it in position and a mortise for hoisting-bar to pass
through.

G. Bracket^ fastened to cap by a bolt, around which it turns.
H. Staging-plank^ resting on brackets.

I. Fulcrum^ resting in mortise in bolster.

J. Lever^ one end resting in fulcrum and the other on hy-
draulic-jack, and having a mortise through which the hoisting-
bar passes.

K. Hoisting-bar, with hooks on lower end for sling-chains and
holes at intervals to receive supporting pins.

L. Shears^ for lioisting into tlieir places the bolster, levers,
fulcrums, and jacks.

M. Hydraulic-Jack, for raising end of lever, and thereby the
weight.

Each gun-lift is provided with two sets of caps and bolsters.
One of these sets has the mortises for the hoisting-bar through
its middle ; this is intended for centre-pintle carriages. The
other set has mortises much nearer one end than the other, and
is for front-pintle carriages. The latter arrangement is intended
to permit ttie carriage to be traversed from under the gun, when
it is raised, or under it, when it is being mounted.

When weiglits are not excessive — that is, not exceeding, say,
fifteen tons — and can be slung with a single sling, but one trestle
need be used. Tliis would be the case with mortars, gun car-
riages, and like weights.

The jacks used must be of a power equal to the weight to be
raised, as there is nothing gained for them by way of leverage.

Twelve men are necessary to erect the gun-lift and mount or
dismount a 15-inch gun.

Implements specially required : Two hydraulic-jacks (30-ton,
or one 30-ton and one 15-ton), two mauls, two hammers, one
measuring-rod (12 feet), one spirit-level (carpenter's).

If the carriage and chassis are to be moved, the following will
be required in addition : One cradle (or truck-wagon), six cradle
rollers, twelve wheel -chocks, four way -planks, two shifting -
planks.

A sufficient number of 44-inch blocks of various thicknesses
should be at hand for any purpose required of such material.

DESCRIPTION OF THE GUN-LIFT. 281

To assemble and raise the gun-lift.

540. Place the sills parallel to each other at the required
clistance apart and on the spot where the trestle is to stand. It
will be convenient to have a wooden rod of a lensjth equal to the
proper distance between the sills. Lay down the brace sills and
key them ; take two legs, bring together the two ends which
form the mitre joint, pass the bolt through them, and drive in
the key ; raise one leg above the other, insert the head of the
legs into the mortise in the cap, put in the bolt, and drive in the
key. At the same time two other men have gone through the
same operation with the other two legs.

Place the ends of the legs that are on the ground close to the
mortises in the sills ; all take hold of the cap a4id raise it, bring-
ing the trestle on its feet and placing the legs in the mortises in
the sills.

A pole with a notch in the end, or hook like a boat-hook, will
be convenient in raising the trestle after the cap is too high to
hold it with the hands ; or the trestle may be raised bj^ the shears
in the same way as the bolster, if the party, be deficient in force,
or if for other reasons it be deemed desirable. Correct the posi-
tion of the trestle, if it be necessary, so as to bring the mor-
tise for the hoisting-bar directly over the centre of gravity of
the weight to be raised. Put up the braces, varying their length
as may be required, by turning the screw in the foot, until they
shall have a good bearing when the legs are vertical, which is
determined bj'^ a plumb-line or spirit-level.

To raise the bolster, a pair of light shears is provided. Place
them so that when raised the head shall be over the middle of
the cap of the trestle ; hook the pulley-hook in the link provided
ior the purpose ; fasten two guys to the head, one to the front
and the other to the rear ; raise the shears and make fast the
^uys ; hook the pulley to the clevis of the bolster and raise it
to its place on the cap ; raise the staging-plank and lay them
•on the brackets.

Two men ascend the steps on the brace to the top of the trestle
and receive the fulcrum, lever, and jack, which are hoisted to
them in turn, and place them in position. The hoisting-bar is
brought by the men on the ground, who insert it into the mor-
tise in the cap and bolster, and raise it, assisted by those on the
trestle, until it be in position.

To raise the weight.
Pass a sling around the weight, bringing the ends over the
hook on the end of the hoisting-bar, taking in all of the slack.
Bring the lever down on the head of the jack ; put in the pin

282 MACHINES AND APPLIANCES.

over it and through a hole in lifting-bar ; commence pumping^
and raise the weight the full lift of the jack ; insert the pin in
the hole in lifting-bar above the bolster and run down the head
of the Jack as far as it will go; bring the lever down as at firsts
and continue the operation as already described. The weight
should not be left on the jack for any length oftime^ hut on the pin.

To mount a lo-inch gun with the gun-lift.

541. The platform is supposed to have nothing on it. Bring
the gun onto the platform by means of the cradle, or truck and
portable railway, the muzzle to tiie front, the vent uppermost,,
and leave it in such a position, with the muzzle about two feet
in rear of where the end of the chassis will come, that when the
gun shall be rais'ed vertically the carriage can be placed on its
pintle and directly under the gun ; place the shears midway
between the place where the two trestles are to stand ; raise the
trestles and place them over the gun so that one hoisting-bar
shall be over the centre of the neck of the cascable and the other
about two feet from the muzzle ; raise the gun to its full height
as already described for raising a weight ; remove the truck,,
bring the chassis (on a truck), and run it between the legs of
the trestles under the gun ; remove the truck and place tho
chassis on the pintle ; bring the top-carriage and place it on the
chas.sis, placing the trunnion beds under the trunnions; lower
the gun into its place, and remove the gun-lift.

If the gun and carriage be already on the platform, or if the
peculiar position of the platform be such as to render the forego-
ing method impracticable, the following plan may be executed i

Place the gun in such a position that the axis of the bore shall
be in the same vertical plane as the central line of the chassis^
when the latter shall be in place ; move the chassis parallel and
close to the gun, the top-carriage rini well to the front; put up
the trestles over the gun and chassis, both of them being between
the legs of the trestles; hoist the gun, raise and slide the chassis-
by means of the jacks under the gun and over its pintle ; run
the top-carriage back under the gun, and lower it into its place.

To DISMOUNT A 10-INCH SmOOTH-BORE (CASEMATE GUN)

BY MEANS OF BLOCKS.

{Figs. 1, 2, Plate 50.)

542. The detachment consists of one chief, one gunner, and
ten cannoneers.

Implements: Two skids, 96 by 12 by 12 inches; seventeen

TO DISMOUNT A 10-INCH SMOOTH-BORE. 283

blocks, 44 by 12 b.7 12 inchess ; five blocks, 44 by 12 by 6 inches ;
five blocks, 44 by ]2 by 4 inches ; five blocks, 44 by 12 by 2 inches ;
ei^lit whole blocks, four half blocks, four quarter blocks, one
bar (raih'oad iron), two hydraulic -jacks, two pinch -bars, tvs^o
hammer-wrenches, two iron wrenches, foui- long handspikes, two
manceuvering-bars (iron), one two-foot rule, two muzzle-chocks y
two breech-chocks, one large chock, five wheel-chocks.

To dismount the piece.

543. Run the piece from battery until the carriage touches the
counter-hurters ; throw it ouc of gear ; remove fulcrum post, rear
transom, rear guides, and depress the piece as far as possible.

Under the rear of the chassis rails, and parallel to them, lay
two 12-inch blocks, their front ends touching the traverse-
wheels; across these place tvio 6-inch blocks about six inches
apart, the front edge of the front one directly under the rear
edge of the middle transom of the top-carriage ; across these
rest on each side a whole and a half block, the whole blocks one
foot apart, their front ends on a line with the front edge of
the 6-inch block under the middle transom ; lay a half block be-
tween the whole blocks for a support for the hydraulic-jack.
Under the chassis, in front, place transversely two i2-inch blocks
about 15 inches apart, the rear one under the rear part of the fork;
across these place a 6-inch block to support the hydraulic-jack ;
across the chassis rails, and resting against the hurters, place two
quarter blocks ; let the front ends of the 6-inch blocks rest upon
these, the rear ends bearing upon the chassis ; build across the
rear ends of the 6-hich blocks, with 12-inch and 6-inch blocks (or
thinner pieces if necessary), until the muzzle is reached ; block
up securely and chock the breech, and. by means of the jack,
raise the muzzle until the gun has a slight elevation ; then raise
the breech and muzzle alternateh' until two whole blocks, in
addition to those already placed, can be put under the former,
and one 12-inch and two 6-inch blocks under the latter ; run the
top-carriage forward until the front ends nearly touch the block-
ing in front; remove eccentric sockets, wheels, axle, and right
front guide ; raise the carriage, and under it, front and rear and
across the chassis, place two iron raanoeuvering-bars ; back up
the casemate truck, chock the wheels, and slide the top-carriage
upon it. The truck having been removed, two skids are placed
under the gun, front and rear, between the blocking, their inner
ends ends resting upon both chassis rails, the outer upon cribs
built of 12-inch blocks as near the chassis as possible. The gun
having been lowered upon the skids, the muzzle resting upon
the railroad iron so that it can be cut. it is rolled until it rests
directly over the cribs, raised sufficiently to permit the skids to-

^84 MACHINES AND APPLIANCES.

■be removed, and lowered to the ground or upon the casemate
truck, as may be desired.

The gun is mounted by inverse means.

Precautions to he observed.

544. After the breech is sufficiently raised, the two upper
whole blocks are backed up by two others placed in rear, in order
to give a broader bearing and prevent the possibility of upsetting.
The gun should never have much elevation when being raised
by the jacks, as it is liable to slide to the rear and upset the jack.
This is especiall}'^ important when the gun is being mounted be-
fore the top-carriage has been run back. In remounting the
gun, care must be taken that it is not too far to the rear (the dis-
tance from the n»ar of the chassis to a point directlj'' under tiie
axis of the trunnions is 5 feet 1 inch) ; should this occur, how-
ever, the carriage can be run farther to the rear by removing
the counter-hurters. Should the gun, upon being rolled back
over the chassis, have its trunnions in line, but not rest directly
over the carriage, it may be moved sidewise, by raising it with
the jack, and then lowering it slowly upon a large ground-chock.

If the blocking under the breech is placed too far forward, it
will not allow the carriage to be run sufficiently far to the rear
to receive the trunnions in the trunnion bed.

Care must always be taken to arrange the blocking and crib-
work so that it will not interfere with the free manipulation of
the jacks.

The foregoing is for a gun mounted on a casemate carriage.
When mounted on a barbette carriage, the operation differs but
little from the former.

Shears.

545. Shears are used for lifting heavy weights over the face
of a wall or cliff, or in other situations where the gin could not
be used for want of footing for the pry-pole.

All shears are constructed and erected on the same principle.
They consist of two spars of suitable size for the weight to be
raised. Tiie following will serve as a guide :

Spars.

"Weight.

Dtameteb.

Length.

Tons.

2
5
12 and
upwards.

Indies.

Head 6 to 9 heel.
" 10 to 14 "
" 14 to 20 "

Feet.

20 to 30
30 to 40
30 to 45

SHEARS. 285

The upper and lower ends are respectively called the head
and heel^ and the part where the lashing is applied is termed the
cross.

The stores necessary to equip a pair of shears are :

Gin tackles — Two single blocks^ two double blocks.

Main tackle — One double blocks one treble blocks one snatch
block.

Cordage — Main-tackle fall, 100 fathoms 3 to 5 inch Manila
rope ; giiys, 50 fathoms 3 to 6 inch Manila rope ; head lashing,
10 fathoms 3 to 4 inch Manila rope ; heel lashing (two each), 10
fathoms 3 to 4 inch Manila rope ; contingencies (two each), 50
fatjjoms 3 to 4 inch Manila rope.

Straps— M'din tackle, one fathom 6-inch Manila rope ; snatch
block, one fathom 4-inch Manila rope ; holdfasts (six), each made
of one fathom 4-inch Manila rope ; contingencies (six), each made
of a half-fathom of 4-inch Manila rope.

Spun-yarn for mousing, stops, &c., one ball of 100 fathoms.

Two cleats for heels, to prevent the lashing from slipping up,
made by cutting lengthwise, diagonally, a piece of 6 by 6 inch
scantling 2 feet long. These cleats are spiked to the heels 6
inches from the bottom. Twelve stakes for holdfasts for guys,
6 feet by 6 feet by 8 inches; four stakes for heel -posts; two
shoes for heels, 6-inch plank, 15 feet by 15 feet.

To rig the shears.

(Fig. 1, Plate 51.)

546. Lay the heads of the spars on a trestle about three feet
high, the right leg above the left, so that they cross at about
twice their thickness from the ends, with the heels in their
proper position.

Pass the head lashing as described in par. 480, or if a very heavy
weight is to be raised, as follows : Take a good piece of 'S^ or
4 inch rope, well stretched, middle it, and make fast to the shear
leg, below the cross; with one end pass the i-equlsite number of
figure-of-eight turns around both spars, heaving each turn well
taut, and hitch the end to the upper part of the shear leg; with
the other end pass riding turns around both legs, filling up the
intervals between the first turns; come up with the hitch of
the first end, and pass trapping turns around all parts of the
lashing between the shears; finish with a square knot, and stop
the ends back with a good spun-yarn stop. If necessary, tighten
up with wedges.

Lay the middle of the back guy in the cross; bring the left-
hand end up around the right leg and over the head of the left
leg ; then carry the right-hand end around under both legs ; let it

:286 MACHINES AND APPLIANCES.

'Cross over the left-hand end, and seize them together with spun-
yarn.

Make a bowline knot in the end of the fore guy and slip it
over the head of both legs.

Lay the middle of the main-tackle sti-ap under the cross above
the fore guy; bring the ends up over the cross; hook the upper
block to them under the cross below the fore guy, and mouse it^
taking care that the splice comes in the middle of the strap and
that the fall leads to the rear.

Drive the heel-posts on each side the heels about a foot toward
the head, and one foot outside; lay the shoes under the heels;
make a timber hitch around the inner posts with the heel lash-
ings; pass three turns over the legs below the cleats, and hitch
the lashings to the outer posts.

Drive four holdfasts for each back guy as follows : Two on
each side the line of the legs prolonged, three feet apart, and
•two six feet in rear of these.

Lay the ends of the guy straps over the front stakes ; connect
each pair of front and rear stakes with a strap twisted up taut to
insure the strain being distributed properl}'.

Drive two holdfasts for the fore guy, one in rear of the other,
in the prolongation of the axis of the shears.

Hook the upper blocks of the guy tackles to a bowline in the
end of the guj^s, and the single block to the guy strap, and
mouse them all.

Ordinarily the fore guy can be worked without a tackle, be-
laying it over the holdfasts, first taking a round turn over the
one next the shears.

If not too heavy, the shears may be raised by lifting the head
and hauling on the guy tackles, slacking the lieel lashings as re-
quired, and tending the fore guy carefully to prevent the shears
falling over toward the rear.

When raised, hook tlie snatch block to a strap placed below
the cleat on either leg.

If the shears are too heavy to raise in this way, bring both guys
together at the heels; form a crutch by lashing together two
poles (or use the legs of the garrison gin) ; place the guys in this
crutch; pass the end of a small rope over both guys, in front of
the crutcli, down under the lashing, and take a rolling hitch
with it around one of the guys in rear of the crutch ; haul the
rope well taut, and secure it to tiie lower end of the crutch leg.

Kaise the crutch with an inclination of one-sixth to the front,
and heave up the shears by the guy tackles. When the crutch
-ceases to act, slack it to the ground by the small rope.

In general, the inclination or rake of the shears should not

SHEARS. 287

-exceed 20 degrees, or four-elevenths of their height, and each
leg should have about one-half this inclination. In this position
the strain on the guys will never exceed one-half the weight.
Allowance of seven or eight degrees, or one foot in eight, should
be made for the sti-etch of the guj^s.

The diagram {Fig. 2, Plate 51) will serve as a guide in plac-
ing shears, holdfasts, &c.

Make A B= J C E.

C D= 2 a 6.

^ ^ |=at least 2 A C.

When the locality will not admit of rigging the shears in posi-
tion as described, they may be raised from the foot of the wall
or cliflF by means of a gin or lighter shears in the following man-
ner : Pass the shear lashing and attach the front guy ; lash a
stout spar across tlie legs about two feet above the centre of
gravit.y, giving the heels the proper spread ; fasten a small rope
to each heel to serve as guys ; hook the gin tackle to a straj)
firmly attached to the middle of the cross-spar, and heave away^^
tending the guys carefully. As the head of the shears comes
above the crest of the wall, put on the back guys and main-tackle
strap, and hook on the tackle ; mouse all liooks; raise the shears,
place the heels in the shoes, pass the heel lashings, set up the
guys, and lower the gin to the ground by means of its tackle,
leaving the spar in position.

Use of the gin as shears.

54'?'. When the garrison or casemate gin is used as shears'
the pry-pole is replaced by a parting block of the same diameter*

'rhe guj'^s are attached as follows : Middle the rope for the back
guys ; push the bigiit through the clevis from below and slip it
around both legs ; haul the ends back tight and lay them over
the head of the gin to the rear, each part lying between the
nearest leg and the parting block, taking care to place canvas
under the ropes to prevent chafing.

The fore guy is hitched around the clevis bolt.

A single back guy may be used, formed of a tackle of the same
size as the gin tackle, hooked into a strap applied as described
for the guy-ropes. In this case particular care must be taken
to bring the axis of the shears in the vertical plane containing the
holdfast and the centre of gravity of the weight to be lifted.

The shears are lowered by slacking the guys and heel-ropes, or
by using small shears. When no capstan is available, a windlass
may be improvised as follows :

Nail a strong cleat on the lower side of each leg, three feet

288 MACHINES AND APPLIANCES.

from the heel, butt end down ; lay a round spar a little more
than one-third the length of the shears across the legs, one foot
above the butt of the cleats, and pass a strong lashing, f rapping
it loosely between the spar and legs, taking care to have the
lashings of equal length; grease the spar under the lashing;
pass a strap around each end of the spar, put one end through
the other, take a round turn around the spar, and put a hand-
spike through the free end, to be used as a lever to turn the
windlass. The straps should be nailed to the spar to prevent
slipping. Additional levers may be applied in the same manner
if required.

The windlass is chocked by allowing the ends of two hand-
spikes (or more) to touch the ground.

The officer in charge of the work should place himself where
he can carefully observe the working of the entire structure,
particular attention being paid to the rake of the legs and the
security of the several holdfasts.

l^o person should be permitted to stand or pass under the shears
while a weight is being raised.

The shears proposed by the Ordnance Department to be fur-
nished for hoisting a 15-inch gun are represented on Plates 52
and 53.

Derricks.

{Fig. 3, Plate 51.)

548. The derrick is a machine used for hoisting or lowering
heavy bodies to or from the top of vertical walls or similar
places. It usually consists of one spar or leg; but the one
employed for raising 15-inch guns consists of two legs made
of round spars of yellow pine, 29 feet long, 11 inches diameter
at the foot and 9 inches at the top; one sill, half round, 16 feet
long and 11 inches in diameter; one cap, half round, 8 feet
long and 9 inches in diameter; two iron straps, with keys and
wedges for securing cap to legs. JS'ear each end of the sill, on
the square side, is a mortise, into which tits the tenon on the
foot of the leg. The cap is similarlj^ mortised to receive the
top of the legs, and is held fast in this position by the straps
fitting over it and kej^ed through the legs.

The following is a list of the stores required for it when hoist-
ing a 15-inch gun to the top of a rampart thirty feet high :

DERRICKS.

289

Material.

Remp rope.

Manila rope... -

L
Hemp

Iron....

Wood.
Iron...

Use.

Main-tackle fall

Guys (single rope doubled)..

Straps for guys.

Fore guy

Lower-block lashing

Uppor-block lashing

Leading-block straps

Muzzle-tackle fall

Gruy-tackle fall

Preventer- tackle fall

Fore-guy-tackle fall

Luff-tackle fall

Muzzle-tackle lashing

Straps for various uses

Trace-rope for lashing

Shear-head lashing

Spun-yarn, 3-yam

Seizing stuff, 12-yam

Stoppers (soft plated)

Thimbles

Sling-chains

Handspikes (man oeuve ring).
Pmch-bars

No.

Size.

Inch.

5.5
6
6
6

4.5
5
6

4.5
4
4
4

3.5
5
4
3

2.5

2.5
3

Len'th,

100

land 2

84 in.
84 in.

each.

each,
each.

each,
each,
each.

heavy,
heavy.

Purchase blocks

USED.

Kind.

Material.

05
%

6
ft

-a

d
13

Mtlin tackle

2
1
2
1

4
2
1
2
1

In.

14
14
10
10

8
5
5
6
4.5

> Wood and Iron.

Iron.

Wood.
'2, wooden.
( 2, iron.

Iron.

Wooden.

Main tackle, leading

Muzzle tackle

""i

Muzzle tackle, leading..

Guy taclde, leading

2
1

2
2

Preventer tackle

Fore-guy tackle

Fore-guy tackle, leading
Luff tackle

1
1

Girtline

Two capstans^ wooden ; four stakes for securing capstan, 8

feet long, 5 inches diameter; eight stakes for securhig capstan,
J. y

290 MACHINES AND APPLIANCES.

6 feet fong, 5 inches diameter; two skids ^ yellow pine, 18 feet
long by 12 by 15 inches ; fifteen blocks^ yellow pine, assorted
(four sizes); stakes for securing sill, 8 feet long, 5 inches diameter.

To raise a lo-inch gun.

549. The derrick is put together on top of the rampart (or
other place to which the gun is to be raised) ; the sill is about
five feet from the edge of the wall ; the main-tackle upper block
is lashed to the cap near one leg, and the, muzzle-tackle upper
block near the other leg.

The ends of the guys {Fig. 3, Plate 51) are hitched to the ends
of the cap ; the middle laid aci'oss the legs, and a half hitch
taken over each end, thus doubling them ; a stout thimble is
placed in the bight of each, into which the guy tackles are
hooked. Secure hold-fasts must be obtained for the guys; to
these the guy straps are attached, and in the bight of each a
stout thimble is placed, into which the guy tackle is hooked.

One end of the fore guy is attached to the middle of the cap
b}'^ a round turn and two half hitches, the end being securely
stoppered to the guy.

A luff-tackle purchase is applied to the fore guy and its hold-
fast, and by means of this the derrick is raised to a vertical posi-
tion .

The sill is firmly secured, with stakes or by bracing with skids,
against some fixed object. The girtline is attached to the cap
by a strap, and having been raised with the derrick, a man is sent
up by it, who, by r,he same means, receives the leading blocks,
which he secures to the cap by means of straps.

The main-tackle fall is next rove through the blocks, and the
lower block lashed to the gun 2 feet 6 inches in rear of the axis
of the trunnions. The muzzle-tackle fall is rove, and the lower
block lashed 3 feet in front of the axis of the trunnions. These
blocks are each lashed to the gun by seven turns with the lower-
block lashing, the lashing being trapped on each side of #the
blocks with its ends. "^

Two snatch blocks are attached to the sill, one near the foot
of each leg, by strong straps. These straps should be laid on
the ground under the sill previous to raising the derrick, and if
the ground is gravelly thej'' should be protected from chafing by
canvas laid under them.

Through these snatch blocks the main and muzzle tackle falls
are severally led, each to one of the capstans.

The capstans are manned by sixteen men each. A strain is
brought upon the falls, and the guy tackles hauled upon until

^ DERRICKS. 291

Ihe head of the derrick is almost vertically over the edge of the
wall.

The capstans are worked and the gun is hoisted, care being
observed to work the capstans so as to keep the piece in a hori-
zontal position. One or more shifting-planks are let down by
ropes against the side of the wall to prevent the gun from chafing
against it and to ease it over the coping.

When the gun reaches the top of the coping, preventer tackles
are hooked to straps around the breech and muzzle. When the
piece is suflSciently high, the guy luft' tackles are hauled upon
and the piece landed on cribs or blocks. The preventer tackles
are likewise used to assist in bringing in the piece and landing it
in a proper position.

If it is desiired to place the gun on the cradle, the falls are
slacked oflf and the sill of the derrick moved far enough back to
admit the cradle. The gun is again raised and landed in its bed
on the cradle.

The derrick should not be allowed to assume an inclination of
less than four upon one.

To lower a 15-inch gun,

550. The piece is brought to the edge of the wall on the
cradle; the derrick is erected over it; the gun-sling and the
tackling attached, all in the manner explained for iioisting; the
capstans are worked ; the piece lifted and eased to near the edge
of the wall bj'' the preventer tackles. The cap of the derrick
having been placed directly over the piece, the strain will in-
crease its inclination sufficiently to allow the gun to be eased to
the edge of the wall. In this position the piece is allowed to
rest on blocks or skids, the cradle is removed, and the sill of the
derrick moved up close to the gun.

The gun is then hoisted, eased over the edge, and lowered to
the foot of the wall.

^'he derrick is dismantled in the inverse order in which it was
put up.

J^ote. — One capstan, if powerful enough, is sufficient for low-
ering or hoisting the gun, in which case the lower block is lashed
to the piece at the centre of gravity. The lashing is executed as
before explained.

The capstan usually issued to artillery posts is, however, not
sufficiently powerful, and it will invariably require two of them.

Care must be taken to keep the guys hauled upon so that the
cap and sill remain always parallel to each other; the derrick is
thus prevented from twisting.

By omitting tlie cap and then lashing the heads of the spars

292 MACHINES AND APPLIANCES.

together with shear lashing, the derrick may be used as shears^
In this case, only the main tackle can be used.

When spars can be procured of sufficient length to construct
shears high enough, it is best to place the shears at the foot of
the wall instead of on top. The shears should be not less than
20 feet higher than the wall. This method permits the piece ta
be raised and eased over to the terre-plein with less inclination^
and consequently less strain upon the legs of the shears and on
the guys.

%xt imxtHt.

OAEE AND PRESERVATION OF ARTILLERY

MATERIAL.

551. All cannon and other artillery material are either man-
ufactured or purchased by the Ordnance Department and turned
over to the artillery arm for use.

It is the duty of the artillery to care for and preserve such
property, and to return to the Ordnance Department for repairs
^uch as may require it.

Officers in charge of permanent works will keep, as far as pos-
sible, the armament complete and in serviceable condition, and
will also keep on hand a proper quantity of ammunition and
other supplies.

55S. A book is furnished to each post for the " record of artil-
lery " and ''''record ofjlring.^'' In the front of this book are printed
instructions fully explaining how it is to be kept. Under appro-
j)riate headings, in the part set aside for record of artillery, each
gun is described by its number and marks; when received and
where from; whether mounted or dismounted; if mounted, in
what part of the work, stating its platform number. The result
of each inspection, made as hereinafter described, will be entered
for each piece in tliis part of the book.

In the portion of the book devoted to record of firing, each piece
has a separate page, which, when filled, is carried on to another.
lEach shot fired is duly recorded as to date of fire, kind and
weight of projectile, kind and quantity of powder, elevation,
time of flight, range, &c. When a piece is transferred from one
post to another a complete record is sent with it, and the pre-
vious number of fires is entered in the book at the last post, so
that the firing may not go beyond the limit prescribed as the
endurance of the piece; this has been fixed at one thousand
service rounds for cast-iron cannon.

553. Marks. All cannon are required to be marked with
the weight in pounds, the number of the piece, the initials of the
inspector's name, the initials or name of the foundry, and the
j^ear of fabrication. All pieces manufactured since 1861 have
ihese marks on the face ; those of previous date have them dis-

(293)

294 CARE AND PRESERVATION OP

tributed on the ends of the trunnions, the face, the breech, an^
the top.

The numbers for each kind and calibre at each foundry are in
separate series.

Cannon that have been inspected and condemned are marlied
on the face X C.

554. Ordnance-sergeant. The ordnance-sergeant of a post
has, under the commanding oflBicer, immediate charge of all the
artillery material at the post. It is his special duty to see to its
care and preservation, and to keep the books and records relat-
ing thereto. He takes an account of receipts and expenditures,
makes a memorandum of all breakages and damages, and keeps
the commanding officer informed as to the condition of the
armament of the post and the extent of the supplies.

555. Preservation of artillery. Cast-iron cannon, whether
mounted or dismounted, should be lacquered once a year. The
lacquer used is coal-tar of the best quality, mixed with sufficient
spirits of turpentine to make it work freely with a paint brush..
It should be applied only in warm weather.

The muzzle of the piece should always be depressed so that
water may not stand in the bore, the tompion kept in, and the
vent closed. At least once a month, especially after a rainy
period, the bore should be sponged dry and oiled by passing:
down it a sponge saturated with sperm oil ; especial attention in
this respect should be given to rifled guns. In cold weather a lit-
tle kerosene oil is mixed with the sperm. The vent at the same
time is examined and oiled, and if the piece is not in use, stopped
with putty or a plug of soft wood. When the piece is mounted,
the trunnions and trunnion beds are kept from rusting by pour-
ing a small quantity of the same oil into the beds and elevating
and depressing it several times.

Once a month the carriage should be traversed so as to change
its place of rest on the traverse circle. At the same time tiie
pintle and axle journals are oiled with sperm oil, and pieces with
hydraulic oi- pneumatic butters run from battery and the pistons
cleaned and oiled. If the pistons are found rusted, the rust is
removed with fine emery-cloth, and the surface polished smooth
with rotten-stone and oil. Such pieces ought always to be kept
in batteiy and the air holes in the cylinder heads carefully closed
wi'h the plugs.

The axles of the truok-wheels are cleaned and cared for in the
same manner as the pistons. Elevating screws, when not in use,
are kept in the store-house, and are cleaned and oiled in the same
way. Guns, especially rifled pieces, in batteries exposed to blow-
ing sand, should, in addition to the tompion, be provided with

ARTILLERY MATERIAL. 295

canvas hoods placed over the muzzle. When firing, this is a
useful precaution.

Cannon not mounted should be placed together, according to
Ivind and calibre, on slcids of stone, iron, or wood laid on hard
ground, well rammed and covered with a layer of cinders or
gravel to prevent vegetation. The pieces should rest on the skids
in such a manner as to be rolled over when necessary for lacquer-
ing, the muzzle depiessed and in such position as to be readily
got at with tlie sponge. Tiie place selected should be free from
shade of either buildings or trees.

Siege mortars may be placed on their muzzles, resting on thiclc
planks or pavement.

556. Carriages. Iron carriages should be painted once a year,
and this in dry, warm weather. The best paint for preservation of
iron is red-lead, but this being comparatively expensive, the kind
generally used is oriental red paint. It is supplied ready mixed,
and is applied in the usual manner of painting. If it should re-
quire thinning down, this i.; effected by adding turpentine and
linseed oil, the latter either boiled or raw.

Before painting, all blisters, rust, or accumnlation of old paint
should be removed with a scraper. The top of the chassis rails
should neitlier be painted nor oiled, but kept clean by dry scrap-
ing. All iron handspikes, elevating-bars, and similar imple-
ments are painted black, using for this purpose comuion black
paint. Heads of bolts and edges of rails may likewise be painted
black.

Tile damp location of most artillery posts is particularly favor-
able to the rapid decay of material. Rust gradually eats away
iron parts of carriages and machines. These defects are fre-
quently hidden by repeated coats of paint or lacquei-, making
them extremely liable to lead to accident or disaster. Such partis
should be carefully examined by means of punches and ham-
mers, and no such material be suffered to remain where it is
dangerous.

The wooden parts of gun carriages and machines frequently
become dry-rotted, while the exterior, covered v/i'di pain::, con-
tinues a shell apparently quite sound. Sounding such parts with
a hammer, and searching into cracl<s and flaws, will indicate the
defects.

Wooden implements become brittle from age, by having tiie
''life seasoned out." This is readily detected, by those familiar
with wood, by the appearance of the fracture, the weight, the
elasticitj'', and by the resonance of the article.

557. Siege-pieces are scraped off* and painted once a year
with black paint or Japan varnish, they being dismounted for this

296 CARE AND PRESERVATION OF

purpose. The carriages are scraped to remove all blisters and
lumps of old paint, and then painted with olive paint. The iron
parts are painted black.

If possible, siege-gun carriages should be kept under cover in
well-ventilated sheds.

The following is the method pursued in the jN'avy for blacking
and polishing guns. Whenever the number of men in charge of
pieces admits of it, the same care should be observed in the land
service.

The piece is first scraped clean and then scrubbed well with
fresh water and sand ; when dry it is washed with spirits of tur-
pentine, and a coat of well-ground red-lead, mixed with boiled
linseed oil, is applied ; this is well and smoothly rubbed in, allow-
ed a couple of days to harden, and then rubbed down with sand-
paper, after which another thin coat of red-lead and oil is applied ;
this is allowed to dry, and is then rubbed until smooth. A coat
of well-mixed and strained black paint is now applied, as smooth-
ly as possible, and allowed to dry, after which a polish of the fol-
lowing preparation is used, viz.: 4 lb*?, of good bees- wax and 1
lb. of spermaceti are melted together in a clean vessel free from
grit; while hot this is strained tlirough a cotton or woollen cloth.
To this mixture is added 1 oz. of dry ground Prussian blue, 0.75
lb. of ivoiy-black, or the same quantity of lamp-black, and 1 gal-
lon of spirits of turpentine. All these ingredients are mixed well
together while warm, and thoroughly rubbed in with the hand;
the rubbing is finished by working the hand around the piece —
not lengthwise. The first coat is allowed to stand a daj^ and
then rubbed lightly with a cotton cloth, after which a second
coat is applied and rubbed with the cloth until a brilliant polish
results.

In case the mixture is not put on smoothly, it may be neces-
sary to cork the surface ; this is done by rubbing with a flat piece
of cork about half the size of the hand. Scratches are generally
corked out, care being taken to avoid all dust or gi'it.

To brown a gun. Scrape clean ; scrub with fresh water, sand,
and canvas; allow to dry; wipe off; apply a strong solution of
salt and vinegar three or four times a day for two days, or until
a good coat of rust is formed; allow to dry, then rub lightly with
old canvas ; apply a thin coat of the following mixture, rubbing
it in well : 4 lbs. bees-wax, melted and strained; 0.50 oz. pure
vitriol (white), or 1 oz. of pulverized alum ; 1 gallon spirits of tur-
pentine ; allow to dry until next day ; then put on another thin
coat, and when dry rub with a clean cotton cloth.

In case of a dull appearance, by reason of having been handled,

ARTILLERY MATERIAL. 297

rub over with a cotton cloth and spirits of turpentine, and then
with a dry cloth.

558. Injuries. The injuries to which heavy cannon are
liable are confined almost entirely to the interior. Rusting
produces roiio^hness and an enlargement of the bore, and in-
•creases any cavities or honey-combs that exist in the metal.

In smooth-bore guns, the principal injuries arise from the wear-
ing away of the metal on the upper and lower surfaces of the
bore at the seat of the projectile and the enlargement of the in-
terior orifice of the vent. This enlargement of the bore can be
measured with accurac)' only bj^ means of the star gauge ; but
^s this instrument is seldom to be had at artilkMy posts, reliance
must be placed upon such inspection as can be made with a
mirror or small lamp. When the enlargement is sufficiently
great to be manifest by such inspection, the piece should not
be further used until it can be gauged and the full extent of tlie
injury determined.

The enlargement of the vent is determined by means of an
impression of it taken with wax or soft gutta-percha, applied by
pressing it up against the bore at the vent as hereinafter de-
scribed. The appearance of a vent {Fig. 4) enlarged by much
firing is irregular and angular, with its greatest diameter in the
■direction of the axis of the bore. When the fissures of this en-
largement exceed an inch in any direction, the piece is no longer
serviceable, and further use of it should be discontinued until a
new vent can be bored and the old one stopped with melted zinc.
One vent in a cast-iron piece will stand five hundred service
rounds. Other enlargements, or cracks in the vent, may be dis-
•covered by means of a searcher made of a piece of bent wire.
The service to which a cast-iron piece has been subjected can
generally be approximately determined by the appearance of the
vent.

All cracks and flaws, in any part of the piece, should cause
it to be laid aside until it can be inspected with the proper in-
struments.

Rifle cannon. These become injured by the wearing away of
the lands, especially upon the driving side.

Any serious damage to the lands can be ascertained by exam-
ining the bore with a mirror. It will also manifest itself in
firing by inaccuracy and frequent tumbling of the projectiles.

Slight cracks in the surface of the bore, particularly about the
seat of the charge, indicate the approaching fracture of a piece,
and should be sufficient warning to cause a discontinuance of its
use.

The bursting of shells in the bore, particularly in rifled pieces.

298 CARE AND PRESERVATION OF MATERIAL.

frequently causes dents and abrasions. Such burstings or pre«
mature explosions are, however, less frequent now than formerly*
owing probably to the fact that milder and slowei* powders are-
now used behind the projectile ; still, such accidents occasionally
take place, and the causes whicii lead to their occurrence are often
obscure and require close investigation to discover.

Most prominent among those usually assigned are the follow-
ing : Too great quickness of burning in the powder charge of the
gun; defects in the working or placing of the fuses; hnperfec-
tions in the metal of the shells themselves, due to faulty casting;
thinness of the walls or of the butt ; concussion and friction of
the powder within the shell itself when the piece is fired ; insuf-
ficient quantity of powder in the shell.

Most of these causes take effect at the instant of ignition of
the powder charge of the gun, and it is probable that most siiells
that fail receive their injuries before they are unseated, or their
inertia fully overcome.

It has been found that roughness on the interior of shells or
the presence of grit contributes to the frequency of premature
explosions, by shock and attrition witli tiie grains of the burst-
ing charge ; hence it is important to remove, b}'^ scraping, all
such gritty substances. It is recommended to coat the interior
of shells witli some elastic composition. A very good kind is com-
posed of : Soap, (common yellow,) 16 ounces ; tallow, 7 ounces ;
rosin, 7 ounces. The tallow should be melted first ; then melt
and add the rosin, and lastly the soap, bringing the mass to a
heat that will make it very fluid.

The shells having been first thoroughly cleaned, fill them
about one-third full of the composition, roll them slowly so a&
to spread the mixture over the whole interior surface, and then
pour off the residue. This coating should be about one-tenth-
(0.1) of an inch in thickness, except at tlie bottom of the shell,
where it should be about three-quarters of an inch thick. Ta
obtain these thicknesses, the operation of coating sliould be per-
formed twice ; then pour into the shell enough of the composi-
tion to produce the desired thickness at the bottom, the shell
standing on its base. After the composition is perfectly cool,.
immerse tiie shell in hot water at as higli a temperature as the
composition will stand without " running " — about 170 degrees^
This second heating of the composition in the bath toughens it^
and causes it to adhere more closely to the shell.

Another method of meeting this difficulty, as also that arising
from friction and packing from the set-back of the grains of the
bursting charge, is to place the charge in a bag. The material
for the bags is the same as for cartridges; they are made in the

INSPECTION OF CANNON. 299^

same way, and of a size suitable for the charge. In chargini^ a.
shell in this manner, the bag is pnshed into the cavity with a,
slender stick, leaving the mouth of the bag projecting out of the^
fuse hole ; this is securely held while the powder is introduced
through a funnel, and worked and settled into the bag with the
stick. When the bag is nearly full the funnel is withdrawn, the
neck of the bag tied, and pushed down to one side of the fuse
hole.

On the occurrence of a premature explosion, or the rupture of
a shell in a gun, the bore must be carefully examined with the
mirror, and by taking impressions, especially about the place of
explosion. A close examination should be made for cracks.
These may not at first be discoverable, but will develop with
subsequent firings. It is important, therefore, that frequent ex-
aminations be made of guns in which shells have exploded.

Inspection of cannon.

559. Every artilleryman should know how to examine the
weapon with which he works, and should understand what de-
fects in guns are serious and what may be disregarded. It is of
great importance that the examination of both guns and fittings
should be very searching and exact ; otherwise, a small flaw left
unnoticed may endanger the life of the piece in future.

Guns, upon being accepted into service, are inspected as pre-
scribed in the regulations for the Ordnance Department.

The following rules are given for subsequent inspections in
service.

Every gun must be examined after firing the following num-
ber of rounds with projectiles :

Smooth-bore cast-iron guns. — ^Firing 50-fb charges and upwards,
50; 10-lb up to 50-lb charges, 100; under lO-lb charge, 200.

Rijies. — 10-inch and upward, 50; 8-inch, 100; under 8-inch,
150.

In the record-book of firing, (see par. 552,) on the pages where
the shots are recorded should be entered the inspections, their
dates, by whom made, and a full description of any defects that
may be found, and particularly whether those discovered at pre-
vious examinations are increasing, and if so, to what extent.

Instruments for inspecting cannon.

560. 1. Star-gauge. Used for measuring the diameter of
the bore at any point.

2. Cijlinder-staff. Used to measure the length of the bore
It is supported in the centre of the muzzle by a T-rest, and the^

•SOO INSPECTION OF CANNON.

•extremity inserted in the gun is furnished with a measuring
point and guide plate.

3. Cylinder -gauge. This is a hollow cylinder of cast-iron,
turned to the least allowed diameter of the bore, and one calibre
in length. When used, it is attached to the cylinder-staff.

4. Searcher., consisting of four flat springs turned up into
points at their ends, and attached to a socket which is screwed
on the end of the cylinder-staff. It is used to feel for cavities
in the surface of the bore.

5. Trunnion-gauge. Used to verify the diameter of the trun-
nions and rimbases.

6. Trunnion-square. Used for verifying the position of the
trunnions with reference to the bore.

7. Trunnion-rule., for measuring the distance of the trunnions
from the base of the breech.

8. Calipers, for measuring exterior diameters.

9. Standard rule., for verifying other instruments.

10. Vent-gauges of steel wire, with shoulders to prevent them
from slipping into the vent. There are three, differing in size
by 0.005 of an inch; one is the exact size of the vent, and one
larger and one smaller than the exact size. To ascertain the
wear of a vent there should be several others, increasing in size
lay the above dimensions.

11. Vent-searcher is a steel wire of the length of the vent, bent
to a right angle at the lower end and pointed. It is used to de-
tect cavities in the sides of the vent.

12. Wooden rule., to measure exterior lengths.

13. Mirror., for reflecting the sun's rays into the bore.

14. Spirit lamp., attached to a staff, used in examining the bore
wiien the mirror cannot be used.

15. Machine for taking impressions of the bore.

561. To ascertain injuries to cannon in service, only those of
the foregoing list numbered 1, 2, 4, 10, 11, 13, 14, and 15 are
required.

The star-gauge {Fig. 1, Plate 54) is composed of the staff, the
handle, and a set of four steel points for each calibre.

The staff is a brass tube, made in three pieces, for convenience
of stowage, and connected together, when required, by screws.
The end that goes into the gun expands into a head (a), in
which are placed four steel sockets, at equal distance from each
other, which receive the points. Two of the sockets opposite
each other are secured permanentlj' ; the other two are movable.
A tapering plate or wedge (6), the sides of which are cylindrical,
runs through a slot in the head ; an aperture in the inner ends
>of the movable sockets embraces the C5dinder, so that when the

INSPECTIOX OF CANNON. 301

wed^e is moved forward the sockets aie forced outwards, and^
when moved backward^! the sockets are withdrawn. The sides
of the wedge incline 0.35 inch in a length of 22 inclies, so that by
pusliing tli(» slide in the thirty-fifth pai-c of this distance, tiie dis-
tance iietween the two soclcets is increased 0.01 inch.

A square sliding rod (c) is connected with the wedge, and runs
through the whole length of the tube, projecting a few inches
beyond the outer end. This rod is in three parts, like the staff,
and, like them, connects by screws. The sections of the rod aie
prevented from falling out of their proper section of the staff by
pins. When screwing the joints of the staff together, if the ends
of the rod are pressed up to each other they become connected
hy the same motion.

The staff is graduated into inches and quarters, so that the
distance of the point from the muzzle of the piece may always
be known.

The handle {Fig. 2, Plate 54) is made to fit over the outer end
of the staff, and to connect with the sliding rod by a screw hav-
ing a milled head at the outer extremity of the liandle. It may
be used on either joint, as most convenient for the length of the
bore. The socket of the handle slips over the end of the staff
made smaller for the purpose, and has a slot in it, allowing the
staff to be seen through it. A scale on one side of the slot is
graduated to show the distance that the rod moves to throw the
points 0.01 apart.

That part of the handle containing the slot and scale is sepa-
rated from the other part, but is made to fit closely over it. On
one side there is a mill-headed screw for clamping the parts to-
gether. Seen through the slot is a small plate of silver inst^rted
in the staff, and a fine mark upon it to show the place of the
zero when the points are adjusted. The zero mark on the
scale is made to correspond with it by means of the screw just
mentioned.

A set of adjusting rings belongs to the instrument — one for
each calibre — reamed out to the exact minimum diameter of the
bore. To adjust the gauge for any calibre, the handle is loosened
by means of the clamp screw, the proper measuring points are
screwed in, the adjusting ring placed over them, and the slider
pushed out until all the points touch the inner circumference.
The zero of the scale is then made to coincide with the mark on
the tube, and the handle clamped; the instrument is then ready
for use.

The arms of the T-rest {Fig. 3, Plate 54) are adjusted for the
particular calibre. It is placed in the muzzle to keep the insti-u-
ment in tiie axis of the piece. A centre line, starting from the

^G2 INSPECTION OF CANNON.

centre of one of the permanent sockets, is marked on the stafl'
throughout its length. In joining the sections together care
must be taken to secure coincidence of this centre line. When
the gauge is in the bore the centre line should be uppermost;
the movable points are then horizontal, and measure the diam-
eter of the bore only in a horizontal plane. To make a thorough
measurement in every direction, the piece should be on skids,
and then by rolling it over different elements of the bore will be
brought uppermost, and can be measured in succession. When
the piece cannot be rolled over, and it is desirable to obtain
measurements all round at any part of the bore, the gauge may
be inserted with the movable points in the direction in which it
is required to make the measurement. The centre line of the
staff will indicate the direction of the measuring points.

To ascertain thoroughly the condition of the bore, measure-
ments should be made at intervals of 0.25 inch in tlie part occu-
pied by the charge and shot; at intervals of one inch in the rest
of the bore in rear of the trunnions, and at about one calibre
intervals from the trunnions to the muzzle.

In the original inspection of the piece, no variation greater
than 0.03 inch beyond the true dimensions was allowed; there-
fore anything exceeding this is an enlargement caused by serv-
ice. The scale upon the handle of the instrument is marked to
correspond to hundredths of an inch of movement of the meas-
uring points. The divisions are numbered both wa3'^s from the
zero. Those towards the handle indicate excess of diameter;
those in the other direction indicate deficiencj^ Rifled pieces
are measured across from the lands — not from the grooves. In
doing this, a special instrument is required for guiding the meas-
uring points so that they will follow the lands as they proceed
along the bore. Tiie hexagonal hole {Fig. 4) in the centre is
fitted on to that portion of the end of one of the measuring
points which is similarly shaped. Two small arms on either side
of the guide-piece face each other, and can be moved toward or
from each other by means of sliding plates to which they are
attached. For this adjustment, finely-divided scales are marked
on the sliding plates. When in the bore the two small arms
rest in two contiguous grooves, and embrace between them the
land which the measuring point is forced to follow.

To prevent obstructing the motion of the measuring point
when it is shoved out by the slider, the arms rest upon light
springs, which are simply compressed during the measurement.

The hexagonal socket is made to turn within the rest of the
guide-piece to allow the necessary freedom to the arms.

Before and after each set of measurements, the rings must be
-applied to the points and the instrument adjusted.

IMPRESSIONS OF THE BORE. 303

Instruments for taking impressions.

562. The machine {Fig. 1, Plate 55) for taking the interior
impression of the vent consists of a wooden head (a), one-half
the length of which is cylindrical and the other half rounded off
to the shape of the bottom of the bore. The diameter of the
head is rather smaller than the bore. A staff (6), flat on the
upper side and rounded on its under side to fit the curve of the
bore, is mortised into tlie cylindrical part of the head so that tlie
rounded side will be coincident with the circumference. A mor-
tise (c) is cut through the head, extending several inches in rear
and front of the position of the vent. Into this mortise a loose
block is fitted, capable of free upward and downward motion.
The top of the block is pierced with holes to secure the compo-
sition spread over its surface. This movable piece rests on a
wedge {d) attached to a flat rod running through a slot in the
head. To prevent this rod and the wedge from coming entirely
out of tlie head, a slot, about four inches long, is cut in it,
through which passes a pin (e) attached to the staff'.

To use the Instrument, withdraw the rod as far as the slot
will permit ; this allows the block to drop below the surface of
the head, and protects the composition which has been spread
on it; push the head to the bottom of the chamber, and arrange
the position of the staff" so that the movable piece will cover the
vent; then press the end of the rod home. This motion will
throw out the block with the composition, and a distinct impres-
sion of the vent and of fire-cracks (should there be any) will be
left upon its surface ; draw the rod back as far as the slot will
allow, and withdraw the instrument; the impression, being pro-
tected thereby, will come out uninjured.

Gutta-percha impressions of a poi-tion of the bore of a gun can
be taken hy means of wooden blocks or wedges. For this pur-
pose use two blocks {a 6, Fig. 2, Plate 55), one about two-
thirds the length of the other, the longer block to carry the
gutta-percha for the impression, the shorter one to be driven
as the wedge, each block with a staff" or handle longer than the
bore of the gun, so as to enable the operator at the muzzle to
place the blocks in any desired position in the bore; also for
driving the wedge and withdrawing the blocks. These blocks
are so shaped that when in one position they form an imperfect
cylinder, whose diameter is less than that of the boi-e, thus en-
abling the longer block to carry the gutta-percha to the required
place in the bore ; then, by driving the wedge, the diameter of
this cjdinder is increased nearly to that of the bore, the gutta-
percha is caught between the surface of the bore and its carry-

304 IMPRESSIONS OF THE BORE.

in^ block, and is thus forced by the driven wedge to take note of
whatever it finds tiiere.

To take an impression, the gnn sliould be tlioronglily washed
out and then oiled witli an oiled sponge; the gntra-percha is
softened by means of hot water, jnst under the boiling point,
to the required consistency, about that of putty; is then placed
on the block, which is well oiled (sperm oil is the best), and
worked and kneaded with oil until it is spread over the required
portion of the block ; the blocks are well oiled, particularly the
surfaces which come in contact ; the two blocks are put together
at the muzzle so as to enable the carrying block to carr}' the
gutta-percha to the desired place ; when both blocks together
are pushed into the bore, the distance may be marked on the
handle of the carrying block ; tlie carrying block is then held
steady by its handle, while the wedge block is driven in by sev-
eral blows of a sledge on the end of its handle ; from two to
five miinites is sufiicient time to allow it to set. The wedge-
block is withdrawn first, and the cari-j^ing block with tlie impres-
sion afterwards. To withdraw the wedge block, run an iron
pin through the handle near the end, and strike against that
with a sledge until it starts, when it is easily withdrawn ; the
carrying block will generally fall or release itself by its own
weight, bringing the impression with it. If the impression ia
taken anywhere in the upper half of the bore, and for this
reason, and also that it is easier to work the blocks, it is always
better to tur-n the gun over, so as to take the impression above
the block. When tiiis cannot be done, and an impression is
wanted from the bottom of the bore, a small block or rider is^
pushed in at the same time as tlie canying block, so as to keep
the gutta-percha from touching the surface of the bore while
being pushed into place. Afterwards the rider block is with-
drawn, the wedge driven, and after the wedge is withdrawn the
rider block is pushed back close to the c irrying block, and acts
as a fulcrum by which the impression is raised free from the
bore, when both are withdrawn together. In taking an impres-
sion on the side, it is better to push in the blocks as if the im-
pression was above, and then to turn the blocks to the place.
Unless the block under the gutta-percha is well oiled, some diffi-
culty may be experienced in releasing the impression from the
block. The carrying block should have a slight raised edge on
each side of the upper surface to prevent the gutta-percha from
spreading out too much when undergoing the pressure from the
wedge, and also to protect it when turning tlie blocks for side
impressions.

In cases where there is any doubt as to the state of the bore

IMPRESSIONS OF THE BORE. 305

of rifled guns, impressions should be taken of the whole leno^th
with ,:^ntta-percha, and for doino^ this the blocks just described
should be long enouo;h to reach from the bottom of the bore to
a foot or more bej'ond the muzzle. They are, in fact, scantling
rounded off and made wedge-shape.

A convenient size to obtain the gutta-percha, is in slabs twenty
inciies long, live wide, and five-eighths thick. Each slab will
make ordinarily two or three impressions. It can be used over
and ovei- again, and need never be thrown away if a little fresh
material be added occasionally to prevent it from becoming brit-
tle. It must be kept free from dust or grit, and should be pre-
served in water when not in use.

As a proper set of instruments is rarely or never to be obtained
at artillery posts, a substitute for taking impressions with the
wax composition may be made by using a block of wood about
a foot in length, one side of which is rounded off so as to have
the curvature of the bore ; to the block is attached a strong staff
or handle. To use it, a biscuit-shaped ball of the composition is
placed on the rounded surface of the block, which is then in-
serted to the flaw and pressed against the bore, using chocks
inside the gun as a fulcrum and the handle as a lever.

Impressions of the vent may also be taken with lead. The
implements required for this are a piece of soft fine wire, about
twice the length of the piece ; a stout lever, about the same
length, and shod to suit the curve of the bore ; and a small but-
ton of soft lead, judged to be of sufficient size to fill the vent at
least one inch from the bore. This is pierced lengthwise to re-
ceive the wire.

To take the impression. Shove the wire through the vent ;
let it pass along the bore and out at the muzzle ; put it through
the leaden button and tie a knot at the end ; draw the wire
back through the vent until the button is introduced firmly into
the inner orifice ; apply the lever, making its shoe bear on the
button, and force it well in by repeated blows, the muzzle being
the fulcrum, or, better, a block of wood placed in the bore as far
as the arm will reach. The button is disengaged by pushing in
the vent-punch.

In taking impressions of the vent and cracks, each button in
turn is used as a pattern for moulding its successor.

All impressions, however they may be taken, should be most
critically examined with a magnifying glass ; otherwise the most
important indications will escape observation.

Water-proof. Cannon, when inspected upon being received
into service, are subjected to an hj'^draulic proof of about 30
pounds to the square inch. This requires a special apparatus
20

306 MODE OF EXAMINING CANNON.

not usually found at posts. Nevertheless, useful application of
the principle may be made by giving the piece as much elevation
as possible, stopping the vent, and tilling it with water. Allow
it to stand thus for a few hours, draw off' the water, wipe the
bore perfectly dry, and examine with a mirror or lamp. Water
seen oozing from any part of the bore indicates a crack or a clus-
ter of cavities, a sure sign of serious defects.

563. Mode of examination. The bore should be thoroughly
cleaned to detect small defects. If care has previously been
taken in keeping a gun tolerably clean, it will probably be suffi-
ciently prepared for examination by washing and drying with
tow, cotton-waste, or a clean sponge. Should there be hard rust
which will not yield, or a thick coating of grease, the bore may
be cleaned by tiring (if circumstances permit of it) one or two
scaling charges of about one-third the full service charge, with-
out projectiles; this will usually loosen the scale. The same
may be eff'ected by using hot water and potash, in the following
manner : About a gallon of boiling water is poured on one pound
of ordinary black potash, and an old sponge, covered with a
cloth to make it fit tightly to the bore, is dipped into the solu-
tion, and the bore rubbed vk^ith it till the dirt is loosened, when
a hard brush will remove it ; it is then wiped dry and slightly
oiled. The potash water must be used very hot and the sponge
made to fit tightly, or the process is ineffectual. The hard brush
is made of wire, and is similar to those used for fowling-pieces.
Brushes of bristles — Turk's-heads — are also used. No sharp-
edged or pointed scrapers should be emplo3^ed for cleaning the
bores of rifled guns, as they would be liable to injure the rifling.

The bore, being thus cleaned, should be examined by the aid
of a lamp, or if there be bright sunlight, with a mirror. If the
bore be slightly wet, the detection of defects is greatly facili-
tated. A sharp-pointed pricker is used to ascertain the extent
and position of any flaw, the staff" being graduated in inches so
that the distance from the muzzle may be readily ascertained.
A spring searcher is also used to detect defects, and, with rifles,
in such manner that each groove shall be traversed in succession
by one of the points.

Should a flaw be found, an impression is taken of it. This is
done in the manner just described, with gutta-percha, or by
using a mixture composed of bees-wax., two parts; treacle., one
part; soft soap., one part. The wax should be melted over a
slow fire in an iron pot ; the treacle is then added and mixed
well by stirring; and lastly the soft soap, a little at a time.
The mixture must be kept in motion, and when thoroughly
stirred poured out, cooled, and made into balls. This compo-

MODE OF EXAMINING CANNON. 307

-sitioii being soft, is always ready for use, but the impression h
easily destroyed by handling.

The gun should be so placed that the impression will be taken
-upwards.

In recording the position of any defect, its distance from the
muzzle is given in inches, and noted as ""'up," "-right of up,"
*' right of down," &c., tlie vent always being considered up, and
the right or left the sides as they would appear to an observer
looking into the muzzle. {Fig. 3, Plate 55.) Impressions of
the vent and of the bottom of the bore can be taken properly
only by the use of the appropriate instrument; nevertlieless,
by the exercise of a little skill and ingenuity, tolerably fair
results may be obtained with the improvised instruments just
described. Considerable practice is required to get good smooth
impressions, and, with the vent, several have sometimes to be
taken before one is obtained which can be relied on to show hair-
lines. When it is desirable to preserve an impression for future
reference or comparison, a label is gnmmed to its back, giving
the number of the gun, date of taking it, and the position of the
flaw.

Should any defects be discovered in the bore (not including the
immediate vicinity of the vent) they need not be considered seri-
ous, unless, in the case of smooth-bore guns, they are 0.1 incli deep
in rear of or 0.2 inch deep in front of the trunnions, or unless
they have jagged edges likely to retain pieces of ignited cartridge ;
and in the ease of rifled guns, unless, in addition, they are new
defects not shown in the memorandum of former inspections, or
old ones which have materially increased. Generally speaking,
the depth of a defect is of more importance than its extent.
With the converted gun, should a defective weld run a consider-
able distance around the tube of the bore, it would be liable to
part at that point, and the piece should be considered unservice-
able. The best method of testing a gun is to take an impression
of the defect; then to tire a few rounds witli service charges and
take another impression. If, on comparing these impressions,
the defect does not appear to have increased, the piece may be
considered serviceable. As a precaution against accident, in case
-of the splitting of the inner tube of converted rifle guns, sl gas
escape or indicator is provided. This is a small hole similar to
the vent bored through the cast-iron case on the side opposite
the vent, and connecting with a shallow spiral groove cut around
the outer tube near the seat of the charge. Should the tube
split, smoke will be seen issuing from the hole, and firing should
be discontinued.

Examination of the vent. Especial care should be given to

SOS MODE OF EXAMINING CANNON,

this, for the reason that the amount of firing to which a piece-
has been subjected is pretty well indicated by the wearing away^
of the vent.

The standard gauge (0.2 inch) will be used to ascertain the gen-
eral enlargement, and the searcher to detect defects that may
have been developed in firing. The vent channel is first thor-
onghlj'' cleaned and then tested with a set of cylindrical gauges
differing from each other by 0.01 of an inch.

The greater the calibre and the heavier the charges, the more
rapidly is the wear manifested on the interior and exterior of
the vent. The following, however, is the average wearing of
the vent for the heavier classes of cast-iron guns.

ISTumber of rounds 100 200 300 400 500

Diameter of vent 0.24 0.26 0.30 0.35 0.40

These, combined with examination of the interior orifice, will
enable a very correct judgment to be formed of the probable
number of fires sustained and the duration of the gun.

The enlargement does not extend very far from the lower
orifice until the enlargement on the exterior has reached a diam-
eter of 0.3 of an inch.

So long as the wear is regular and the fissures, although nu-
merous, do not exceed 0.5 of an inch, the indications are good.
If the cracks are few or diminish in number, running into each
other and extending rapidly, it is a very unfavorable sign.

Should it be found that the vent has enlarged so as to admit
the 0.4-inch gauge, the vent is either bushed or is filled with zinc
and a new one bored, as the character of the gun may require.
A clean impression should be taken of the bottom of the vent.
Unless the proper instrument is provided for doing this, it will be
fotuid to be a ditficult operation, and should be repeated several
times. If the vent be unbushed, the effect of service is seen by
a gradual increase of the channel and by an irregular wearing
away of the bottom {Fig. 4, Plate 55) and the formation of fis-
sures and hair-lines radiating from tlie edges of the orifice. The
extent of these defects is measured on the impression, and if
found to be less than half an inch in extent from the original
centre, the piece will be reported for bushing or to have a n^w
vent bored ; if greater than this, the piece should be reported as
unserviceable.

The defects usually found around the vents of bushed guns
are the giving way of the iron around the bush from the gas
getting in between the two metals {Fig. 5), and the fissures or
hair-lines which radiate in the iron from the edge of the bush.
{Fig. 6.) The metal around the bush gives way almost immedi-
ately after a gun is bushed, forming ii hollow ring around it

DISABLING CANNON. 309

which gradually increases. So long as this wear is uniform and
the edges are not jagged, it. 1.-^ of lirtle importance, and guns need
not be rebushed or condemned for this cause until the ring has
become 0.1 of an inch deep or 0.1 of an inch wide. If, however,
the edges are jagged, or if one side has given way much more
than the other, so as to be likely to hold pieces of unconsumed
cartridge, tiie examiner must use his discretion as to condemning
the gun, it being impossible to lay down fixed i-ules suitable for
all cases. Fissures or hair-lines radiating in the iron from the
edge of the bush, should be carefully tiaced on the gutta-percha
impression, and if they extend more than one-twentieth of the
circumference of the bore in any direction, measured from the
original centre, the pieces should be condemned.

564. Disabling cannon. 'Vh\f> is either permanent or tem-
porary. The first is accomplished by bursting, or \t the piece is
rifled, by scoring the siu-face of the bore so as to destroy the
efficiencj'' of the rifling.

To btu'st a piece, load it with a double charge ; musket or other
violent powder is the best; put in a projectile and ram down
around it iron wedges, the more tapering thie better; throw sand
in to make the wedges take hold, and tiie the piece. If wedges
are not at hand, large spikes or similar pieces of iron will answer
the purpose ; or load the piece as before, fill it full with its own
projectiles, and fire at a high elevation.

To fire the piece, when electrical primers are not to be had,
prime with fine-grained powder, and place over the vent a p.'ece
•of port-fire long enough to permit the man firing it to reach a
place of safety before the charge explodes. The port-fire is
held in position by being set in clay or putty, or it may be tied
to the piece with twine.

If port-fire is not at hand, a slow match can, in a few min-
utes, be made of any ordinary paper by saturating it with a
solution of saltpetre (gunpowder dissolved in water will an-
swer); after drying, cut it into strips, and slightly twist them;
place one end of a tvvist in contact with the priming of the vent,
and apply fire to the other.

To disable a piece by scoring the bore, load it with a charge
of powder and a shell filled with powder. The shell is without
a fuse, and the fuse hole is closed sufficient onlj'^ to keep the
powder from spilling out; the shell is inserted with the fuse-end
foremost and the piece fired. The bursting of the shell in the
bore and the scoring effect of the fragments will moat likely tear
4iway the lands and render the piece unserviceable.

Cannon are temporarily disabled to prevent them from being
immediately used by the enemy, and also when they are ex-

810 PRESERVATION OF PROJECTILES.

pected to be retaken. This operation is accomplished by means
of a spike.

A spike is made of hardened steel, with a soft point that may
be clinched on the inside of the piece. A nail without a head^
or the point of a file, may be used instead of a regular spike.

To spike a piece. Drive in tlie spike flush with the outer
surface of the vent, and clinch it on the inside with the rammer.
To prevent the spike from being blown out, wedge a shot in the
bottom of the bore by wrapping it with cloth, or by means of
wedges driven in with a bar.

To unspike. If the bore is unobstructed and the spike be not
screwed or clinched in, put a heavy charge of powder iu the
piece and ram jiuik-vvads tightly over it, laying on the bottom
of the bore a strip of wood, with a groove on the under side, for
a strand of quick match, by which fire is communicated to the
charge. Wlien the bore is obstructed, endeavor to drive tlie
spike into the bore with a punch. If this succeeds, introduce
fine-grain powder into the vent to blow the obstacle out. If,
after several trials, neither of these methods succeeds, drill out
the spike or drill a new vent.

A gun upon an iron carriage is readily dismounted and the
carriage disabled by removing the counter-hurters,^ running the
piece from battery, throwing the axles in gear, and then tiring
it. The recoil will carry the top-carriage oft' the chassis, and
the fall will smash it to pieces. If the pintle key be removed,
the chassis will also be thrown off and injured. When it is not
desirable to fire the piece, the top-carriage may be hauled off by
means of a tackle.

Preservation of Projectiles.

565. Projectiles for rifle guns should be neither lacquered
nor painted, for tlie reason that either of these substances would
adhere to and foul the grooves of the piece. When practicable,
they should be kept under cover, in a dry place, and if unboxed,
should be oiled once a year with sperm oil. They are piled, ac-
cording to kind and calibre, on tlieir sides, in tiers of convenient
height. The fuse holes should be stopped with tow or cotton-
waste. Great care should be taken when handling them to
avoid injuring the sabot. No shells of any description should
be kept habitually charged. This is done, as occasion requires,
when firing.

Rifle projectiles for all calibres above 4.5-inch are packed sep-
arately in boxes. The boxes have rope handles, and are marked
with the kind of projectile. Projectiles thus packed should be-

PRESERVATION OF PROJECTILES. 311

stored in a dry place, and not removed from their boxes until
required for use.

Projectiles for siege guns are packed in boxes, painted differ-
ent colors to indicate their contents. Those for solid shot are
painted olioe; for shell, black; for case-shot, red; for canister,
light drab. The kind of ammunition is furthermore marked, on
each end of the box, in Uu"ge white letters, and the place and
date of fabrication on the inside of the cover. Each box for
siege-gun ammunition contains four projectiles and weighs about
145 pounds. The box is 20 inches long by 11.5 inches wide and
13.5 inches deep, outside measurement; it has two pariitions
across it, the space between the partitions holding the car-
tridges; the two outside spaces, two projectiles each. The
boards of which the partitions are formed are thick enough to
allow of a recess being cut in each, in which are carried the req-
uisite number of fuses and friction-primers. The boxes have
rope beckets on their ends for convenience of handling.

Ammunition for the 3.5-inch guns is put up in a similar man-
ner, each box containing ten rounds and weighing about 135
pounds.

When projectiles of anj^ kind are received at a post, they
should be cai-efully examined and gauged, to see that they are
of the proper calibre and quality required for the particular
piece.

Spherical projectiles are lacquered. This is done as soon as
possible after they are received. The lacquer used is coal-tar,
applied with a brush, as for guns. All rust should be carefully
removed, bj^ scraping and wiping, before the lacquer is applied.

The projectiles are assorted as to kind and calibre and piled
in a dry locality where there is a free circulation of air. The
ground is prepared for the base of the pile by raising it above
the surrounding level so as to drain oft' the water; it is made
level, rammed well, and covered with a layer of sand. The
bottom tier of the pile is made of unserviceable balls, buiied
about two-thirds of their diameter in the sand ; this base may
be made permanent. The pile is then formed, putting the
fuse holes of shells downward in the intervals, and not rest-
ing on the shells below. The bed may also be made of brick,
concrete, or stone pavement, with borders and braces of iron ;
or the bed and border may be made of lieavy plank and scant-
ling. These, however, in consequence of decay, will require
renewing every six or seven years. AVhen for this or any other
purpose the pile is taken down, the projectiles should be freshly
lacquered. It is generally sufficient that the projectiles be lac-
quered, without disturbing the pile, by applying it to those on

312 STORE-HOUSES.

the outside. This is done once a year in warm, drj' weather.
When the lacquer accumuhites so that the projectiles will not
pass through the large gan<?e or into the piece, it must be re-
moved. This is done by rolling and scraping; or for those of
10-inch and upwards it may be burned oif, provided the burning
be qnick, so as not to heat "the projectile to a.n}'^ great extent.

Piles of projectiles should not exceed eight feet in width.
Square piles are to be preferred where there is room ; where this
is wanting, the piles may be extended in length. The piles
should be examined every spring to see that the projectiles are
not rusting ; this can be sufficiently done by removing a few
from each pile and looking through the crevices.

To find the number of halls in a pile. Multiply the sum of
the number of balls in the three parallel edges by one-third of
the number in a triangular face. In a square pile, one of the
parallel edges contains but one ball; in a triangular pile, two of
the edges have but one ball each.

Store-houses.

566. Every post furnished with heavy artillery has one or
miore store-houses for the preservation and safe-keeping of equip-
ments, implements, and such machines as should not be exposed
to the v.'^eather. They should be light, dry, well ventilated, and
furnished with shelves, racks, and tables for the accommodation
of the stores kept therein. The articles are sorted according to
their natures and arranged in appropriate places. These places
are distinctly labeled, and. furthermore, each article, as far as
possible, should be marked, so that under no circumstance there
may be mistakes or confusion.

Cartridge^bags are presei'ved from moths by packing them
with an hydraulic press ; by enveloping them in paper bags her-
meticall}'- sealed, the paper being similar to that used for pre-
serving army clothing; or by heading them up in tight casks. A
mild infusion of colocynth will preserve them from moths. The
bags are steeped in it, afterwards dried, and then packed away.

Sponges are preserved from moths and packed away in the
same nianner as cartridge-bags. They should not be kept on
the heads of sponges in store, as they are then always damaged
by rats and moths. Sponge-covers must never be put on the
sponge-head unless both are clean and dry ; after use the sponge
should be washed clean and dried, and then the cover put on.

Sponges^ rammers^ worms, and ladles are generally placed on
racks, with supports, not over three feet apart, to prevent the
staves from warping.

STORE-HOUSES. 313

Articles composed of brass are spread out on shelves, and are
kept clean and free from verdigris. It is forbidden by regula-
tions to use oil or grease upon them ; alcohol or vinegar, with
rotten-stone and afterwards wiiiting, are the most suitable pol-
ishing materials for them; all scouring is to be avoided. A good
lacquer for brass articles is composed of : Alcohol, 95 per cent.,
2 ounces; seed-lac, 1 ounce. Put the mixture in a glass vessel
for rive or six days, exposed to the light ; shake well once each
<]ay ; a])ply with a brush while the article is as hot as it can be
made without injury.

Steel or iron implements should be painted black or kept bright,
according to the use for which they are intended. For polish-
ing, use crocus-cloth, oil, and rotten-stone ; after which, oil with
sperm oil.

For the preservation of the bright parts of machinery, elevating
screws, &c., when not in use, the following preparation is used,
viz. : One pound white-lead and 0.25 pound tallow or lard oil,
heated and mixed together. This is applied warm with a brush
or cloth. It is removed by rubbing off with a cloth, using a
little tui-pentine.

Leather equipments are hung on pegs in a cool, airy place.
Those of russet leather should be taken down three or four
times a year and brushed off to prevent accumulation of mould.
Those of black leather should, once or twice a year, be washed
with castile soap and water, well rubbed, and before thoroughly
dry oiled with a mixture of neat's-foot oil and tallow ; lamp-
black may be added to the oil for blacking.

Fuses^ friction-primers^ and water-caps are kept, as far as pos-
sible, in their original packages, and are stored in the driest
and safest place in the store-house ; it is preferable to store such
articles as indicated mpar. 567.

Ropes are stored and cared for as explained in par. 481.

Pulley-blocks arc hung up or piled where they have free circu-
lation of air ; those of wood are occasionally oiled with raw lin-
seed oil. The hooks^ cheeks^ and partitions of iron blocks are
painted black. Journals should be coated with black-lead, or if
this is not available, lubricating oil must be applied before using.
The greatest care must be observed to keep them free from sand
or other gritty substance.

Boilers^ manosuverinq blocks, shifting-planks, chocks^ cradles,
capstans, and capstan-bars are stored in dry places. They should
not be painted, but occasionally oiled witli raw Unseed oil.

Gins are painted olive, with the iron parts black. The wind-
lass, however, should never be painted, but oiled with linseed
oil.

814 STORE-HOUSES.

As strict uniformity is not observed in the construction of gins^
each one should be numbered and its parts so marked that if part^
of different gins become mixed they may be readily separated.
Each gin should be placed by itself, the braces fastened to the-
legs by their bolts and keyed up ; the clevis jind clevis bolt are-
left on tlie pry-pole.

Trunnion rings^ sling-chains^ &c., are hung on pegs and pre-
served from rust by a ithin coat of black paint.

Hydraulic-jacks should be kept filled. The ram or piston and
the journals are frequently oiled to prevent rusting, but when
used, the head of the ram, to prevent slipping, must be free
from oil or gi-ease. The outside of the jack may be painted.

Galling guns are kept in dry store-houses, and require the
greatest care to preserve them from rust. The use of emery-
cloth or other scouring material must be avoided. They must
be kept covered, and well oiled with a mixture of about equal
parts of sperm and kerosene oil. Every two or three days they
should be wiped oft', a rag passed through the barrels, and fresh
oil applied. The journals are oiled through the oil holes in the
breech casing. The carriages, limbers, and caissons are painted
and cared for as other wooden carriages.

Gun-lifts are painted olive, and when not in use are kept
under cover.

Hand-carts^ sling-carts^ garrison trucks and wagons are painted
the same as siege cari-iages, and should be kept under sheds^
The small sling-cart, being entirely of iron, excepting the pole^
is painted the same as iron carriages.

Faints^ turpentine^ oils,, lacquers, &c., are kept in a room sepa-
rate from other stores ; a cellar or casemate is preferable. The
floor should be covered with two or three inches of fine sand^
which should be renewed occasionally. Sawdust should never
be used for the floor.

Volatile oils, such as kerosene or benzine, must not be kept
stored in the paint and oil room, but in such place that the least
possible damage will arise from it should it take fire.

Faint brushes, when new, and before using, should be wrapped^
or, as painters term it, bridled with strong twine, and soaked in
water to swell them. After using, they should be cleaned with
spirits of turpentine and put away in a vessel containing water
to keep them from drying and becoming unpliable.

dCi. The following table gives the quantity of material re-
quired for the preservation of the armament of a fort. It is made
upon the basis of what is required annually for ten pieces, car-
riages, &c., of each kind :

STORE-HOUSES.

31S

'subS ^j^nbovj

•siitj:;^ 'jaup uvdv£

2^ ;« ;s?;:^;s?;!?;j?-^;^-^

•sxi'bS 'no euasojag;

O lO CO CO »CS (M T-(

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516 PRESERVATION OF POWDER.

Armament of Works.

d6S. The kind, calibre, and number of cannon constituting
the armament of a permanent work, as likewise the emplace-
ment of the piece, is determined by the Engineer Bureau. The
different parts of a work receive tlieir specific designation from
the same source, which likewise numbers, in regular series, the
position of the pieces occnpj^ing each part. Tliese numbers, run-
ning from right to left as you look outwards, are placed on the
parapet opposite the platform.

It is the duty of the Engineer Bureau to furnish each work
with a chart showing the water channels, with their soundings,
and other approaches to the work. From this it is the duty of
each artillery officer in charge of pieces to study and familiarize
himself with the method of using them so as to make them most
effective in carrying out the object for which they were placed
in the work.

Supply of ammunition.

The amount of ammunition which should constitute a supply
for artillery in a permanent work, depends so much upon cir-
cumstances that no fixed i-ule can be laid down for it. A place
li^ible to close siege should be more amply supplied than one
Avhich can be replenished, and less would be required to repel
attacks from vessels than from a besieging force on land. Two
hundred rounds per piece maj^ be taken ordinarily as a good
supply for 15-inch guns and the heavier calibres of rifles; greater
amounts are required for smaller calibres.

For all guns, the projectiles should be about equally divided
between shell and solid shot.

The amount of ammunition for siege guns, when used in cam-
paign as heavy field-pieces, is 200 rounds per piece, together
with a small reserve.

Preservation of Powder.

569. Powder is kept in magazines constructed with the works.
The number of these magazines depends on the number and
•calibre of pieces in the work and the probable amount of ammu-
nition required for each.

Magazines are of two kinds, viz.: storage and service. The
former are for the accommodation of powder in bulk ; the latter
are smaller than the former, and are placed as convenient as
practicable to the pieces to be served, and contain only sufficient
powder for immediate use. Adjoining or convenient to each
^service magazine is a filling-room, in which cartridges are made

PRESERVATION OF POWDER. 317

up and shells filled. Powder is brought from the magazhie for
this purpose, but only in such quantities, at a time, as may bo
necessary. In the filling-room are kept the filling implements
and such small articles of equipment as are required to be near
the pieces.

Tlie storage magazines of a post are conspicuously marked
A, B, C, &c.; the service magazines are numbered 1, 2, 3, &c.,
and, in addition, are marked for the particular pieces tliey are
to serve.

A magazine of sufiicient size, and fitted up with shelves,
tables, and racks, is set aside for tlie storage of rockets, port-
fires, fuses, primers, slow and quick match, and other similar
articles. No such stores will be permitted in a magazine with
powder.

The keys of the storage magazines are kept by the command-
ing officer of the post. Those of the service magazines, unless
otherwise ordered, are in possession of the officers having charge
of the particular pieces to be served from them, a competent non-
commissioned otflcer being assigned to the immediate care of
each. The ordnance-sergeant of the post will have charge of
the storage magazines and of the one containing fuses, port-fires,
&c.

Powder is stored in barrels containing 100 pounds each ; the
heads of the barrels are painted black, so as to show more plainly
the marks, which are stenciled in white. Each barrel is marked
on both heads with the number of the barrel, the name of the
manufacturer, year of fabrication, and the kind of powder — can-
non^ mortar^ musket^ mammoth^ or hexagonal ; the mean initial
velocity, and the pressure per square inch on the pressure piston.
Each time the powder is proved the initial velocitj^ is marked
below the former proof-marks, and the date of trial opposite it.
Each manufacturer has, in addition, certain private marks —
initial letters — denoting the particular grade to which the powder
belongs. A book is kept, by the ordnance-sergeant, which shows,
besides all these marks, when the powder was received, where
stored, and how much on hand.

Barrels of difi^erent kinds of powder are piled separately, and,
besides being recorded in the magazine - book, each parcel is
marked with a card, showing the kind and the entries and issues.

In the magazine, the barrels are placed on their sides, gener-
ally three tiers high, or four tiers if absolutel}' necessary. Small
skids are placed on the floor and between the several tiers, and
the barrels chocked at intervals to prevent rolling. The tiers
must be so arranged that the marks can readily be seen and any
particular kind reached. There should be an unobstructed space

318 PRESERVATION OF POWDER.

•of several square yards at the door, and this space, as likewise
the alleys, should be covered with carpet or matting. The mag-
azine is provided with a well near tiie door; into this the sweep-
ings are put ; they should never be swept out at the door. For
the preservation of tiie magazine, it is of the greatest importaitce
to keep unobstructed tlie circulation of air, under as well as
above tlie flooring. The magazine should be opened and aired
only in clear, dry weather, when the temperature of the air out-
side is lower than that inside of the magazine. It should not be
ojiened in damp weather if it can be avoided. The ventilators
must be kept free and no shrubber}'^ or trees allowed to grow so
near as to screen the building from the sun. The magazine
yard should be of sand or clay and well drained. The moisture
•of a magazine may be absorbed by chloride of lime kept in an
open vessel and renewed from time to time. Quick-lime is dan-
gerous, and should not be used.

Candles, in lanterns, are used for lighting the magazine. ISo
one should enter without first removing his shoes or putting
India-rubbers over them. No cane, sword, or anything which
might occasion sparks, must be carried in.

Barrels of powder must not be rolled in transportation; they
should be carried in hand-barrows, or in slings made of rope,
-canvas, or leather. All implements used in the magazine or on
the barrels should be of copper or wood. The barrels must never
be repaired in the magazine. When it is necessary to roll them
for the better preservation of the powder and to prevent its cak-
ing, this is done, with a small number at a time, on boards in
the yard.

Occasionally, especially in the spring, the barrels should be
inspected, and, as far as possible, brushed off, to prevent insects
irom destroying the hoops. A light brushing over with carbolic
acid will be good for this.

When practicable, a sentinel should be posted over the maga-
zine, to keep unauthorized persons away and to prevent smoking
•or fire within dangerous proximity. The lightning-rods must
never be out of repair.

Should a fire occur near the magazine, the ventilators and
windows must be immediately closed, and the building covered,
if possible, with paiilins, blankets, or carpets saturated with
water. It is extremel}'^ hazardous to attempt to remove the con-
tents at such a time.

Neither loaded shells, fire-works, nor composition for fire-
works will be stored in a magazine with powder. Shells should
be filled in the filling-room of the service magazine.

Transportation. In v^^agons, the barrels of powder must be

FILLING CARTRIDGE-BAGS. 319

packed in straw, secured in such a manner as not to rub against
each other, and the load closelj'- covered with canvas. Sufficient
guard should accompany the ti-ain to prevent all smokino; or lire
near the wagons. I^o camp-fires should be allowed near the
park. On railroads, each barrel should be tightly boxed and
packed so as to avoid friction ; the cars, if practicable, sliould
have springs similar to those for passenger cars.

570. Filling cartridge-hags. Cartridges for all pieces larger
than the siego gun should be made up only as required for use,
and when any are left over after firing, they are stored away in
the service magazine on shelves. The cartridges are filled in the
Jilling-room of the service magazine. Under no circumstances
will filling be done in a powder magazine. The powder, in bar-
rels, is carried from the storage magazine to the service maga-
zine in powder-carts or hand-barrows.

To fill the cartridges, the implements required are : One cop-
per liammer^ one wooden drifts one counter hrusJi^ one scoop., one
counter scales and weights (brass or copper), one filling funnel.,
one set powder measures., cartridge-hags, and twine.

The barrels are opened by first loosening the upper hoops,
when the heads can be taken out easily. Care should be taken
not to handle the barrels or powder roughly.

Should the powder be caked or lumpy, caution should be ex-
ercised in breaking the lumps. When the lumps are small and
not very hard, they may be broken by pressing them with the
hands ; but when large and hard, requiring more force to break,
the powder is taken to some safe place away from the magazine,
spread upon a paulin, and broken with a mallet. The grains
must be separated, but not crushed.

When cartridges are to be used with projectiles, the powder is
carefully weighed ; for blank cartridges, it is measured. When
the piece for which the cartridges are to be prepared has a cali-
bre of less than 7 inches, the filling funnel is used, one man hold-
ing open the mouth of the bag while another pours the powder
into it through the funnel. The bag is then tied with twine
close to the powder. For cartridges of more than 7 inches diam-
eter, the powder is poured into the bag by means of the scoop ;
the bag is tied as before. When cartridges are filled, each one
should be marked with a pencil or by stenciling, showing the
kind and weight of powder and for what kind of piece it is to
be used.

TRANSPORTATION OF ARTILLERY.

To Embark and Disembark Artillery and Artillery Stores,

General Rules.

571. When artillery and its stores are to be shipped for an
expedition, prepare first a list of all the articles, stating their
number, individual weight, and the total weight of each kind.

In estimating the weights, allow double for that of bulky
articlf^s which occupy ranch space without weighing much.

Divide the total quantity to be transported among the vessels,
and make statements in duplicate of the articles on board each
vessel, one of which lists should go with the vessel and the other
remain with the officer shipping the stores.

The articles must be divided among the vessels according to
the circumstances of the case ; but, as a general rule, place in
each vessel everything necessary for the service required at the
moment of disembarkation, so that there will be no inconven-
ience should other vessels be delayed.

If a siege is to be undertaken, place in each vessel with each
piece of artillery its implements, ammunition, and the carriages
necessary to transport the whole or a part; the platforms, tools,
instruments, and materials for constructing batteries; skids,
rollers, scantling, and plank.

If a particular calibre of gun is necessary for any operation,
do not place all of one kind in one vessel, to avoid being entirely
deprived of them by an accident to it.

Dismount the carriages, wagons, and limbers by taking off
the wheels and boxes and, if absolutely necessary, the axle-
trees. Place in the boxes the linch-pins, washers, &c., with the
tools required for putting the carriage together again. Number
each cai'riage, and mark each detached article with the number
of the carriage to which it belongs.

The fixed ammunition must be carefully packed in its pre-
scribed boxes ; the cartridge-bags, fuses for shells, and their
ammunition, either in substantial boxes with rope handles or in
21 ( 321 )

322 TRANSPORTATION OF ARTILLERY.

barrels ; powder in barrels, in a magazine constructed in a
vessel to hold it.

Sponges, rammers, worms, and ladles should be united in
bundles ; other implements, intrenching tools, levels, rules, &c.,
in bundles or boxes; implements, in bundles and boxes of com-
plete sets, as far as practicable.

Small-arms should be in their prescribed boxes.

The contents of each box, barrel, or bundle should be marked
distinctly upon it. The boxes should be made small for the
convenience of handling, and have rope handles to lift them by.

The position of the different articles in each vessel should be
noted in a column in the list on board.

Place the heaviest articles below, beginning with the shot and
shells, (empty,) then the guns, platforms, carriages, wagons,
limbers, ammunition-boxes, &c. Boxes of small-arms and am-
munition in the driest and least exposed part of the vessel.
The skids, scantling, and boards may be in the more exposed
parts, or in the run.

Articles required to be disembarked first should be put in last,
or so placed that they can be readily got at.

If the disembarkation is to be performed in front of the enemy,
some of the field-pieces should be so placed that they can be dis-
embarked immediately with their carriages, implements, and
ammunition ; also the tools and materials for throwing up tem-
porary intrenchments on landing.

When there are several vessels laden with artillery and stores
for the expedition, each vessel should have on each quarter and
on a signal at mast-head a number that can be easily distin-
guished at a distance. The same number should be entered on
a list of supplies shipped in each vessel. The commander can
then know exactly what resources he has with him. Some
vessels, distinguished by particular signal, should be laden solely
with such powder and ammunition as may not be required for
the immediate service of the pieces.

If it is necessary to reship or leave any articles on board the
vessels, care should be taken to note them on the list.

Boats of proper capacitj'^ must be provided for the disembarka-
tion, according to the circumstances in each case.

It may be necessary to establish temporary wharves on tres-
tles, and to erect shears, cranes, or derric]«.

.On a smooth sandy beach, heavy pieces, &c., may be landed
by rolling them overboard as soon as the boats ground, and
hauling them up with sling-carts.

572. Railroad transportation. The most suitable car for
carrying horses, especially in warm weather, is the ^*sla^ stock-

TRANSPORTATION OF ARTILLERY. 323

«car," built of slats and open all around, but tight in roof.
Another kind, known as the "combination car," is made with
live doors on each side and one at each end, which may be
closed tight for stores, or with iron grates when carrying horses.
These are suitable for either warm or cold weather.

Both kinds are usually 27 feet 4 inches long, 7 feet 9 inches
wide, and 6 feet 8 inches high, inside measurement. Each car
will carry fourteen artillery or sixteen common horses or mules.

The horses all face towards the same side of the car, and are
hitched by their halters to the frame-work. If the journey is
to be continued beyond eighteen or twenty hours, the horses
will require to be watered and fed. ^N'ose-bags are generally
used for the grain. If the drivers are attentive, they, by taking
advantage of the short halts made by the train, can feed grain
and hay quite easily by hand. Half rations will be sufficient
under an}' circumstances. Before placing the horses on the cars,
they should be thoroughly groomed and cooled; they should
iiave nothing more on them than their halters.

If the Journey is to continue for several days, (but never be-
yond four without unloading,) the horses should stand length-
wise of the car, facing each other, and hitched to two bars
placed for the purpose across the car. The bars have space
between them sufficient for feeding purposes and for a man to
remain in charge. When thus arranged only about one-half as
many can be carried in each car as in the other case. By load-
ing in this way, close "box "-cars may, even in hot weather, be
used, the doors being left open for ventilation.

Horses are best loaded and unloaded from a "stock shute,"
but where this convenience is not available, and there is no plat-
form, a ramp or shute may be improvised, using for it planks
about 12 feet long and from 2 to 3 inches thick, depending on
the strength of the wood.

The ramp should be about four feet wide, with the planks
firmly fastened together with transverse battens. These battens,
furthermore, prevent the horses from slipping. A strong trestle
or crib of logs supports the end of the ramp next the car, while
the other rests on the ground and is secured from slipping by
strong stakes. An intermediate trestle or a support of logs
should be placed to prevent the planks from springing with the
weigiit of the horses. Three or four posts of suitable height are
set in the ground on each side, to which side rails are lashed or
spiked for the purpose of keeping the horses from stepping off.
A board' should be placed on each side to prevent the horses'
feet from slipping over the edges of the planks. When planks

324 TRANSPORTATION OF ARTILLERY.

are not procurable, a ramp of earth, supported bj^ means of logs^
or stone on the end next the track, may be constructed.

The cars are brought up in succession to the ramp to be
loaded or unloaded. Mules and ordinary horses are usually
driven in loose and stand unhitched.

In the field, where no shute or ramp is to be found at the
place of unloading, material ready prepared for constructing one
should be carried with the train.

Artillery carriages and transportation-wagons are carried on
platform or '•'flat " cars.

Tiiese cars are generally 28 feet long by 8 feet wide. When
properly loaded each will carry two field guns and two caissons
complete. To load them the carriages are unlimbered and the
spare wheels removed from the caissons; the rear train of a
caisson, its stock to tlie rear, is run to the front end of the car
and its stock rested on the floor; anothei* rear train is run
forward in like manner until its wiieels strike or overlap those
of tlie first, when its stock is rested on the floor. A limber
is then placed on the car with its pole to the front, resting
on the rear train ; the second limber is backed on and its pole
held up until a gun, trail foremost, is run under it; the trail of
the gun is rested on the floor and the pole of the limbei- on the
gun carriage. The other gun is run on in the same manner, and
its trail rested on the floor under the first gun ; a limber is next
run on and its pole rested on the last gun ; the remaining limber
is run on with its pole under the preceding limber. All of the
carriages are pushed together as closely as possible and firmly
lashed. Where the carriages are liable to chafe each other, they
are bound with gunny-sacking or other stufT.

A side platform, such as are fou!id in depots, is the best for
loading. The carriages are first run onto a spare car; from this
they are crossed over on planks to the one upon which they are
to be carried, and arranged on it as already described. When
there is no side platform, the carriages are run up at the end of
the car b}' means of way-planks.

Siege guns can be loaded and carried in a similar manner, but
when there is no side platform, blocks and tackle will be required
for hauling them up the way-planks. Two siege guns with their
carriages and limbers complete can be carried on one car, and,
in addition, boxes of ammunition or stores may be piled between
and underneath the carriages. One '"flat" car will carry two
army transportation-wagons standing, besides a large quantity
of other material. If the wagons are '•'"knocked down^'''' the same
car will carry four.

Twenty-four tliousand pounds is considered a safe load for one

TRANSPORTATION OF ARTILLERY BY SEA. 325

car on a good track. Baggage, harness, forage, &c., are usually
carried in box-cars. These cars have the same dimensions as
heretofore given for those carrying horses.

The average size passenger car will seat sixty men, but a small
car will seat only fifty. The men must be provided with cooked
rations for the whole trip. Each car must be liberally supplied
with drinking water, lights at night, and all other conveniences,
to make it unnecessary for the men to leave them during stop-
pages of the train.

The officer in command of troops on a train will act in har-
mony with the railroad officials, and must not interfere in any
manner whatever with the running of the train.

Ten to fifteen passenger or sixteen to twenty-two freight cars
go to make up a train drawn by one locomotive ; but when the
grades are light and but little curvature in the road, the maximum
weight of trains may reach double these figures.

Passenger trains generally travel at the rate of about tw^enty-
two miles per hour, and freight trains about fifteen, including
customary stoppages. Troop trains should not be dispatched
from a station with less intervals than ten minutes between
them.

The experience gained during the war of the rebellion shows
that to supply an army of 100,000 men in the field by means of
a single line of rails, the proportion of rolling stock should be —
engines 0.25 and freight cars 6.0 to every mile of road. This does
not provide for the conveyance of troops. In calculating the
amount of rolling stock available for use, a deduction of 50 per
cent, for locomotives and 30 per cent, for all other carriages
must be made for those usually undergoing repairs.

From the foregoing data, a small calculation will give the
amount of railroad transportation required for any given num-
ber of troops, artillery, or material, and the capacity of a road
for performing the work.

573. Transportation of artillerij hy sea. In the United States
service there are no vessels fitted up especially for transportation
of troops, horses, or artillery material. Even during the four
years of the war of the rebellion no attempt was made towards
it further than temporary arrangements for some particular voy-
age. The voyages were short, lasting generally only two or
three days, never exceeding eight. Embarking and disembark-
ing were usually accomplished with wharf facilities. In only
three or four instances were the movements of an expeditionary
character, requiring these operations to be performed on an open
beach or in front of the enemy. As desirable and advantageous
::as it would have been to have had suitable transports properly

826 TRANSPORTATION OF ARTILLERY BY SEA.

fitted up, the absolute necessity for it was never felt, and conse—
quentl.y they were never adopted. It maj^ not always occur
that the same conditions will exist, and it is therefore well to
collect such information on the subject as may be needed.

Tlie horses and material belonging- to artillerj'^ require so
great an amount of space in proportion to that required for the
men, the latter need scarcely be taken into account when esti-
mating for ship room. Any vessel capable of carrying' horses
and guns will accommodate the men belonging to them in those
parts where neither horses nor guns can be stowed.

Guns, caissons, ammunition, and other material of this char-
acter are cai'ried in the same manner as ordinary merchandise.
When once within reach of the ship's tackle, the officers and crew
of the vessel will know how to stow and take care of them to the
best advantage. When practicable, it is not only the most expedi-
tious, but altogether the best way to leave the carnages mounted.
The length of the voyage and the character and capacity of the
vessel will determine whether or not this should be done, and
in what part of the ship stored. Other considerations, such as
facilities for embarking and disembarking, will likewise go to
determine these questions.

The horses are more difficult to provide for, and it is with ref-
erence to their accommodation and safety that vessels for the
transportation of artillery sliould be selected.

During tlie rebellion a species of transportation was employed
upon the Chesapeake Bay, and even for short voyages at sea,
which proved ver}'- successful, and which might again find useful
application.

Tliis consisted in embarking the horses on large schooners and
the batteries on steamers, (frequentlj^ ferry-boats,) which, tak-
ing the scliooners in tow, conducted them to their destination.
Eacli schooner carried upon an average fifty horses; three were
therefore required for one battery. The ferry-boat carried easily
the material of two batteries. The advantage of this kind of
transportation consisted chiefly in the ease of loading and un-
loading tile vessels. Their light (h-aught enabled them to lie up
to almost any kind of wharf. Strong gang-planks were pro-
vided, over which the horses were led to the decks of tlie
schooners, upon which they stood, facing outwards. To prevent
them from gnawing and injuring the gunwales, stout boards
were temporarily nailed thereon. The batteries were run by
hand onto the feny-boats, the carriages unlimbered and stowed,
the whole occupying but a few minutes of time. Disembarking-
was accomplished with equal facility.

TRANSPORTATION OF ARTILLERY BY SEA. 827

Each schooner carried its due proportion of the men of the
batter}'-, who looked after the hoi-ses.

When the voyage is to extend beyond six or seven days at sea,
the vessel should have room between decks where stalls can be
fitted up in the manner hereinafter described. But if the voyage
is of shorter duration, stalls are not absolutely necessary. In
this case the vessel best adapted is a long low steamer, with a
clear upper deck for the accommodation of the horses. The
guns, carriages, harness, and baggage are stowed between decks,
where likewise the men find ample room. In many steamers a
large gangway on each side leads to the main deck, through which
the carriages can be run by hand. In vessels not so provided
they have to be lowered by means of tackle down the main
hatch, — a slow and laborious process.

Horses, in all cases, should stand ath wart-ship; in this posi-
tion they better accommodate themselves to the rolling motion
of the vessel. When on the upper deck they should face in-
wards ; this, for the reason that the spray will not then strike
them in their faces, and, besides, when facing each other in this
manner they will suffer less from fright and nervous excitement.

A vessel of not less than 25 feet beam will accommodate two
rows of horses, leaving a space between the rows, and between
the croups of the animals and the sides of the ship, ample for
the proper care of the horses. These spaces are, furthermore,
necessary as gangways for working the vessel. The average
artillery horse occupies a deck space of 8 feet b}^ 2 feet 4 inches.
It results, therefore, that the whole lengtii of the deck in feet
divided by the last dimension will give the number that maj'' be
accommodated in each row. As they stand better when close
together, side by side, no allowance need be made for vacant
space between them.

The horses are secured by their halters to hitching-bars (B B,
Fig. 1, Plate 56), of strong scantling, running longitudinally
in two lines along the deck. A space of about five feet is left
between the lines for the gangwa}^ before mentioned. These
bars should be about four feet from the deck, and supported by
stanchions (A A) secured to the deck by strong angle-irons fast-
ened with screws. The bars are braced from the sides of tlie
vessel with stout scantling (C C). These braces are arranged so
that the spaces between them will include rive horses, (more or
less, depending upon the strength required to give entire secu-
rity to the structure,) and are fastened with bolts and nuts, so
that in loading they ma}' be removed and replaced successively
as the horses are put in their places. The}'- must be smoothed
oft", or wrapped with gunny or other material, to i^revent tlieir

328 TRANSPORTATION OF ARTILLERY BY SEA.

chafing the horses. Holes are bored or i-iiigs attached to the
h itching-bars for the halter-straps The horses should be hitched
short, and when putting them on board care should be observed
to have those accustomed to each other placed togetiier. Kick-
ing and vicious animals are placed, as far as practicable, where
they can do least mischief.

AH stalls, hitching-bars, or whatever other arrangement for
eecuring horses, must be strong beyond any possibilit^'^ of giving
way. The living force exerted by a row of horses as they swing
with the motion of a ship in a heavy sea-way, is very great, and
it is better to have no securing arrangements whatever than to
have those that, by giving way, will wound and injure the ani-
mals in the wreck.

If the transport is to be used in very inclement weather, the
spar deck, over the liorses, should be covered. Canvas stretched
over a secure frame is better than boards, as the latter, in a
severe storm, might be carried away, and its wreck would cause
disaster among tiie liorses.

During heavy weatlier, horses sometimes become exhausted
and fall. The best thing that can be done in such cases is to
back out the horse on each side, so as to give the fallen horse
plenty of room. The next horses adjoining are prevented from
trampling him by having placed against them braces such as
heretofore described. There should be several of these braces
spare foi- this special purpose. The fallen horse should be pro-
tected from rain and spraj' by a paulin, and great care and ten-
derness exercised towards him ; otherwise he is very liable to
perish. The horses may be fed from nose-bags, but it is better
to have for each one a small trough, suspended to the hitching-
bar by means of two iron hooks passing over the bar. The
troughs are moved out of the way when not in use. Haj'' can
be fed to them by tying it up tightly in bundles with rope-yarn
and fastening the bundles to the hitching-b;i.r. It may also be
fed in small quantities by hand, and the more attention the
horses receive in this way from the men, the less fretful and
uneasy they become.

When the embarkation takes place from a wharf, and the ves-
sel is not too high, it is best to use gang-planks and lead the
horses on board. The gang-plank leading up from the wharf
to the gunwale should be about 20 feet long by 10 wide, aiul
be made vei-y strong. This width admits of its being used for
gun carriages. It should be provided with ropes at the corners,
rollers, side rails, and boards upon the sides to prevent the
horses from getting their feet over the edges. Another similar
gang-plank, but not so long, leads from the gunwale to the

SLING. 329

deck, the two being securely fastened together by their ropes.
These gang-phini<8 should be carried^ by the vessel, ready for
<lisembarking. Every provision for this latter operation should
be thoroii<2;hl\' loolved after before starting on the voyage.

Wht-n it is not practicable to use gang-planks, the horses are
boisted on board by means of a sling and lifting tackle.

5 '74. Sling. This is made of stout web, or double ISTo. 1
canvas. It is 5 feet long and 2 feet wide, secured at each end
by a stick of strong wood 2 inches in diameter. The sides are
bound with strips of canvas doubled, thus making the edges four
tliicknesses. Loops of 4-inch rope are attached to each stick.
{Fig. 2, Plate 56.)

The loop attached to onestick is 9 inches long; that attached
to the other is 2 feet 11 inches, and has an iron e.ve — 3 inches,
inside measurement — fixed in the end. Breast and breech ropes
{2-inch) 9 feet long are fixed to each side, and are tied together
when the sling has been put under the horse. The slings should
be tested by an excess of weight, A donkey-engine is used for
hoisting.

Five men are required to sling a horse quickly and well. One
man holds the head guj'', which is attached to a neck-collar; two
men, one on each side of the horse, pass the sling under his
belly; both then hold up the ends over his back, passing the
long loop through the shorter one and hooking on the e,ye of
the former to the lifting tackle, continuing to hold up the sling
until tlie horse's legs leave the ground; another man stands at
the breast and fastens the breast-rope, w^hile the fifth stands at
his rump and fastens the breech-rope. The officer superintend-
ing commands : HoiST AWAY. The first man slacks away at
the gtiy-rope, holding it just sufficiently taut to keep the horse's
head steady. When hoisting, no delay should be permitted ; it
should be done in the shortest time compatible with safety. At
the commencement, aftei- a certainty that all is right, it should
be done rapidly, to raise the horse off his feet and free him from
surrounding objects before he has time to do any injury by kick-
ing. After attaining the necessary height, he is carefully and
steadily lowered to the deck. Care should be taken to have two
or three careful and active men stationed to seize the liorse and
prevent his plunging until the slings are removed. While one
Iiolds him by tiie head-stall, another rapidly unhooks the tackle
purciiase, and two others let loose the breech and breast bands,
or ropes. Wiien the liorses are to be lowered through a hatch
to a deck below, the combings of the hatch, as well as stanchions
about it, should be well padded. As an additional precaution,
a head-collar should be provided, with a large pad on top to pre-

330 STALLS.

vent injury shoulrl the horse strike his head against the deck
beams when liorhting on^his feet. Everything being in readi-
ness and skillfull}'' managed, an average lot of one hundred
horses can be hoisted on board in from two to three hours.^
Hatches for horses must be at least 10 by 10 feet.

Allowing 1100 pounds as the average weight of artillery horse*
and 150 pounds as that of men, and estimating for ten days' sup-
ply of food, water, and forage, the total weight of a field battery
of six pieces, fully equipped and provided for field service, and
including two baggage-wagons loaded with camp equipage and
baggage, wiil be 329,000 pounds, or about 165 American tons.
Horses embarked as described — i. e., without stalls — require
each a space equal to 3.5 tons, marine measurement; therefore
about 550 tons will be required for the horses alone. It is thus
seen that the actual weight of a battery forms but a small pro-
portion of the shipping tonnage required for it. The class of
sea-going steamers usually chartei-ed for transportation service
are those that ply between points along the sea-board. They
are generally propellers, ard vary in tonnage from one to two^
thousand tons. Owing to the fact that a considerable part of
their room is usually taken up with passenger accommodations,,
they are seldom able to carr}"- more than one full battery. A
steamer of 2000 tons burden, with a free spar and main deck, is
capable of carrying two complete batteries.

5'7'5. Stalls. The extensive experience of the British Army
during the Crimean war and in the Canadian, East Indian, and
other colonial service, has enabled the English to arrive at great
pei-fection in fitting up transports for horses. The following is
the method adopted : Each horse is provided with a stall ; these
are placed in two rows, one on each side of the ship, with the
heads of the horses facing Inwards. {Fig. 3, Plate 56.) The
rear end of the stall is not less than two feet from the side of the
vessel; three feet is allowed when breadth of deck admits of it..
The stalls in each row are built together, so as to be continuous..
Thej^ are 6 feet long from inside of padding on the breast-piece
to the Inside of haunch-piece, and 2 feet 2 inches between the
padding on the side bales ; ten per cent, are 2 inches narrower,,
and five per cent, are 6 inches longer.

To construct the stalls, two lines of scantling (A and B) are
laid down parallel with the keel of the ship, and 7 feet 5.5
inches apart; the outer line is at the required distance (2 to S
feet) from the ship's side; tiie scantling are 5 by 5 inches, and
are secured to the deck b}'' 1-inch screw bolts of wrouglit-iroiu
They are scored three-fourths of an inch deep on the inside, at
intervals of 2 feet Q.o inches (from centre to centre of score), to re-

HAUNCH-PIECE — BREAST-PIECE. 331

ceive the heels of the stanchions (C and D). These stanchions are
of scantling the same as the sti-ingevs. and ai-e ont to the exact
height from deck to declv ; the}^ rest below on the deck, fitting-
into the scores of the strin^^ers; tiiey are secured to the deck
above by means of cleats fastened with lieavy spikes ; the stan-
chions are seemed, in addition, both above and below, with spikes
driven obliquely into them and the deck ; against the i ear side
of the front stanclnons are placed shoi*t pieces of scantling (E)
for the purpose of securing tlie breast-piece and side bales ; these
pieces are 4 feet long, 7 by 6 inrhes thick, and of good stiong
wood; in the top are two slots for the reception of ihe end- of
the breast-piece and side bale ; they are secured to the front
stanchion by a 0.75-inch bolt at 12 inches from the top; below
they are secured by spikes toed into the deck and by the floor-
ing cut awa}'" to receive them.

The flooring is of 2-inch plank spiked to the deck ; the spikes
are driven so that thc}^ are covered by the cross-battens; the
planks are laid lengthwise, not across the stall, extending from
the front scantling (A) to within 7 inches of the rear one (B)»
with intervals between them of 0.75 inch. The upper edges are
beveled ofi' half an inch. These intervals are for the purpose of
drainage.

Six battens (F F F) of hard wood, 2 by 3 inches, are laid across
the planks, beginning 9 inches from the rear ends of the planks ;
the others at intervals of 12 inches. These battens are contin-
uous, running the entire length of the stalls; scantling 5 inches
deep by 3 inches wide and 6 feet 9 inches long are laid along
each side of the stall, fitting tightly between the front and rear
stanchions, and scored underneath to fit on the cross-battens ;
each is secured b}'^ spikes driven through the floor-planks into
the deck. These pieces are for the purpose of holding the cross-
battens beyond any possibility of breaking away.

To facilitate cleaning the stalls without at the same time
weakening the construction, these pieces are sawed through at 6
inches from the hind stanchions, and a strap-hinge fastened on
top so that the short end can be thrown back when it is neces-
sary to sweep the stalls. A clear drainage space is thus left along
the whole line of stalls.

The haunch-piece (G) is a continuous piece of scantling 9 inches
deep by 5 inclies thick ; it is secured to the inside of the rear
stanchions by bolts, with its top 3 feet 8 inches above the floor-
planks; the top and inside surface are rounded off and smoothed
so as not to chafe the horse ; opposite each stanchion a mortise
is cut in the haunch-piece for the reception of the side bale.

The breast-piece (H) is of hard wood 6 inches thick by ^

332 HORSE-HAMMOCK.

Inches deep ; it is hollowed ont in the middle and ronnded so as
to conform to tlie breast of the horse. The breast-piece of each
stall is ^'movable; its ends, cut to the proper shape, rest in the
slots of the short npri*yhts (E) ; a wooden key (J), tnrnino^ on an
iron bolt, secures both the breast-piece and side bale from lift-
nigout; the upper edge of the breast-piece is 3 feet 11 inches
above the floor-planks.

The side hales are of 9 by 3 inch wood ; in front, they are on
a level with the breast-piece; in rear, with the haunch-piece;
behind, they are tenoned into the haunch-piece; in front, they
slide into the slot in the short uprights, being kept there by
the key (J) ; they are smoothed off and padded with sheepskin
long in wool, put on double. The same kind of padding is used
ior the breast-piece ; none is put on the haunch-piece. About
15 per cent, of .spare side bales are provided.

The manger (L) is made of inch boards 18 inches long, 15 inches
wide at top and 12 at bottom, and 9 inches deep, inside meas-
urements; it is lined with tin or zinc; an iron band passes un-
derneath and up over the ends, terminating in two holes, by
means of which the manger is suspended to two iron pins fixed
to the front stanchions.

Zinc or iron hooping is nailed around the stanchions wher-
ever horses can get at them to gnaw.

The horse's head is secured by means of a head-halter, the
strap of which is fastened to a ring attached to the front stan-
chion. It is best to iiave tvro straps to each halter^ one fastened
to each side.

Kicking hoards are provided for such horses as require tiiem ;
they are attached to the inside of the rear stanchions with
screws.

Four pulley blocks for the ropes of the horse-hammocks are
placed, two ovei- each side bale, one at 12 inches from the front
stanchion and the other 2 feet 3 inches from the hind stanchion.
Those in fiont are double, the hind ones single. These blocks
are screwed to the deck above.

576. The horse-hammock is similar to the sling before de-
scribed, except that the sticks at the ends project on each side
3 inches beyond the canvas. A 2-inch rope 30 feet long is passed
around each stick in a single clove hitch, {Fig. 4, Plate 56,)
the liitch being secured at its crossing with spim-yarn. The end
of the rope from the rear side of the hammock is 3.5 feet longer
than that from the front side, and passes up through the rear
block and over one of the sheaves of the front block; the front
■end of the rope passes over the other sheave ; both are carried
iforward and secured b}'^ an iron belaying cleat fastened to the

CARE OF HORSES AT SEA. 333

deck above. The hammock is kept in position on the horse by
a breast-band 40 inches long and a breeching* 56 inches long and
4 inches wide. These straps are held in position by a wither
and a croup strap, both of which are nnited along the back by
another strap. All of these straps are made of canvas or strong
webbing, and secured with buckles.

There must be ten per cent, of spare stalls, and there should
be a loose box constructed near a hatchway to admit of a sick
horse Ij^ing down. Each stall is numbered, the side bales, breast-
pieces and mangers being marked with the number of the stall
to which tiiey belong.

It is advisable to have as many stalls on the upper deck as
possible, unless extremely bad weather is anticipated. They
are constructed like those already described, except that they
are covered in above by a sloping roof laid upon rafters connect-
ing the stanchions.

The Himalaya^ of 3500 tons burden, fitted up in the manner
described, successfull}' carried, during the Crimean war, 3000
horses with a loss of only three. They were arranged : 200 on
the spar deck ; 130 on the main deck; 50 on the orlop deck, —
making 380 carried at a trip.

On the spar deck, the platforms of the stalls were placed 2
inches above the deck to admit of cleaning, draining, and wash-
ing. The platform was in sections of two stalls each, and could
be shifted.

The horses, when put aboard, were led, the first one to the
most distant stall; then the side bale was put in place, another
horse brought and placed alongside, and soon until the embark-
ing was completed.

When a horse becomes sick or disabled at sea, and it is found
necessary to move him from his stall, the feed-box is unhooked,
the breast-piece unshipped, and he is taken into the narrow
passage or gangway separating the two rows of stalls.

577. Care of horses at sea. For the first few days on ship-
board food is to be given rather sparingly, and bran is to form
a large portion of it ; but after the horse becomes accustomed to
his new situation and his appetite increases, he is to be more lib-
erally fed. A bran mash, or oats and bran mixed, is to be given
to him every other day.

Tile spare stalls admit of the horses being shifted, rubbed
down, their feet waslied, and the stalls cleaned out every day
when the weather permits. -Hand-rubbing the legs is of the
greatest consequence to the comfort and well-being of the horse,
and is to be practiced, if possible, ever}^ day, or whenever the-
horses change stalls.

^34 CARE OF HORSES AT SEA.

Horses are to be slung in smooth weather, and allowed to
stand on their legs in rough and stormy weather. In smooth
weather, they will rest their legs and feet by throwing tlieir
whole weight into the slings. To sling a horse in rough weathei-,
whereby he is taken off his feet, would only have the effect of
knocking him about with tlie roll of the ship. Horses standing,
accommodate themselves to the motion of the vessel. They are
not to be placed in the horse-hammock until they have been at
sea for a week, as some would only be made uneas}' by the at-
tempt to do so.

The hammock is to be placed around the centre of the horse's
?)elly, and tlien the breast-band and breeching fastened to the
required length and degree of tightness. When everytliing is in
readiness, and not before, the horse is quickly raised until all, or
nearly all, of his weight is off his legs. He will very soon learn
the relief the hammock affords him, and will not be slow in
availing himself of it by throwing his weight into it. With some
horses it is necessary to use great quickness in making the ropes
fast before they throw their whole weight into the hammock.

When the horses are between decks, too much attention can-
not be paid to 4:he constant trimming of the wind-sails, so as to
insure plentj'^ of fresh air. The wind-sails should be well for-
ward, and extend down to within two or three feet of the deck.
When a horse between decks becomes ill, and the weather is at
all fine, he should be removed to the upper deck, where the fresh
air and change will probably soon bring him right again.

Besides the ordinary grooming utensils for stable service, there
should be a plentiful supply of stable brooms, hoes, and shovels
for cleaning out the stalls, and baskets or other light vessels for
removing the manure. The ship must be well lighted and the
guards attentive ; sea-sick men must not be intrusted with this
important duty.

Disinfectants, such as chloride of lime and of zinc, copperas,
powdered gypsum, &c., should be freely used, and upon embark-
ing the artillery commander will see that they are supplied.

The feed-troughs and nostrils of the horses are washed every
morning and evening with diluted vinegar.

Water is allowed at the rate of six gallons a day per horse and
one gallon per man.

During the \oya.ge the artillery commander will make it his
especial study to act in harmony with the master of the vessel.
There must of necessity be divided authority and responsibility.
Order and neatness among the men and cleanliness with the
horses are to be looked after by the commander of the troops.
^In attending to these duties, care will be observed not to inter-

DISEMBARKING. 335

fere needlessly with the duties of the crew, nor with the belong-
ings of the ship.

OflBcers are alwa5'S to be furnished with cabin accommodations
^nd the men with proper messing arrangements. This sliould
be specified in the charter, and should be clearly understood by
all parties previous to setting out on the voyage.

The fitting-up of the vessel is generally done by the Quarter-
master's Department, but the commander of tlie artillery to be
embarked will, as the one most concerned, give his special at-
tention to see that the work is thorough and complete.

Masters and owners of vessels always dislike to have them
bored, spiked, and bolted into in the manner necessary for fit-
ting tliem up for artiller}'^ transports. To remove all causes of
complaints and objections, and of contentions between the
master of the vessel and the oflScer embarking his troops, arising
on this score, the charter party should cleai-ly specify the extent
and nature of the work required to be done.

When an expedition of considei-able size is to start out, a
steamer suitable for the purpose should be converted into a
workshop, containing forges capable of doing heavy work, to-
gether with carpenter and shipwright facilities. She should carry
a plentiful supply of such material as will probably be required.

A steam pile-driver should always form part of the outfit of
an expedition.

5T8. DisembarJdng. Wlien this can be done at a wharf, it
is simply the reverse operation of embarking.

When wharf accommodations are not available, arrangements
will have to be made for transferring the men, horses, and
material from the vessel to the shore.

An army or other considerable body of troops embarked for
^n expedition, to be landed under such circumstances, will be
provided with general means for disembarking, and the artil-
lery, which usually constitutes an important feature of the out-
fit, shares with the rest in these general arrangements; but,
owing to its nature, much of a special character is required for
it, demanding the most careful consideration and attention from
artillery officers.

Such expeditions usually embark at sea-ports where there are
accommodations that make the operation comparatively simple
and easy, and for this reason the many preparations necessary
for landing on an open shore are apt to be overlooked, or to be
inadequately provided for. It becomes the especial province of
the artillery commander to look out for this, and to give his
advice and make liis wants known to the army commander, so
that the latter may cause proper provision to be made.

336 DISEMBARKING.

The following method for the disembarkation of an armj^
corps proved successful during the war of the rebellion, anci
the same, or some modification of it, will apply in every case.

The essential articles for forming a landing-place were, sev-
eral canal-barges ; a number of pontoon-boats, with balks, chess,
oars, anchors, &c., complete; a number of gang-planks; a plen-
tiful supply of lumber, and the necessary amount of ground
tackle, coi'dage, and tools.

The canal-barges were about 14 feet wide and 70 to 80 feet
long, (drawing, wlien loaded, 5 feet of water; when light, 2 feet,)
and of about 80 tons burden.

The gang-planks were from 12 to 30 feet long and 10 feet wide,
and very strong; ropes were attached to their corners, and the
larger ones furnished with rollers.

By la hing two of the canal-barges together, placing the boats
some 12 feet apart, and thi-owing a false or additional deck over
the wliole, a platform was formed about 40 feet wide and 45
feet long, capable of holding all the pieces and caissons of a six-
gun field battery, or from forty to fift}^ horses. This boac or
raft, wiien thus loaded, drew about 4 feet of water.

Several of these rafts were prepared for the purpose of form-
ing a wharf-head^ alongside of wfiich vessels could lie and dis-
charge.

From this wharf -head to the shore a pontoon-bridge was con-
structed. {Fig. 5, Plate 56.)

The wharf-head was formed by bringing up as near the shore
as possible one of the lightest of the double canal-boats just de-
scribed ; this was securely moored in proper position at high
water, when it at once grounded. Outside of and parallel to it,
at a distance of some twenty feet, was placed, and in like man-
ner securely moored, the double canal-boat next heaviest in
draught of water ; the space between the two being bridged by
one of the largest gang-planks.

In the same manner was placed a third double canal-boat,
alongside of which was moored a light draught steamer, which
formed the pier-head to the wharf and secured depth of water
sufficient for the transports to come alongside.

From the double canal-boat first put in position, a roadway
to the shore was made by constructing a pontoon-bridge in the
usual m. inner.

The operation of disembarking consisted in bringing the
transports alongside of tlie wharf-head, placing a gang-plank
from the deck to the gunwale, and another from the gunwale
to the wharf-head. Over these gang-planks the horses were led
and taken ashore. The guns, caissons, and other carriages were

DISEMBARKING. 337

run down the gang-plank and over the bridge by hand. In this
way but two or three hours were consumed in disembarking an
entire battery.

For disembarking artillery by this method, oi* indeed by any
method, smooth or comparatively smooth water is a siJie qua
non. Infantry, and even artillery material, may be landed with
small boats or lighters througli a heavy surf, but a smooth sea is
required for horses.

When it is not considered expedient to construct a wharf-
head and bridge as just described, and the water near shore is
of sufficient depths double canal-boats may be used for rafts to
disembark both horses and material. The rafts must have rail-
ing around them ; this should be strong, the stanchions extend-
ing into the boats and secured throughout with bolts and nuts.
The horses are loaded from the vessel onto the i-aft either by
means of gang-planks or by slinging them. The raft is towed to
the shore by small boats or, better, by a small steam-tug; a
gang-plank is run out and the liorses led ashore. The guns and
caissons are brouglit ashore in the same manner.

When canal-barges are not to be had, small coasting schooners
may, by removing their deck hamper, be used instead. Large
decked-over scows, such as are to be foimd in sea-port towns,
make excellent rafts. When the distance from the vessel to the
shore does not exceed 1000 yards or thereabouts, a warp-line
may be used for bringing back and forth the raft. Every exer-
tion should be made to erect a wharf, rough and temporary
though it be, using for the purpose any kind of boats or scows
tliat can be obtained. It may sometimes be advisable to sacri-
fice a ship for the purpose of forming a wharf-head, by scuttling
and sinking her in such depth of water as to leave her spar deck
three or four feet above high water. With a sandy or muddy
bottom, a ship might be sunk by loading her down until she
rests firmly on the bottom. If the weather is calm she will
sufi'er no great injury, and can be fl.oated off when no longer
required.

The business of constructing rafts and wharfs as described,
belongs, as a general rule, to the engineers; but should the
artillery commander of an expedition anticipate, even in the
remotest degree, a failure to provide the requisite means for
disembarking, it becomes his duty to look after it, and he can-
not be too zealous in doing so. The best plan under such cir-
cumstances is for each transport to carry along with it an outfit
capable of discharging its cargo.

The most useful boat for lightering, that can be carried, is the
wooden pontoon, such as is used for military bridges. It is 31
22

338 DISEMBARKING.

feet long, 5.5 feet wide at top, 4.5 feet wide at bottom, and 2.5
feet deep. Besides the three men required for managing it, it
is capable of carrying 40 infantrymen with their arms and knap-
sacks, and it will very readily carry six horses. It is better,
however, when disembarking artillery, to form rafts by uniting
two boats in the usual manner for a bridge, except that a double
number of balks should be used. The platform may be twice
the width allowed for the roadway of a bridge ; tims formed, it
will be 24 feet long by 20 wide, and capable of carrying two
field-pieces and caissons complete, or from 15 to 20 horses.

The platform must be provided with a secure railing. All of
the parts should be fitted and numbered previous to embarking,
and the men practiced until they become skillful in putting the
raft together. In consequence of the lowness of this platform,
it is impracticable to use gang-planks from the decks of ordinary
vessels, and the horses have therefore to be lowered onto it by
slinging. A vvarp-line to the shore is the best means of taking
it back and forth.

Each transport should carry four f)ontoon -boats and all the
equipment for two rafts. If there is not sufficient room on deck
for the boats, they may be carried stowed flat to the sides of the
ship, bottom outwards, resting on strong solid chocks bolted to
the wales. A strong parbuckle-sling passes around each, with
which it is hoisted into place by the yard and stay purchases,
and secured by lashings ; by the same means it is lowered into
the water.

With several transports, each carrying the above-described out-
fit, it is generally practicable, by combining all, to form a bridge.
Suitable vessels can nearly always be obtained for forming the
wharf-head.

When there are several transports unloading at the same time,
conspicuous and well-understood signal marks must be placed op-
posite each, on the beach, so that it may be known to what points
to direct the boats and rafts without confusion. A strong party
for each should be on shore to secure the rafts upon touching, to
haul up the guns and caissons, and to take care of the horses.

Unless there is some special reason to the contrary, 'horses
will always be landed first. This gives them an opportunity of
resting and recovering from the trip while the material is being
landed.

When pontoon-boats are not available, scows, fishing-smacks,
or other small craft must be collected and used instead.

As a last resort, tlie horses may be swuai ashore, and the mate-
rial landed in the ship's boats, — a very tedious operation. The
horses are lowered over the side by slinging ; a boat must be in

DISEMBARKING. 389

«,ttenflance below to unhook the fall and clear the sling. The sling
ior this purpose must be without breast or breech straps, and the
loops should be closed up with canvas, so that there may be no pos-
sibility of the horse getting his legs entangled in any part of it.
A very slight embarrassment of this kind will cause the horse to
drown. A man in the small boat takes liim by the halter and,
conducting him a short distance, gives him the proper direction
to the shore ; without this precaution, horses sometimes become
bewildered and swim around the vessel until exhausted. Horses
will very readily swim, in smooth water, half a mile. When
the deck of the vessel is low, say not over ten feet, and tliere is
a gangway, the horses may be backed off into the water without
slinging. This method should not, however, be resorted to if it
can possibly avoided; it is liable to strain and injure the animal,
and will ever after make him timid and shy about taking the
water when it is necessary to cross streams on the march.

Siege guns are embarked and disembarked in the same general
manner as light tield-pieces. When gang-planks are used, they
are hauled up or let down by means of tackle. When embarking
fi-om a wharf or raft without gang-planks, the piece is run with
its carriage under the ship's tackle ; the gun is slung and hoisted
aboard and lowered onto the deck or into the hold. In disem-
barking, the carriage is first put upon the wharf or raft under
the ship's tackle, and the piece then lowered onto it.

When it is necessary to land heavy guns by means of lighters,
or from small vessels, the latter may be beached at high tide;
the pieces are raised b}'' blocking and skids until they can be
rolled down two inclined skids from the vessel to the beach,
where they are received upon skids or blocks of sufl3cient size to
prevent them from burying themselves in the sand. At low
tide thej'^ are removed from the beach.

Sieges, and similar operations calling for the use of the
heavier classes of ordnance, are usually of such a protracted
nature as to allow of substantial wharves being constructed, and
cranes, derricks, and shears provided for unloading weighty
inaterial. It is but loss of time and labor, often ending in fail-
ure, to proceed with imperfect arrangements of this kind. It is
the duty of the artillery commander to study the situation and
see that proper facilities are prepared. Such preparations re-
quire considerable time to make, and he should therefore antici-
pate the probable wants of the service in this direction, and not
wait until the vessels carrying the material arrive, or the demand
for it becomes urgent.

5'y9. The disembarkation of an army must be considered
under two heads : 1st. When made without any chance of inter-

840 DISEMBARKING,

ruption fiom an enemy; 2d. When made in presence of an?:
enemj% or where an attack is possible.

So far as artillery is concerned, the first of these conditions
has been discussed in the foregoing; paragraphs.

With regard to the latter, all questions, political^ strategical,
or otherwise, entering into the object of the expedition, having
been settled by the proper authorities, and the array for carrying
it out having been organized, embarked, and the transports
arrived within the general limits of the field of operations, the
first thing to be decided upon is the exact place or places where
the various parts of the command are to be put ashore. Many
local circumstances will influence tliis decision ; among the most
important of which will be to secure good anchorage and depth
of water near the shore, a general configuration of ground in
front which will admit of its being swept by the fire of the fleet,
a firm and commodious beach, and freedom from prevailing winds
or currents w^hich may interrupt the disembarkation.

Tlie fire of the fleet must clear the country in front. The in-
fantry is first landed and pushed out sufliicientlN^ far to keep the
enemy beyond cannon range of the landing-place; here it in-
trenclies itself, forming a tete-de-pont around the landing.

Meanwhile preparations will be made for laiiding tlie batteries.
All the boat-rafts will be put together, and if a wharf-head and
floating bridge is to be constructed it will be commenced at once.
Steam-tugs must be in attendance for towing the rafts, cari-ying
orders, and other miscellaneous duties. The artillery commander
designates tlie order in whicli the batteries are to disembark, and
will see that the transports take proper positions for effecting
this without causino: intervals of unnecessary delay.

If the attacks of the enemy are formidable and persistent, de-
manding tlie immediate service of artiller3% the guns of several
or of all the batteries may be landed without their horses, and
taken to positions on the line by hand, or by the horses of one
of the batteries landed for that special purpose. The cannon-
eers will accompany their guns.

If the resistance of the enemy cannot be overcome at this
period, the expedition is a failure, and the army will have to be
reembarked. To accomplish this a strong defensive work should
be constructed, and well armed with "such artillery as may be
required.

The remainder of the disembarked artillery is next put aboard
the transports ; afterwards the infantry and, if possible, all the
artillery. The fire of the fleet should cover the reembarkation,_
and keep the enemy at such distance that he will not be able-
to use his artillery upon the transports or the place of landing.

WEIGHT OF TROOPS ON BRIDGES. 341

When the expeditou is lar^^e and the number of transports,
-store-ships, &c., great, the worst of confusion will arise unless
-some s\^stem of marking and distinguishing them is adopted.
The best method is for each one to carry, instead of her own
burgee, the distinguishing flag of the corps to which the troops
•on board belong. This will show at a glance whether they are
infantry, artillery, or cavalry, and to what corps, division, and
brigade they belong. Besides this, each vessel should have a
number painted, as large as possible, on each quarter. When
embarking, a memorandum is kept and furnished to command-
ing and staff officers sho-wing what troops are on board of each
transport.

The chief-of-tran sports, who should be a quartermaster select-
ed for his practical capacity in such business, designates the
anchorage-ground for each part of the command, and sees that
they move up at the proper time and in the required order to
the place of debarkation. It is with him that the artillery com-
mander communicates in reference to the movements of the
artillery transports.

When boats are to be used either for lightering, rafting, or
bridging, it is important to know their sustaining capacity.
With small craft, this is best ascertained by calculating the area
of several cross-sections, from which a close approximation of
the cubic contents in feet is obtained ; this, multiplied by 62.5,
gives the weight in pounds of the displaced water.

If the boat can be put in the water, the operation is simplified
and made more accurate by calculating the volume of that part
between the water-line when the boat is empty and the line to
which it can be safely sunk when loaded.

When boats of different sizes are to be used in a bridge, the
largest should be where the current is swiftest, so as to have
there the greatest space possible between the boats. Anchors
for ordinary ships' boats should weigh from 50 to 100 pounds;
for regulation pontoons, they should weigh 150 or 200 pounds. -

The length of the cable should always be at least ten times
the depth of water in which the boat is anchored. The anchor
should be taken out in a boat and dropped over at the required
spot.

Weight brought on a bridge by the passage of troops. Infantry
marching by fours cause a load of 225 pounds for each lineal foot
of roadway. When crowded bj^ a check in front, the load is in-
-creased to about 550 pounds.

Cavalry in column of twos, each man and horse weighing
:about 1400 pounds, and occupying 12 feet of bridge, cause a

342 WEIGHT OF TROOPS ON BRIDGES.

load of about 230 pounds per lineal foot of roadway. When^
crowded by a cheek, this is increased to about 350 pounds.

When artillery carriages cross a bridge, the weight is nat
equally distributed. With the carriages of light field batteries^
the weight is about 400 pounds per lineal foot. The 4.5-inch
siege gun and carriage, equipped for traveling, weighs 7400
pounds, and has a distance of S feet between bearing parts of
hind and fore wheels, giving 925 pounds per lineal foot of
bridge. The 100-pounder Parrott, carried on a mortar- wagon,
gives 1737 pounds per lineal feet.

A 10-inch siege mortar mounted on its carriage and carried
on a mortar-wagon causes a load of 800 pounds per lineal foot.

To each running foot of bridge musi be added about 100
pounds as weight of superstructure.

When heavy carriages are to be crossed, a substantial tram-
way made of long way-planks should be laid, and the carriages
moved on it by iiand.

In constructing a bridge with ordinary boats, great care must
be observed not to allow the balks to rest on the gunwales;
they must be supported from the middle of the boat.

Ice^ when from 3 to 4 inches thick, will sustain infantry march-
ing in single file. With a thickness of 4.5 inches, cavalry and
light guns can pass over ; with 6 inches, heavy field-pieces ; 8
inches will support siege guns, but, for greater security, the
wheels should be locked and secured upon way-planks which
sUde upon the ice, the pieces being moved by hand.

In yery cold weather the thickness of the ice may be increased
by covering it with a layer of straw or brush and throwing
water over it, or two rows of logs may be laid at a distance
apart equal to the width of the roadway; a layer of earth is
spread between them and water thrown on and allowed to
freeze. This operation is repeated until a solid roadway is
formed.

Ice, when very thick, and therefore difficult to remove, may
be broken up by charges of powder in water-tight cans or bags,
fixed underneath or placed in lioles bored in it. Charges of
from five to ten pounds of powder placed in ice two feet thick
will break up an area twenty feet in diameter. Eight ounces^
of dynamite will produce a like result.

M ^ixth.

HARBOR DEFENSES.

5 SO. The entrance to a harbor may be considered, and is in
fact, a defile, the defense of which follows the rules applicable to
defiles generally.

The means usually employed to prevent the passage of hostile
ships are divided into three classes, viz.: 1st. Forts and land bat-
teries; 2d. Submarine mines ; 3d. Floating defenses.

The latter class, which includes monitors and offensive torpe-
does, is under the exclusive control of the Navy.

Submarine mines will be considered further on.

The first class is the one now to be considered, and this con-
sideration of it is intended to refer especially to the use of guns
on land against armored ships.

581. Position of batteries. Whenever practicable, batteries
should be well strung out ni groups, the strength of which should
increase as they are approached from the outside. This arrange-
ment has a peculiarly discouraging effect on an enem3\ The
first batteries will at least damage him and cause confusion, thus
weakening his attack on the stronger; and when his discom-
fiture finally takes place, tiie batteries already passed will pre-
vent his return and insure his total destruction. The islands,
headlands, and narrows usually found at the entrances of har-
bors will generally, to a greater or less degree, enable this
arrangement to be carried out.

Experience teaches that where the channel is unobstructed
steam vessels can run past shore batteries, however well the
latter may be served. But, on the other hand, where obstruc-
tions to their rapid transit exist, they have not the endurance
and aggressive power to effect much damage to land defenses.
In the smoke of battle and tide-way of the channel they become
unmanageable, get aground, or collide with each other. The
most effective class of channel obstructions are submarine mines ;
tlie position, planting, and working of which are explained under *
the head of Submarine Mines.

It is a well-settled fact that a hostile fleet, by concentrating
its fire on an open work, may temporarily silence its guns. For

(343)

344 HARBOR DEFENSES.

this reason the accumulation of guns in works exposed to such
concentration should be avoided by distributing them in bat-
teries, each containing but a few pieces, due regard being had to
their security from assault and capture by any force that ma}^ be
landed for that purpose. The best arrangement is to place them
hi detached batteries of, sa}'', two, four, or six pieces each, well
secured from the enemy's fire by earthen epaulments and trav-
erses. This arrangement makes it difficult for the enemy to
discover the exact position of the guns, and every peculiarity of
ground should be taken advantage of to increase this difficulty.
Whatever tends to make batteries difficult to see, and conse-
quently to liit, is as much a protection as that which makes them
capable of resisting a hit when made. Guns tinis dispersed have
greater freedom of lateral range of fire, and do not interfere so
much with each other by reason of their smoke as when concen-
trated, — a matter of no little importance with heavy artiller3%
which emits such volumes as, in certain conditions of the atmos-
phere, to greatly interfere with accuracy of aim.

"When batteries are extended, a larger area will be swept by
their converging fire than when the guns are assembled en
masse. An additional advantage conferred by distributing the
guns is, that while obtaining concentrated fire on an important
or decisive point, a similar fire cannot be directed on tlie guns
in return.

This arrangement would, furthermore, tend to neutralize the
power which a fleet might have of forming on a wide arc of a
circle, and moving slowly under steam, so as to render the task
of hitting the individual ships more difficult, throw a converg-
ing fire upon the works on shore.

In the design of such works, it is of primary importance that
conjoint action of the various parts should be maintained ; and
to prevent the individual batteries from being captured by coup
de main^ small inclosed earth-works, heavily stockaded lo resist
escalade, and each armed with field, siege, and machine guns,
and siege mortars, should be constructed so as to have complete
command over all land approaches.

These earth-works should contain the infantry supports. In
this manner most of the existing sea-coast forts may be utilized,
making of them protecting works for exterior earthen batteries.

The defenses of a harbor should, in every instance, be capable
of repulsing all attacks that the enemy is likely to make on them.
The power and persistencj^ of these attacks will depend upon
the importance to him of the object to be gained. Large and
opulent cities, naval establishments, and ship-yards are among
the first prizes sought for. The aggi'essive power of modern

HARBOR DEFENSES. 345

navies is sneh as to make it quite impracticable to effectually
.guard every harbor on an extended coast. It is, therefore, bet-
ter to entirely abandon those that are unimportant to the enemy,
for whatever use he may make of them, than by feebly guarding
them to invite his attacks and thus afford him the moral effect
and consolation of cheap victories, and to the country the morti-
fication and disadvantage of defeat and loss of prestige.

58^2. Number of troops required for harbor defense. The
number of troops required for tlie manning of a work erected for
harbor defense depends chiefly upon the nature and amount of
armament contained therein. Works of this nature are armed
principally with pieces of the heaviest calibre, but, for reasons
hereafter given, all kinds should generally find place. The
amount of armament depends upon the extent of the work and
the part it is to play in the scheme of defense.

Three full detachments are necessary for each piece. Know-
ing the number of pieces in the work and the number of men
required for the service of each, the entire strength required is
obtained. Three relief detachments are necessarj'', for the rea-
sons that the labor of manipulating and serving heavy artillery
is very great, and when a rapid and continuous fire is to be main-
tained, strong fatigue parties are required in carrying ammuni-
tion from the service magazines to the pieces; damages done
to the works during the- day have to be repaired at night, and
casualties occurring, whether from the fire of the enemy or from
accidents, must be provided against, so that at any moment an
efficient detachment may be at every piece.

As a general rule, batteries should not be incumbered by an
attempt to include musketry defense within their limits. The
place for this arm is on the flanks of the batteries, and in
strength sufficient to prevent an enterprising enemy from land-
ing and assaulting the work, and from approaching to keep down
the fire of the guns while his vessels run by it.

However well it may have answered with the old style of
artillery to have the troops serving batteries charged, in addi-
tion, with musketry duty, it certainly is not advisable with the
artillery of the present. Steam-propelled iron-clads, carrying
guns of enormous power, range, and accuracy, demand the
undivided attention in action of those using the only weapons
effective against such adversaries.

The labor of handling and caring for the kind of artillerj'',
ammunition, material, and machines now used, together with
the construction, preservation, and repair of batteries, will re-
quire all the time and the whole attention of the troops serving

846 HARBOR DEFENSES.

guns in war. The care of infantry arms and equipments, together
with the drills and parades incident thereto, have a tendency to
draw away the attention of officers and men and prevent thetn
from keeping in an efficient state of readiness, the only safe-
guard that stands between an enemy and the object for which
he may desire to enter a harbor.

When a work containing batteries for harbor defense is inclos-^
ed, the amount of musketry necessary for it is determined by
allowing two muskets for each lineal yard of parapet not occu-
pied by the batteries.

583. Artillery being the main feature in such works, the
command should be vested in an artillery officer. Where there
are several forts and batteries guarding the entrance to a harbor
or constituting a line of works, they should, for the purpose of
administration and command, be united in groups, eacli group
being under an artillery officer of appropriate rank, and the
whole combined and commanded b}'^ the senior officer of artil-
lery present. B}'^ this means thorough cooperation is secured
throughout the entire system.

584. In order to avoid the weakening effect of divided re-
sponsibility, submarine mines, when employed in conjunction
with a fort for the defense of a channel, should be under the
control of the commandant of the fort, who should select from
his command the proper number of officers and men to be in-
structed in the method of working this branch of defense.

No more troops than are necessary to carry out the foregoing
rules should be crowded into a work; otherwise, unnecessary^
casualties from the fire of the enemy will be added, stores con-
sumed, and unhealthiness engendered ; and, besides, in time of
war, when troops are not required at one place, their servicer
are generally needed elsewhere.

The high standard of practical gunnery required of artillery
troops demands a proportional degree of intelligence and capacity"
for instruction in the individual soldier. Artillerymen should
be selected with a special view to this, artisans and mechanics
forming a large proportion. Steam-power and the application
of labor and time saving machinery should, wherever practicable,
be introduced to assist in making the defensive ability of forti-
fied places more perfect.

In conducting the defense of a work, too much importance
should not be attached to the battering of it by an enemy ; for
experience teaches that a place is formidable, if resolutelj'' de-
fended, long after it has lost all semblance of the form and sym-
metry possessed by it when it came from the hands of the con-
structing engineer.

ARTILLERY AGAINST ARMOR. 347

585. Elevation of batteries. Against iinaimored vessels^
ricochet firing, owing to the greater ciiances of hitting the
object, is the most effective ; and in order to secure flattened;
ricochets, so that the shot, in bounding, may not pass over the
hostile vessel, batteries should be placed as low as possible; but
since the introduction of iron-clads, special importance is; given
to the kind of fire most effective against them.

Ricochet firing with elongated projectiles is exceedingly un-
certain, and the loss of power from ricochet with spherical shot
is so great as to make this kind of firing of little or no avail
against armored vessels as now constructed. Direct hits must
be resorted to, and these, too, from rifled guns of heavy calibres.
Direct hits can be made as well from a moderate elevation as
from near the level of the water; and, besides, the chances of
striking the deck — always the most vulnerable part of an iron-
clad — are thus considerably increased. An elevation of fifty
feet above the water will deprive the enemy of the advantage of
ricochet firing, which, although not effective against iron-clad
vessels, is nevertheless very damaging to defensive works on land.
The interior of the work is obviously more sheltered from the
missiles of the enemy when it is above his level than when low
down ; his projectiles then either lodge in the epaulment or pas»
over the work far to the rear, with greatly diminished chance of
hitting the guns, either in barbette or in embrasure. (See table^
par. 210.)

586. Artillery against armor. Rifled guns of heavy calibres
are, for reasons hereafter given, the only kind capable of inflict-
ing much damage upon iron-clad ships. This damage is effected
by shot penetrating through the iron shield and reaching the
active enemy within — the men, guns, and the machinery.

The first thing, therefore, to be considered in this connection,
is the power of rifled guns to penetrate armor. A vast amount
of experimental firing, by various nations, has been done to as-
certain this and to arrive at the laws governing the effect pro-
duced by the impact of cannon shot against metal plates. These
laws have been formulated, and the results obtained therefrom
agree, with remarkable precision, with those obtained by obser-
vation from actual practice.

These experiments have been more exhaustive abroad than in
the United States, and as the English system of rifled ordnance
includes all the calibres of the United States system, and is like-
wise muzzle-loading, the diagram on Plate 76 is inserted to show
the penetrating power of rifles.

The following table, from calculation, gives the penetrating^
power of projectiles fired from smooth-bore guns against backed.

ARTILLERY AGAINST ARMOR.

-armor, for the velocity, charge, and weight of projectiles set
opposite :

b
6

Foot ton for
1" of circum-
FERENCE.

In.

20
15
10

Lbs.

1070
450

127

Lbs.

200

100

Ft.

1400
1487
1600

In.

10.15
7.30

234

143

Prismatic powder.
Prismatic powder.
Cannon powder.

The penetration above given is for the velocity at the muzzle;
but as the velocity for smootij-bores rapidly diminishes, the pen-
etration likewise diminishes, and to such a degree as to render
this class of guns almost powerless to perforate modern armor
at the distances usually required of guns on shore.

It will be observed from the foregoing diagram that iron-
clads are classified with reference to their armor — chiefly as to
the thickness of the plating. The thickness and arrangement
of the wood backing has more reference to the strength of the
vessel to resist racking than to power of resisting penetration by
shot ; for the best oak timber possesses only about one-sixteenth
of the resisting power of wrought-iron.

The foregoing penetrations are for impacts normal to the sur-
iace of the plates. When the impact is not normal, the pene-
trating effect is diminished increasingly with the obliquity of the
direction of the shot. Flat-headed projectiles encastrent and
penetrate at as low an angle as 45 degrees, but ogival-headed
or spherical projectiles glance from the surface when the angle
reaches about 20 degrees from the normal at the point of impact.

The full penetrating power of rifle projectiles requires that the
armor should be struck perpendicularly to its surface. This can
never occur in action except by rare accident. The trajectory
of the shot forms one angle; the curvature of the ship's side
forms another; the inclination of the ship's course forms a third,
all of which are constantly varying by reason of the motion of
the vessel.

SST. Besides monitors, which of themselves forma distinct
class of iron-clads, bearing little or no resemblance to any other,
there are many varieties of armored vessels. The following,
however, is a fair type of the class that, in the event of war,

ARTILLERY AGAINST ARMOR. 349'

would probably prove most troublesome to our harbor defenses :
Length of hull, 300 feet; breadth, 56 feet; height of main deck
above water, 6.5 feet. The enth*e hull is protected by armor
from 6.5 feet below the water-line to tlie main deck, thus cover-
ing not only the middle part of the sliip where the machinery
and turrets are placed, but also the quarters for oflScers and men.
The thickness of the armor opposite the turrets is 8 inches ; that
on the remainder of the midships is 7 inches, which is slightly
reduced towards the ends of the vessel. The plates rest on a
backing of hard wood 12 inches thick, through whicii they are
bolted to the iron skin, 1.5 Inches thick, tlie whole being sup-
ported by the massive fi-ame-work of the ship, 10 inches deep.

Tlie upper deck, which, as before stated, is at a level witli the
top of the armor on tlie sides, is covered with iron plating 4
inches thick for the length of the turret spaces, and with about
half the latter thickness over the remainder. The plating is laid
on a deck of hard wood 6 inches thick, the whole being supported
by iron beams 14 inches deep. The draught of such a vessel is
about 26 feet.

The turrets, two in number, project through circular openings
in the upper deck, that part above the deck being covered with
armor plates 10 inches thick about tlie ports and for one-tliird
of the circumference, with 9 inches for the remainder. The part
below the deck and all tlie gearing is protected b}'^ the 8-inch
armor of the sides of the hull. The height of the guns in the
turrets is 10 feet above the water-line.

A vessel of this description carries an armament, usually, of
six guns, four of whicli are in the turrets and are 12-inch rifles;
the other two are 100-pounder rifles, and are carried on the up-
per deck, fore and aft, as chase guns. The turrets are about
27 feet in diameter.

The hull of such a vessel, wdien broadside-on, presents, exclu-
sive of the turrets, a vertical target, above water, 300 feet long
and 6.5 feet high ; any part of which, at a range of 2000 yards, if
fairly struck, is vulnerable to the racking etlect of shot from the
15-inch smooth-bore, or to penetration from rifles of not less
than 10 inches calibre ; and it would not require man)' such hits
to disable her or cause her to withdraw from action.

When bow-on, the liull presents a vertical target, above water,
56 feet long by 6.5 feet high, alike vulnerable to the same
shots. The difficulty of striking normally the curved surface
thus presented would be partlj'' compensated for by the large
liorizontal target presented by the deck of the vessel when in
tliis position. This target would be 360 feet long in the direc-
tion of the shots, with an average width of about 45 feet. The

^50 ARTILLERY AGAINST ARMOR.

angle of fall cine to shot at the distance usually employed against
iron-clads would give them a very considerable striking power,
enabling tliem, most probably, either to penetrate or seriously
rack tlie deck. It is thus seen that in whatever position the
vessel may be with reference to tlie batteries on shore, slie will
present no inconsiderable mark to fire at.

Rifle projectiles are not liable to ricochet upon water, and will,
especially tliose that are pointed, pass through it to a distance
of fifteen to twenty feet with but small diminution of force.
Against this class of projectiles, the target presented by the ves-
sel is increased by at least three feet below the water-line. At
ranges not exceeding 2000 yards, ricochet from the 15-inch gun
is formidable, and with anything like good practice, shots strik-
ing short would stand a good chance of hitting the vessel upon
the first rebound.

Line-of-battle cruisers of the broadside class present greater
dimensions, as a target, than the turreted vessels of the type just
given. At the same time, they carry no greater thickness of
armor, and are consequently more vulnerable. The best protec-
tion for harbors upon the American side of the Atlantic against
100-ton guns carried in vessels protected by two feet or more of
armor, will be the clumsiness and unseaworthiness of such ves-
sels themselves. As armor increases in thickness, the belt of it
that can be carried diminishes in width; and thus what is pro-
tection in one sense may be regarded as weakness in another.

It is important with artillerists to know the character of ves-
sels opposed to them. To enable them to ascertain this, it is
the duty of the proper department of the government, in the
event of hostilities with a maritime power, to supply diagrams
showing the general appearance of each of the enemy's iron-
clads, or at least of each class, and by a brief description to point
out the most vulnerable parts. This would enable the artillerist
to determine not onlj'- the proper guns and projectiles to be used,
but where his shots may be aimed to the best advantage.

588. A vessel moving at the rate of 10 miles an hour passes
over a distance of nearly 15 feet per second. The time of flight
of a rifle projectile for a range of 3000 yards is within a fraction
of 9 seconds. Allowing one second to elapse from the time the
gun is aimed to the moment of being fired, the time required
for the projectile to reach its object at the above range will be
10 seconds; in which time the vessel will have passed over a
space of 150 feet, or half the length of the average iron-clad. If
she is at the above distance, and moving at that rate of speed
-directly across the line of fire, it will be necessary, in order to
strike her amidship, to aim directly at her bow.

VITAL POINTS OF IRON-CLADS. 351

If she is moving at the rate of 15 miles an hour, she will in
the same time pass over a distance of 220 feet; and to strilie
her amidship, it will be necessary to aim 70 feet, or about one-
fourth of her lenijth, in front of her bow.

The time of flight of a projectile from the 15-inch smooth-bore
for tliis distance is about one second greater than the rifle shot.
It will thus be seen that tlie problem of aiming becomes greatly
complicated by the motion of the vessel. Her distance; the
direction in which she is moving, whether perpendicular or ob-
lique to the line of fire; her rate of speed ; her size, and the time
of fliglit of the projectile fired, are all elements of the problem,
to be determined on the instant, by the judgment of the artil-
lerist. Both officers and men should be thoroughly instructed
^nd practiced in these matters for the particular guns they are
serving.

Almost every localitj' will afford stations for obtaining cross
bearings, by means of which, with telegraphic and other arrange-
ments, the exact position of a vessel at any moment may be
known at the piece. The method of doing this is explained
under the head of Submarine Mines.

By this means guns and mortars, tmined upon any particular
point of a vessel's course in a channel, may be fired at the pre-
cise moment when the vessel is at the point.

589. Vital points of iron-dads. The most vital part of an
iron-clad, or, indeed, of any ship as against shot, is the water-
line, where, if an irreparable leak can be effected, she must
inevitably go to the bottom. Shot holes of small calibre may,
especially in wooden vessels, be plugged; but projectiles capa-
ble of piercing modern armor make breaches impossible to stop
in this manner. The projectile alwa3^s makes a hole larger than
its own diameter, and the plating at the exit of the shot is
usually bulged, cracked, and carried away to a still greater ex-
tent. The wood backing is torn, splintered, and racked for sev-
eral feet around, in such a manner as to make immediate repair
impossible. An iron-clad penetrated in this way, by even a
single shot, is at once put hors de combat. Her well-known
want of buoyancy, although provided, as most are, with water-
tight compartments, will cause the most resolute crew to desist
the fight and look to their own safety.

The machinery of sea-going iron-clads is always below the
water-line, and is generally protected b5^an additional thickness
of armor. It is consequently difficult to reach, but should a
shot enter there, especially into a boiler, the most serious calam-
ity to the vessel must follow. It not only destroys the locomo-
tive power of . the vessel, leaving her without the means of

352 PHENOMENA OF IMPACT.

manoeuverint^ or possibility of escape from stranding, but it is
lilioly to cause great destruction of life. The position of the
maclVmery and boilers of a steamer is prettj'^ well indicated by
that of the smoke-stack.

When the vessel is broadside-to, fire should be dii-ected so as
to strike her at or just below the water-line, opposite the ma-
chinery.

Experience teaches that tiie most vulnerable part of a turret
is its lower circumference, which, when once jammed, totally
disables it for the fight. If, from weight of armor, tiie vessel is
known to be invulnerable to the guns employed against her,
their fire should be directed with a view to jamming her turrets.

The ports of a turret are generally each 2 feet 2 inches wide
by 3 feet 7 inches high, thus forming no inconsiderable tai-get,
through which a projectile entering would destroy, at one blow,
half of her armament without possibility of repair. The ports
of broadside iron-clads are generally about two inches in both
directions greater than those of turrets, and in number average
ten for each side. It will therefrom be seen that a considerable
area of the ship's side is thus vulnerable.

The accuracy of fire at objects on water is generally superior
to that at objects as they usually occur on land ; this, for the
reason that the distance of the object, though it may be moving^
is more readily determined by its relative position to known
objects, the position of which are well understood beforehand.
The effect of the shot can be more easily observed on water than
on land. The size of the object, if a vessel, is large, and its ap-
pearance generally well defined.

590. Phenomena of impact. When a heavy beam of wrought-
iron — one, say, twelve or fourteen inches square — is struck by a
heavy shot at high velocit}', the beam snaps short ofl", as though
it were cast-iron. The same shot, striking a wrought-iron plate
backed in the usual manner of armor, penetrates or perforates
it in a manner similar to the action of a hand-punch on a sheet
of iron laid on a block of wood. The eff"ect is entirely local ; the
hole is made without bending or twisting the plate in one case,
or the sheet in the other.^ The same projectile, propelled with
a low velocity, will bend the beam and produce the ordinary
fracture of wrought-iron, and in case of the plate, the latter will
be distorted, strained, and loosened from its fastenings.

A simple way of explaining these phenomena is' as follows :
In the case of the high velocity the efi'ect is wholly local., because
the surrounding material has not^meto propagate the vibration
of impact throughout the mass. In other words, the cohesion
of the material is not sufficient, in the time allowed, to overcome

RACKING — PUNCHING. 353

the inertia of the surrounclhig mass. The distribution of the
eftect in the other case is due to the low velocity, wherein a
certain length of time is consumed in accomplishing the blow.
During this interval, all surrounding particles of iron have time
to sustain the point struck; the force of the blow is thus spread
over a large surface and the cohesion of the particles is undis-
turbed, since each particle is enabled to contribute the force of
its attraction towards uniting the whole. These two distinct
effects are called, respectively, punching and racking.

The work done by a shot is represented by its weight multi-
plied by the square of its velocity at th(? moment of impact;
from which it will be seen that a small projectile moving with
great velocity is capable of doing the same amount of work as a
large projectile with low velocity. The character of the work
is, however, as above explained, entirely different. In case of
a given projectile, whatever power is employed in racking the
side of the vessel does nothing towards penetration, and vice
versa.

Racking. The theory in favor of the racking system is, that
heavy projectiles may be fired with low velocities without strain-
ing the gun; that blows given in this way waste no power in
punching mere holes, but that the entire work will be expended
in straining, loosening, and dislocating the armor and breaking
its fastenings, tearing it off and exposing unprotected spots eas-
ily vulnerable to shells, at the same time racking and breaking
the ribs and sides of the vessel to such extent as to render her
unseaworthy. For producing these effects the 15-inch gun,
throwing solid cast-iron balls, is quite as formidable as the pow-
erful rifle expending costly bolts ; but the accuracy of fii-e from
ihe rifle is so greatly superior to that from the smooth-bore, as to
leave a large margin in its favor. Spherical shot, and slow shot
of any form, will do very little execution under water. The
.*,oncussion from racking blovvsj although it may not seriously
Injin-e the vessel, stuns and temporarily paralyzes many of the
2rew, and, spreading terror to all, greatly interferes with the
Bfficient working of the ship and of her armament.

Punching. The theoiy in favor of punching is, that the vital
parts of the vessel and the active enemy within — the men, guns,
and machinery — are reached at once. A projectile piercing the
armor of a vessel carries with it portions of the broken plate,
which, together with bolts, nuts, and fragments of wood from
the backing, form a species of langrage, the effect of which is not
less to be feared on a crowded deck, or in a turret, than tlie
explosion of the most formidable shell. But to produce this
result the projectile must penetrate entirely through. A pro-
jectile moving with a punching velocity has only local effect,
23

354 ARMOR-PUNCHING PROJECTILES.

penetrating' without racking the armor. If it goes but partly-
through, it does no damage either to the ship or to the enemy
within. Therefore, whether from the greatness of range, the
thickness of the armor, or want of power in the gun, entire per-
foration cannot be effected, it is only a waste of ammunition to
use it in simply indenting armor.

Although a spherical projectile may have, upon starting, great-
er velocity than a rifle projectile of equal calibre, and conse-
quently may have greater punching power stored up in it at this
part of its flight, nevertheless, owing to its greater cross-sectional
area in proportion to its weight, it will lose its velocity more
rapidly, and the rifle projectile will soon overtake it in its flight
and go far beyond it in range.

At the distances that iron-clads usually engage land batteries,
smooth-bore projectiles would possess no punching power ;
therefore for this kind of work rifles are the only suitable arma-
ment for such batteries. They should be powerful enough to
do the work effc^ctually.

When lieavy enough for this, all additional weight is rather a
detriment than an advantage, from the fact that light guns are
less cumbersome, can be fired mores rapidly, are more easily re-
placed when disabled, and less costly in ammunition. They
likewise stand greater relative charges and yield higher veloci-
ties with safety.

The 8- inch rifle, carrying a projectile 185 pounds in weight,
fired with a charge of 35 pounds hexagonal powder, is the mini-
mum calibre that can be successfully used against the present •
style of sea-going iron-clads.

591. Armor-punching projectiles. Spherical solid shot of
cast-iron, as usually furnished, almost invariably break into
many fragments upon striking armor plates. When made with
particular care as to quality of metal and mode of casting, they
will penetrate, provided the velocity is not too much reduced by
range, but in doing so have a tendency to break after entering
the armor, — a circumstance, however, rather in their favor when
they pass entirely through, as they then scatter their fragments
in the interior of the ship. Spherical shells of cast-iron have
not strength to penetrate unimpaired armor, and are useful
against iron-clads only when they chance to strike a weakened
part of the vessel.' They nevertheless have other uses; their
large fragments may enter the ports and do the work of solid
projectiles within ; an unremitting fire with them will blind the
enemy by their explosion and bewilder and distract him to such
an extent as to render his fire scattering and uncertain. The
best material for rifle projectiles for punching purposes is Bes-
semer steel, but as it is too expensive for ordinary service, chill-

STRENGTH AND COMPOSITION OF BATTERIES. 355

«d cast-iron is used. Tlie form of head best suited for the per-
foration of plates, whether direct or oblique, is the ogival or
pointed arch. The flat-headed projectile possesses some advan-
tage over the ogival in taking hold of the plate at a greater angle
of obliquity, but this advantage is counterbalanced by less range
and accuracy of flight. The effect of striking a plate obliquely
is diminished, as regards power of perforation, in tlie proportion
of the sine of the angle of incidence to unity. Elongated shells
oi good metal and thickness have a power of penetration but
little inferior to corresponding solid projectiles.

The heat generated by impact against armor will usually ignite
the charge, and the bursting takes place about the time the shell
reaches the backing of the armor. The head and walls of the
shell require to have sufficient thickness to resist crushing by
the force of the blow.

592. Strength and composition of batteries. In determining
the armament necessarj'' to protect a harbor from an enemy's
fleet, it may be laid down tliat no iron-clad carrying a certain
number of guns can successfully attack a battery on shore prop-
erly situated and armed with a like number of guns of calibre
equal to the task of racking or punching her armor. But as
vessels are capable of moving, and can pass by and out of range
of batteries on shore in a given period of time, the chance of
their being crippled or disabled will be in direct proportion to
the number of guns employed against them ; hence this number
should be as large as circumstances will admit.

Assuming 4000 yards as the maximum effective range against
a vessel, 8000 yards would be the distance she would have to
pass over in running b}'' and beyond the range of a battery. At
a rate of speed of 15 miles an hour, she would accomplish this
in a little less than 18 minutes; at 10 miles, in a little over 27
minutes. Supposing everything in the battery to be in the most
complete order and state of readiness, not more than three shots
from the 15-inch smooth-bore or 12-inch rifle could be flred in
the flrst interval, and not over flve in the second. Twipe this
number might, however, be fired from pieces of less calibre.
The movement of the vessel would greatly diminish the chances
of 1 lifting her, and, besides, it is by no means every hit that
seriously injures an iron-clad. This suggests that the number
of guns should be as great as possible.

The pieces in each battery should, as a rule, be of the same
calibre and kind; but the batteries themselves should be mixed
as to armament. The smaller calibres are more easily worked,
and are capable of rapid fire. Tliis would be effective against
wooden vessels assisting in the passage or attack. When a ves-
sel is stopped by an obstacle in the channel, fire should be con-

356 MORTARS AGAINST IRON-CLADS.

centrated upon it, for the reason that in this position it is most,
liable to be disabled, and, being disabled, will embarrass the-
remainder of the fleet and tend to frustrate the plans of the
enemy.

To guard against ships taking advantage of night to run by a
work, the gnus should be trained upon the channel-way, prefer-
ably that portion exposed to enfilade fire, and the traverse circle
so marked that the pieces can be readily aimed after each dis-
charge. The marking should be done in such a manner as to be
readily used in the dark. This may be eff'ected by placing a
straight-edge against one side of the fork of a traverse-wheel,
and making a nick in the traverse circle with a cold-chisel; the
straight-edge placed in the same position will show when the
gun has the same direction. The chances of hitting a vessel be-
ing greatly diminished by darkness, it is most advantageous
und^r sucii circumstances to use shells. This kind of firing car-
ries with it at night a peculiar moral effect which may greatly
interfere with the navigation of the vessel. When the vessel
arrives within easy range, round shot, fired in ricochet, will be
found effective.

593. Mortars against iron-dads. Vertical fire is effective
when it is desirable to prevent an enemy from occupying certain
anchorage. The deck of a ship is as completely vulnerable to
falling shells as the bottom is to submarine mines and torpedoes.
Judiciously-placed batteries, if armed with a sufficient number
of mortars throwing showers of shells, would make it perilous
for an enemy to remain within their reach. But mortar firing
from smooth-bore mortars is at best somewhat wild, and depends
on quantity for its effectiveness. It is, however, safe to sa}' that
no fleet nor vessel can remain under well-directed fire from
heavy mortars. A battery of one hundred heavy mortars will
keep at bay all the iron-clads that can manoeuvre or anchor
within their range. T'he moral effect of mortar firing is appall-
ing, and increases vastly with the numbers of mortars used.

The armor that a vessel is capable of carrying on her deck, in
addition to that upon other parts, is not sufficient to resist the
crushing power of a 13-inch shell with maximum velocity — 419
feet per second. The 10-inch mortar is serviceable only against
unarmored decks, or those very slightly protected. In firing at
iron-clads the shells should not burst before striking ; in fact, it
is best to fill the shells with sand instead of powder. Solid shot
would be preferable to either.

Mortars mounted on the centre-pintle traversing chassis, and
pi-ovided with the pointing apparatus described on page 64, are
c i|):ible of following the course of a moving vessel with the same-
facility as a gun.

^art ^mntU.

FIELD INTRENCHMENTS.

594. In active service it is frequently necessary for artillery
troops to construct works for the emplacement of their weapons,
^uch troops should therefore be instructed in the art of select-
ing sites, laying out and erecting batteries, magazines, bomb-
proofs, traverses, and other works immediately connected with
the efficient service of their special arm.

When positions are to be taken up and lines of intrenchments
or detaclied works are to be constructed, it is the duty of artil-
l(uy officers, in cooperation with those of engineers, to select
positions for batteries and determine the kind and amount of
armament therefor. It is therefore necessary that they should
be thoroughly conversant with the principles of military engi-
neering, especially those oi field intrenchments.

The object of every fortihcation is to shelter the troops occu-
pying it from the view and fire of an assailant, and at the same
time to afford them a commanding view and sweeping fire over
their enemy.

Earth is the principal material employed on land for resisting
the fire of artillery. Wood, iron, and masonry are used in con-
junction with it, principally for sustaining purposes.

As a material for fortifications, earth possesses advantages over
all other, in being found ready at hand in almost all localities
where wanted for such purposes, in being easily handled, and in
possessing unrivaled properties of resistance as a covering mass
against projectiles.

595. Penetration. At moderate distances there is but little
difference between the penetrating power of rifle and smooth-
bore guns throwing projectiles of equal weight; but as the rifle
has great superiority in range, its penetrating power at long
distances greatly exceeds that of the smooth-bore.

The following tables, the result of actual firing, show the
maximum penetration, for various calibres, in different earths,
and convey a good idea of the enormous power of modern artU-
ery.

Since the dates of these firings, great improvement has been
OQade in the character of powder used with the heavier classes of
^uns, whereby much larger charges are used and greater range
^nd penetrating energy gained.

( 357 )

358

FIELD INTRENCHMENTS.

In a hluff hank of natural soil of clay and sand.

Kind op Piecb.

Oalibee,

Weight
OF Pro-
jectile.

Chaegk.

of
Powder.

iz;
<

Pene-
tration.

lOO-pdr. rifle (Par't.)
Solid shot

Siege gun (rifle.).
Shell

Brooks rifle.
Shell

Parrott rifle...,
Solid shot ......

Inches.
6.4

4.5

Pounds.
'98."6

Pounds.

io""

597

3.5

Yds.
180a

1800

2700

200

Feet.

is"*

ih'"

31*5

1863

1863
1864

In a well-settled parapet of clay and sand, .

Kind of Piece.

Oaubre.

Weight of
Projec-
tile.

Charge

Powder.

{z;

Pene-
tration.

Pounds.

Yds.

Feet.

98*.'5
92

ib"*

383

"is*

••••••

30.5
27.5

**3*.*5

383

12
12

16***
14.25

**2*"

••••••

383

**io*

••••••

10.6

..«..

383

••••••

lOO-pdr. rifle (Par't.)

Solid shot

Shell

Inches.
6.4

30-pdr. rifle (Par't.)

Solid shot

Shell

20-pdr. rifle (Par't.)

Solid shot

SheU

10-pdr. rifle (Par't.)
Shell

4.2

3.67

1863
1863

i86ar

FIELD INTRENCHMENTS. 859

In a parapet of pure quartz sand, well rammed.

Kind of Piecb.

U. S. rifle

Solid shot

Shell ,

U. S. rifle

Solid shot

Shell

U. S. rifle.
Solid shot.
Shell

U. S. smooth-bore.
Solid shot

Calibre,

Inches,
13

"Weight of
Projec

TILE.

Pounds.

630

485

298
266

141

451

Charob

Powder.

Pounds.

*Vo*

30
25

14.5

100

Yds.
175

400

200

Pene-
tration.

Feet.

20
18

15.1
16.1

14.1
11

1867

1866

1867

7« a parapet of clay^ well rammed.

Kind of Piece.

U S. rifle.
Solid shot.
SheU

U. S. smooth-bore.

Solid shot

Shell

Calibre.

Inches.
12

"Weight of
Projec-
tile.

Pounds.

625
485

450
330

Charge

of
Powder.

Pounds.
**70

100
55

Yds.
175

175

Pene-
tration.

Feet.

36
34

38
24

1867

In a parapet of clay and sand, well rammed.

Kind of Piece.

Calibre,

Weight of
Projec-
tile.

Charge

Powder.

Pene-
tration.

U. S. rifle ^..

Solid shot

Inches.
12

8
15

Pounds.

625
150

450

Pounds.

"To

18
*100

Yds.
175

24
175

••••••

Feet.

34*"
18.5

22"* '

1867

200-pdr, rifle (Par't.)

V. S. smooth-bore...
Solid shot

360

FIELD INTRENCHMENTS.

English guns.

BIlND OP PlECB.

Parapet of clay and

sand, well rammed.

Range, 1060 yds.

Natural bank of clay

and sand. Range,

1060 yards.

Shot.

Shell.

Shot.

Shell.

100-pdr. Armstrong.
70-pdr. Armstrong...
40-pdr. Armstrong...
20-pdr. Armstrong...
12-pdr. Armstrong...

10-inch smoothlbore
8-inch smooth-bore..
68-pdr, smooth-bore.
32-pdr. smooth-bore.

Ft. In.

21 3
14 4
14 11
10 10

••• •••

19 ii

Ft. In.
16 8

i'i 8*

11 1

11 5

11 6

14 10

9 5

Ft. In.

10 3
5 9
7 2
4 7

"9 3
3 9

Ft. In.
10 5

"5 "9

5 5

2 7

6 7
4 10

7 6
2 8

In.

7.09
6.48
4.84
3.84
3.07

9.84
7.85
7.85
6.17

The foregoing tables, both American and English, are abstracts
from many shots, from which it will be seen that, even with
smooth-bores, penetration is quite variable. It will be observed
also that there is a great difference in the resisting properties
of the various earths, pure clay possessing the least and sand
the greatest. It may here be stated that the resistance of dry
sand is slightly greater than that of wet, and dry clay very much
greater than moist.

Spherical projectiles are much more uniform in penetration
than elongated. With the latter, it depends in a great degree
upon the direction preserved by the axis of the shot; when this
remains so tliat the projectile strikes directly, point foremost,
the penetration is greatest, but a very slight object will fre-
quently cause it to turn while penetrating, and thereby diminish
the penetration, sometimes nearly one-half. When the medium
is homogeneous, the tendency of the projectile after entering it
is to turn to the right or in the direction of the twist, to curve
upwards, and to lodge with the base towards the left. After the
primary impact it does not, as a general rule, continue to pene-
trate point foremost ; this, in earth, causes it to have a plough-
ing effect not possessed in so great a degree by spherical pro-
jectiles. Percussion shells attain fully three-fourths of tiieir
entire penetration before bursting. Time-fuses, unless protected
by water-caps, are liable to be extinguished upon entering earth.
Percussion shells should, therefore, be preferably employed
against magazines, where, by entering and bursting, they will
cause an explosion.

FIELD INTRENCHMENTS. ' 861

As a o^eneral rule, penetration, both for smooth-bores and for
rifles, increases with the calibre of the piece and the weight of
the projectile.

The craters formed by the explosion 0/ shells are much greater
in clayey earths than in sand. In faet^ but little impression is
made on the latter, as the sand, whe»i throvvrn up by the explo-
sion, settles back almost in its former position.

The ratio of increase of craters is generally in excess of the
increase of weight of the shells Oi^ of the bursting charges. A
rifle projectile tears a long f urrov previous to explosion, scatter-
ing the earth to either side, and on bursting uplifts and displaces
-a large mass of earth, whereas^^pherical shells merely bury them-
selves and raise up a comparuively small quantity of earth, the
larger portion of which fall^ back into the crater. Hence the
rifle is superior to the smocth-bore for demolishing earth-works.

When a projectile, spherical or elongated, strikes a slope, as,
for instance, the superior slope of a parapet, and takes a direc-
tion approximately paralel to it, it makes an opeji furrow, pro-
vided the depth below tan surface is not greater than about four
times the diameter of t^e shot. This indicates, what experience
has proved, namely, tjat the best method of breaching earth-
works is to direct a concentrated fire of shells from rifle guns,
with full service chaj-ges, upon the parapet in such manner as
to cut it gradually Jown from the superior slope to the base.
The great accuracy of rifle guns enables this to be done. The
shells, after having performed their work in the parapet, send
their fragments bej-ond and carry destruction to the interior of
the work. A fewheavy pieces are far more effective in accom-
plishing this objfct than a greater number of smaller calibres,
although the agoi-egate of metal thrown may be in favor of the
smaller guns.

In this connetition it may be mentioned that a vigilant and
active garrison, by taking advantage of the darkness of night,
will repair an eirth-work faster than the most powerful artillery
<^an reduce it. N"evertheless it is possible to maintain such a fire
during the day as will cut down the parapet and uncover the
interior of tlfe work sufiiciently to allow of the destruction of
magazines, jomb-proofs, and other arrangements for defense
not so read'iy repaired, and the destruction of which may event-
uate in the loss of the work.

For tht" purpose of retarding as much as possible repairs
during th» night, the assailants should maintain upon that part
of the wo k a constant shower of shells from mortars.

596. '7o provide a safe margin against the cutting-down
effect of the enemy's fire and to preserve the interior revet-

362 \ FIELD INTRENCHMENTS.

ments of a work l^m destnictioii or injury hy the impact of
shot or explosion of >|it'lls, the epaiilment must be made consid-
erably thicker than thVactual peneti-ation of the projectiles used
against it. Formerly tA.i'^ additional thickness was put down at
one-half, but this is man'^estly greater than is necessary for the
artillery now in use.

An addition of one-third dlthe maximum- penetration is ample.
Assuming this as the rule, parapets constructed of ordinary
earth — i. e., clay and sand mix^'d and well rammed — should liave
the following thicknesses : i^aw^e 150Q yards — To resist 12-inch
rifle, 45 feet; 10-inch rifle, 35 !eet; 8-inch rifle, 25 feet; 6.4-
inch rifle, 22 feet ; 15-inch smoo'Ji-bore, 3Q feet. Range 1000-
yards — To resist 4.5-inch rifle, 16 feet; 3.67-inch rifle, 15 feet;
3-inch rifle, 14 feet.

For parapets constructed of sandv Range 1500 yards — To-
resist 12-inch rifle, 30 feet; 10-inch jifle, 25 feet; 8-inch rifle^
20 feet; 6.4-inch rifle, 18 feet; 15-lnch smooth-bore, 25 feet.

Common earth, (mixture of clay and Si»d,) loosel}^ thrown np^
offers much less resistance to penetratDi^ than when settled ;
with sand the diff'erence is not so great.

Interior revetments of ordinary thickness, whether of ma-
sonry, sods, or gabions, give but little addiuonal resisting power
to a parapet, and should not therefore be taken into accoiuit
when estimating its thickness.

From experiments made for the purpose ^f determining the
best form and dimensions for masonry breast-height walls, it was
found that 15-inch smooth-bore projectiles filed at a butt 200^
yards distant, after passing through 20 feet of \\ell-rammed sand»
overturned a wall of best-laid granite masonry \ feet thick and 5
feet high. The penetration was but little inferOi'to that of sim-
ilar shot fired into unsupported sand. The projectiles, although
not coming in actual contact with the wall, (in most instaiices
lodging several feet from it,) transmitted the fo'ce of their im-
pact through the intervening sand, eacii one fd'cing the wall
more and more from the perpendicular, until at ^»e sixth it fell
bodily.

With a parapet of 12 feet of well-rammed sand against a breast-
height wall of concrete 6.5 feet high, 5 feet thick at ipp and 7 feet
2 inches at bottom, pi-ojectiles from the same gun, V'th a range
of 430 yards, demolished the wall; not, however, a^i" the pre-
ceding ease, by overturning it, but b}^ cracking and crumbling^
it. In this case the shot penetrated to the concrete anci destroyed
it by direct impact. ^

With a parapet of 9 feet of sand against a concrete breast-
height wall 8 feet thick at top and 10 feet 2 inches ii bottom.

PENETRATION OF RIFLE-MUSK^T. 363^

projectiles from a 12-inch rifle, at a range of 430 yards, demol-
ished the wall in a manner j»imilar to the foregoing case.

With a parapet of 7 feet of sand against a concrete breast-
height wall 10 feet tliick at top and 12 feet 2 inches at bottom,
projectiles from a lo-incli smooth-bore gun (the range being as
above) cracked the wall, but did little or no other damage to it.

In these experiments it was denvonstrated that when the wall
is stont enough to resist the projectiles, the latter invariably
glance upwards and, passing out through the interior crest, fail
within the parapet at distances varying from a few yards up to-
a thousand or more. After thus glancing they are still capable
of doing considerable damage to the interior of a work.

These facts go to prove that however massive a sustaining wall
may be, there should be sufficient earth in front of it to arrest
the projectiles the same as though there v/ere no wall at all.
Hence it will be economy of labor, material, and space to have
revetments as slight as is consistent with the object of holding
up the earth of the parapet.

597. Penetration of shells from mortars. In sand and in
compact clayey earths, such as would generally be employed for
the coverings of magazines and bomb-proofs, the penetration of
mortar shells falling with maximum velocities is about three
times their diameters; but in order that the lining of the maga-
zine or bomb-proof may not be injured by their impact, double
this thickness should be given.

Shells fired from guns at high elevation possess many of the
properties of mortar shells; but as the velocity is much greater,
the penetration also is greater, and their effect upon striking is
more destructive; consequently, additional thickness of earth is
required for magazines and bomb-proofs exposed to this kind of
fire.

In clayey earth the mouth of the crater formed by the explo-
sion of a raoi-tar shell is about four times the diameter of the
shell ; in snnd it is considerably less.

The maximum velocity of a descending mortar shell is 419 feet
per second, or about one-third that of the striking velocity of
projectiles fired from guns at ordinary distances. This accounts
for the comparatively small penetration of the former.

Shells of any kind striking on marshy ground hnvj themselves
so deeply as to produce but little effect by explosion.

598. Penetration of rifle-musket. Kecorded experiments
give somewhat conflicting results on this head, but, to be on the
safe side, the following thicknesses appear to be needful to give
security against infantrj^ fire : Clay, loosely thrown up, 4 feet;
sandy or gravelly earth, loosely thrown up, 3 feet; sand-baga.

:864 \ INTBEI^OHED CAMPS.

\ "^

iilled, 1.25 feet; gafeions (wicker), filled with earth, 1.75 to 2
feet; phie (soft), 16 toNiS inches; oak and elm (green), 6 inches;

?ish (green), 4.5 inches ^^ap-roller and fascines (green), 12 to 15
nches; brick-work, 4.5 ihfihes; boiler-plate, ^^ inch,
nie above are for distairces not exceeding 100 yards; beyond
that, penetration diminished rapidly with the range. At a dis-
tance of twenty yards a rope mantlet 4 inches tliick is proof
•against a rifle-musket shot. As weight is a consideration in
mantlets, they need not be giv(3n a gieater thickness than this
to insure all necessary security from such fire.

599. Field intrenchments may be classified as follows : 1.
Intrenched camps; 2. Intrenched lines of battle; 3. Detached
nvorks; 4. Lines of works; 5. Works auxiliary to permanent
fortifications ; 6. Works for sie<T^e operations.

600. So far as artiller}'^ is concerned, the first object to be
-considered is position, tlie general principles of which are the
game for eacli of the above classes, and which may be briefly
stated as follows :

1st. Artillery should, if possible, overlook all the ground with-
in range over which an enemy miglit advance, and the pieces
l)e so placed as to sweep the entire surface witli their fire, those
-of longest range occupying the most commanding positions.

2d. All the lines of approach of the assailant should be swept
not only by the frontal, but by the flank or cross-fire of the
assailed.

3d. The features of the ground should screen the assailed from
the assailant's view, and affbrd cover from his fire whilst that of
the assailed can be delivered with full eff'ect.

4rh. The position should, if possible, present natural obstruc-
tions to the advance of the assailant.

5th. It should offer no obstructions to the free movements of
the assailed, either for the offensive or defensive, and should
afford facilities for active offensive rpovements at the opportune
taoment.

6th. It should have secure supports, both on its flanks and in
the rear.

7th. It should afford every convenience for encamping and
l)eing supplied.

601. Intrenched camps. Troops, when within striding dis-
tance of the enemy, should, to avoid the consequences of a sur-
prise, be encamped always in order of battle. The modern
practice of armies is to intrench, if encamped even foronf*. night.
Such intrenchments are usually of the slightest and most liastily-

'Constructed kind, merely sufficient to afford shelter agiinst a
.night attack. The artillery in this case is only that usually ac-

INTRENCHED CAMPS. 365-'

compaiiying troops on the march, and for it ^un-pits will snf—
fice. These are made by simply throwing np the earth in front
of each piece so as to form for it a crescent-shaped epaulment-
If rails or any similar material are convenient, a sli;jjht revet-
ment may be constructed to support tlie earth on the side toward*
the piece. In dry weather the earth ma}'^ be du^^ from the inside
and thrown up in front, thus forming a depressed position or
liole for the piece to stand in. The cliest of the limber will hold
sufficient ammunition for immediate use. To protect it, the
limber is turned with its poleyrom the piece, and is covered with
an epaulment similar to that for the ^un ; or, removing the horses,
it may be backed np near to and on one side of the piece, occupy-
ing with the latter a portion of the gun-pit. Tlie caissons, horses,,
and other material of tlie battery may be placed in some shel-
tered position a little way to the i-ear. The positions occupied
by artillery on such a line ought to be those that would be se-
lected for it on any well-arranged line of battle.

When, in consequence of attack by the enemy, or of his
threatening attitude, the army stands upon the defensive, the
slight intrenchments of a temporary camp are increased and
strengthened until they become a strong intrenched line of
battle.

602. The gun-pits, which before were separate for each piece,,
are now united by a continuous epaulment, and an interior re-
vetment of logs, rails, watling, or sods is given to it. All woods
witliin musket range in front of the line are slashed, for the
double purpose of destroying them as cover foi- the enemy and
for transforming them into an entanglement difficult for iiim to
pass. This work is done by tlie infantiy, the artillery having its
full sliare of labor in intrenching tlie batteries.

An array taking up a defensive position, intrenches itself m
the manner above described. When such a line is attacked, and
the assault is repulsed, the assailing force falls back to the nearest
cover, and there, hugging the ground closel.y, usuall}'^ intrenches
itself. To accomplish this, the men use their bayonets, tin cups,,
or in fact anytiiing for loosening and throwing up the soil. Only
a few minutes are thus required hy veteran soldiers for cover-
ing themselves. This line grows b}'' degrees into a formidable
epaulment, along which, in positions the most advantageous, the
discomfited assailant places his artillery, the intrenchments for
which are similar to those just described.

In these positions the oppo>ing forces remain, usually expend-
ing, without much effect, a large amount of ammunition, until
one or the other withdraws for the purpose of making a new
move. The operation of withdrawing is one of great delicac3V

-866 DETACHED WORKS.

•and is generally performed at night with all possible secrecy.
The artillery commanders at such times have to exercise great
care and foresight, that their batteries may take the proper
routes and not obstruct their own movements oi- those of otlier
troops. An officer from each battery should make himself
familiar with the road to be taken by it, and act as its guide.

603. Detached works are those that are situated beyond the
range of fire of any other works, and which, for their security,
have to rely upon their own strength and resources.

The object of such works is to defend and hold isolated
points that are of importance; such as railroad or other bridges,
mountain passes, narrow defiles, fords, points upon rivers to
-close them against the passage of hostile vessels, &c. The char-
acter and extent of a work of this class will depend upon the
degree of importance attached to the object for which it is con-
structed, the amount of force available . for its occupancy, and
the nature of the locality. In every instance, artillery would
form an important element in its means of defense, and the posi-
tion of the work should be selected so as to allow free use of it.

Works of this kind may be classified under three heads :

1st. Those which, being secure on the flanks and in the rear,
are assailable only in front. Under this class may be placed
open batteries located on the banks of rivers, or at the entrance
of harbors, to prevent the passage of an enemj'^'s vessels.

2d. Those which are assailable in front and on the flanks, but
not in rear.

3d. Those which are assailable on all sides.

604. First class. This is applicable to narrow defiles where
the flanks are secure against being turned. {Fig. 1, Plate 57.)

When the width of the defile is not greater than 1800 yards,
the line may be a straight one (AB) for infantry, with short ad-
vanced lines on the flanks, as represented in the figure, for artil-
ler3^ Should the conformation of the ground be not suitable for
placing artillery precisely as represented in the figure, then the
most commanding position on some other part of the line will be
selected for it, bearing in mind always to secure as far as possi-
ble cross-fire over the ground in front. When the defile exceeds
1800 yards in width, a cremaiUere or serrated line is adopted, and
•on it the artillery is disposed as represented in Fig. 2, Plate 57.

605. Second class. The plan of works of the second class
admits of great varietj', depending on the extent of the position.
The most simple is that of a work of only two faces, the salient
being towards the assailant's line of approach. This work is
termed a redan. {Fig. 3, Plate 57.) AB, gorge; AC and BD,
faces; CD, pan-couple; BE, a small fiank sometimes used.

STRENGTH OF GARRISON. 367

The faces should receive such direction as to sweep the ap-
proaches to the flanks of the position. As many pieces as possi-
ble are placed in the salient, and others disposed alon^ the faces
in the most coramandin^^ positions for sweeping the ground in
their front. The angle formed at the salient by the faces should
never be less than 60°. This rule is general for all salients.

606. When the flank approaciies extend somewliat to the
rear, (as in Fig. 4, Plate 57,) a flank is added to each face of the
redan ; it then becomes a lunette. The flanks receive such direc-
tions as will sweep by their fire that portion of the flank ap-
proaciies whicli cannot be reached from the faces except by a
very oblique fire. BC and CD are the faces; AB and DE, the
flanks.

The artillery is placed in position at the salients, in each of
which is a pan-couple.

GOT*. Third class. The works comprised in this class are
termed inclosed works; as, beina^ assailable on all sides, they
must, for security, present a complete line throughout to any
assault.

These works may be divided into three orders: 1st. Polygonal
works., or redoubts ; 2d. Tenailled works., or star forts ; 3d. Bas-
tioned works.

608. Redoubts. These are polygonal figures having anj^
number of sides; and when the site is horizontal, or sensibly so
within cannon range, there is no reason for adopting anj^ other
than a regular polygon for a plan. The most simple, and the
one usually taken, is the square, {Fig. 5, Plate 57,) the angles
of whicli are formed into pan -couples for the reception of
artillerj''.

The size to be given to a redoubt, or generally to any inclosed
work, will depend upon the number of men available for its
defense, taking it as an established rule that it is better to have
a force concentrated than too much distributed, and therefore
injudicious to make works of a greater extent than can be well
manned and vigorously defended. The number of men will
depend upon the particular circumstances of the case; as, for
instance, its situation with regard to distance from the enemy ;
whether it is liltely to be attacked by a powerful force or only
by raiding parties ; whether it is of such vital importance as to
require it to be heM at all hazards, and its distance from sup-
porting force.

609. Strength of garrison. One double-rank file — that is,
two men — is required for the defense of every lineal yard of
parapet; the number of yards in the crest-line of any redoubt
•should not, therefore, exceed half the number of men to be con-

368 STAR FORTS.

tainecl in it. This number makes allowance for the sick and the
various details and duties which deplete the effective strength of
garrisons.

For the actual defense of lines, with modern arms, one man
per lineal j'^ard is ample.

Every man in an inclosed work requires for lodojing-room 3
square yards of the interior space ; that space, clear of the ban-
quette, magazines, gun spaces, and traverses, must not therefore
contain less than three times as many square yar<ls as the number
of men to be contained in it. From these considerations it fol-
lows : 1st. To find the least number of men sutHcient to man
the parapet of an inclosed work, multipl^^ the number of yards
in the crest-line by 2. 2d. To find the greatest number of men
that an inclosed work can accommodate, find in square yards
the area, clear of the banquette, magazines, and traverses, and
divide this number by 3.

Each gun requires 300 square feet; this multiplied by the-
number of guns must be subtracted from the whole interior
space.

In estimating for the number of men required for any given
length of interior crest-line, no account is taken of the space
taken up by guns, as the number of men required for eacli piece
is about equal to the infantry allowance, i. e., two for each lineal
yard occupied by the piece.

The minimum len<>th of side for a square redoubt capable of
holding artillery is 40 j^^ards ; this gives a work capable of con-
taining one field-piece at eacii angle and about 250 men.

The redoubt has sectors without fire, except that delivered
from the pan-couples, and is without flanking arrangements.

610. Star forts. A star fort in plan consists of a polygon
having alternately salient and reentering angles. The object of
this disposition is to obtain cross-fires on the; approaches to the
salients. The simplest form of the star fort is planned by ])lac-
ing redans on the middle of the faces of a square redoubt, {Ficf^
6, Plate 57,) thus giving alternate salients of 90 degrees and 60^
degrees. A B C D, square redoubt ; ahcd^ redans.

The guns would naturally occupy the pan-couples of the at-
tached redans, and likewise those of the square. The star fort,
from its imperfect flanking dispositions, is but little, if at all,
superior in strength to tlie redoubt. For the same interior space
for the uses of the garrison, the star fort presents a much longer
line of parapet to be defended than the redoubt. It is therefore
only on iuregular sites or broken ground that application of it
will be found advantageous.

Remarks, — Since the introduction of modern improved arms.

BASTIONED FORTS. 369

but little reo^arcl has been given to flanking arrangements in field-
works, experience liaving developed the fact that they are of very
little practical advantage. Lines and groups of works are now
laid out so as to cover each other by flank and cross-fire.

A work entirely detached should, however, have within itself
flanking arrangements.

611. Bastioned forts. The bastioned fort has been devised
to remedy the defective flanking dispositions of the preceding
classes of works.

This fort may consist of a polygon of any number of sides, but
for field forts the square and pentagon are generally preferred,
on account of economy of labor in construction. To plan a work
of this kind, a square (A B K, &c.. Fig, 1, Plate 58) or a pentagon
is laid out, and the sides bisected by perpendiculars; a distance
(C D) equal to one-eighth of tlie side is set off on tlie perpendic-
ular in the square, or one-seventh in the pentagon; from the
angular points of the polygon, lines (AU and HB) are drawn
through the points thus set off"; these lines give tlie direction of
the lines of defense; from the salients of the polygon distances
(AE and FB) equal to two-sevenths of the side are set ofi'on the
directions of the lines of defense, giving the faces; from the
extremity of the faces the flanks (E H and F G) are drawn per-
pendicular to the line of defense of the other face of the same
front; the extremities of the flanks are connected by a straight
line termed the curtain.

A B is the exterior side ; H, the angle of the curtain ; C D, the
perpendicular; H B, the line of defense; A, the salient angle;
A E, the face ; F, the shouldcn- angle ; E H, the flank ; B P, the
capital; HG, the curtains; GO, the gorge of bastion; CAE,
the diminished angle.

The side of the polygon is termed the exterior side; the line
bisecting it, the perpendicular ; the angle at the salient is the
flanked angle; the one formed by a face and flank, the sJiouldcr
angle; the one between the flank and cnrtain, the angle of the
curtain; tlie line bisecting a bastion, the capital; the portion of
the work inclnded between the capitals of two adjacent bastions
is denominated a bastioned fronts or simply 2i front; the interior
space of tlie work not included in the bastions is called the
parade.

Eemark.— The foregoing nomenclature applies also to perma-
nent works. In the latter class the parapet is generally much
above the parade. The space behind the parapet for the accom-
modation of the guns is termed the terre-plein, which is united
witli the parade by earthen slopes or vertical walls. Communi-
cation with the parade and terre-plein is generally provided for
24

370 BASTIONED FORTS.

by means of roadways termed ramps. The whole mass of struct-
ure thus raised above the parade is called the rampart.

An examination of the arrangement of a bastioned front shows
that there are neither dead angles nor sectors without fire ; that
the salients, and all the ground within range of fire, are pro-
tected by columns of direct, flanlv, and cross fire.

Permanent fortifications are, when the site admits of it, con-
structed on the bastioned-front principle, and generally have
auxiliarj'' outworlvs, which are usually omitted in field-worlvs.
The object for which permanent worlds arc erected is to afford a
powerful artillery fire, and the entire interior crest may, there-
fore, be occupied by cannon. In field-works tlie proportion of
artillery is less, and is usually disposed of b}^ placing a piece in
each pan-coiip^e, two or more on each face and one on each
flank, leaving the curtains entirely free for infantr3% Siege
howitzers, when used, are placed on the flanks, where their
capacity for tiring canister is most serviceable in sweeping the
ditch in front of the opposite face. Machine guns occupy a like
position.

The sides of the pol3'^gon upon which a bastioned fort is laid
oflf should not exceed 600 yards, nor be less than 125 yards. If
greater than the former, the range from the flanks will be too
great to cover properly the salients of the bastions ; if less than
125 yards, the flanks will be too short for efficiency, and the
bastions too restricted in space for artillery.

Calling the exterior side X, the parts of the front will be as
follows :

Diminished angle =14° 2^ 10^

Salient angle . =61° 55^ 40^
Shoulder angle . =118° 4^ 20^
Curtain angle . =1040 2^0^

Line of defense=0.71804 X

Face . . . =0.2857 X

Flank . . . =0.10808 X

Curtain . . =0.39320 X

Gorge . . . =0.18279 X

The entire front is equal to X multiplied by 1.1824.

With a pentagon the above numbers are slightly changed, but
so slightly as to make no appreciable difference when estimating
the dimensions of the sides of a polj''gon for a bastioned work to
accommodate a specified number of men. In making an esti-
mate for the number of men required to man the parapet of a
work, no allowance is made for the space occupied by guns ; this,
for the reason that the number of men so required is about equal
to that of infantry for tiie same space ; that is, two men for each
lineal yard of interior crest.

AT F

The foregoing is expressed by ■2L= g x N X 1.1824

In which F = the number of men: S = the number of sides

BASTIONED FORTS. 871

of the polygon ; and N = the nnmber of men per yard of interior
•crest; X beinj^, as before, the exterior side.

In actnal field service, it seldom happens that the ground will
admit of a bastioned work constructed on a regular polygon ;
but whatever it may be, the foregoing principles will apply and
give a close approximation to the size of the required work.

To ascertain the number of men required to man a given
work, measure the interior crest (in yards) and multiply by 2.

Allowing two men for each yard of parapet, the exterior sides
of a square bastioned fort to accommodate 4000 men would be
422.8 yards.

A fair proportion of artillerj'^ for a work requiring 4000 men
would be 36 guns, disposed of as represented in the figure — i. c,
one in the salient of each bastion; one on each flank ; one in
the shoulder angle, and two on each face.

A bastioned work constructed on a square of 125 yards will
accommodate about 1180 men and an armament of 8 pieces.

612. For ordinary field-works the pieces would generally be
those on traveling carriages, and consequentl}'' readily moved
from one part of the work to another, as required by the nature
of the attack. As a general rule, the heaviest pieces would be
placed in the salients, and howitzers, if used, in the flanks to
sweep the ditch with canister.

Machine guns are especially adapted to the defense of field-
works, and should never be omitted as part of the armament.
Being breech-loading and easily handled, they require but little
exposure either for themselves or the cannoneers. The oscillat-
ing apparatus with which they are provided allows the fire to be
delivered in a horizontal line, which is superior to the cone of
dispersion of canister from howitzers or guns. When practica-
ble, the machine gun should be fired from a platform ; but as
the piece is light and the recoil small, the platform may be slight
and laid without counter-slope. As a general rule, all platforms
for pieces on traveling carriages should be laid horizontally, as
this enables them to be fired in any direction with equal facility.
A bag of earth placed at a proper distance behind each wheel
will check recoil.

Since the fire of the Gatling gun is that of infantry alone, its
introduction should not diminish the amount of artillery prop-
erl)'- requisite for a work. Machine gnns may partly replace
infantry, but not artillery.

Whenever practicable, mortars should constitute a part of the
armament of field-works. These should be placed in such posi-
tions, usually behind traverses, as not to prevent, bj'' their blast.

872 LINES OF WORKS,

any portion of the parapet from being occupied by guns oir
infantry.

Ill actual service it seldom occurs that tlie configuration of the
ground admits of works being laid out with the exact dimensions
and figures above described. These are intended to illustrate
general principles capable of being modified and adapted to suit
each particular case. Tiie plan of the work siiould be adapted :
Ist. To tlie natural form of the site, taking advantage of all
undulations to diminish the labor of construction f 2d. To tlie
object in view; 3d. Tlie time available for construction and the
number of men to form the garrison.

The prolongation of all the principal lines of a work should be
directed as much as possible on ground inaccessible to tiie ene-
my, or at least where he cannot obtain an enfilade fire with his^
artillery.

When circumstances permit, a field fort should be constructed
with such care that the enemy will be forced to abandon an
attempt to storm it and be obliged to resort to the method of
regular approaches used in the attack of permanent works. To
effect this, no ground around the fort within range of cannon
should offer shelter to the enemy from its fire ; the ditches
should be flanked throughout, and the relief be so great as to
preclude any attempt at scaling the work. Approaches to it,
particularly on the salients, should be obstructed by abattis,^
fraise, wire entanglements, &c.

613. Lines of works. {Figs. 2 to 5, Plate 58.) When it is nec-
essary to hold for a time a line of considerable extent hj a force
inferior to that which may be brought against it, the line should
be fortified by intrenchments, consisting of a series of works
laid out according to the foregoing principles. The kind of
work for any particular position on the line will depend upon
the nature of the locality it is to occupy and the manner iu
which it will combine with those adjacent in securing mutual
support throughout. Such lines are frequently from fifteen to
twenty, or even thirty miles in length, extending over every
variety of countr}', and in their construction call for the highest
skill in military engineering.

They are constructed, usually, either for the protection of
important towns, cities, and depots; or to make secure the base
of operations and lines of communications of an army manoeu-
vering in the field; or, by stretching across peninsular regions,
to restrict the theatre of operations of the enemy; or for sur-
rounding and besieging a place ; or for the purpose of holding
the enemy in position with a part of an army while the remain-
der makes a flank or other strategic movement. The civil war

LINES OF WORKS. 873

«of 1861-65 afforded numerous instances of each of these condi-
tions.

The same general principles apply to lines as to other field-
works ; but from their great extent they usually receive only a
slight relief, and the simplest angular figures are adopted for
their plan. In laying them out, advantage should be taken of all
the natural features presented by the position, so as to diminisli
the labor of erecting artificial ones.

The flanks of a line or position are generally weak points.
When possible, one or both should rest on natural points of sup-
port. A flank not so supported must be secured by strong works
especially well garnished witli artillery.

A point tliat has not a clear field of fire is a weak point, and
should be strongly intrenched, so that the enemy may not have
advantage of hills, ravines, or other shelters in approaching the
line. Care should be exercised in determining the kind of artil-
lery for such positions. The field of fire being contracted, long
range is not of so much importance as ability to search behind
the enemy's shelter, or to throw a great mass of projectiles in a
limited time. Mortars, howitzers, and machine guns will be
found serviceable.

In establishing a line of works, the main object should be to
cover every portion of the front within range with direct or
crossfire. To accomplish this, all prominent points along the
line are fortified, each with a work having a trace most suited to
the conformation of that particular site. The most important of
these should be inclosed works upon the bastion-front principle,
and of considerable size, capable of enduring an independent
attack.

Smaller Inclosed works, such as redoubts and star forts, occupy
the secondary points. Between the works thus located extend
rifle-trenches capable of sheltering infantry. The line is there-
fore composed of a series of works mutuall}'^ supporting each
other and covering iiYfiry avenue of approach.

The artillery, of which there should be an abundance, will
naturally be placed in the works occupying the most command-
ing and salient positions. These works should never be so far
apart as to be out of mutual flanking range of the artillery with
which they are armed. It is the duty of officers of artillery to
cooperate with those of engineers in selecting the positions of
the works that are to be armed with artillery, and to determine
the kind and quantit}'^ to be placed in each.

As infantry troops constitute the chief garrison of works of
this nature, they will be required to construct them, leaving to
2the artillery the construction of magazines, embrasures, plat-

374 LINES OF WORKS.

forms, and other accessories pertaining to their special arm^
Generally these works are thrown up very hastily, and often,
when an immediate attack is apprehended; this, to a considera-
ble extent, decides not only the nature of the works, but the
parts of them that require the first attention. Subsequently,
if time permits, they are strengthened, improved, and worked
into better shape.

As far as practicable, the line should be composed of inclosed
works, for the reason that should the enemy concentrate and
break through at any point, he will not be able to sweep the line
to the right and left by taking it in flank and rear. To storm
and capture each work in succession would be an operation too
costly for him to undertake.

It is advisable in most instances to have in front of the line,
witiiin easy musket range, a line of small redans or lunettes at
intervals of about 1500 j'^ards. Each of these should be capable
of holding from one to two hundred infantry and four to six
field-pieces. This line of outworks would form, as it wei'e, a
species of picket line, keeping the enemy from closely observing
and harassing the main line, and would constitute an advanced
line of battle, against which the first shock of the enemy is par-
tially thrown away, and he dare not attempt to neglect them;
for an endeavor to penetrate through the intervals would expose
his flanks to a close and deadly flank and cross fire. The redans
being open towards the main line, could not be held if captured
b}"" the enemy.

A somewhat similar line of works should be established in rear
of the main line. They should, however, have their gorges stock-
aded or otherwise closed to prevent the enemy, should he suc-
ceed in forcing his way through the main line, from obtaining
easy possession of them by the rear. Sites for them should be
selected with a view of obtaining from them a searching fire of
the front line in reverse. This line of works, although appar-
ently inert in rear, must be kept full^^^ armed and manned, ready
to drive the enemj'' from anj'' part of the main line that he may
succeed in obtaining possession of.

Prominent salients in the main line are especially inviting to
the enemy; behind these a second line should be prepared, so
placed, if possible, that should the enemy obtain the main line
he will be within musketry range of the second, and be forced
with v/earied troops to undertake the capture of it.

614. An approximate estimate of the number of troops re-
quired to man such a system of intrenchments may be obtained
by allowing 300 men per mile for the first or redan line, 4000 for

LINES OF WORKS. 375

the mtiin line, 300. for the rear line, and 1200 for reserves; mak-
ing a total of 5800 per mile of actual lii^htiiig force.

The amount of artillery required will depend upon such cir-
cumstances as the kind employed ; the kind and quantity brought
up by the enemy ; the nature of the country, and the quality of
the troops on either side. From four to five pieces per thousand
infantry is a fair estimate.

To break a line of works the enemy would secretly concentrate
as powerful a force as possible and assault some particular part
of the line. As it would be impracticable to have at ever}' part
of the line a force capable of successfully resisting such a con-
centration, the probabilities are that he would succeed in his
assault, if vigorously made. To dislodge him from any portion
he might thus capture, it is advisable to hold strong reserves of
both artillery and infantry at central and convenient points in
rear of the line of works. One reserve of say 5000 infantry and
20 fleld-pieces for each four miles of line would make it almost
impossible for an enemy of ordinary strength to hold any part
of it that he might capture. Telegraphic communication should
be established from one reserve to another and to every part of
the line. This would insure a prompt cooperation of all the
forces.

In tracing field-works, care must be taken to direct, as much
as possible, their faces upon ground least accessible to an enem}^
so as to reduce to a minimum the eff*ect of his enfilade.

615. When the importance of the case demands it and the
means are available for carrying it out, lines of field-works some-
times assume — as was the case during the rebellion — a semi-
permanent character. These are laid out with great care and
constructed witii skill and nicety; the.y are furnished with sub-
stantial and commodious magazines and bomb-proof; the slopes
are sodded and the revetments constructed for endurance.
Works of this cliaracter are frequently armed with the heaviest
classes of ordnance, the emplacement, care, and preservation of
which, together with the ammunition therefor, will be governed
by the same rules as for permanent works.

616. Tlie camps, parks, trains, hospitals, depots, &c., should
be sufficiently far to the rear to be out of range from the fire of
the enemy, and should have through communication to the vari-
ous parts of the line b}'' means of well-constructed roads. These
roads should be laid out in sucli manner as to be, as much as
possible, out of view of the enemy. The horses of the artillery
in the works, with their drivers, and all parts of the batteries
not absolutely required for tlie efficient service of the guns,
should be encamped, as above, in rear. The cannoneers, ofti-

376 DISTANCES — PARAPET.

cers, and non-commissioned officers will invariably remain in
the works, read}' for action at smy moment.
. 61*7'. Distance of works frorn towns ^ cities^ fyc. Rifled artil-
lery, of large calibre, is capable of doing- (rrent damage to towns,
cities, dock-3'ards, and other objects of large extent, up to a dis-
tance of five miles. A few pieces of enormous calibre have been
constructed capable of throwing hnge projectiles to a distance of
about nine miles. These are, however, exceptions, and as they
can be made available only by means of a certain class of almost
impracticable vessels, it is not necessary, at present, to embi'ace
them in this consideration. Five miles being the limit within
which the enemy must not be allowed to establish his batteries,
the distance of defensive works within this limit will depend
upon the character and power of the artillerj^ with which they
can be armed. Heavy calibres are more capable of keeping aa
enemy at a distance than small calibres, and rifles are superior
to smooth-bores. About two miles is the limit of eflectlve range
against ships of war, and beyond this distance It would be im-
possible to prevent an enemy from carrying on operations by
land; this, therefore, is the maximum distance that it is admis-
sible to subtract from tiie live-mile limit of the enemy. In other
words, if an enemy is able to bring heavy rifle guns against a
large object, as a city or a dock-yard, works for its protection
should be at least three miles distant therefrom. No snch area
can therefore be surrounded and protected by a line of works
of less extent than 18 miles ; generally It would be much more,
depending upon the size of the city, town, or other objects.

618. Parapet. In fleld fortlflcatlons the main features are
the covering masses of earth of which they are constructed, and
which are intended to shelter the assailed from the view and flre
of the assailant. When the covering mass Is so constructed as
to afford the assailed a view and flre over the assailant's line of
approach, it is termed a parapet; when intended simply as a
screen or cover from the flre of the enemy, it is termed an epaul-
vient; and when used to cover troops or guns from an enfllading
flre on the flank or In the rear, a traverse.

The simplest form of work is the rifle-trench or pit. {Figs. 1
and 2, Plate 59.)

In this, the parapet Is formed by throwing the earth from a
trench within to tlie front. The earth thus thrown up, togetiier
with the depth of the trench, affords the desired shelter. The
troops stand or squat in the trench and deliver their flre over
the bank of earth in front. This method of intrenching affords
the speediest means of obtaining cover, and is the one resorted
to when troops are under flre, or when thej'^ intrench their camp

PARAPET. 377

or position for a temporary stay. Rails, logs, in fact, almost
anything at hand may be nsecl as a rough interior i-evetment
for sustaining the earth. For artillery, the trench is made some-
what wider than is necessary for infantry.

619. In the more elaborate class of field fortifications, such
as the inclosed works previously mentioned, the earth to form
the parapet is taken from the exterior, thus forming in front of
the parapet a ditch which makes a formidable obstacle in the
way of an assailant attempting to enter the w^ork by escalade.

Fig. 3, Plate 59, shows the usual form of the profile of such an
intrenchment in ordinary soil.

B C D E F G, profile of parapet ; H I K L, profile of ditch ; M
]N" O, profile of glacis; A B, terre-plein, or parade; B C, ban-
-quette slope, having a slope of one upon two ; C D, tread of the
banquette, having a slope to the rear of two inches; D E, inte-
rior slope, having a slope of three upon one ; E F, superior slope,
having a slope of one upon four to six ; F G. exterior slope, having
a slope of one upon one; G H, berm ;'H I, scarp, having a slope
of about two upon one ; 1 K, bottom of ditch ; KL, counterscarp,
having a slope of about two upon one; B, foot of the banquette
slope ; C, crest of the banquette ; D, foot of the interior slope ; E,
interior crest ; F, exterior crest ; G, foot of the exterior crest ;
H, crest of the scarp ; I, foot of the scarp ; K, foot of the coun-
terscarp ; L, crest of the counterscarp ; M, foot of the glacis ; N",
<}rest of the glacis ; a 6, thickness of the parapet. The tread of
the banquette is placed 4 feet 3 inches below the interior crest.

The following table, giving the slope for various degrees of
elevation, will prove useful.

By referring to tables of ranges, and bearing in mind that the
angle of fall of a projectile is always greater than the elevation
of the piece, the table will also afford useful suggestions and
data with reference to defilading works.

In seeking protection from the fire of an enemy, either hy nat-
ural or artificial cover, the drop of the projectile must be taken
into accoinit. This depends upon the range, kind of piece used,
and nature of fire employed.

The table, furthermore, furnishes useful assistance, when
studying defensive positions, as to locating batteries and deter-
mining the kind of artillery to be placed at the various points
for reaching ground that may be occupied by the enemy, and
which is sheltered by undulations or by timber growth from view
from the work.

In connection with this, see^ar. 650 and tables of ranges for
the 8-inch and 100-pounder rifles.
t

878

DITCH.

Angle.

Rise.

Angle.

Rise.

Angle.

Rise.

Angle.

Rise.

Deg.

One on.

Deg.

One on.

Deg.

One on.

Deg.

One on.

57.3—

6.3+

3.2 +

2.1

28.6 +

5.7+

3.0+

2.0

19.0+

5.1+

2.9—

1.9

14.3—

4.7 +

2.7+

1.85

11.4+

4.3 +

2.6

1.80

9.5-

4.0+

2.5—

1.75

8.1+

3.7+

2.3+

7.1+

3.5—

2.2

The dimensions of the parapet will depend upon the kind of
eartli used and tlie time and means that can be employed in its
construction, together with the time that the work is to remain
occupied, and, finally, with the time and means the enemy can
dispose of in the attack, and the degree of resistance the work
should offer. The relief, which is the vertical hei<>;ht (E a>
of the parapet above the terre-plein, should not be less than 8-
feet, and it will be seldom necessary or expedient to exceed 12
feet. Its thickness, which is the horizontal distance (a b) be-
tween the interior and exterior crests, is regulated by the kind
of earth u.sed and the kind of attack it is expected to meet. If
it is to resist artillery, the thickness is that given in par. 596, in
which the minimum is laid down at 14 feet.

The relief of a work, or of any part of a work, is its height
above the ground on which it stands.

The command of a work is its elevation with reference to the
surrounding country, especiallj'' that within striking distance,
which may be occupied by an enemy.

620. Ditch. The dimensions of the ditch should be i-egulated
to furnish the earth for the parapet. To present a respectable
obstacle to the enemy, its depth, however, should not be less than
6 feet, nor its width at the top less than 12 feet. For approxi-
mate purposes, the dimensions of a ditch to supply earth neces-
sary for a given parapet may be obtained by assuming the depth
of the ditch and dividing the area of the profile of the parapet by
it to obtain the width.

In turning the salients, keeping the dimensions of the ditch
the same, there will be an excess of earth, — a circumstance
which may be taken advantage of by making the parapet thicker
in these parts. Due allowance must be made for this when lay-
ing out the work. The salients should always be the thickest
and strongest.

621. Tracing. In laying out the figure of a work on the

SOD REVETMENT. 379^

ground, which operation is called tracing^ the interior crest is
taken as the governing' line ; all other lines are laid off with ref-
erence to it.

Profiling. The trace being laid otf and marked by stakes at
the angles, profiles of the parapet, [Fig. 1, Plate 60,) constructed
of strips of light wood, are set up at the angles, and at other
points along tlie parapet where long stretches of the latter occur.
The method of establishing these profiles will readily suggest
itself.

When strips of wood are not easily obtained, stout cord may
be used instead, the cord being attached to the uprights at the
points where the strips of wood are or would be nailed.

When a sufficient portion of the profiling is completed, work-
ing parties are set to work excavating the ditch and forming the
parapet. The latter, as the work progresses, should be well
rammed. If the soil is stony, the vegetable mould on tiie sur-
face should be removed, and reserved to form the top of the par-
apet. Tills should always be free from stones to a depth of at
least three feet, to prevent injury to the troops from tlie eff'ect
of shot striking and scattering the pebbles and fragments.

Those portions of an eartli-work within effective range of the
enemy's artillery, and upon the endurance and integrity of
which depend the support and safety of valuable batteries or
magazines, should be made strongest by additional thickness and
height. The material and workmanship should be of the best
quality.

It is almost impossible to make a breach in a work constructed
of sand of sufficient thickness to prevent penetration through
and through it and having flat slopes towards the breaching
batteries of the assailant. In such cases the sand displaced by
successive shots falls back again and again within the area-
attempted to be breached.

62^. Revetments. A revetment consists of a facing of stone,
wood, sods, or other material to sustain an embankment which
has a slope steeper than the natural slope of the particular kind
of eartli used.

In field-works, revetments are used only for the interior slope
of the pai'apet and for the scarp. For the first, sods, palisades,
fascines, logs, gabions, and plank are chiefly used; and for the
last, timber.

6!23. Sod revetment. Sod-work forms a strong and durable
revetment. Tlie sods should be cut from a well-clothed sward,
with the grass of a fine short blade and thickly-matted roots*
If the grass is long it should be mowed before the sod is cut^

^80 FASCINE REVETMENT.

The more tenacious the soil the better will be the sods. Those
cut from sandy localities are of but little value.

Sods are of two sizes : one, termed strechers^ are 12 inches
square and 4^ inches thick ; the other, termed headers, are 18
inches lonj^, 12 inches broad, and 4^ inches thick.

The sod revetment {Fig. 2, Plate 60) is commenced as soon
as the parapet is raised to the level of the tread of the banquette.
A course of sods is then laid, either horizontal or a little inclined
from the banquette. The course consists of two strechers and
one header alternating, the end of the header being laid to the
front; the grass side is laid downwards, and the sods should
protrude a little beyond the line of the interior slope, for the
purpose of trimming the course even at top, before laying an-
other, and to make the interior slope regular. The course is
firmly settled by tapping with a spade each sod as it is laid, and
the earth of the parapet is packed closely behind the course. A
second is laid on the first so as to break joints with it. The top
course is laid with the grass side up, and in some cases pegs are
driven through the sods of two courses to connect the whole
more firmly. When cut from a wet soil, the sods should not be
laid until they are partiall}'' dried; otherwise they will shrink
a,nd the revetment crack in drying. In hot weather the revet-
ment should be watered frequently until the grass puts forth.
Sod revetment, on account of its durability and freedom from
splinters, is the best of all revetments.

Log revetment. {Fig. 3, Plate 60.) This revetment is made
of trunks of small trees or saplings laid horizon tall}'^ one on the
other and supported by posts set into the banquette. At fre-
quent intervals tie beams are dovetailed between the logs, and,
extending six or eight feet into the parapet, are secured to
horizontal anchoring logs. For intrenchments hastily thrown
up, this is the most usual form, rails or timber of anj?^ kind being
used.

6124. Fascine revetment. A fascine {Fig. 4, Plate 60) is a
bundle of twigs closely bound together. There are two sizes of
fascines : one size is 9 inches in diameter and about 10 feet long;
the other, which is generally termed a soucisson, is 12 inches in
diameter and 20 feet long. It is chiefly used for the revetments
of batteries.

To make a fascine straight twigs are selected, between the
thickness of the little finger and thumb, — the longer the better.
They should be stripped of the smaller twigs. A support, term-
ed a fascine-horse, {Fig. 5. Plate 60,) is put up by driving two
stout stakes obliquely into the ground about two feet, so as to
«cross each other about two feet above the ground, where they

GABION REVETMENT. 381

are flrml}^ lashed together. As many of these supports as may
be required ai*e put up in a straiglit line, about 18 niches apart.
Tlii.^ forms the horse, on which the twigs are laid to be bound
together,

A machine (C D) termed a fascine choker is formed of two
stout levers about 5 feet long, connected near theii- extremities
by a chain or strong rope, which must be long enough to pass
once around the fascine and be drawn tight by means of the
levers.

The twigs are laid on the horse with their laige and small
ends alternating; the choker is applied to bring them together,
and they are bound by wire, or by withes made of tough twigs,
properly prepared by twisting over a blaze, so as to render them
pliable. The ties are placed 12 inches apart, and every third or
fourth one should be made with an end about three or four feet
long, having a loop at the extremity to receive a stake through
it. This stake is termed an anchoring stake^ its object being to
secm'e the fascine firmly to the parapet.

To form the revetment, the first row of fascines is imbedded
{Fig. 4, Plate 60) about half its thickness below the tread of the
banquette, and is secured by means of the anchoring stakes, and
also by several stakes driven, through the fascine itself about 12
Indies into the earth. The knots of the ties are laid inside, and
the earth of the parapet is well packed behind the fascine. A
second row is laid on the first, so as to give the requisite interior
slope ; it should break joints with the first row, and be connected
with it by several stakes driven through them both. The other
rows are laid with similar precautions, and the parapet is usually
finished at the top by a course of sods.

625. Post revetment. {Fig. 6, Plate 60.) This is construct-
ed of posts from 4 to 6 inches in diameter, cut into lengths of 5.5
feet, and set with proper slope, in close contact, in a trench two
feet in depth, at tlie foot of the breast-height. The tops of the
posts, if not alreadj"- so, are sawed off level, to receive a horizon-
tal capping piece, which is spiked on. Anchor ties are dove-
tailed into the cap and secured to an anchor log imbedded in tlie
parapet. On top of the cap are laid several courses of sods, rais-
ing the interior crest to the proper height. With a good quality
of timber this revetment is durable. It is easily constructed, and
next to sods is the best.

6:26. Gabion revetment. {Fig. 7, Plate 60.) The gabion is
a basket of a cylindrical form, open at each end. Its height is
usually 2 feet 9 inches, and diameter 2 feet.

To form a gabion, a directing circle is made of two hoops, the
difference between their radii being such that, when placed con*

^82 PLANK REVETMENT — SAND-BAGS.

-centrically, there shall be about If inches between thera. They
are kept in this position by placing small blocks of wood between
them, to which they are tied with pack-thread. The directing
circle is placed on the ground, and seven or nine stakes, about
1 inch in diameter and 3 feet long, are driven slightly into the
ground between the hoops, at equal distances apart ; the directing
circle is then slipped up midway from the bottom, and tied in
that position. Twigs about half an inch in diameter, and as long
as they can be procured, are wattled between the stakes like or-
dinary basket-work. When finished to within about 2 inches of
the top, the gabion is placed with the other end up, the directing
circle taken off, and the gabion completed to within 2 inches of
the other extremities of the stakes. The wicker-work at the two
ends is secured by several withes, and the ends of the pickets are
sharpened. The gabion is then ready for use.

To form the revetment, a fascine is first laid partly imbedded
below the tread of the banquette; {Fig. 4^ Plate 60;) the gabion,
which is placed on end, rests on this, so as to give it the requisite
slope ; it is then filled with earth ; others are placed in like man-
ner, and the parapet is raised behind them ; another fascine is
laid on top, and in some cases two.

In making gabions, iron hoops, similar to barrel hoops, may
be used instead of- wattling. The number of stakes should be
increased to eleven or thirteen. Gabions made either of wattlings
or hoops are not good for holding dry sand.

Sheet-iron is preferable to either iron hoops or brush for ga-
bions. For this purpose rectangular sheets of suitable dimen-
sions to form cylinders of the same height and diameter as the
ordinary gabion, are prepared with three holes punched near to
and parallel with the shorter sides of the sheets. These are to
secure the ends with wire when the sheet is bent into the cylin-
drical form. The advantages of this description of gabion are
greater strength, lightness, and durability than either of the
other two, offering great facility for transportation, and resist-
ing better the blast of guns when used for reveting the cheeks
of embrasures. Galvanized iron is less liable to rust than plain
iron ; when not galvanized, the gabions should be lacquered with
coal-tar.

627. Flank revetment. This may be made by setting stout
posts of scantling about 3 feet apart, 2 feet below the tread of
the banquette, giving them the same inclination as the interior
slope. Behind these stakes boards are nailed to sustain the
^arth. The posts should be securely anchored into the parapet
with wire and stakes.

638. Sand-bags are sometimes used for revetments when

SCARP REVETMENT. 383

other materials cannot be procured; though their object in most
<jases is to repair damages done b}'' the enemy's fire. They are
made of canvas, or a good quality of gunny-cloth, sewed with
cotton twine with lock-stitch ; the bag, when empty, is 2 feet 8
inches long and 1 foot 4 iuclies wide. When filled and laid they
occupy a space of 6 by 10 by 24 inches, and contain 0.85 of a cubic
foot of sand, weighing about 85 pounds. Thirty-two make a cubic
yard.

The bags are laid as headers and strechers, either in the Eng-
lish or Flemish bonds. They should not be more than three-
fourths full when laid; if full, they do not lay well, and are more
liable to burst on becoming wet, or under great pressure. When
time is of importance, the bags need not be tied, but the throat
is given a twist and turned under the end of the bag as it is laid.
To prevent decay, they should be payed with coal-tar before be-
ing filled or before being laid; this, furthermore, renders them
less liable to take fire when dry. One hundred and forty-four
sand-bags, laid as above, make ten superficial yards of revetment.

Sand-bag reveting requires less anchoring to make it stand
than any other. If the reveting is kept wet, the sand will not
so readily escape througii rents, nor will the bags take fire frod^*
the blast of the pieces ; this, however, hastens their decay. From
six to ten months, depending upon usage, is the duration of
reveting made of sand-bags. When used near the muzzle of
the piece in the revetment of embrasures, they soon wear away,
from the blast of the piece, unless well protected.

629. Scarp revetment. {Fig. 1, Plate 61.) This revetment is
serviceable where the foot of the scarp is subject to wash, as in a
wet ditch. It is formed of a frame-work of heavy timber, and is
used chiefiy for important field forts. A piece, termed a ca/?, is
imbedded in a trench made along the line of the berme ; other
pieces, termed land-ties^ are placed in trenches perpendicular to
the cap, with which they are connected by a dovetail joint;
they are about 8 or 10 feet apart. Cross-pieces are halved
into the land-ties near their extremities, and two square piles,
about 5 feet long, are driven in the angles between the land-
ties and cross-pieces; inclined pieces, serving as supports to the
cap, are mortised into its under side at intervals of 8 or 10 feet.
These supports usually receive a slope of ten perpendicular to
one base ; tliey rest on a ground-sill at the bottom of the ditch,
to which they are mortised, this sill being held firm by square
piles.

Behind this frame- work thick plank or heavy scantling are plao-
<i(\ horizontally, having the same slope as the supports; or else a
rabbet may be made in the cap and ground-sills, and the scant-

884 INTERIOR ARRANGEMENTS — BARBETTE.

ling let in between these two pieces, serving as a support to the
cap. This is the more difficult construction, but the better,^
since, should the heavy supports be cut away, the cap will still
be retained in its place.

In constructing the scarp revetment the cap-sill and land-ties
are first laid, and then a narrow trench is dug to the bottom of
the ditch to allow the ground-sill and frame-work to be set in.

In many of the earth-works constructed during 18G1-65 the
berme was dispensed with, the exterior slope being continued
down to the bottom of the ditch. This plan worked successfully..

When circumstances admit of it, all the slopes of an earth-
work should be sodded, or else be manured and sowed with
grass seed.

630. Interior arrangements. Under this head come batteries^
magazines, traverses, bomb and splinter proofs, and interior
redoubts.

631. Batteries. The term battery, in this connection, is
usually applied to a place in a work prepared for the accommo-
dation of several guns. It is also used when speaking of the
arrangements made of a parapet to enable the guns to fire over
it or through openings in it; as, a barbette battery, an embrasure
battery, <fec.

63^. Barbette. This is a construction by means of which a
piece can fire over a parapet. It consists of a mound of earth
thrown up against the interior slope; the upper surface is level,
and 2 feet 9 inches below the interior crest, for light field-
pieces, and from 4 to 6 feet for heavy guns. If the barbette
is raised behind a face, its length should be suflficient to allovv 16
(or 18) feet along the interior crest for each gun ; and its deptli,
or the perpendicular distance from the foot of the interior slope
to the rear, should be 24 feet. The earth of the barbette at the
rear end receives the natural slope. To ascend the barbette a
ramp is made of earth, connecting the top of the barbette with
the terre-plein. The ramp is 10 feet wide on the top, and its
slope is six base to one perpendicular. The earth at the sides
receives the natural slope. The ramp should be at some con-
venient point in the rear, and take up as little room as possible.

633. As barbettes are usually placed in the salients, an ar-
rangement is made for guns to fire in the direction of the capital.
The construction in this case is somewhat dilFerent from the
preceding. A pan-coupe {a b) of 11 feet {Fig. 2, Plate 61) is fii-st
made, and from the foot of its interior slope a distance of 24
feet is set oft' along the capital ; at the extremity of tins line a
perpendicular is drawn to the capital, and 5 feet are set oflf
on this perpendicular on each side of the capital; from these

EMBRASURES. 385

points on the perpendicular a line is drawn perpendicular to
each faoe, respectively ; the hexagonal figure thus laid out is the
surface of the barbette for one gun. The ramp (c) in this case
is made along the capital.

If three or more giuis are placed in the salient, a pan-coup6
is formed as in the last case, {Fig. 3, Plate 61,) and 24 feet
are, in like manner, set off on the capital ; but instead of pro-
ceeding as in the last case, a perpendicular is drawn from this
point to each face, and the pentagonal space thus inclosed is
taken for the gun in the salient; from the perpendicular last set
off, as many times 16 (or 18) feet will be set off on the interior
crest of each face as there are guns required. This gives the
length of the barbette along each face; the depth is made 24
feet, and the two are united in the salient. One or more
ramps may be made, as most convenient.

The advantages of the barbette consist in the commanding
position given to the guns, and in a very wide field of fire. On.
these accounts the salients are the best positions for them.
Their defects are, that they expose the guns and men to the
enemy's artillerj^ and sharp-shooters.

634. Embrasures . The embrasure {Fig. 4, Plate 61) is an
opening made in the parapet for a gun to fire through. The
bottom of the embrasure, termed the sole^ is 2 feet 9 inches,
or from 4 to 6 feet above the ground, on which the wheels
of the carriage rest, according to the size of the gun and the
kind of carriage. It usually slopes outward to allow the gun to
be fired at a depression. The base of this slope should never be
less than six times the altitude. In most cases it may be hor-
izontal, or even have a slight slope to the rear. The interior
opening, termed the mouth., is from 18 to 36 inches wide, accord-
ing to the calibre of the gun, and is of a rectangular or trapezoidal
form.

The line which bisects the sole in the direction of the line of
fire is called the directrix. The sides of the embrasure arc termed
the cheeks; these widen out towards the exterior, whicli widen-
ing is termed the splay., the inclination upon each side from the
directrix being one upon ten. They furthermore liave an in-
clination outwards from the vertical: this inclination, at the
line of the exterior crest, is three upon one.

When the directrix is perpendicular to the interior crest, the
embrasure is termed direct; {Fig. 4, Plate 61 ;) when oblique,
the embrasure is termed oblique. {Same ^figure.) In order that
the part of the embrasure which is next to the muzzle of the
gun may be nearly of the same width in both the direct and
25

386 EMBRASURES.

oblique embiasnres, the mouth of the latter is wider in propor-
tion to the obliquity.

Embrasures are reveted with the same material and in the
same manner as described for the interior slope.

If the exact position for the embrasure is known, it is best to
lay it oat and make it while the parapet is being constructed.
As soon as the latter is built up to the sill of the fiitnre embra-
sure, a light stake is planted in line with the interior slope on
each side of the directrix, in such position as to represent the
sides of the mouth of the embrasure ; a strip is nailed across at
the proper height to represent the sill, and another above on the
line of the interior crest. The earth being smoothed off to give
the desired slope to the sole, the directrix is marked out on it
by means of a cord ; the splay of the cheeks is obtained by
giving the sides an inclination of one-tenth with the directrix.
These lines being laid off on the sole, the revetment is placed
along them and is given an inclination corresponding with the
two profile stakes at the mouth, and three upon one at the exte-
rior crest. Should gabions be used for reveting the cheeks,
fascines are first partly imbedded along the edges of the sole,
and the gabions placed on them in such manner as to obtain the
proper flare. The gabions are held in position by being an-
chored with telegraph wire to a beam of timber imbedded in
the parapet parallel to and about 8 feet from the cheeks of the
embrasure. The beams are held bj^ securing stakes. Revet-
ments made of other material are secured in a similar manner.
This precaution should be thoroughly looked after in the first
instance, because when the revetment is broken by the blast of
the gun or the shots of the enemy it is diflScult to repair it, and
the necessitj'^ for repairing would probably come at a time when
it could not be done.

If the embrasure is to be cut out after the parapet is com-
pleted, the mouth is marked off with stakes and strips as before ;
the earth is removed so as to obtain approximately the sole,
which is then laid off and the work completed as just described.

The sole of the embrasure should be secured from being worn
away by the blast with boards, poles, or some similar material
running lengthwise with the embrasure. Raw-hides will greatly
assist in preserving the revetments of the cheeks from the effects
of abrasion produced by firing. For this purpose the hide, while
green, is stretched, with the flesh side outward, over the part to
be protected, and is there confined by stakes driven through it
'iito the parapet.

The best method, however, for securing the mouth of the em-
brasure, and the sole and sides for 5 or 6 feet from the mouth,

PLATFORMS. 387

Is a lining made of J-iuch boiler iron. {Fig. o, Plate 61.) The
.plates are cat to the proper form to fit the sole and cheeks, and
are fastened together with angle-irons and rivets. Wings, about
a foot wide, extend ont on each side against the interior slope to
.prevent the lining from being moved to the front by tlie blast.
A round bar of iron passes across the top about 18 inches from
the throat; to this a door of sheet-iron is suspended, forming a
mantlet against musketry. In the centre of this door is a cut or
slot, about a foot high and 6 inches wide, for the double purpose
-of allowing the rammer to pass through while loading the piece,
and for sighting it. A vertical lever of wood or iron is fastened
to one side of the door ; to this a rope is attached, so that by pull-
ing on it the door is tlirown up to allow the piece to be fired.

That part of the interior slope lying below the mouth of the
embrasure is termed the genouilUre. The mass of earth between
two embrasures is termed a merlon.

The advantages of embrasures are, that the men and guns are
less exposed than in a barbette battery. Their principal defects
are : the}'' have a very limited field of fire ; they weaken the par-
apet, and present openings through which the enemy may pene-
trate in an assault. Owing to their limited field of fire, they are
generally used for the protection of particular points ; as, to flank
-a ditch, protect a salient, enfilade a road, &c. The most suitable
position for them in a work is on the flanks.

635. Platforms. When a gun mounted on a traveling car-
riage is fired often in the same direction, the ground under the
wheels is soon formed into ruts. It is to prevent this that plat-
forms of timber are used in such cases. Those for field service
are described in par. 254, et seq.

The shape of the platform for works is usually a rectangle ; in
some cases, where a wide field of fire is required, the form is a
trapezoid. The rectangular platform is 10 feet wide and 17 feet
long for siege-pieces, and 9 feet wide and 15 feet long for field
guns. It consists of three sleepers of 6-incli scantling, either 15
or 17 feet long, laid parallel to the directrix of the embrasure
and covered with 2-inch plank cut into lengths of nine or ten
feet. Between the ends of the sleepers and the foot of the gen-
^uill^re a piece of 8-inch scantling 9 feet long, termed a hurter^
is laid; it should project about 6 inches above the platform and
be bisected by the directrix. The object of the hurter is to pre-
vent the wheels from striking against the revetment.

To lay a platform, the earth on which it is to rest should be
well rammed and leveled. Three trenches are then made for
the sleepers, two of which should be under the wheels and the
middle one under the trail. The sleepers are laid flush with the

888 PLATFORMS.

ground and firmly secured by stakes driven at their sides and'
ends, and the earth is solidly packed around them. The planks
are then laid and secured by nails.

When the piece is to be fired habitually in the same direction,
a platform may be constructed of three pieces of timber, one
under each wheel and one under the trail, firmly secured by
stakes and connected by cross-pieces, into which they are halved.

Guns and mortars in field-works are best in pairs, with trav-
erses between each set of pairs. A good platform for guns may
be made of 3-inch plank laid on timbers 3 feet apart. If lumber
is abundant, it is best to have the planks extend over the whole
space occupied by each pair of guns.

636. In many field-works, especially those erected for the
defense of rivers and the entrances to harbors against armed
vessels, artillery of the heaviest calibre is mounted. The gen-
eral features of works for such an armament are the same as
those previously described for light armament, but in many of
the details — notably in the method of mounting the guns — there
are dificrences of especial interest to artillerists. As such works
are intended to resist fire from the heaviest artillery, they should
receive the maximum thickness of parapet. {Par. 596.) The
parapet is much higher, the merlons being simply masses of
earth thrown tip in mound shape and reveted on the interior
slope, without any attempt at arrangement for infantry fire.
Tlie magazines, traverses, and splinter-proofs are of greater size
and thickness. The guns are mounted on iron carriages the
same as for permanent fortifications; the height of these carri-
ages admits of from five to seven feet from the interior crest, or
from the sill of the embrasure to the top of the platform. Each
piece requires 18 feet in width of clear space, and in most cases
a splinter-proof traverse should be placed between each gun, or
pair of guns, and Its neighbor.

The gun platforms are constructed of heavy beams of timber
in two or three layers, crossing each other and firmly secured
together with iron bolts. Plate 62 shows in detail the construc-
tion of the platform for the 8-inch converted rifle, which is also
the same for the 100-pounder Parrott and 10-inch smooth-bore.

For the 12-incli rifie, the platform represented in Plate QZ has
been proposed by the Engineer Bureau.

The platform adopted for the 15-inch smooth-bore (front pin-
tle) is shown in Plate 64. This platform is designed for a carri-
age with depressed traverse circles, admitting of the terre-pleln
being 11 feet below the interior crest, thus giving increased se-
curity to the cannoneers.

Plate 64 shows the details of construction of the platform

POWDER MAGAZINES. 389

■adopted for the 15-in<;h smooth-bore, mounted on a centre-pintle
Kiarriage.

These platforms are supplied, when needed, by the Engineer
Department. To lay one, a pit of the proper size is dug; the
bottom of it is thoroughly settled by ramming, and the platform
is laid in it, and the earth filled in and well rammed about the
timbers. Great care should be observed to have the circles per-
fectly level. Previous to laying the platform the timbers should
be coated with coal-tar.

In case of war with any maritime power, it would be necessary
to erect earth-works of the foregoing character for the protection
of our harbors. The permanent works constructed and intended
for that purpose were designed when the 10-inch Columhiad rep-
resented artillery of the greatest power. Since then artillery of
a new type and vastly greater power has been introduced, against
which fortifications of old style are capable of oflering but feeble
resistance. The construction of these old works, furthermore,
does not, except to a small degree, admit of the changes that
would be nc^cessary to adapt them for receiving armaments of
modern artillery. An officer in command of the defenses of a
harbor being called upon to place them in a state of efficiency,
"Would, therefore, select positions exterior to the permanent
works, and erect thereon earth-works of the character just de-
scribed, and ai-m them with appropriate artillery. The new
works would, generally, be simply uninclosed batteries bearing
upon the charmel. They should, if possible, hold defensive rela-
tionship with the old works and the latter be utilized as redoubts,
armed with light guns and musketrj^ to prevent the enemy from
landing and assaulting the new works in rear. The old works
would, furthermore, serve as places of arms and depots secure
irom capture hy coup de main.

Whenever railroad or water transportation is available, artil-
lery of heavy calibre is made use of in siege operations. Guns
thus used are mounted on wooden platforms of the foregoing
models, and placed in earth-works of the character herein de-
scribed.

63'^. Powder magazines. The main objects to be obtained
in constructing a powder magazine are, to place it in a position
convenient to the pieces to be served, and one least exposed to
the fire of the enemy ; to make it shot-proof, and to secure the
contents from moisture.

Magazines are of two kinds : the storage magazine., in wliich
is kept the general supply of powder for the work, and service
■magazines., which are small, containing only a limited supply
ior the immediate use of a few pieces. The latter should be

890 STORAGE MAGAZINE.

near the pieces to be served ; generally they wonld be placed
in the traverses separating guns, or else close in rear of the
platforms.

Storage magazine. The size of the storage n>agazine will
depend upon the number and calibre of pieces in the work
and the number of charges to be kept for each. This data
being known, the amount of storage room required will be de-
termined by allowing 5780 cubic inches for each barrel contain-
ing 100 pounds of powder.

Projectiles and cartridges for siege and field guns are put up
in boxes, as explained in par. 565, and are stored in magazines
kept especially for this kind of ammunition. Each box of siege-
gun ammunition contains four projectiles and four cartridges,
and measures about 2950 cubic inches. Each box of field-gun
anunnnition contains ten projectiles and cartridges, and meas-
ures about the same. From this it is easy to obtain the storage
capacity required for any amount of these kinds of ammunition.

The dimensions of the interior of the magazine should be so
regulated as to entail no unnecessary loss of space in storing its
contents. The exterior dimensions of a powder barrel are :
Length, 20 inches ; diameter at bilge, 17 inches. With the bar-
rels stored in the usual way, on the side, {Fig. 1, Plate Q^.) a
magazine 6 feet 6 inches high would afford space for four tiers,
leaving 8 inches on top for handling room. A magazine 10 feet
wide will give room for four rows, leaving 40 inches for passage-
way ; therefore each 17 inches of length of a magazine 10 feet
wide by 6.5 feet high will contain 16 barrels. A magazine of
this height and width and 30 feet long would store 400 barrels
and leave a space of about one yard in width, extending across
it, at the entrance.

At the rate of 100 rounds for each 15-inch gun, a fair allow-
ance for such guns in field-works, a magazine of the foregoing
dimensions will give storage for a supply of powder for four
pieces. The number of rounds per gun should increase as the
calibre diminishes. It would, however, seldom be necessary to
have more than 300 rounds for any calibre above 100-pounders.
An ordinary packing- box containing the number of rounds
before specified measures, in exterior dimensions, 19 inches in
length, 13.5 inches in width, and 11.5 inches in height. These
dimensions allow the boxes to be compactly packed in a maga-
zine of any ordinary shape, and it requires only a small calcula-
tion to determine the storage room required for any given num-
ber of rounds for guns of these calibres.

It is best not to exceed, for any one magazine, the dimensiona^

STORAGE MAGAZINE. 391

above laid clown, Damely, 30 by 10 by 6.5 feet. When greater
storage room is required, two or more should be constructed.

Precautions to secure drainasfe are of the utmost importance.
Generally the ground is sufficiently undulatmg to effect this by
means of a covered di-ain leading from the bottom of the maga-
zine. Where this is not practicable, the bottom of the excava-
tion must be formed so as to collect the water at one point,
whence it may be removed by pumping or bailing.

Figs. 1 and 2 illustrate the best method of constructing a stor-
age magazine. The sides of the interior of the magazine are
formed of 12-inch logs, either square or round, placed verticall}''
hi juxtaposition, and resting on aground-sill. These are capped
on top by a 2-inch plank, a strip of the same being spiked on
within the cap. The roof is formed of 15-inch logs, laid across,
in juxtaposition, each having a shoulder of 3 inches to fit it to the
cap and inside strip. Longitudinal logs with varying diame-
ters are laid on these, so as to give a proper pitch to the roof.
Earth is solidly packed upon the top and between the roof logs,
receiving the proper slope for the roofing boards. These boards,
carefullj^ joined, are laid on in two thicknesses, each being covered
with a coating of asphalt or coal-tar; upon these boards rest the
covering of earth. The flooring is of joists and boards. The
sides of the magazine are surrounded with an air-chamber formed
of inclined logs supported on a ground-sill and resting against tlie
top logs; these are placed at tln-ee or four feet apart, each one
being braced at the middle to resist flexure from the pressure of
the earth. The air-chamber is covered in by saplings laid upon
each other horizontally. Ventilators are placed between the
magazine and the air-chamber, near the top, and also between
the latter and the external air, the two not being opposite, and
the usual precautions to guard against sparks, by covering the
mouth with wire cloth or perforated tin, are taken. The whole
is covered with earth, the thickness of which will depend on tlie
character of the enemy's artillery. In no case should it be less
than 14 feet on the exposed side; 10 feet will be sufficient for
the other sides and the top. The entrance may be either upon
an end or side, depending upon how the magazine has been
located with reference to the enemy. In all cases the entrance
must be on the side from the enemy, and should be secured by
a bomb-proof covering. The magazine chamber should, if prac-
ticable, be placed at least two-thirds of its lieight below the sur-
face of the ground. The ammunition is stored and cared for as
explained in par. 569.

In this and all similar structures railroad iron is a highly serv-

392 SERVICE MAGAZINES.

iceable material for roofing, the bars being laid in juxtaposition
in place of the logs before mentioned.

Service magazines. The size of these will depend upon the
number of rounds it is desirable to have ready for immediate
use ; usually, twenty rounds for sea-coast guns, and from fifty to
a hundred for those of smaller calibre, will be sufl3cient. The
capacity of the magazines to hold this amount or any other that
may be fixed upon will be determined by the rules just given.
If the magazine is to hold barrels, it should be 6.5 feet high and
7.5 wide ; this will accommodate four tiers of three rows, leaving
a passage-way of 30 inches. The length will depend upon the
number of barrels, and this will be governed by the number and
calibre of pieces to be provided for ; generally, 15 feet will be
ample.

A magazine of this description is usually constructed of coffer-
work.

A coffer- work is formed by making frames {Fig. 1, Plate 66) cor-
responding in dimensions with the cross section of the magazine ;
each frame is composed of two uprights, termed stanchions, and
a cap and sill of stout timber or scantling, not less than 6-inch.
The cap and sill pieces are slightly notched to fit tlie stanchions,
and all seciu'ed togethei* with nails or spikes. These frames are
placed upright and parallel to each other, about 2 feet apart;
they are covered on the top and sides with 2-inch plank, termed
a sheeting. The magazine, otherwise, is constructed as in the last
case.

A very good magazine, and one easiest of construction, is made
of logs notched together at the corners after the fashion of a log
cabin. {Fig. 2, Plate 66.) Other logs are laid in juxtaposition
across the top, and the whole covered over with earth. This is
the most substantial for those placed in traverses.

For field and siege pieces the magazines are not required to be
so large. A height and widtli of 6 feet with a length of 12 feet
will generally be sufiicient.

Magazines of this size may be made as just described, or they
may be made of gabions. {Fig. 3, Plate 66.) When the latter
are used, a hole is usually dug in the ground to form part of the
magazine; the gabions are placed in three rows, side by side,
around the hole, and are filled with earth. The top is formed
of timbers laid across in juxtaposition and covered with fascines,
the whole being covered with a proper thickness of earth. The
bottom is covered by a fl.ooring of joists and boards, a shallow
ditch being left under the flooring to carry any water to a drain
outside. This, at best, is but an inferior method of constructing
a magazine.

TRAVERSES. 393

Entrances to maoazines must always be on the side from the
<>neiny, and protected by a splinter-proof shelter large enough
to afford easy access to the door.

Splinter-proofs are usually constructed of scantling or trunks
of trees cut into suitable lengths and placed in an inclined posi-
tion over the magazine door. {Fig. 4, Plate 66.) The timbers
are placed side by side, and covered with at least two feet of
•earth or sods.

To prevent rain from percolating through the earth on top,
the magazine is covered with a paulin laid on the earth and
secured with pickets. To prevent rapid decay of the paulin, it
should be payed with a mixture of tar and grease boiled to-
gether — about two parts of tar to one of grease ; this composi-
tion is applied to both sides. In dry weather the paulin should
be removed to let the earth dry.

Boards, bark, or shingles may be used instead of paulins.

Adjoining or near the service magazine is a tilling-room, in
which the powder barrels are opened and the cartridges made
up and the shells tilled. A room 10 feet square hj 6J feet high
will generally be sufficiently large. It is constructed in the same
manner as the magazine, and is fitted with shelves, &c., for the
convenient keeping of primers, fuses, implements, and other
small articles required in making up cartridges and preparing
shells.

While being convenient to the magazine, it should be so sit-
uated that an explosion taking place in it will not communicate
tire to the magazhie. Fig. 2, Plate 65, represents the ground
plan of one form that may be adopted.

The powder is carried from the magazine to the filling-room
in canvas or leather stretchers, and only in such quantities at a
time as may be necessary for keeping the pieces served.

63§. Traverses. Those which are placed between guns or
on their flanks to cover them from an enfilade fire, are usually
termed gabionades.

To form a gabionade, gabions are placed in a row {Fig. 5,
Plate 66) side by side, inclosing a rectangular space of about 15
feet in width from out to out, and about 24 feet in length, per-
pendicular to the parapet. A second row is placed within this
and touching it, and a third row inside of the second. The area
thus inclosed is filled in with earth to a level with the top of the
gabions. Six rows of large fascines are next laid on the gabions
to support a second tier consisting of two rows. The second tier
is filled in like the first, and the earth is heaped up on top. Four
rows of large fascines are placed on these to support a third
•consisting of one row, making the gabionade nearly 12 feet

394 BOMB-PROOF SHELTERS.

high. The ends are hiclosed by filHng in with gabions, as for
the sides. A passage-way of about two feet is left between the
end of tlie traverse and the parapet. This space ma}' be roofed
over with logs and earth to form a cover in which the cannon-
eers may shelter themselves against fragments of siiells.

Splinter-proof traverses xn^j be made by placing two thick-
nesses of gabions side by side filled with earth, with a second
tier of one thickness on top. When a service magazine is to be
placed in a gabionade, the rows of gabions are set farther apart,
and the excavation for the magazine is made between them.
The chamber of the magazine is constructed in one of the ways
heretofore described. t

639. Bomb-proof shelters. These are for the protection of
the troops when not on duty. They should be located on the
parade, convenient to the pieces to be served, yet not so near as
to interfere with the defense. They are usuall}'" constructed in
half excavation of logs built up like a log house, or of a frame-
work in the manner shown in Fig. 1, Plate 67, the exterior
side being of heav.y logs placed vertically in juxtaposition, rest-
ing on a ground-sill and capped at top. Parallel to this is an-
other row, forming the other side, which may also be placed side
\)y side or at short intervals apart, and capped like tiie outside^
row. The roof, consisting of heavy logs laid in juxtaposition
and covered with thick boards joined, rests on the capping, the
whole covered over on the side of the enemy with earth to a
depth of at least 14 feet from the wood-work. To prevent this
mass of earth from pushing the structure over to the rear, one
in every two or three of the roof-logs are cut of sufficient length
to extend about 8 feet beyond the front of the wall, and dove-
tailed to a longitudinal log held in position by vertical posts, the
anchor-log being sufficiently covered with earth to protect it
from injury by shot from the enemy.

These bomb-proofs are made to serve the purpose of traverses,
and are frequently arranged with a staging or gallery along the
rear side for the accommodation of infantry, who deliver their
fire over the top, arranged for this as a parapet.

In all interior arrangements, system and regularity should be
observed from the first ; otherwise the work will grow into a
labyrinth of confusion greatly opposed to efficiency and comfort.

64®. Splinter -proofs made after the foregoing plan, but
smaller, may be placed against the parapet between the guns.
These not onlj^ afford slielter for the men, but give a place to-
keep implements and a few rounds of ammunition readj^ for
immediate use. Another convenient form of splinter-proof may

BATTERIES. 395

be made b}^ leanino: logs or railroad-iron bars against the sides
of traverses and covering them over with earth.

Works exposed to anything like constant and protracted artil-
lery fire, shonld be provided with bomb and splinter proof shel-
ters sufficient to comfortably lodge the entire garrison. This is
made more necessary now than formerly, from the very great
range and searciiing power of modern artillerj^ which makes it
impossible for a garrison to obtain rest without going to too
great a distance from the work.

As a general rule, troops should, for sanitary reasons, be
quartered as much as possible outside of the works.

Tlie importance of protecting guns and their carriages with
traverses and epaulments bears an increasing ratio to the size
of the piece.

Formerl}', when guns were comparative!}'' light, works were
garnished with them in great numbers, and the fact of having a
few of tliem disabled was of but little consequence ; it required
but simple appliances and only a few hours to replace them by
others. With modern heavy artillery, it is impracticable to have
many pieces in a work, and when one. is disabled it requires
days instead of hours, and the employment of much machinery
and labor, to replace it.

641. Batteries. The field-work that artillery troops are most
frequently called upon to construct is the battery. This may be
for one piece or for several. Fig. 2, Plate 67, represents a bat-
tery for four siege-pieces.

In this instance, tlie parapet (A) is made of earth taken from
the front, thus forming a ditcli (C). To protect the pieces
(XX XX) from flank tire, the parapet is continued around on
one or both ends, forming epaulments (BB). The guns are in
pairs, separated by a traverse (D). The interval between the
axes of the embrasures of each pair is 16 feet for guns on travel-
ing carriages, and from 18 to 22 feet for sea-cpast guns. Be-
tween the two middle pieces, this distance is increased by the
thickness of the traverse, generally about 15 feet. Tlie entire
length of the interior crest of the parapet, from a to 6, will there-
fore be 79 feet. This and other giv^en dimensions are not abso-
lute, but indicate tlie method of obtaining the data necessary
for laying out an?/ battery. The length of the flank epaulments
will depend upon the direction of the enemy's fire; in all cases,
it must be sufficiently great to give full protection to the whole
interior from an enfilading fire; generally it would be about 24
feet. The thickness of the parapet and epaulments will depend'
upon tlie power of the artillery they are expected to resist..

396 BATTERIES.

(See par. 596.) The details of the various parts are the same as
heretofore given.

Wiieii the earth is thrown up from the rear to form the para-
pet and epaulments, the work is termed a sunken battery. The
ditch (C) is then dispensed with. In many instances a ditch is
of but little importance, and for economy of labor the earth may
be taken from both front and rear.

Embrasiu'es for guns firing with great angles of elevation may
receive a counter-slope, giving the sole nearly the same inclina-
tion from the sill upwards as the least angle of elevation uuder
which it may be required to aim the piece. {Fig.. 4!^ Plate 61.)

Batteries for even the heaviest pieces may be constructed on
marshy ground by laying a grillage of timber over the surface
and building up the parapet on it with sand-bags. To prevent
the parapet fi-om settling over towards the fnmt, the grillage
should extend several feet beyond it in that direction. In or-
der that the platform of the piece may not be moved from its
true horizontal position by any settling of the parapet, the space
to be occupied by it is inclosed with strong sheeting piles. In
this inclosed space several la5''ers of fascines are laid, crossing
each other at right angles; on these earth or sand is rammed,
and the platform laid in the usual manner. If sand is used
on top of the fascines, two or three thicknesses of paulins should
be spread over them to hold the sand. Magazines in such locali-
ties must, of necessity, be entirely above ground, and supported
on grillage in the same manner.

64*2. Batteries are classified according to their construction,
use, and armament, as follows: Covered battery., intended for a
vertical fire and concealed from the enemy ; breaching battery^
intended to breach the works of the enemy ; Joint batteries., unit-
ing their fire against the same object ; counter-battery, one bat-
ter}'^ opposed to another; cross-batteries., forming a cross-fire on
an object ; oblique battery forms an angle of 20 degrees or more
with the object against which it is directed, in contradistinction
to direct battery ; raised battery., one whose teiTC-plein is elevat-
ed considerably above the ground; sunken battery., where the
sole of tlie embrasure is on a level with the ground, and the
platform consequently sunk below it ; enfilading battery., when
gthe projectiles sweep along a line of troops, a ciiannel, road, or
part of a work; liorizontal battery., when the terre-plein is that
lOf the natural level of the ground; open battery., without epaul-
ment or other covering — wholly exposed ; indented battery, or bat-
.terj'^ a cr^mailli^re., one constructed with salient and reentering
angles for obtaining an oblique fire as well as a direct fire, and
sto afford shelter from the enfilade fire of the enemy; reverse baU

WIRE ENTANGLEMENTS, ETC. 397

tery^ that which fires upon the rear of a work or Ihie of troops ;
ricochet battery^ that whose projectiles, beino^ fired at low eleva-
tion, graze and bound along without burying themselves ; masked'
battery^ artificially^ concealed until required to open upon the
enemy ; mortar batteries^ gun batteries^ &c.

64t$» Mortar batteries. These have the principal features of
batteries for guns. It is desirable that they should be located
where good views of the enemy's position may be had ; this, in
order that the gunner may himself see the eflfect of his shot, and
not, as is too frequently the case, have to depend upon the im-
perfect report of a distant observer. For siege mortars, the
platforms are placed the same distance apart as for siege guns,
viz., 16 feet ; for sea-coast mortars, tlie distance is the same as
for sea-coast guns, viz., 18 to 22 feet. They are usuallj'- placed
in pairs, with traverses between each set of pairs. Embrasures
are not required, and as the platform must be at such distance
from tlie parapet tliat the blast will not injure the interior crest,
it is not necessary to revet the interior slope, the earth being
allowed to assume its natural slope.

The siege-mortar platform furnished for field purposes is too
light to sustain much firing. For fixed batteries, they should be
constructed of heavy timbers, and, to insure anything like accu-
racy in firing, nuist be both level and stable. The sea-coast
platforms {par. 229), when properly laid, are in every respect effi-
cient. A good kind of raiT platform may be made by using two
pieces of timber {Fig. 4, Plate 67) 12 to 15 inches square and
9 feet long for the rails, to which planks 2 or 3 inches thick and
8 or 9 feet long are spiked. The rails are parallel, and have
their centres 28 inches apart for the 10-inch mortar, and 22 inches
for the 8-inch. A pit is dug large enough to receive this struct-
ure, and the bottom being made perfectly level, it is placed in
it with the planks down. Earth is filled in on top of the plank-
ing. This Idnd of platform is particularly well adapted to sandy
localities. If the mortar is intended to be fired in various direc-
tions, a sufficient number of rails are used to extend over the
whole surface, the planks being spiked to all of them.

644. Wire entanglements^ abattis., S^c. Every approach
which an enemy might use to reach a work, should be so ob-
structed as to keep him as long as possible under a close fire of
musketry. The best thing for this pui-pose is wire entangle-
ment, made by planting stout stakes, {Fig. 5, Plate 67,) about
3^ feet long, 2 feet in the ground and 7 feet apart, in quincunx
order and in three or four lines. Around the tops of these
stakes, at from 12 to 18 inches from the ground, in notches pre-
pared for the purpose, telegraph or other strong wire is securely

^98 TORPEDOES.

wound, extending from one stake to another. This obstacle is
rapidly made, is difficult to remove, and can be injured but little
by the fire of the enemy.

645. Ahattis is formed of the large limbs of trees, or of small
trees themselves; the small branches are chopped off and the
ends, pointed and interlaced, are presented to the enemy. The
large end of the limb or tree is secured to the ground by stakes.
Obstacles should be in two or more lines, and not too close to the
work ; the first line should be about 100 yards in front, and the
others beyond, at about 50 yards intervals.

646. Torpedoes^ if used, would be placed in these intervals.
These weapons depend for their utility more upon their deter-
ring than upon their actual destructive power. Men who will
march bravely up through a blaze of musketry will wallc timidly
overground in which they suspect the hidden mine. Torpedoes
maj^ be simply shells charged with powder and slightly buried
in the gi'ound ; or they may be wooden boxes, kegs, or any other
vessel capable of holding and keeping dry a charge of powder.
Shells produce their effect from their fragments, and likewise,
if large, from the blast of the explosion. Charges otherwise in-
closed produce effect only by the blast ; consequently the greater
the quantity of powder the greater will be the effect.

The chief difficulty in planting torpedoes is in the arrange-
ment for igniting them at the proper moment. This may be
done by electricity, as for submarine mines, or by a self-acting
device whereby the charge is exploded by the tread of an enemy
passing over it. The device used by the Russians at Sebastopol
is perhaps the best of many that have been tested. The case
consisted of a cubical wooden box {a b c d^ Fig. 1, Plate 68)
large enough to contain a charge of 10 to 20 pounds of powder.
This box was contained in another box (ABC D), leaving a space
between of about 2 inches, which was filled with pitch, render-
ing the powder in the inner box secure from moisture. The top
of the exterior box was placed 6 or 8 inches below the surface
of the gi'ound, and on it rested a board about the size of the top ;
this board stood on four legs of hoop-iron about 4 inches high.
The top of this board was near the surface of the earth, and
covered slightl}'^ so as not to be perceived. On any slight press-
ure upon the board, such as a man treading upon it, the hoop-
iron supports yielded and the board came in contact with a glass
tube (X) containing sulphuric acid ; the tube breaking liberated
the acid, which came in contact with a priming of potassa chlo-
rate and loaf-sugar within the box, causing instant combustion
and, as a consequence, explosion of the powder. The glass tube
18 placed within another of lead, tin, or other metal which bends

MANTLETS. 399

readily, yet strong enough to afford a certain degree of protec-
tion to it. The metal tube conducts the acid to the interior after
the ghiss is broken. Instead of the interior box, a shell filled
with powder may be used. Other devices for exploding tlie
•charge are frequently employed. They are constructed upon
the principle of a plunger striking upon fulminating composi-
tion, but these are diflScult to construct so that moisture will not
enter and destroy either the fulminate or charge. When torpe-
does are planted, the position of each one should be so marked
as to be known to friend, but not to the enemy. They should
not be planted in front of any work from which sorties are to be
made. They are useful along beaches to prevent the enemy
from landing.

647. Mantlets. A mantlet is a shield placed over the mouth
of an embrasure to prevent musketry bullets and fragments of
shells from flying through and injuring those serving the piece.
A hole in the lower part allows the muzzle of the piece to pass
through into the embrasure when it is to be fired. The size of
these openings will depend upon the dimensions of the piece.
Rope is the best material for constructing mantlets. The usual
size of a mantlet is 5 feet high, 4.5 feet across, and 4 inches thick.
For siege guns the opening is 1.6 feet high by 1.3 feet across.
Three-inch rope is a suitable size ; it is laid in three or five thick-
nesses, each of the two outer layers being in one piece bent ver-
tically. {Fig. 2, Plate 68.) The inner layers are bent and laid
horizontally, and the whole well tied together. The mantlet is
hung on a horizontal pole supported by forked uprights set in
the ground, on each side of the embrasure, at the foot of the
interior slope. The elasticity thus aflbrded by the supports
greatly increases the resistance of the mantlet. A small hole or
filit is pierced in the mantlet to allow the piece to be aimed.

Mantlets of this size weigh about 400 pounds.

A small ring mantlet of rope {Fig. 3, Plate 68) placed upon
the chase of the gun is sometimes used.

When rope cannot be obtained, one of similar shape may be
made of w^ood.

Mantlets may be made of wood or of iron, or of wood and
iron combined. Those of the latter kind furnished for the siege
of Yorktown were made of two thicknesses of ^incli wrought-
iron spiked to 3-inch oak plank. On the head was a 2-inch
siquare iron bar riveted to the edge of the iron plates, against
which the oak planks abutted. The ends of this bar projected
Q inches, and were rounded, serving as supports to rest upon
upright stakes or timbers standing against the interior slope of
the parapet.

400 GUN-SHIELDS — BLOCK-HOUSE.

Mantlets, when supplied at all, are supplied by the Engineer
Department.

64§. Gun-shields. Wlien railroad iron can be obtained,,
shields, with embrasures in them, can be made as represented in
Fig. 1, Plate 69. One thickness of iron is sufficient protection
against projectiles from field guns, two from siege guns, and
four from pieces of the 8-inch rifle class.

The same material may be used for constructing field case-
mates.

Block-house. {Fig. 2, Plate 69.) This is a species of small
redoubt, usually built of wood, and intended for an isolated
point wiiich can be approached by stealth or stratagem, requir-
ing the garrison to be constantly on tlie aleit, with their arms in
hand. It is at once a house and a fort. They are usually con-
structed for tlie defense of bridges against cavalry raids. Tliey
are also used in the Indian countrj'^ as a defense against savages,^
in which case the}^ are usuall}'- placed at opposite angles of a
stockade for flanking purposes.

They are made 10 feet high in the clear, and from 20 to 25
feet square. Logs 16 to 18 inches in diameter are used; these
are hewed on two sides and placed together, their hewed sides
in contact. They may be built up in the manner of a log-house,
but it is preferable to set them up vertically. The roof is made
of heavy logs extending over the walls about 18 inches on all
sides. On these logs a covering of earth is placed 4 feet thick at
the crown and running down to a depth of 6 inches at the eaves.
This earth is thoroughly rammed, and in it are imbedded pur-
lins, upon which is constructed a roof of boards or shingles.
Loop-holes for musketry are cut through the walls, the splay
being on the inside., and the height above the floor 8 feet. A
banquette of plank 3.5 feet from the floor and 6.5 feet in width
is carried around the interior ; this serves also as a substitute for
bunks.

Machine guns are eminently adapted for block-houses ; next
to these are howitzers, or other pieces effective with canister.
Each house should be supplied with two or more such pieces,
embrasures for which are cut so as to sweep the main avenues
of approach. The throats of the embrasures are closed when
not in use by heavy timber doors, barred on the inside. The
embrasures are cut at a proper height from the floor for the car-
riage used, and the banquette made in movable sections behind
each embrasure.

Around the outside is dug a V-shaped ditch, the earth being
thrown up against the sides of the house, at an angle of 45 de-
grees, as high as the soles of the loop-holes. The cheeks of the

BLOCK-HOUSE. 401

embrasures through this bank are of hewn timber, and a roof of
the same is laid across to sustain the slope just mentioned. A
small magazine is placed below the floor. A well-constructed
abattis and wire entanglement should surround the work at a
distance from it of about 100 yards. A block-house thus con-
structed is pretty secure against any artillery accompanying
cavalry raids.

The general idea of a block-house may be utilized in the con-
struction of bomb-proof covers or casemates for guns in field-
works,

wnvt mm^*

ATTACK AND DEFENSE OF POSITIONS.

649. In the attack upon intrenched positions, the points
Tegarded as the most advantageous are those in which the gen-
eral combination of the defensive line forms a salient with ref-
erence to adjacent parts. Such positions can receive but little
support from collateral portions, and can, to a greater or less
degree, be enveloped by a line of intrenchments of much greater
extent than itself, affording opportunities for establishing enfi-
lading and other batteries, the fire from which will be conver-
gent upon the point of attack.

Fig. 3, Plate 69, illustrates some of the advantages to be gained
by the selection of a salient as the point of attack. The full line
represents the trace of a regular work following theoretically
tlie general contour of the salient to be attacked. An inspection
of the figure shows that A, upon the prolongation of the face
E F, will be the best possible position for the attacking artillery ;
as from this position the projectiles, after grazing the parapet
at the point E, will rake the entire face E F. It is quite impos-
sible to protect such a line by traverses and at the same time
maintain a stout defense against a front attack.

From the point B, within the prolongation of the face, the
latter is struck in reverse under so small an angle as to weaken
but slightly the advantage of enfilade. It becomes less efficient
as its distance from the prolongation of the face is increased.
The next most advantageous position is at C, on the other side
of the prolongation of the face, striking its exterior direct but
under a small angle, thus taking in flank the embrasures of the
face and more readily destroying them without being exposed
to direct fire from the face.

The locality sometimes renders it obligatory to make the artil-
lery^ attack a direct one, as at D. This is the least advantageous
of all.

The dotted line of the figure represents more nearly actual
lines of field-works. The principles, however, remain the same.

In determining positions for batteries, those nearest the enemy
are not necessarilj"^ the best ; in fact, the greater the range the
more searching will be the fire. The projectiles will not have
the same power of penetration and destruction at long as at

(403)

404

ATTACK AND DEFENSE OF POSITIONS.

short range ; nevertheless, for ordinary warfare they possess snf—
ficient of these qualities to perform the work required of artillery
against field hxtrenchments.

650. The following table, showing the drop of projectiles at
various ranges, indicates the importance of this factor in actual
warfare. Fig. 1, Plate 70, illustrates this graphically, and, fur-
thermore, furnishes useful suggestions as to defilading works by
means of traverses and epaulments. See also table and remarks^
\n par. 619.

Drop of projectiles.

Range.

Yards.

200

400

600

700

800

1000

1100

1200

1400

1500

1600

1700

1900

2000

2500

3000

3500

4000

4600

RiFLK-MUSKET.

Drop. Seconds.

85
50
30
25
20
14

0.5

1.75

2.*5'
3.75

Veloc-
ity.

Feet.

1120
915
800

7*66
625

558

506

412

8-Inch
Rifle.

Drop.

57.3

28*6

r9*.*6

14.3
11.4
8.1
6.3
5.1
4.1

100-Pdb. Parkott.

Drop.

57.3
28'.'6

19.0
14**3

11.4
8.1

7.1
5.8

O D 3

Son

to S ©

;h rj O

S fl f^

Eh a 13 .-3

2; O d

When the distance to the object can be determined and the
range is such as to require considerable elevation, it is by no
means necessary that the object should be seen from the gun,
provided i*ange-points can be accurately established, as in mortar
firing. This is illustrated by Fig. 2, Plate 70. In many cases
it will be a great advantage to locate guns in this manner, for
the reason that the enemy will probably not be able to ascertain
their position witli sufiicient accuracy to do them much damage.

Should the distance behind which cover can be obtained be
quite short, as represented in Fig. 3, Plate 70, the charges for
guns may be reduced so as to allow the necessary elevation to
be given to carry the projectiles over the cover, and at the same
time drop them into the enemy's works. A few trial shots will
enable the artillerist to accomplish this with certainty. Siege
howitzers are used advantageously in this way.

ATTACK AND DEFENSE OF POSITIONS. 405

651. In nearly all cases the attack has the advantage over
the defense, in the amount of fire that can be brought to bear
xipon any particular point. When a position can be completely
-surroundecl, as is frequently the case in sieges, there is no limit
to the amount of fire that may be brought to bear upon it, ex-
Xiept the limit of ability to obtain the requisite quantity of pieces
and ammnnirion. It is therefore possible to throw into tlie place
such a hail of projectiles as to make it impossible for the defend-
ers to show any resistance. In most cases, however, the place
can be but partly surrounded ; nevertheless, the great range and
ability for concentration possessed by artillery enable it to ac-
complish like results. It is very certain that, under such cir-
cnmstances, the endurance of a place is only a matter of time.

The belief at present prevails, to a considerable extent, that it
is almost impossible to carry by assault intrenched positions, if
resolutely defended by troops armed with the breech -loading
■musket. Such being the case, the only alternative for dislodg-
ing an enemy so situated, and who cannot be starved out, is by
the use of artillery, — a fact that calls for the more liberal use of
this arm and the most skillful handling of it.

65S. With suflicient artillery an enemy can be driven, as
before stated, from any position he may occupy. But as there
is a practical limit to the amount that can be supplied — and this
may fall below what is necessary for actually dislodging him —
all that can be expected of it is, to so extinguish the fire of the
enemy as to enable the infantry to gain possession of the works,
as formerly, by assault.

In preparing to make such an attack, the first thing to be done,
after determining the particular part of the work to be assaulted,
is to establish the batteries and ascertain by experimental firing
how to use them so as to make every shot tell. Every available
piece should be put in, and other parts of the line stripped tem-
porarily in order to make the assault certain of success.

653. The infantry, in the meanwhile, has intrenched itself
on a line as near as practicable to the enemy, and organizes into
three lines for the assault. The artillery opens and keeps up
an incessant fire. When it is seen that the enemy have been
driven to cover, the first line of infantry advances as a thick line
-of skirmishers composed of detachments, each detachment being
under control of its chief. If the enemy show themselves, this
line opens fire and assists the artillery in suppressing them. The
men of each detachment keep together, and the detachments,
taking advantage of everj'' accident of ground for cover, rush
forward from point to point as opportunity offers. This line is
constantly fed and strengthened from the next line in rear,
-each detachment sent forward gaining ground until the reverse

406 ATTACK AND DEFENSE OF POSITIONS.

side of the enemy-s work is gained ; seeing which, the second or
main line rushes forward, and the whole clamber over the works
and drive out or capture the enemy.

The second or main line is formed in company columns, and
follows the first, or line of skirmishers, at a distance of about 500
yards — less when possible. The third, or reserve, is about 300
yards in rear of the second, and Is massed by battalions ready
to be moved where required. The lines of infantry are about
of equal strength; i. c, each one-third of the assaulting force.

654. The artillery at first uses shell, but as the infantry ad-
vances, and it becomes necessary to fire over it, only solid pro-
jectiles will be used ; and fire with these must be discontinued
when the infantry has approached so as to be in danger from it.
This is the most critical moment; but if positions for the bat-
teries have been selected with skill, those on the flanks will be
able to keep up a cross-fire until the final rush is made. The
artillery commander must have this matter so in hand as to be
able to commence or stop the fire from any battery at any mo-
ment. To accomplish this each battery should be in telegraphic
communication with him, and he must have a position where he
will have a clear view and knowledge of what is going on at the
point of assault.

As a general rule, it is well for the batteries, instead of sus-
pending their fire, to increase the elevation so as to throw their
projectiles beyond. This, besides checking and disorganizing
reinforcements coming up to the enemy from the rear, will have
a salutar^y moral effect upon him at the point of assault.

When, as is generally the case, the front of the work is pro-
tected by abattis or other obstructions, pioneers must accom-
pany the first line to clearways for the company columns of
the second line to pass through.

The artillery commander will select a proper number of de-
tachments, placed under suitable oflScers, to advance with the
second line for the purpose of turning upon the enemy such
pieces as may be captured with the works. These detachments
will carry with them sponges, rammers, primers, and lanyards.
Ammunition will generally be found with the captured pieces.

The most precise instructions are usually given to division,
brigade, and battalion commanders as to what they are to do
after getting possession of the work; otherwise the troops take
no precautions against a counter-attack. As soon as practicable,
the artillery commander moves batteries forward to establish a
new line on the works just captured. It is his duty to take pos-
session of all captured artiller}' material. An accurate and com-
plete inventory must be made of it, together with an account of
the part it had in the defense of the place ; this, in order that

SIEGES. 407

there may be no uncertainty as to the honors dne to various
parts of the capturing force.

Assaults should be made early in the day, so that the assault-
ing force will have time by daylight to push and make perma-
nent its success. If night intervenes, the assailed may take
advantage of it to reorganize a new line as strong as the first.

A dense fog is most favorable for an assault, as the assaulting
force is then able to see plainly that which is immediately
around it, without itself being seen by the assailed. For the
same reason, if made at night, bright moonlight is favorable.

It may here be mentioned that artillery of batteries in posi-
tion possesses an advantage over all other arms, in being able
to be used as well by night as by day ; and this is one powerful
element in its favor when protracted operations are carried on
against an enemy established in works.

If the strength of the works is such that they cannot be car-
ried in the manner just described, then recourse must be had to
regular approaches and siege operations.

Sieges.

655. A place is said to be closely besieged when it is so in-
vested as to prevent those within receiving succor from without.
When such an investment can be effected and maintained, time
alone will effect, by starvation, the work of reduction. When
the operations against the place are confined to a simple inter-
ruption of communications, it is termed a blockade.

In most cases, however, a place can be but partly invested.
The besieging operations then consist in regular approaches
against particular parts of line of the besieged, reducing them
in succession so as to force him to abandon the place which he
has attempted to defend.

No siege can be successfully prosecuted unless the resources
of the attacking army, especially in artillery, are superior to those
of the besieged.

656. When a siege is to be carried on by regular approaches,
the work so attacked should be enveloped as far as possible by a
line of batteries containing the heaviest pieces within the re-
sources of the besieging party. These batteries are connected
by a rifle trench for the accommodation of the infantry supports,
and to form a covered communication from one end of the line
to another. It also serves as a secure and convenient place for
the accumulation of material for the prosecution of further opera-
tions. The line thus formed is called the first parallel ; its dis-
tance from the besieged work depends, in a great measure, on the
character of the ground ; if this is undulating and broken, so as

408 SIEGES.

to form natural approaches to the batteries, the distance may be
much less than when the country is level and open to the tire and
view of the besieged. As a rule, it should be just without the
zone of very destructive fire from small-arms. This, with the
present rifle-musket, is about 1500 yards, a distance permitting
of the effective use of the artillery mounted along the line. The
batteries containing guns, especially those of heavy calibre,
should be located on the flanks of the line, leaving the interme-
diate batteries for mortars; this, for the reason that guns so sit-
uated will not be masked and have their fire checked by subse-
quent operations. Mortars can at all times maintain their fire
over the heads of troops occupying advanced positions.

If the enemy occupy intrenched positions in front of the main
work to be attacked, fire must be concentrated first upon one
and then another of these positions until he is successively driven
from them into his main work.

Every piece of artillery capable of throwing a projectile into
the works should be brought into requisition, and a superiority
gained as soon as possible over the artillery of the besieged.

657. In the meanwhile preparations have been made, b5'"the
accumulation of material, for the establishment of a second par-
allel, several hundred yards in advance of the first. This should
be done under cover of night by a line of infantry throwing up
a rifie trench. This trench is enlarged until it forms, like the
first, a covered way secure from the view and fire of the be-
sieged. Communication with the first parallel is secured by
means of zigzag trenches, technically called hoyaux. {Fig. 1,
Plate 71.) The branches of these boyaux are so laid out that
the enemy will not have an enfilading fire along them. Batteries
are constructed along the second parallel ; the boyaux are en-
larged to accommodate artillery carriages; the batteries are then
armed. Gun-shields, mantlets, and all similar devices must be
employed for the protection of the guns and cannoneers of these
batteries. The distance of this line will admit of the use of the
smaller class of mortars, and an abundance of them should be
put in it. As a rule, it is not advisable to place in this line
pieces of a heavier calibre than siege guns ; this, for the reason
that heavier calibres are more difficult to serve, and, besides, the
range from the first parallel is quite within the limits of eftect-
ive fire from heavy calibres.

An unremitting fire is kept up upon the besieged place. Dur-
ing the day the guns will be directed so as to sweep along the
faces of the works, disabling the guns of the enera}^ and demol-
ishing his traverses, magazines, and bomb-proofs. During the
night an incessant shower of mortar shells must be kept falling,
to prevent repairs and to keep the garrison constantly harassed.

SIEGES. 409

658. Usino^ tlie second parallel as a secondary base, the boy-
anx are pushed forward towards the salients of the work; when,
advanced to within about half the distance from the second par-
allel to the work, a third parallel is constructed by running
trenches to the right and left of the heads of the boyaux. The
third parallel is for the accommodation of strong guards of in-
fantry supporting the w^orking parties, who, under this protec-
tion, contrive to push forward the boj'^aux. They also use their
lire to suppress musketry fire from the vv^orks and to prevent
the enemj^ from serving his guns. An abundance of small mor-
tars should be placed in the third parallel and vigorously served.

As the boyaii-x are continued, it may be found advisable to
<istablish a fojirth parallel.

Fire from adjacent or collateral vv^orks must be attended to, so
as to prevent it from interfering with the progress of the ap-
proaches.

If the artillery of the besiegers is sufficiently numerous and
powerful, the foregoing arrangements will enable it, if vigor-
ousl,v served, to drive to cover the garrison of the place, and to
so destroy the means of defense as to make further resistance
of little avail. The garrison will either capitulate or withdraw ;
or if they still hold out, an assault made by infantry from the
advanced parallels will have a fair prospect of success. The
batteries having prepared the way for assault, render assistance
to it by the most spirited fire. This must, however, be directed
so as not to interfere with the assaulting force as it enters the
work. The practice which the batteries have had up to this time
will enable tliem to direct their fire with precision, and each one
must have pointed out to it the precise duty it has to perform.

Instead of an assault, sappuig and mining may be resorted to,
and the work made untenable b}^ these means. These operations
are conducted by engineers, the functions of the artillery, mean-
while, being confined to what has heretofore been laid down.

659. Masonr}' revetments readily crumble under blows from
heavy rifle projectiles. The precision with which the firing can
be done, and the drop of the projectile at long range, enable
the artillerist to reach scarp walls without, as in former times,
establishing batteries on the crest of the glacis. The debris
from the scarp, whether the latter, be of masonry or earth, and
that from the parapet resulting from constant hammering, will
generally make a ramp practicable for assaulting parties.

The particular work to be attacked by siege operations should
be selected with a view to the eftect that its capture will have
on other parts of the line; in other words, that its capture,
when accomplished, will be productive of decisive results, such
as leading to the capture or abandonment of other works in the

410 SIEGES.

line, the uncovering of communications important to the besieg-
ed, or securing lines of approach to tiie besiegers.

660. The defense of worlvs attacked by regular approaches
calls for the most active and vigilant exertions on the part of the
besieged, especially so from the artillery. So soon as the opera-
tions of the besieger indicate what work of a line, or the par-
ticular part of a work, is his objective, every effort must be made
to restrict the extent of his lines of envelopment. To this end,
adjacent and collateral works must be armed with pieces of the
heaviest calibre, so situated as to take the lines of approaches as
much as possible in flank. These batteries will give special
attention to the long-range batteries of the besiegers. Every
available piece of artillery must be brought forward and placed
in battery so as to strike the besiegers at some point or other.
Unremitted fire must be maintained against the heads of the
approaches ; these, from their open character, are peculiarly vul-
nerable to mortar fire. As many mortars as possible should be
placed in batteries established for this special purpose. It is^
not advisable to crowd artillery into the objective point of the
enemy, but rather to the right and left of it ; this secures a cross-
fire, and at the same time withdraws the pieces from the points
upon which the besieger concentrates his fire.

If an assault is to be apprehended, batteries, especially of
machine guns, should be established so as to sweep the clitch
and prevent the enemy from making a lodgment by digging
into the scarp and parapet. These batteries must be well secured
by means of bomb-proof covers and gun-shields. Traverses
must be thrown up to protect the guns, and bomb and splinter
proofs constructed to shelter the cannoneers. An interior line
of intrenchments should be constructed in rear of that part of
the main work attacked. This should be well supplied with
light pieces of artillery, which may be kept under cover until
the proper moment and then run up to drive the enemy from,
his lodgment on the main work.

The supply of ammunition must be closely attended to, and
under no circumstances, w^here it is possible to avoid it, should
it be allowed to fall below the probable needs.

All of the operations of the artillery in the defense, as well as
in the attack, should be directed by one head.

661. From the foregoing'sketch it will be perceived that the
operations of a siege maj^ be classed under two heads : those which
are necessary to prevent tlie besieged from obtaining succor, and:
those which are required to gain possession of the w^orks.

The line established by the besieging army to prevent succor
from without, is called the line of circumvallation ; that estab-
lished for carrying on the approaches against the work, is called

SIEGES. 411

the line of countervallation. Between these two lines the besieg-
ing army is established.

As a rule, the engineers have charge of the planning and con-
struction of the parallels and boj-aux; the artillery, of locating,
constructing, arming, and serving the batteries. All of these
operations are minutely connected with each other, and pro-
ceed together. It is, therefore, the duty of officers having them
in charge to act in accord in carrying them out.

662. Xo specific rules can be laid down regarding the amount
of artillery required for siege operations.

The most remarkable sieges that have taken place since the
introduction of the present style of artillery and small-arms have
emplo3^ed about 6500 fighting men per mile of investment, with
5 pieces per thousand men, or 33 per mile.

The conditions of each particular case must govern as to the
kind and calibre of pieces and the number of each, together
with the quantitj'^ of ammunition necessary. As a general rule,
a large proportion of the pieces should be of heavy calibre. In
some cases the means of transportation will admit of none
heavier than can be carried on traveling carriages. When rail-
roads are available still heavier classes maybe brought up, while
with water transportation there is no limit.

The object of the siege must likewise be considered. If it is
intended to simply cut the place off from supplies and reduce it
by starvation, an intrenched line of battle armed with ordinary
field artillery will be suflScient. If the place besieged is a town
or city to be reduced by bombardment, long range and heavy
calibres are most desirable; the same class would also be re-
quired for a work approachable only on one side, to be destroyed
by battering. When a work of this nature is to be reduced by
regular approaches, there will be required, in addition to guns
and mortars of heavy calibres for long range, a large proportion
of regular siege artillery capable of being readily moved up as
the works of the besiegers approach the enemy.

The amount of ammunition required will depend upon the char-
acter of the work to be done and the duration of the siege. If the
source of supply is certain and regulai-, the quantity to commence
with may be small compared with what should be provided un-
der other conditions. Considering the source of supply reason-
ably certain, about 200 rounds per piece for sea-coast and 1000
rounds per piece for other classes will be a fair allowance.

663. When a siege is determined upon, the chief engineer
and artillery oflflcers must study every condition of the particu-
lar case and decide upon what seems to be the best for carrying
out the general plan. Nothing must be omitted to make thft:
preparation complete.

412 SIEGES.

In commencing siege operations, tiie first thing necessary is
to gain possession of a large area of ground as near as possible
to the place to be besieged, for the purpose of establishing
depots, artillery parks, hospitals, and camps. This area must
be made entirely secure by intrenchments, after the manner of
an intrenched camp.

Depots, parks, camps, &c., should be screened as much as
possible from the view of the enemy, and a thorough system of
roads and telegraphic communication established between them
and with the batteries on the line. When practicable a railroad
should be laid, forming a main artery from one end of the line
to the other. Wharves are constructed for the unloading of
vessels, and depots established convenient thereto. These will
^consist of buildings for the accommodation of engineer and quar-
termaster's stores and subsistence supplies, together with work-
shops for repairs.

The water supply must be carefully looked after, not only as
to quantity, but as to purity. This is demanded upon sanitary
grounds. All springs, wells, and running brooks should be
guarded so that they may not be fouled by the watering of
animals or by bathing and washing of clothes. Reservoirs
should be constructed to prevent loss of water at night.

In localities where the supply is not convenient, water-carts
should be used for bringing it to where it is required for use.
This prevents sti-aggling and idling.

The site for the artillery park and depot should be easily
^accessible from all parts of the line. Magazines for powder and
iixed ammunition must be constructed in the safest places. Ar-
tillery carriages will be parked systematically in such manner as
to allow of any being withdrawn when required. The artillery ,
transportation trains, parked in the same manner, consist of a
number of wagons sufficient to carry supplies to the artillery depot
and to keep the batteries alongthe line supplied with ammunition.

Materials required in the construction of batteries, such as
gabions, fascines, mantlets, and sand-bags, together with those
for platforms and magazines, are usually supplied from the
engineer depot.

664. The character of the artillery employed in a siege will
determine the nature of the machines, implements, and stores
required. Supposing that the heavier as well as the lighter cali-
bres can be used, a fair allowance for each 100 pieces, large and
small, would be as follows : Six traveling forges^ with stores as
per par. 258 ; six battery-wagons^ with stores as per par. 258 ;
five sling-carts (large), ten sling-carts (hand), twenty hajid-carts,
five truck-wagons (heavy), ten mortar-wagons^ one hundred hand-
'barrows^ two hundred paulins^ ten gaiTison gins with tackle

SIEGES. 413:

complete, five siege gins with tackle complete, five 30-fon liy-
draiilic-jacks^ five li)-ton hydraulic-jacks^ tvv^o gun-lijh^ five era-
dies with rollers, two Imridred and fifty way-planks^ and five sets
of blocks^ skids^ &c., as specified in pa?-. 534.

Each piece of artillery is furnished with the implements and
eqnipments heretofore specified in connection with its service
and mechanical manoenvres.

Each service magazine will be supplied with a set of appro-
priate scales, measures, finniels, &c., and each battery with a
field-glass and set of signal flags.

One or more officers will be detailed to ascertain the distances
from the various batteries to the objects to be fired at, and will
be fiuMiished with the necessary instruments for the purpose.

Each artillery officer will provide himself wiih a pocket com-
pass, a pair of dividers, a protractor scale, and pencils; also
paper for notes and field-sketching. The instruments are con-
veniently carried in a shoulder-pouch, as represented in Fig. 2^
Plate 71.

Intrenching tools are furnished from the engineer depot.

665. The preparations for the siege having suflSciently pro-
gressed, and the engineers having laid out the lines of intrench-
ments, the artillery commander will select sites for the batteries,
determine their armament, and designate the troops to con-
struct, arm, and serve them.

The teams of the light batteries are used for transporting
artillery from the landing-place to the park, and thence to the
batteries on the line of investment.

Important works along the line are named, open batteries are
numbered in regular order, and the whole line and system of
communications mapped, so that there may be no confusion in
distributing material and supplies.

.666. When the siege is fully opened, the question of supply-
ing the batteries with ammunition is by no means a small one,
and requires thorough systematizing to prevent an undue accu-
mulation at some points and deficiency at others.

The allowance of ammunition for the immediate use of each
piece varies to suit cii'cumstances ; those batteries in most prom-
inent positions have the greatest supply, 100 rounds being about
the maximum and 50 the minimum. The number of rounds per
piece diminishes as the calibre increases. The supply is main-
tained by means of a train of wagons kept specially for the pur-
pose.

In order that the daily expenditure may be known at the
depot, the commanding officer of each battery on the line will
each morning make out and forward to the depot a report of
the followins: form :

414

REPORT OF BATTERY.

•CD

§■

■^S

5!i
-rO

M
PS

•qoi-^Tn ^ois

•qo^'Bra 2iomtO

•sasiij jadtJ^i |

•sSnid-asn^

•japM.od atfia

•japiSA.od JT3W0W

•lI^^S

•sSnid-asn^

•aapMod apiH

•japMod Jt3qaoi\[

•II^^S

r-t

■sSnid-asu^

•japAVod auiH

•japMod JtJ^ojtt

•nans

•sasuj jadT;<j

•sjauiud-uoi^OTJj[

-a

•saSpiJuiJO

•ja^sTUTJO

";ot[s-asTJO

Trsiis asn J

"naxis UjSsnojaj

•saSptJjjuo

•ja^siTi'BO

•'^oiis-as'BO

snaxis asn^

•siiaqs U(Ssnoja<i

•sa:Spu^j'BO

•sSnid-araix

•sSnid u,ssnoj9<i

•ja'^stutJO

•?otis piios

•^otis-astJO

•siiaqs

i 1
^ 1

O p:

Total M

Expended »m

REPORT OF BATTERY.

415

^■8:^1010 JO unS
JO jaquinu oouxjupjo

1
1

'jvuoxa Jto uti3 aaqaTa
uiojj paag s^oqs jo '6^

•un3
JO jaquiTiu aoutjupjo

•unS aaq^ia
raojj paxij snaqs jo -o^i

•un2
jo jaquiuu aouTJupjQ

•un3 jaqjia
Tuojj pajg s?.oqs jo 'o^

•aacliid

•uapooAS.

•uapooAV

•uapooA\

•PTIOS

•uijouoa

•uoT:^'BUTquioo

•asTJO

•asnj;

•Tioissnoj;a<j

•pnos

•uoT'i'BaTquioo

•as-BO

•asu^

•uoissnoia<i

•Plios

•Tioi:^BXiiqraoo

•as^o

•asuj

uoissnaja^

p -c

En "^

Burst well

Burst short..........

Burst long

Did not burst

•sani^o

a Co J

a -sasnj^

a
a

416

REPORT OF FIRING.

The oflScer in charo^e of the ammunition at the depot loads his
wagons with the amount required, and gives to each teamster a
ticket stating the contents of his wagon and to which battery it
is to go.

The train, under competent wagon-masters, starts out before
night-fall and proceeds so as to reach the batteries after dark.
Guides from the several batteries meet the train at appointed
places and direct the particular wagons to the proper batteries.
Upon the arrival of the wagons, an officer of the battery gives
nis personal supervision to the unloading, and signs the ticket
brought by each driver, noting an}^ discrepancy. The ticket is
returned by the driver to the officer at the depot.

All articles that have become unserviceable or are useless in
the battery, together with all empty packing-boxes and barrels,
are returned by the wagons to the depot, a list of them being
sent back with the teamster.

To simplify accountability, the officer at the depot will be
responsible for all the artillery, ammunition, and material.
Battery commanders give him memorandum receipts, and are
held accountable for any loss. The ammunition fired is ex-
pended by the depot officer upon the reports made by the officers
commanding the several batteries.

As a general rule, cartridges will be made up at the depot, and
sent to the batteries either in budge-barrels or in chests of con-
venient size made for the purpose.

The latter part of the report on the foregoing form is for the
information of the commandant of artillerj'^, and for the purpose
of keeping a complete history of the artillery firing. From the
daily reports a monthly abstract is made for each piece upon
the following form :

Monthly report of artillery firing^ siege of. tMay 18...

Kn>rD OF

d
1^

o
o
u
tx

o
o

1
u
o
o

•d

u
o

-d

Remarks.

No. and calibre
of piece.

Pkojectilk.

Percuss'n shell .
Fuse shell

10
6
4

8
5
4

7
6

Where located.

Solid shot

Canister

Case-shot ~

...

DEFILES. 417

The command of the enth-e artillery is vested in an officer of
that arm of service, who, besides other necessary qualifications,
should have rank commensurate with the importance of his
position.

The line of works is divided into sections, each of a size capa-
ble of close supervision by the officer assigned to the command
of it.

Defiles.

66 Y. A defile, in a military sense, is any narrow place the
passage of which can be made by troops only when undeployed.

Mountain passes, river crossings, narrow isthmuses, and roads
through close forests represent the usual forms of defiles. They
necessarily imply obstacles in the way to the free movement of
armies, and are therefore important features in a theatre of war,
and consequently points demanding special attention byway of
defensive arrangements. For these no precise rules can be laid
down ; nevertheless some general principles may be stated.

The chief advantage offered by a defile i$, that witli but com-
paratively slight intrenchments a small force is able to hold a
position against a much greater; this, for the reason that, owing
to the essential nature of a defile, the attacking force must oper-
ate in a constrained position, not admitting of much develop-
ment of fire. The main object, therefore, is to secure such a
column of fire over the defile as to make it impossible for the
enemy to stem it ; this is best accomplished by selecting such
points as will give an enfilade fii'e. They should be selected
with a view to mutual support, and intrenched in such manner
as to be secure against capture by coup de main. The enemy
must be compelled to make his attacks with divided forces and
inferior numbers. This is best accomplished by occupying sev-
eral positions within flanking distance of each other. He will,
probably, not be able to attack all simultaneously, and it will be
a costly operation for him to attack them in detail.

The positions should be so chosen as to allow them to con-
centrate their artillery fire upon any point where it might be
advantageous for the enem}^ to establish batteries, and the artil-
lery of the defense should be of such power as to preclude all
possibility of his doing so. All hollow approaches, such as
would be formed by ravines in a mountain pass, must be search-
ed by the fire of artillery. This, as a rule, will require pieces to
be placed in open batteries exterior to the inclosed works. Such
batteries must be well supported by infantry sheltered in rifle
trenches. The whole system should be so connected as to leave
27

418 DEFILES.

110 part isolated or without the support of other parts, and the
defense of each point must be stubborn in the extreme to pre-
vent the enemy from gaining possession of advantageous posi-
tions.

All parts of the line or group of works must be in communi-
cation by telegraph, telephone, or signaling, or by all three.
This is a matter of the greatest moment in securing not only
the physical, but also the moral support of the parts.

In every case artillery should form a chief feature in the
means of defense ; the kind of pieces for the different parts of
the system will depend upon the character of the ground and
of the nature of the attacks that may be expected. As a rule,
all approaches must be covered by fire; wherever horizontal
fire cannot be made to roach, mortars must be used. However
much the pieces may be scattered, they must be capable of con-
centrating their fire upon any position the enemy may assume.

As defensive works in defiles are required to be self-sustaining,
frequently for long periods, the supply of ammunition must be
ample for all probable wants.

If a defile is to be held for the purposes of an army either
advancing or retiring in front of an enemy, the head of it to-
wards the enemy must be secured by a line similar to a Ute-de-
pont; this, for the purpose, if advancing, of giving room for the
army to deploy after passing the defile, and to prevent the en-
emy from striking it while defenseless in column; if retreating,
the same disposition is necessary to hold the pursuing army in
check while the troops are defiling to the rear. In both cases,
as the object is to keep the enemy from closing in for a pitched
battle, artillery must be freely used.

In the attack upon a defile, intrenched, armed, and defended
as it should be, artillery will be the most important weapon ;
this, for tlie reason that, from the very nature of defiles, other
arms can act but feebly, while artillery possesses the power of
reaching its object beyond intermediate obstacles. As much
artillery should be brought to act as possible, and, although it
may be widely dispersed, its fire must be concentrated upon
some particular work in the system of defenses. The work must
be attacked with such vigor and persistency as to insure its
destruction and easy capture. Other works, successively, are
attacked in the same manner.

The operations upon both sides thus partake of the nature ol
a siege, and are governed by the same principles.

RIVERS. 419

KlVERS.

668. Rivers traversino- the theatre of war occupied by hostile
•armies have a marked influence on the operations of each.
Wlienever they are to be crossed in the presence of an enemy,
either in advancing or retiring, the use of artillery and of field-
works becomes of great importance ; this, for the reason that the
operation of crossing necessarily consumes considerable time,
during wliich the army is divided — astraddle, as it were, the
stream — and requites the aid of that arm which, from a fixed
position, possesses the power of covering at long range the
movements of other troops.

The place of crossing, whether bridge, ferry, or ford, is sim-
ply a defile through which the army has to pass, and which must
be completely covered from the fire of the enemy, who must not
be permitted to establish batteries within range of the crossing.
This is best effected by covering every point accessible to him
with the fire of artillerj'".

A river in front of an army operating on the defensive, stands
to it, somewhat, as a wet ditch does to a fortification, and should
be so guarded as to make the crossing of it a difficult, if not a
hazardous, operation to an advancing enemy. Points at which
the communications of a country converge are those most ad-
vantageous for an enemy to select for crossing. These should
be secured by strong inclosed works, armed with artillery of
such power as to cause liim to make a long detour and to adopt
a less advantageous point.

If the stream is navigable, such works form a place of refuge
for the craft that ply on it, and which, falling into the hands
of the enemy, would furnish him with means of crossing and
Assist him in carrying on his operations.

The size of the work will, to a great degree, depend upon the
force that can be detached from the main body for garrisoning
it ; but, generally, a well-constructed work containing a thousand
men, adequately supplied with artillery, will prove a formidable
obstacle to the crossing army. Points thus established should
not be so numerous as to cripple the efficiency of the defending
army b}^ dispersion. They should be rather in the nature of
bases for temporary points of observation along the river, secure
against capture by coup de main, and threatening to the flanks
and rear of the crossing army.

Tete-de-pont. A bridge is protected by a tete-de-pont, the
nature and extent of which will depend upon the character of
the attacks to be expected. Against mere raiding parties, a
redan or lunette — as represented in Fig, 1, Plate 72 — is sufficient.

420 RIVERS.

Tu-0 or three pieces of artilleiy may be put in it, but it is prefer-
able to locate batteries, as at B and C, on the opposite side of
the river, to flank the redan and cross their fire in front of it.

Against a large force well supplied with artillery, a line of
works (a 6) must be thrown up and well armed with artillery,
for tlie purpose of keeping him beyond artillery range from the
bridge. Batteries of heavy pieces are placed, as at c d, to flank
the line.

Tlie operation of crossing a river by an army in presence of a
vigilant enemy, is one of great delicacy, as it necessarily con-
sumes considerable time, during which it is more or less divided
and subject to every disadvantage. Judicious use of artillery
is of tlie first importance. The first thing to be done is to
gain a footing on the opposite side. This is usually accom-
plished by stratagem or by surprise. Before a large opposing
force can arrive, batteries must be established on the side from
which the crossing is made to cover with their fire a large area
of ground opposite. Every available piece must be put in, and
the enemy kept back until bridges can be laid and a strong
line of infantrj'' passed over and intrenched. Siege guns, owing
*o their great range and power, are the best adapted for this
service. The batteries should be extended up and down the
stream for three or more miles on each side of the crossing-place ;
this, for the purpose of enfilading the flanks of the enemy and
preventing him from bringing his artillery to bear upon the cross-
ing. The place for crossing should be selected, as far as practi-
cable, with a view to advantageous positions for batteries. The
convex side of a curve {Fig. 2, Plate 72) with hills dominating
the opposite side gives every advantage. This secures a cross-
fire upon the opposite peninsula, under cover of which the in-
fantry line and light field batteries can be thrown forward to a
distance of two or three thousand yards and established in an
intrenched line as represented in the figure.

If the enemy has gun-boats on the river, especially if they are
iron-clads, provision against them must be made by laying across
the channel lines of submarine mines, with heavy batteries es-
tablished for their protection. These batteries must be strongly
intrenched.

The operation of crossing a river by an army pressed in rear
b}'^ another, is the reverse of that just described.

When practicable, the concave side of a bend is selected, across
which a line of temporary intrenchments is constructed ; bat-
teries are established on the opposite side, and the army with-
drawn under protection of their fire. The batteries should cover
themselves with gun-pits, and give special attention to such

DEMOLITION. 421

:artillery as the eneinj^ may bring forward for the purpose of
reaching the place of crossing. *

Demolition.

669. Buildings. In military operations it sometimes becomes
necessary to destroy buildings, bridges, &c. Wooden structures
are readily and effectually destroyed by burning. Ordinary
dwelling-houses of stone or brick may be blown down by placing
against the walls charges of from 25 to 50 pounds of powder, each
contained in a bag, box, or any convenient vessel, and exploded
by means of an electric primer, a slow-burning time-fuse, or a
piece of slow match. The effect of the explosion is to blow
away a portion of the foot of the wall, that above settling down
without, as a rule, toppling over. An inside angle or corner of
the building is the most advantageous place for the charge, for
the reason that, being confined on two sides, the explos^ive force
acts more powerfully than when, against a plain surface, and
also because the angle or corner of the building, being a point of
greatest support, when blown away leaves the remaining parts
greatly weakened.

Against strong and massive walls, such as are generally found
in large public edifices, charges of powder, unless very heavy,
have but little effect when simply exploded against the wall
without tamping. Inside angles should, if possible, be taken, or
when the building has buttresses, the angles formed by them are
advantageous for confining the explosive force and causing it to
take effect on the wall. The powder is placed in a box or keg
and covered with earth and stones. When placed five or six
feet above the foot of the wall the effect is greatly increased.

In all cases where demolition is to be produced, dynamite may
be used instead of gunpowder. Its destructive effect is about
thirty times that of powder, weight for weight.

Bridges. To destroy the arches of a masonry bridge, exca-
vate a hole down to the crown or haunch of the arch, place in it
a charge of one or two hundred pounds of powder, according to
the thickness of the arch, tamp it well with earth and stones, and
explode it.

The amount of powder is determined from the formula X=5
A2 X B : in which X is the charge in pounds, A the line of least
resistance through the arch, and B the breadth of the bridge,
both in feet.

When the width of the arch is over 25 feet, two charges should
3)e placed, to prevent the chance of blowing a hole through the

422 DEMOLITION.

middle without bringing down ,the sides. These should be
exploded simultaneously, if possible.

When the side walls are lightly built, it is better to pull enough
of the stone away to allow a tunnel being run on top of the
arch to the middle of the roadway. This does not interfere with
the use of the bridge during the operation, and if it is not de-
sired to destroy the bridge immediatelj'", the charge may be kept
in its place ready for use at any moment. In this case the charge
should be in a tight box or barrel, well pitched to protect ife
against moisture.

The charge may be exploded by means of an electric primer,
the ordinary fuse used in blasting, or with a powder hose. This
latter is made of canvas or any stuff that will hold fine-grained
powder, and is inclosed in a trough to protect it from the moist-
ure of the earth.

The ordinary blasting fuse is known in this country under
the name of tlie safety fuse and Toy's fuse; in England, as
Bickford's fuse.

It consists essentially of a column of fine-grained gunpow^der
inclosed in flax, hemp, or cotton, and made up with different
coverings, according to the use to which it is applied. When
intended for immediate use on light work in dry sand, it is
unprotected by additional coverings; when intended for use in
wet ground or under water, it is covered with varnished tape or
gutta-percha.

These fuses are somewhat uncertain in their rate of burnings
but average about one yard in a minute.

The ordinary varieties must be kept in a cool, dry place, and
preserved from contact with oil.

Wooden bridges are easily burnt ; but if great secrecy is neces-
sary, a hole may be bored with an auger in a main-brace and a
charge of powder or dynamite exploded therein, blowing it to
pieces. Charges should be placed in several of the braces and
exploded as near simultaneously as possible.

During the war of the rebellion a small torpedo was devised
for this purpose. It consisted of a tin cylinder 1.75 inch in di-
ameter and about 7 inches long. Both ends of tiie cylinder were
open, and through it passed a bolt of 0.75-inch iron, with a stout
head at one end and a nut at the other, each having a diameter
of 2 inches. A washer of the same size as the head was placed
under the nut; through a hole in the washer passed a strand
of slow match to communicate fire to the powder with which
the cylinder w^as filled. A coat of varnish protected the powder
Irom moisture. To use it, a hole 2 inches in diameter was bored?

DEMOLITION. 423

in the timber; into this the torpedo was driven, head down-
wards, and the fuse ignited. •

The most effectual way of destroying an iron bridge is to at-
tacli the abutments by mining down so as to get behind the
masonry a large charge of powder or dynamite, which being
exploded, destroys the supports of the superstructure. When
time and means permit, remove as many bolts as possible, so as
to weaken the parts, after which build a strong fire and heat the
main-braces to tnake the bridge sag and warp out of shape, or to
come down entirely.

Canals. These may be temporarily disabled by cutting em-
bankments. The most effectual way, however, is to blow up a
lock, which maj^ be done by digging down behind a facing wall
and placing against it a charge of two or three hundred pounds
of powder or a few pounds of dynamite, tamping well and ex-
ploding it. A lock destroyed in this manner requires a long
time to repair. The arches of an aqueduct may be broken by
drilling holes and blasting.

An arm)-^ depending upon a railroad for its supplies should be
provided with an organized construction corps, fully equipped
with every means for making speedy repairs. Damages done to
railroads are easily repaired, in comparison with those done to
canals.

prt ptttft.

SUBMARINE MINES.

CTO* The term torpedo^ when used in a niilitary sense, desig-
nates those contrivances for producing explosions calculated to
act destructively against an enemy coming into their immediate
vicinity.

Tliej^ are chiefly used for obstructing rivers and entrances to
harbors, and are either stationary or capable of movement.
When stationary they are called submarine mines^ leaving the
term torpedo for all ofl:ensive and movable combinations of this
nature. The use and application of the latter fall more partic-
ularly to the province of the Navy, the former to the Army, and,
being employed as auxiliary to shore batteries, constitute a
branch of service naturally belonging to or intimately connected
with the artillery arm.

Submarine mines are applicable to almost any situation liable
to be attacked by ships, but in every instance they should be so
arranged as to be covered by the guns of forts or detached bat-
teries, so that, while acting as outworks of these latter, they will
be protected from destruction by boats from a hostile fleet.

The comparatively small cost of this species of defense allows
of its extensive use as an agent to deter an enemy from approach-
ing a fortified position, and to cause him to begin the tedious and
dangerous operation of clearing the channel, or to land and at-
tempt to capture the place without the aid of his ships. This in
most cases would enable the defenders to hold out until the arri-
val of a relieving force.

The materials required for most submarine mines are articles
of commerce easily procurable, or capable of being kept on hand
without damage or loss, and a system of defense by such means
<ian be carried on by a comparatively small number of men.

671. Siihmarine mines may be briefly described as charges
of gunpowder, or other explosive agents, inclosed in water-tight
cases of iron or other material, and placed under water at such
depths that, by their explosion, they may sink or seriously dam-
age a vessel passing in their vicinity. They are classed under
two heads, viz.: Mechanical, those which depend for the explo-
sion of the charge on mechanical means, such as the simple per-

(425)

426 SUBMARINE MINES.

cussion of a vessel coming in contact with them ; and Electrical^
those which are tired by electrical agency, either by the vessel
closing the circuit, or at will from the sliore.

The former class, or mechanical mines, are capable only of
very limited use. When once placed in a channel they make it
equally impassable to friend and foe. They are, therefore, only
applicable to certain cases ; as, for example, when it becomes
necessary to block up a channel completely, that is to say, to
render it altogether impassable till the mines have been removed.
They might, howevei-, be employed on a flat beach, dry at low
water, to cover the flanks of electrical mines defending the navi-
gable channel. In such case they could be planted or removed
at low water with comparative security. The number of elec-
trical cables, &e., required would be reduced by such an arrange-
ment. Mechanical mines are not applicable to harbors of refuge,
in which merchant ships might run to avoid an enemj'-.

It would, fui'thermore, be absolutely necessar};^ to make some
arrangement by which they could be exploded at will, as the
most eff'ectual way of getting rid of them when it became neces-
sary to clear the channel, as the process of removal in the ordi-
nar}'" way, by boats, would be far too dangei-ous an operation to
undertake. On the order hand, submarine mines of this descrip-
tion possess the advantage of capabilit}^ of being kept in store
and ready for use at short notice ; they require no knowledge of
electricity in their management, and they might be used with
advantage in certain cases where electrical submarine mines are
not obtainable.

The second class of submarine mines, those to be fired by elec-
trical agency, admit of a very much larger field for their employ-
ment. They may be fired either at will by an observer, who,,
judging of the position of the vessel, closes the circuit, so that the
charge may be exploded at the right moment; or the vessel her-
self may be made to complete the circuit, causing a current to
pass and fire the charge. *

The disadvantages of electrical submarine mines, as compared
with those fired mechanically, are the multiplicity of wires re-
quired and the necessity of having a certain number of espe-
cially trained men. This number, however, is compai-atively
small.

The advantaoes of electrical mines are, that they are always
absolutelj^ under the control of the observer in charge of them.
By simply detaching the battery used in firing them they become
perfectly harmless, and friendly vessels may pass over them with
safety, which is not the case with those arranged for mechanical
ignition. Again, they can be rendered active at a moment's

POSITION OF SUBMARINE MINES. 42T

notice by reconnecting- the battery. By means of electrical con-
trivances, arrangements are so eftected that vessels passing over
mines give notice of their presence without exploding the mine.
In tins respect electrical submarine mines are a great safeguard'
against attack by surprise, and against vessels passing at night,
or in a fog. Nor can they be tampered with by an enemy with-
out its being immediately known, and exactly what mine. In
the electrical system, when a mine is exploded, or becomes inef-
fective from any cause, another can be laid down in its place^
without danger, by simply making the neighboring mines in-
active for the time being. Another important advantage of
this system is the power of testing electrically, without going
near it, the condition of each separate charge at any time after
submersion, and of ascertaining, with almost absolute certainty,
whether it can be fired or not. None of these advantages apper-
tain to mines of the mechanical system.

61'2. Position of submarine mines. The following general
rules govern in selecting sites for these mines :

1st. They may be used in combination witii floating obstruc-^
tions, as booms, or with grounded obstructions, as sunlveu ves-
sels, piles, &c., or without them.

2d. They should be placed in such positions that their explo-
sions will not injure any passive obstructions combined with'
them, or destroy the electric cables of adjoining mines.

3d. At least two. and, where practicable, more, rows of mines-
should be arranged across the cliannel to be defended.

In deep water, it is more necessarj?^ to employ several lines of
mines tiian in shallow, because in the latter case a vessel sunk
by a mine would lierself offer an impediment to others follow-
ing; but in deep water the explosion of a mine leaves a gap,
through which there is a safe passage.

4th. Submarine mines should be placed in the channels through-
which large vessels oidy can pass; the shallower places being, in
all cases where such a course is practicable, rendered impassable
by passive obstructions resting on the bottom.

5th. Submarine mines should be placed in the narrowest part
of a channel. The advantages of such a position are evident, as
a smaller number will answer the purpose.

6th. When the depth of the water and other circumstances-
admit of it, a submarine mine should alwaj^s rest on the bottom.
Under such circumstances, all complications originating in moor-
ing arrangements are avoided ; its position is more easily de-
fined, and it is not so easily displaced by accident, or discovered'
and destroyed by an enemy.

7th. No indication of their position should be allowed to appear-

428 ARRANGEMENT OF SYSTEM.

on the surface of the water. Under certam conditions it may be
impracticable to conceal them altogether; as, for example, where
there is a large rise and fall of tide. Under such circumstances,
the smallest possible indication of their position must be allowed,

8th. When, from the depth of the water, the charges cannot be
placed on the bottom, they should be so moored as to float from
15 to 40 feet below the surface. In places where there is a con-
siderable rise and fall of tide, special arrangements would be
necessary for this.

9th. The place in which batteries and instruments connected
with the ignition of electrical submarine mines are arranged,
should be in those portions of the defensive works which are
likely to be held longest, so that a command may be kept over
the mines to the latest possible moment in the defense.

10th. Great care should be taken to lay the electric cables in
such positions as to render their discovery bj^ an enemy as diffi-
"Cult as possible, and likewise to secure them against every acci-
dent.

11th. The position of the mines should be well covered by the
fire of the guns of the forts or shore batteries of the place to be
defended, to prevent their destruction by boats.

12th. Submarine mines should not be thrown away by firing
them at small boats, except under very exceptional circum-
stances, but should be reserved for larger vessels.

6'?3. Arrangement of system. The object to be obtained in
arranging any system of mines for the defense of a channel, is
to place them in such a position that a vessel passing along that
<ihannel must, at some one moment, whatever course she may
take, come within the radius of destructive effect of one of the
mines. This would be attained by placing the mines in a sin-
gle row across the channel, so that their circles of destructive
effect may at least touch each other. To this simple arrange-
ment there are, however, practical diflaculties; among which is
the danger of entanglement between the mooring cables of adja-
'Cent mines, or their electric cables, especially wlien there is an
ebb and flow of the tide. When mines are very close together,
it is impossible, with the most perfect mooring arrangements, to
prevent entanglements of this nature, particularly when laying
down the mines and arranging the gear in connection therewith.

The dijQflculty of grappling for and raising a mine for exami-
nation is greatly increased by this very close approximation.
Again, when mines are very close to each other the explosion of
one is very likely to injure its neighboi'; or, where an electrical
system is adopted, to disturb the particular mechanism of the
system. It becomes necessary, therefore, to allow some lati-

ARRANGEMENT OF SYSTEM. 429^

tucle, in order to obviate these difficulties and at the same time
to preserve the theoretical precision and closeness of a sino^le line.
This is effected by placino- the mines in two or more lines, at a
distance from each other something greater than the radii of
destructive effect of the mines. Fig. 3, Plate 72, explains this
method.

In this figure, a h represent the theoretical line required to
close the channel, and it is only necessary to move back every
second mine to the line c cZ, and every third mine to the line e/*,
to secure the object required. A fourth line {g h), or even a
fifth (t /c), may be added with advantage, taking care that these
last shall cover the intervals left between tliose in advance of
them in such a way that a vessel passing obliquelj'' through the
intervals of the first three lines may come in contact witii a mine
in the fourth or tifth. This arrangement overcomes the great
objection that attaches to a single line, which, in case a breach
is once effected, affords a safe passage until repaired. It like-
wise makes it more difficult for an enemy to discover the limits
to the area of danger, and consequent!}' weakens the efforts of
the enemy by the moral effect of uncertainty.

The arrangement in lines is the best, both for facility in lay-
ing the mines so as to space the area with certainty, and for
finding their positions wlien it becomes necessary to raise them
for examination. It also affords facility in determining what
particular mine it is necessary to explode to strike a vessel
attempting tlie passage.

So much depends upon local circumstances — such as the nat-
ure of the channel or roadstead to be defended, the probable
means of attack at the disposal of an enemy, the draught of
water of the vessels of a hostile fleet, &c. — tliat a great deal
must be left to tlie officer commanding the defense.

The size, strength, and character of the vessels to be guarded
against will determine the power of the mines to be used, and
this, again, will decide the distance between tlie lines and the
intervals thereon of the mines.

674. Neither experiments nor observations in actual warfare
have yet determined, except approximatelj% the size of charges
necessary to perform the work required of mines under the vari-
ous circumstances that would arise in service. The stronger the
vessel the greater, manifestly, will be the charge required to
destroy it. As a general rule, the strength of vessels increases
with their size, as likewise does their draught ; therefore a mine
of sufficient power to destroy a large vessel will evidently de-
stroy a smaller one, and this notwithstanding the cliarge be

430 EXPLOSIVES.

placed at a depth suitable for the larger vessel and of the con-
sequent intervening cushion of water.

The depth of water in a channel decides very closely the char-
acter of vessels that can pass; this, for war vessels, may be
placed at 15 feet for the minimum. Furthermore, it has been
decided that a charge of 2000 pounds of gunpowder, if properly
placed, is sufficient to destroy the largest vessel. This, there-
fore, is laid down as the maximum charge to be used in any one
mine. A rule for approximately determining the charge for
depths of water from 15 to 40 feet is, that the square of the
^epth in feet gives the quantity in pounds of gunpowder re-
quired. Gunpowder being the most common and best known of
the explosives, is taken as the standard. So far as known, the
-explosive effect of gun-cotton, when used for submarine mines,
is about four times, and that of dj^namite about ten times that
of gunpowder, weight for weight. The character of the bottom
on which submarine mines are planted has considerable effect
on their destructive power, a yielding, muddy bottom being
tnuch less favorable than a hard and resisting one. In the fore-
going rule, about ten per cent, should be added to the charges
when the bottom is soft, or when the mines do not rest on the
-bottom. It is evident that the nearer the lines of mines are
to each other the less will be the chances of a vessel passing
through safely; they should, however, be so far apart as to ena-
ble the electric cables connected with them to be laid in a safe
position when carrying them to the electrical-room from which
the system is to be worked. The distance likewise should be
sufficiently great to enable the observers, taking cross-bearings,
to determine with certainty when a vessel is over any particular
line. These conditions will, as a rule, give 100 yards as a mini-
mum and 200 j^ards as a maxiraiun.

The distance apart at which two mines on the same line may
be placed so that the explosion of one will not injure the other,
-depends upon the size of the charges employed. For the maxi-
mum charge — 2000 pounds— this interval should not be less than
200 feet; for charges not exceeding 500 pounds the interval
maybe reduced to 100 feet. This necessary interval between
the charges in a line is one reason which renders the employ-
ment of two or more lines of mines essential to a proper main-
tenance of the defense. It also sufficiently explains the object
to be attained in placing them in such a way that the charge in
the second line shall cover the intervals in the first, and those
in the third shall cover the intervals in the second, and so on.

6*75. Explosives. The explosives used for submarine mines

DYNAMITE — NITRO-GLYCERINE. 431

are confinerl almost exclusively to gunpowder, dynamite, and
gun-cotton.

Gunpowder has already been discussed in Part First, pars,
180 et seq.

Dynamite. This explosive compound is merely a preparation
in vviiich nitro-glycerine is itself presented for use, its explosive
properties being those of the nitro-glycerine contained in. it, as
the absorbent is an inert body. Dynamite is formed of 75 parts
of nitro-glycerine absorbed by 25 parts of '' kieselguhr," a porous
siliceous earth.

In appearance dynamite is a loose, soft, readily-moulded sub-
stance, of a bufr color. It is prepared by simply mixing, with a
wooden spatula, the nitro-glycerine with finely-powdered kiesel-
guhr in a leaden vessel. It freezes at 39° — 40° F., and when
solidly frozen cannot be exploded ; but if in a pulverized state,
it can be exploded, though with diminished violence. It is eas-
ily thawed by placing the vessel containing it in hot water.

Friction or moderate percussion does not explode it. Its fir-
ing point is 356° F. If flame be applied to it, it burns with a
strong flame. It is fired by means of fulminate of mercury, and
its explosive force is about seven times that of gunpowder.

This explosive compound is now most extensively used for
general blastiiig purposes all over the world, especially for sub-
marine work, where, for removing rocks, it is exploded by sim-
ply placing it on the surface of the rock, the water forming the
tamping.

For ground and buoyant mines, where actual contact between
the hostile vessel and the torpedo will be rarely achieved, this
being, next to nitro-glycerine, the most violent of all known ex-
plosive agents, and being cheaply and readily procured, is the
very best explosive for such torpedoes.

Dualine. This is prepared by mixing nitro-glycerine with
sawdust and saltpetre. It possesses the principal qualities of
dynamite, tliough inferior to it.

Lithofracture. This is prepared by mixing nitro-glycerine,
kieselguhr, charcoal, soda, saltpetre, and sulphur. It likewise
is inferior to d5'^namite.

Nitro-glycerine. Tliis is an explosive compound formed by
the action of nitric acid upon glj^'cerine at a low temperature.
At ordinary temperature it is an oily liquid, having a specific
gravity of 1.6. Freshly made, it is creamy white and opaque,
but clears and becomes colorless on standing for a certain time,
depending on the temperature.

It does not mix with, nor is it affected by, water. It has a

432 GUN-COTTON.

sweet aromatic taste, and produces violent headache when placed
on the tongue.

The opaque, freshly-made nitro-glycerine does not freeze un-
til the temperature is lowered to 3° — 5° below zero F., but when
cleared it freezes at 39° — 40° F. It freezes to a white crystalline
mass, and in this state it can be thawed by placing the vessel
containing it in water at a temperature not over 100° F.

If flame is applied to freely-exposed nitro-glycerine, it burns
slowly without explosion. When in a state of decomposition it
is very sensitive, exploding violently when struck, even when
unconfined. When pure it is not sensitive to friction or mode-
rate percussion. If struck with a hammer, only the particles
receiving the blow explode, the remainder being scattered.

The firing point of nitro-glycerine is about 365° F., though
it begins to decompose at a lower temperature. The mode of
firing it usually employed is by means of a fulminate-of-mercury
detonating fuse. In a frozen state it cannot be fired even by
large charges of fulminate.

It is kept in tight tin cans of 40 to 50 pounds each, and should
not be transported or handled except when in the frozen state.

It is the most violent of all known explosive agents, its force
being about ten times that of gunpowder.

Gun-cotton. This is formed by the action of concentrated
nitric acid and raw cotton. When thus acted on the cotton is
little changed in appearance, though more brittle and slightly
harsher to the touch.

If a flame be applied to it in a loose, dry state, it flashes up
without explosion ; if compressed, it burns rapidly, but quietly.
Moist compressed gun-cotton under the same circumstances
burns slowly.

In the compressed state in which it comes from the hydraulic-
press it contains about 15 percent, of water; in this condition
it may be cut, sawed, bored, or perforated with a red-hot iron
with perfect safety. If placed on a fire, a feeble transparent
flame flickers over the surface from time to time as the exterior
becomes sufficiently dry to inflame ; in this way it burns away
very gradually.

This comparative safety of wet gun-cotton, coupled with the
fact that its detonation in that state may be readily accomplished
through the agency of a small quantity of dry gun-cotton termed
a primer., which, by means of a fulminating fuse or detonator,
is made to act as the initiative detonating agent, gives it impor-
tant advantages over other violent explosive agents, w^hen used
for purposes which involve the employment of a considerable

FULMINATE OF MERCURY — CASE. 433

quantitj^ of the material, on account of the safety attending its
storage and necessary raanipuhition.

Gun-cotton is not sensitive to friction or percussion. Its firing
point is about 360=" F. It is insoluble in and unatFected by water.
When not in water it is liable to spontaneous decomposition,
which, under favorable conditions, maj^ result in explosions.

Compressed gun-cotton is free from such danger, as it may be
kept and used saturated with water. It is stored in the wet state,
care being taken that it is not exposed to a temperature that will
freeze the water in the cakes, as this would disintegrate the cakes
by the expansion of the water in freezing.

Compared with dynamite, it is not so violent, and occupies
more space, weight for weight, and also requires a more compli-
cated means of detonating it. On the other hand, gun-cotton is
infinitely safer to store and manipulate, and is not so subject to
detonation by concussion as dynamite.

The explosive effect of dynamite and gun-cotton is a rending
or a shattering one, while that of gunpowder is an uplifting or
heaving one, and alwaj^s in the line of least resistance — difter-
ing in this respect from the first two substances, in which the
explosive effect is nearlj' equal in every direction. This prop-
erty of dj'namite and gun-cotton makes them most suitable for
demolitions. (See Demolition^ par. 669.)

Gun-cotton, while in tlie pulpy state, is pressed into cylinders
of about 3 inches in length by 2.5 inches in diameter. For trans-
portation these cylinders are placed in boxes, each containing
about three dozen ; the box is filled with water, which, after re-
maining a few minutes, is drained off and the box closed.

Fulminate of mercury. This is the composition used in the
detonating primers employed for the ignition of dynamite and
gun-cotton. It is the substance in percussion caps that detonates
and produces fire when the cap is struck a sharp blow.

Dry fulminate of mercury explodes violently when heated to
367° F., by the electric spark, or when struck. When wet it is
inexplosive, and therefore it is always kept wet, being dried in
small amounts when required for use. Great care is i-equisite
in handling it.

For the purpose of detonating nitro-glycerine or its prepara-
tions, 15 grains of the fulminate are sufficient, but to detonate
gun-cotton 25 grains are necessary. The fulminate in detonat-
ing fuses should be inclosed in a copper case or cap, and must
never be loose. The fulminate should be wet when charging
the detonators, and afterwards dried.

676. Case. Whatever may be the form and construction of
28

434 CASE.

the case which contains the charge of a submarine mine, the
following conditions are essential :

1st. It must be water-tight, to prevent damage to the charge
by leaJjage.

2d. It must be sufficiently strong to bear handling \vithout
danger of becoming leaky by straining, and must be able to sus-
tain the external pressure due to the depth of water at which it
is to be placed.

3d. When gunpowder, or gun-cotton fired with an ordinarj'
fuse, is used, it must be sufficiently strong to hold the charge
together, as it were, for an instant at the moment of ignition, so
that its full effect may be obtained by as thorough a combustion
as possible of the charge.

4th. In the case of a buoyant mine, it must be capable of being
arranged with a large excess of flotation, so that wlien moored it
may remain as stationary as possible at the required point.

5th. It should be of such form as to be capable of being han-
dled and moored conveniently.

6th. It should be of such form as to secure the thorough igni-
tion of the charge with the smallest possible number of fuses.

7th. It should be easy of construction, and not too costly.

First, with reference to the form of the case. This generally
is either conical, spherical, or cylindrical. The former is the
best for self-acting buoyant mines. The apex (a, Fig. 1, Plate
73) ol the cone forms a convenient point to which the mooring
cable may be attached, while the base, terminating b}'^ a curved
portion (6), serves as an air-chamber, giving the necessary buoy-
anc3'' to keep the mooring cables taut and to hold the mine in a
comparativelj'' stationary position in a current or tide-way. The
nipples (c c) containing the fulminating composition are placed
on the rim uniting the base with the conical surface. In this
position they are most likely to be struck by a passing vessel.
There should be four or more of these nipples, depending upon
the size of the case.

For all other cases, except the one just mentioned of a floats
ing mine, intended for small charges to be exploded by mechan-
ical means, the cylindrical form is best, and the one most fre-
quently adopted for both ground and buoyant mines containing
heavy charges. Fig. 2, Flate 73, represents the form so suc-
cessfully used by the Confederates, 1861-65 ; Fig. 3 represents
that of the Austrians ; Fig. 4 that of the Englisli for small buoy-
ant mines, in which J is a wooden jacket, giving buoyancj' and
protection to the case ; C is the circuit-closer.

For large ground mines, the best form of case seems to be
that of the turtle mine, represented in Fig, 5. A heavy charge

MOORING. 435

may be eontalnecl in it; it forms its own anchor, and it would
withstand an explosion of an adjacent mine without sustaining
any injury. This is the best form for resisting strong currents.

The difficulty and cost of making spherical cases have hereto-
fore debarred theii- adoption on a large scale, but recently Gen-
eral Abbott, U. S. Engineers, has simplified the process of man-
ufacture and made them practicable. This process consists in
pressing circular disks of steel into hemispherical segments,
which are united by flanges, as represented in Fig. 6.

As regards the material of which the cases may be most advan-
tageously constructed, several substances have been tried and
used; such as wood, iron, and vidcanized India rubber. For
actual war service, regularly- constructed torpedoes or mines
would generally be turned over to the posts ready for use ; but
it might become necessary to improvise cases out of such mate-
rials as would be available. Tight barrels and hogsheads, when
properly strengthened, are a good substitute for even the most
improved form of case. The barrel or cask is simply an exter-
nal shield for the protection of the charge, which is contained
in a water-tight envelope, and may be an India-rubber bag or
a tin or zinc can. The strengthening of the cask is to guard
against collapsing when submerged in deep water. Under ordi-
nary circumstances the depth of the water will not be so great
as to require strengthening of good casks beyond stout hoops
of iron. As the charge must generally remain a considerable
time — perhaps many months — under water before explosion, it
is most essential to have the case, whatever it maj'^ be, completely
water-tight ; and with this view the cask is coated, both inside
and outside, with a composition of pitch and tar. The envelope
containing the charge within the cask should be firmly fixed, so
that no independent motion may disturb the connections of the
electrical apparatus.

677. Mooring. This is the most difficult operation connected
with submarine mines. It is a problem containing so many
conditions that it is impossible to give more than general sug-
gestions concerning its solution.

In order to possess a maximum of efficiency, no indication
of the position of a mine should appear on the surface of the
water, and yet the spot, to within a few feet of where it is
deposited, must be known to the defenders of tiie channel in.
which it is used. In certain cases — as when there is consider-
able rise and fall of the tide — it is impossible to totally conceal
the position of a system of mines. When such is the case, the
very smallest indication possible should be allowed to appear on
ihc surface of the water. It has been found that the least cur-

436 MOORING.

rent, or so much roughness as only a moderate breeze would'
cause, renders the placing of even a single mine in a definite
position a matter of very considerable difficulty. When a series
of mines are to be moored in proper relative position, this diffi-
culty is much increased, and it is, furthermore, augmented in
proportion to the depth of the water.

The objects to be obtained in mooring are as follows :

1st. That the charge should be kept as nearly as possible sta-
tionary at the point where it is required to act. This is partic-
ularly necessary where there is a tide which, flowing first in one
direction and tlien in anothe.r, tends to cause the mine to shift
its position, and is indispensable in the case of mines intended
to be fired by judgment.

2d. Tlie moorings should be so arranged that there shall be as
little twisting as possible, which might break or injure the insu-
lation of the electrical cables.

3d. Tiie anchors or heavyweights used should be suited to
the nature of the holding ground or bottom.

4th. Mooring cables should be so arranged that they may not
be likely to become twisted together or entangled.

The best special mooring apparatus for general purposes is
the musliroom anchor. {Fig. 1, Plate 74.) It is decidedly so for
a soft, muddy bottom. On a hard, rocky bottom the dead-weight
of the mooring must be depended upon to keep a mine stationary,
and if a heavy mushroom anchor is used, its edges should be fur-
nished with toes or points to catch in the crevices of the rocks.
The weight of tiie anchor would depend on the buoyancy to be
overcome, and would usually be from 500 pounds upwards.
Ordinary mooring-chains and hemp cables may generally be
employed in connecting the charges or circuit-closers with the
anchors. Where there is any tendency to twist, a wire cable is
the best to counteract it. Any considerable amount of twisting
must be checked, as it is liable to entangle the moorings and to
rub and injure the electric cables,

N'ext to th(^ mushroom sinker the ordinary anchor is the best.
For make-shifts, any heavy weights — as large stones, pigs of
metal, or bars of iron — may be used. These must necessarily be
sufficiently heavy to hold a mine in position simply by their
dead-weight. The material just mentioned can be fastened to
frames of wood, and the whole sunk as one mass.

The weight necessary for a mooring, whether anchor, sinker,
or other apparatus, will depend upon the buoyant force of the
mine, the nature of the bottom, and the currents.

The buoyancy of a mine is its excess of flotation over its
weight. This would be measured by the number of pounds

MOORING. 437

required to sink it, and no more. When wooden casks are used
^the buoyancy may be roughly taken as equal to the weight of
the charge of powder. With heavy metallic cases theh* weight
must, in cU cases, be taken into consideration.

In water free from currents twice its buoyancy is considered
necessary to keep the mine in a vertical position over the moor-
ing; this, therefore, would be the weight required for the moor-
ing. Where there is a current, additional weight to keep it
from swinging off with it is required, and this increases witii the
strength of the latter. When the mine is moored by a single
cable, a convenient rule, approximating closely to results from
experiments, is to allow one additional buoyancy for each mile
per hour of current; i. e., two buoyancies being allowed for still
water, three would be allowed for a current of one mile ; four for
tvv^o miles; five for three miles, and so on. These represent the
weights for the mooring in each instance. In a tide-way where
there is a current of more than five miles an hour, two anchors
may be advantageously used, placed up and down stream at a
considerable distance apart, depending upon the force of the
current and the distance from the bottom at which the mine is
to float. It is extremely difficult to moor mines in proper lines
and depths by this means.

When the mine is small, say one containing a charge not
greater than 200 pounds, a single large barge may s[iffice for
placing it. The anchors can be let down at a suitable distance
apart from the extremities of two outriggers, one from each
end of the barge. The mine, attached to the middle of the cable
connecting the anchors, is weighted down by a heavy saddle,
which, after the anchors are down, is hoisted in and the mine
permitted to rise to the proper depth from the surface.

In order to place a large buoj'^ant charge of, say, 1000 pounds
and upwards, three of these large boats are required to carry it
^and its anchors, one for each anchor or mooring sinker, and one
for the charge itself. They are connected by a rope, which, if
kept stretched, would insure the anchors being placed at the
proper distance apart. The sinkers and mine are carried out
and lowered from the davits at the s'^ern of each boat. Skillful
boatmen and sailors are required for all operations connected
with the placing of mines, and a handy steam-tug is the most
convenient craft to use.

The floating mine is used where the depth of water is so great

that, if placed on the bottom, the mine vv^ould require for elH-

-ciencN'' an excessively large charge. In this case it is held to

the bottom by moorings in such position as not to rise to the

surface at low tide, nor at high tide be so deep as to be beyond

438 LINES.

effective ran^e of over-passing vessels. To arrive at this ex-
act point, it is best to haul the mine down towards the sinker.
For this purpose there are various contrivances, some one of
which would be supplied with the rigging furnished with the
mine.

When the mines are to rest upon the bottom, they are lashed
to some heavy object sufficient to sink and hold them in posi-
tion, and then lowered to their places.

el's. Lines. Submarine mines will generally, if not always,
be moored in straight lines. In practice, the greatest difficulty
is experienced in mooring any object in a paitieular spot, espe-
cially when two mooring-chains are required, as will sometimes
be the case, to prevent twisting. To overcome these difficulties
it is suggested that instead of anchors a heavy chain cable be
employed to moor the mines. '

"A section of the channel to be defended having been made
from soundings, the line assumed by a chain could be laid down
to scale. The positions of the mines and their distances apart,
depth from the surface, &c., having been arrived at by calcula-
tion, could also be laid down on the section. The points where
the small mooring-chains of each mine meet the large chain
would appear on the drawing, and the distance of each point
from either extremity having been measured off, the scale could
be marked on the chain.

''Before sinking the heavy chain the small mooring-chains
should be rove through the links at the places marked, and the
ends buoyed, sufficient length being allowed for the buoys to
reach the surface.

"The conducting wires could next be laid and the ends at-
tached to the same buoys which support the mooring-chains. In
this way everj^thing could be prepared, the cables tested, &c.,
before the mines were required at all ; indeed, if the operation
of fixing the same were practiced beforehand, it could be left
out until there was considerable probability of the mines being
required for use. By keeping the mines ready loaded in suita-
ble magazines, and having the cables frequently tested, the
probability of injury would be greatlj'- diminished.

"The great advantage of using a heavy chain would be the
absolute certainty of having all the mines in their proper places;
it would also simplify the moorings by doing away with a mul-
tiplicity of anchors and anchor buoys.

" A 2.5-inch chain cable weighs 400 pounds per fathom. The
mines would probably never be nearer than 70 or 80 feet apart, so
it is evident that the chain would be quite heavy enough to coun-
teract any flotation which would in practice be given to the mine

IGNITION OF CHARGE. 439

"• In a ciiiTent of any streno^th it would be necessary to nse
two parallel chains across the current to prevent the mines
swingino- with the change of tide, but the same advantages would
hold good."

Instead of a chain cable, a strong hempen cable may be stretched
across the channel. Previous to immersion, this cable is marked
at intervals, at the points where it is subsequently intended to
lay down the mines. To place the moorings in position, the
cable is slacked up sulEficient to allow of its being underrun. At
each point marked upon it to indicate the position of a mine, one
end of a branch hawser is bent onto it, and the other extremity
made fast to a mushroom anchor, the necessary amount of slack-
being left to allow the anchor to be passed into its proper posi-
tion. A buoy is attached to the mooring cable fastened to the
anchor; the latter is then carried out to one side of the directing
cable and dropped into its place. Any further arrangement for
attaching the charge, the electrical cable, and circuit-closer may
be carried on without difficultly.

Fig, 2, Plate 74, represents this method of planting mines; «,
5, c, d, &c., are the mooring-chains attached to the hawser HH.

This plan affords considerable facilities for the examination of
charges after tliey have been submerged, as it would be necessary
only to underrun the muhi liawser until the required branch
hawser is reached, and then by it raise the mooring anchor, and
with it the mine to be examined. In the event of the main haw-
ser being broken, it would not be a verj'' difficult operation to
grapple it and bring it to the sin*face for repair.

6i'9. Ignition of cha7^ge. For mechanical mines various con-
trivances have been used. All those constructed on the princi-
ple of the gun-lock have, however, been found to soon become
worthless from oxidation and incrustation of the more delicate
parts. A very simple form is the nipple, upon which is placed a
percussion cap, but this is apt to become damaged when im-
mersed. Another kind is ^'the well-known sulphuric-acid fuse,
formed on the principle of ignition by sulphuric acid dripped
upon a mixture of equal parts of chlorate of potash and loaf-
sugar. The sulphuric acid is placed in a small glass globe, which
is so arranged as to be broken bj'^ the blow given on touching the
side of a vessel, and the acid set free, falling on the mixtuie of
chlorate of potassa nnd loaf-sugar, produces the required igni-
tion." The ignition produced by tills means is comparatively
slow; it has, however, been found that an addition of one-third
of ferro-cyanide of potassium to the mixture of equal parts of
chlorate of potash and loaf-sugar produces an ignition as rapid
as that of gunpowder. The glass globe is best inclosed in a lead

440 ELECTRIOAL FUSE.

tube, which, by bending- or being crushed by the blow, breaks
the glass. This is the fuse sometimes used for land torpedoes.
(Par. 646.)

To secure the fuse and charge from moisture, a composition
made of 1 part of tallow, 8 of pitch, and 1 of bees-wax will be
found good. To this may be added a little gutta-perclia, which
will have a tendency to harden it. This composition, when soft-
ened by heat, is pressed around the fuse-plug.

The great superiority of electrical fuses over meclianical, causes
the latter to be employed only under exceptional circumstances.
The universal use of the electric telegraph makes it eas.y to ob-
tain all material and apparatus necessary for firing submarine
mines; even fuses are an article of commerce, and there is no
difficulty, if required, in obtaining the services of electricians or
other operators capable of arranging and manipulnting all parts
of it.

680. An electrical fuse consists essentially of a priming of or-
dinary sporting powder, gnn-cotton, or of a mixtui-o of the two,
in contact with which is the conducting wire of a galvanic battery
arranged at this point in such manner as to generate heat bj'^ the
passage of the electric current. The fuse is imbedded in the
charge of the mine, and the conducting wires passed out from it
through a water-tight plug or bimg-stopper in the case, and ai-e
connected with the electrical cable passing to the operating case-
mate of the fort.

The platinum fuse is formed of a very fine piece of platinum
wire Y^^ of an inch long, to the extremities of which are soldered
the two ends of the conducting wire; the priming is secured in
contact with the platinum, which latter is fused b}'^ the passage
of the electric current.

This fuse requires a batteiy pi-oducing a current of large quan-
tity. Grove's, Bunsen's, and Walker's are among those most
suitable for such fuses.

Platinum maj' be dispensed witli by bringing the ends of the
conducting wires so close together as barely to be apart, thus
forming a break or interval in the conductor. The ends of the
wire are held in exact position, usually by being passed thiough
a short plug of wood. Around this plug is wrapped paper,
which, projecting at I he end where the conductor is broken,
forms an envelope for the priming. This wrapping or cap is
afterwards covered with a strong shellac varnish.

When regularly-manufactured fuses cannot be obtained, it may
become necessary to improvise th(^m. This may be done in sev-
eral ways, one of which is to take a small cylindei- of hard wood
[Fig. 3, Plate 74) about an inch in diameter and half an inch

POSITION OF FUSE. 441

long; this is pi'ovidecl with a groove aroniul its circumference, in
Avhich is tied the paper envelope before mentioned. Two Iioles
about a qiiartei- of an inch apart and of suitable size to receive
two moderately-fine pieces of copper wire are made lengthwise
through the cylinder. One extremity of both of these wires is
sharpened with a file, and about a quarter of an inch of the
wire bent over at right angles, and slightly flattened with a
liammer. the extreme point being bent over in the form of a
hook. The straight ends of the wire are then passed through
the holes in the cylinder, and the flattened heads are fixed in the
wood b}^ diiving the pointed extremities into the latter. In this
waj^ the broad, thin metal surfaces which form the poles of the
fuse are fixed in a parallel position on the surface of the wood,
and should be as close together as possible without actually
touching. Before, howevei-, the wires are thus placed in posi-
tion, the surface of the cylinder, upon which the poles are to
be fixed, is brushed over lightly with a solution of ordinary
photographic collodion. When the poles have been fixed into
the cylinder thus prepaied, the small surface of wood which in-
tervenes between them is coated with graphite by drawing a
pointed black-lead pencil across it two or three times. A cap of
paper is then tied lound the cylinder so as to inclose the poles of
the fuse ; this cylinder is filled compactly with fine gunpowder,
and the open end is then choked.

The protruding wires of the fuse, which serve to connect it
with the conducting wires, are coated to within a short distance
of their extremities by moulding ordinaiy bees-wax around them
with the fingers, and then tightly wrapping tlie wax with thin
strips of tape or i ag, which is secui-ed to the ends with thread.
'J'he entire fuse, except the bare ends of the wires, is then coated
with shellac or lacquer.

This fuse may be fired by means of a constant battery of suf-
ficient power, or by a magnetic exploder, the former of which
geneiates a continuous current, and the latt.er a rapid succession
of short cuiients. Currents of this character are required to
produce the heating power over the plumbago bridge necessary
to ignite the priming.

681. Position of the fuse in a charge. ''It has been already
stated that, in order to develop the full explosive efi"ect of even
a small charge of powder when fiied under water, a very strong
case is lequired ; with very small charges this is quite practica-
ble, but for large charges of 500 pounds and upwaids it is quite
impossible to make cases proportionately stiong, because thej'
would become enormously .heavy. This diflaculty. however, to
a certain extent, may be overcome bj" igniting the charges, when

442 POSITION OF FUSE.

of u largo size, at several points, providing, in fact, centres of
ignition, and thus burning as much as possible of the charge
and converting it into gas before the envelope is broken and the
water admitted.

"The radius of ignition due to a single fuse, when fired under
the circumstances above described, is supposed to be about one
foot, and starting with this basis, the maximum charge to be
fired from a single centre of ignition is at onct; determined to be
about 250 pounds. Therefore a single centre of ignition may be
used for all charges of less than 250 pounds of powder, adding
a fresh fuse, suitably placed, for each additional 250 pounds or
fraction of 250 pounds in the charge to be fired.

''This has reference to gunpowder fired with an ordinary fuse.
"When gun-cotton and a detonating fuse are used, a mucli greater
bulk may be exploded from a single centre of ignition.

"'•The distribution and holding in proper relative position of a.
number of fuses in a large charge of powder is a matter of some
little nicety, and, in addition, tliere is the increased diflSculty of
testing the fuses after being placed in the charge, and the in-
ci'eased chance of failure and trouble in replacing a defective
fuse or adjusting any accidental derangement of the conducting;
wires should a defect occur in the heart of the charge itself,
which would render the emptying out of the case necessary."
In order to obviate these defects, it is suggested to use a brass^
tube and a single fuse primed with powder.

The brass tube should be suflSciently long to run the whole
length of the charge, and should have an internal diameter of
about 1 inch. Slits 0.5 inch wide and 1.5 inches long are cut
at central intervals of 3 inches, following a spiral line around
the tube. These slits should be covered with a brass-wire gauze^
of a mesh sufficiently small to exclude the powder of the charge.
One end of this tube is closed and the other arranged to receive
and hold the fuse.

A fuse primed with about one-fourth of an ounce of powder is-
placed in the end of the tube and well secured. The tube is
then put in the central line of the charge and secured so that it
shall not vary its position. On igniting the fuse, jets of gas and
tiame are driven from the openings in the tube and fire the pow-
der within reach. The result is the complete ignition of the out-^
lying portions even before the gas evolved by the grains first,
ignited has time to rupture the case and let in water. Two or
more fuses may be attached to the saine tube, so that in the event.
of one of them failing, ignition may be secui-ed through another.

Instead of using a tube, a pound or two of gun-cotton may be
placed in actual contact with the fuse ; and tiiis substance being

ELECTRIC CABLES. 448-

much quicker of io^uition than gunpowder, the gas and flame^
produced are sufficient to permeate the intei*stices between the
grains of the latter and thus secure a thorough combustion of
the chai-ge.

682. Electric cables. The qualifications required for these
are as follows :

"1st. Capacitj'' to bear a certain amount of strain without
breaking.

"2d. Good insulation, composed of such a substance that it
may be readily stored and kept for a considerable time without
being injured. This is essential, as the lines will onl}^ be sub-
merged while actually in use in time of war, for which purpose
they must consequently be kept in store, and always ready in,
sufficient quantities.

" 3d. For situations where there is a rocky or shingly bottom,
they must be provided with an external covering capable of
protecting the insulation from destruction. Special precautions
must, of conrse, be taken to secure the cables at points where
they may be necessarily exposed to a considerable wasli of the
sea, such as the places where they may be led into a fort, &c-;
but as there are others where no such special precautions can
be applied, an external protecting covering over the insulation
must be provided.

" 4th. Pliability, so that it may be wound or payed out from a..
moderately-sized drum witliout injury. The conducting wire is
either soft iron or copper. The best substance for covering it to
etFect insulation, is vulcanized India rubber; this is capable of
standing any degree of heat likely to occur to a cable, and docs
not harden and crack as does gutta-percha. The conductor
should, however, be galvanized and covered with a thin coating
of raw India rubber, to protect it from the action of the sulphur
of the vulcanized rubber.

"India-rubber insulation possesses one defect as compared
with gutta-perclia, viz., that it does not adhere to the metallia
conductor; and that, consequently, if the India rubber is once
cut through, any strain on the cable lias a tendency to pull the
conductor away and increase the fault. This does not occur
with gutta-percha, which seems to cling to it and prevent such a
result. Gutta-percha cracks and perishes unless considerable
care is exercised in pi-eserving it, which is best done by keeping
it under water. India rubber possesses higher dialectric proper-
ties than gutta-perciia."

Ordinary gutta-percha and India-rubber insulated wire is an
article of commerce, and is the kind that in most cases would;^
be used for submarine mines ; but, as before stated, where there?

444 BUNG-STOPPERS — JOINTS.

Is any strain, or any chance for abrasion against rocks or grav-
elly bottom, an exterior covering is necessary for protection.
The ordinary American form of submarine cable is the most
suitable. The smallest size, such as is used for crossing rivers
-and harbors, is quite sufficient, except, perhaps, in some cases.

A multiple cable may in man}'^ cases be found convenient
where it is required to carry a large number of wires in a com-
pact form into a fort.

It is composed of seven distinct cores, each of which consists
of a strand of copper or iron wire insulated with rubber or gutta-
percha. For a rocky bottom, or situation where the cable is lia-
ble to injury, a further external covering of iron wires and tarred
hemp, laid on as usual for the protection of submarine cables,
becomes necessary.

Frictional electricity must not be used with such cables, as it
w^ould be nearly certain that every mine attached to the cable
would explode by induction.

683. Bung-stoppers are the contrivance for closing the hole
in tiie case thiough which the charge is inserted, and through
which the insulated wires pass from the fuse to the cable leading
to the fort. The essential condition to be fulfilled is to have it
water-tight and keep the arrangement in proper condition for
ignition at any moment required; it should likewise be capable

«of being unscrewed, so that the fuse maj'^ be taken out for exam-
ination and replacement if defective.

Various forms of stoppers have been devised, the principal feat-
ure of each being a stuffing-box, in vi^hich gutta-percha packing
is used. When regularly-constructed mines are supplied for serv-
ice, stoppers will accompany them. For extemporized mines,
:any device which will hold the insulated wires and at the same
time keep the water from the charge will answer. A composi-
tion composed of 1 part of tallow, 8 of pitch, and 1 of bees-wax
will be found good for tightening the joints. It becomes plastic
at about 150° F. The addition of a little gutta-percha hardens
the composition, and renders it less liable to be affected by at-
imospheric heat.

684. Joints. This is a very important point in connection
with a system of mines. In many instances it will be found
necessary to join either two lengths of cable, or an insulated
wire and a cable, together, in both of which cases great care
must be used in making the joints, so that the insulation and
the continuity of the circuit may be perfect.

In making a joint, the great object is to totally exclude the
ingress of water, or even moisture, which would at once afford
ra path for the current and cause a loss or a leak in the cable.

LAYING SUBMARINE MINES. 445»

Various methods of forming joints are in use and prove effective,
Tliese are explained in works on submarine telegrapliy, and are
well known to those engaged in that business.

685. Buoj/s. These are used for temporarily marking the
positions of mines, circuit-closers, &c. Small nut-buoys of iron
are the best, but when these are not to be had, empty casks, such
as beer-kegs, well lashed with rope, are convenient to handle,
and answer every purpose. In all cases they must be sufficiently
large, or have enough of flotation to secure the mooring cable or
other object which tliej^ are intended to liold.

6S6. Laying suhmariiie mines. " The position of the mines
having been first determined, should be marked off by means of
buoys arranged to correspond witli tiie mines to be subsequently
placed in position, and points on sliore are marked to guide the
vessels employed in laying tliem. A complete cliart of the wliole
is made to guide in subsequent operations. The moorings may
either be first placed in position, and the mines and circuit-closers
hauled down to them, or the whole (moorings, mines, and circuit-
closers) may be launched overboard, attached together in proper
relative positions, at the same time. In deep water it would prob-
ably be found preferable to adopt a system of hauling down to
moorings previously placed, while in shallow water it would, un-
der certain circumstances, be found quicker and more convenient
to adopt the latter mode of proceeding. The cases ready charged
and with the electrical cables, &c., attached, having been low-
ered into position at such intervals as may be required, according
to the size of the charges to be used, and each carefully marked
with a numbered buoy, the paying out of the electrical cables
may be proceeded with. The cable attached to each having been
previously arranged on a drum, is placed on board a launch,
which proceeds to pay it out in a line as nearly as possible per-
pendicular to the line of the mines. {Fig. 4, Plate 74.) Each
boat should be provided with a small testing battery and astatic
galvanometer, by which the insulation and electrical resistance
of the system is tested at intervals from the moment of submerg-
ing the mine till the other extremity of the cable is safely lodged
in the testing-room. Any defect likely to cause a failure in firing
at the proper moment would in this way be immediately discov-
ered during the operation of submergence. As the boat, in pay-
ing out the cable, passes the position marked out for the second
or covering line of mines, care should be taken to have it as near-
ly as possible midway between two adjacent mines in this line.
In passing this line the position of the electric cables should be
marked off by buoys as a guide to those laying down the second
line of mines, which, as soon as the work of the first has pro-

446 LAYING SUBMARINE MINES.

ceeded thus far, may at once be commenced. In order to distin-
guish between the buoys marking the positions of the mines from
those indicating the direction of the cables, different colors are
used. As the third line of mines would be placed to cover the
intervals of the second, it would be necessary, after proceeding
in a direct line for about 100 3^ards in rear of the second line of
mines, to change the direction in which the cable is to be laid by
carrying it perpendicularly to the direction hitherto followed till
a point directly in rear of some one of the mines of the second
line is reached, when it is again turned inward to a position to
pass safely through the centre of an interval between two mines
of the third line, as it had previously passed through those of the
second. In passing this third line of mines it should again be
buoyed for guidance in laying the mines belonging thereto, and
soon till the extremity of the cable is connected to its corre-
sponding wire in the multiple cable, or if taken in singl}^ till
safely landed in the fort in which the operating-room is placed,
when it is attached to its proper binding-screw, and its insulation
and resistance carefully tested and registered.

''The same process is gone through with every charge, the ut-
most care being taken to so lay the cables that they shall be as
far as possible away from the mines in the vicinity of which they
may be required to pass. By the arrangement just described
they are also in a favorable position for underrunning and pick-
ing up, shou-ld such an operation become necessary. A certain
amount of slack, depending on the depth of water, should be
allowed in lajing the cables to facilitate this operation,

''The position of each mine should be identified by means of
bearings taken by two theodolites, from points well situated for
the purpose, and marked in position on the plan, with the num-
ber of each mine, as a guide to facilitate its discovery at any fu-
ture time. This done, and the whole sj'^stem having been proved
to be electrically correct, all the surface buoys should be removed,
to prevent any indication of their position being given to an en-
emy. Dummies to deceive an enemy may be judiciously arranged
in a manner not too ostentatious, but they should never be placed
in such a position as might, in ever so remote a manner, lead to
the discovery of a real mine. The cables should be laid as far as
possible parallel, and never be allowed to cross directly over each
other; otherwise the operation of underrunning will be much
complicated.

"The arrangement of cables just described is that in which
the shortest possible length wonld be consumed. In certain
cases, however, it might be desirable to carry them by a detour
*o the fort, as, for example, around the flank of the second and

PLANTING THE MINES. 447

third lines of mines, and there is no difficulty in this, always
bearing in mind that they should, in the first instance, be carried
directly back for about 100 yards, so as to be safe from injurj'-
due to the explosion of their own line of mines, and that their
subsequent course should be so arranged as to keep them safe
from damage from the explosion of anj' other mine in the sys-
tem.

''In selecting any line to be taken, places where the cables
would be subjected to a wash of the sea should be, as much as
possible, avoided; and when it becomes necessary to place them
in positions where they are necessarily subjected to the friction
and rubbing consequent upon the motion of the water, special
precautions must be employed for their protection. A good
method of doing this is to lash the cable securelj'^ to a chain
heavy enough to keep it in position on the bottom. A wire-cov-
ered cable of ordinary size will have weight of itself sufficient to
hold it steady on the bottom."

In all cases the cables should be laid where they will be sub-
jected to the greatest amount of supervision, and where they
can be most easily defended from injury by an enemy.

Lines of mines should, when practicable, be directed on a
point where an observer can, in secm'ity, observe the crossing of
the lines by a vessel of the enemy. This point should be in elec-
trical communication with the fort "containing the operating-
room ; if not by electrical communication, then by signaling.
The bearing of each mine is taken from the operating-room as
it is put down. By means of observation from these two points
it is determined when the vessel is over any particular mine,
and tlien the charge is exploded.

The direction of a line of mines may be determined by two
poles previously erected on the shore. These serve as ranges.
The interval between the mines on the line are best determined
with a cord measured and marked to the exact length. In many
positions it may be practicable to erect range-poles, the lines of
which, intersecting the line of the mines, will establish the
points for the respective mines. It is impossible to lay down
rules for each case which may arise in service ; the ingenuity
of those in charge must be relied upon to solve the particular
problem.

OS'S'. Planting the mines. The following will indicate, gen-
erally, the manner of planting the mines. The positions having
been determined as just explained, soundings are taken at each
one, and the length of the mooring-line for each charge deter-
mined accordingly. The anchor is suspended from the davits
of the working-boat, and everything made ready to let it go with

448 PLANTING THE MINES.

a run. The electric cable is stoppered to the mooring-liiie be-
tween the charge and the anchor, and a strong moorlng-chaiu
or wire rope is provided to connect the charge to the circuit-
closer, so that, by this chain, both the charge and anchor may
be raised if required. The electric cable between the circuit-
closer and charge should be stoppered from the chain to the wire
rope in the same manner as from the charge to the anchor. The
length of the electric cables, from the anchors of the different
charges to the point where they are united to go into the fort,
are determined, and each one coiled on a small portable drum,
so that it may be easily moved in and out of the boat.

''To place the first charge, the boat (with the anchor con-
nected to the charge and circuit-closer by moorings of proper
length, as above described, and suspended from the davits at the
stern) is turned out into the exact alignment of the poles mark-
ing the line of mines, proceeding only fast enough to obtain
steerage-way ; as soon as the stern of the boat arrives at the point
marked out for the mine, Met go' is given, and immediately an-
chor, charge, and circuit-closer are dropped into position. The
electric cable is then payed out, at first directly away from the
charge, and finall}^ taken to the fort. The next charge, with all
its attachments complete, having been arranged as before, the
boat is again moved slowly across the channel along the align-
ment till her stern arrives at the point for the next mine, the
anchor is let go, and the cable disposed of as before. Thus all
the charges of a line are deposited."

It is advantageous to have, during the operation, a boat an-
chored at some central point about 100 yards in rear of the rear
line of mines. To this boat all the electric cables of each line of
mines are brought. This dispenses with the use of long cables,
and consequently unwieldy drums. Furthermore, from this
point to the fort a multiple cable may be used, or if single, they
may be tied together with spun-yarn and laid out as one. When
everything is completed the boat is removed, its position having
been previously determined bj^" bearings, to facilitate any future
searcli for the cables at that point. All range-poles are removed,
their positions having been carefully marked, but without leaving
any indications to guide the enemy in ascertaining the locality of
the mines.

The first line of mines having been completed, the next is laid
in the same manner, and so likewise the third.

In working from a chain or hawser on which the distances
have been marked, as heretofore described, ranges are used in
the same manner, to guard against any error caused by the sag-
ging of the chain or cable.

THE TESTING-ROOM. 449

Junction-boxes. When it is necessary to employ a multiple
cable, a junction-box is used to facilitate the connection of the
several separate wires diverojing from the extremities of such a
cable. In one ano*le of such a box the multiple cable is intro-
duced, while the separate cables make their exit on the opposite
sides and pass to diiFerent mines.

The ends of the cables are secured from pulling out by hooked
nippers. Each multiple cable is composed of seven cores, and
each of these is connected by means of joints with the mine
cables within the junction-box. The boxes are usually made of
cast metal, and must, as an essential condition, be perfectly
water-ti(^ht. They are of various forms, depending upon the
object for which each is to be used. They would be supplied
with the other apparatus for laying mines.

A junction-box should be placed in such a position as to be
easily attained, even in the presence of an enemy, and its buoy
should, if possible, not be seen. It is also very essential that it
should be in a safe and guarded position, for any injur}^ to tlie
Junction-box or multiple cable would be fatal to the group of
mines in connection.

688. ''The next point to be considered is the best mode of
introducing the cables into a fort. In doing so they should be
protected to the utmost, not only from injury by an enemy, but
from the friction and rubbing necessarily caused by the wash of
the sea. Bearing these objects in view, advantage must be taken
of local circumstances, which, presenting an endless variety of
conditions, must be met by expedients suited to the nature of
each particular case. As already stated, they should be carried
into such forts and positions as are likely to hold out longest in
any system of defense, and not, as a matter of course, into those
nearest to them. They must be covered to the utmost from an
enemy's fire, and, as far as possible, be protected from his inter-
ference in any way, as his great object would be to break and
destroy the electrical current."

689. The testing-room is in the most secure part of the work.
It sliould bo about 16 feet square, with a suitable store-room
attached. From the testing-room a gallery, about 4 feet wide
b}^ 5 higli, passes out through or under the fort. In this gallery
are placed frames for supporting the cables, so arranged that
there will be no confusion as to the identity of the cables. The
frames should be of bronze ; iron is apt to oxidize, and wood is
liable to decay and render constant repairs necessary. The
frames occupy half the breadth of the gallery, leaving the other
3jalf for access and examination of the cables. Each cable is

450 FIRING.

attached to a binding screw of the testing-table, the bhiding:
screws bein^ numbered to correspond with the mines.

In the testing-room is the apparatus for producing the agent
by which tlie mines are to be exploded. This may be frictional
electricity, a magnet current generated by a dynamo-electrical
machine, but usually it is a galvanic current similar to that for
electric telegraph purposes. The main conditions for such a
battery are, that it should remain constant — that is, that it should
be capable of being allowed to remain mounted and ready for
use for say a month — and that it shall generate a sufficient quan-
tity of electricity to allow of a certain amount of leak or fault in
a cable and yet fire a fuse beyond the leak.

The Leclanche battery is the one best adapted and most gener-
ality used. The advantages possessed by it are, the absence of
chemical action when the battery circuit is not complete, and
consequentlj'- there is no waste of material. It requires but
little looking after. It may be kept ready for action in store
without in any way deteriorating, and, finally, it is compara-
tively inexpensive.

690. Firing. The efficiency of a mine or system of mines
depends upon the accuracy and certainty with which they may
be discharged at the right moment, this moment being when the
hostile vessel is directly over any particular mine of the group.
This may be done at will, the position of thifr ship having been
determined by intersection, or the vessel herself may be made
to complete the circuit by striking a circuit-closer.

When the mines are placed in position, accurate bearings of
each one are taken from two secure points of observation. These
stations should be within the defensive works, and selected so
that the lines passing from them over each mine shall intersect
in such a manner as to give as nearly as possible a right angle,
or at least an angle not too acute. The mines have each a num-
ber, and the intersecting lines are correspondingly numbered ;
it is therefore obvious that when a ship is observed from both
stations to be upon a line having the same number, she will be
at the intersection of the two lines, or over the mine having a
like number.

The simplest form is where one of the stations is on the pro-
longation of the line of mines, as at A, {Fig. 1, Plate 75,) and
the other directlj'' in rear of the mines, as at B. C represents
the galvanic battery, from which runs a conducting wire through
the station A to station B, and connects at the latter point with
a series of keys, through which the current can be closed to each
of the mines 1, 2, 3, &c. Till the key at A is pressed down, no
current can pass from the battery C past the station A ; but di-

FIRING. 451

Tectly it; is pressed clown, the circuit is so far completed and the
line is cliarged up to the station B. From the station B is a
series of electric <?ables (Bl, B2, B3, &c.) attached to a series of
■contact points, perfectly distinct and carefully insulated from
each otiier; these cables pass to the mines (1, 2, 3, &c.j through
the fuses in connection with them and to earth. At the second
station B we have, therefore, a second break in the electrical
current, and it is easily seen tliat in order to pass the current
through and fire any particular fuse, both these breaks must be
bridged over, under which circumstances the current of the bat-
tery will be completed and the mine fired.

Let it now be supposed that a vessel is approaching this line
of mines. As her bow passes across the prolongation of the line
B 7 the observer at B puts down key No. 7 in connection with
mine 7 ; but as the ship has not come onto the line from A pass-
ing through the line of mines, the observer at A does not put
down his key, a break still exists in the circuit, and no current
can pass to fire the mine 7. When the vessel passes the line
B7 the observer at B allows the key to spring up and break the
connection. As the vessel passes the line B6 the observer at
B presses down key N"o. 6, but as she is still not on the intersec-
tion of the lines B 6 and A 6, the same result as before is ob-
tained, and the mine 6 will not be fired. Let it now be sup-
posed that she passes on in her cours# till she arrives over the
mine 3; in this position she is on the intersection of the two
visual lines A 3 and B 3 ; the observers at A and B in this case
both put down their respective keys simultaneously, the current
of the battery is completed through the mine 3, and that mine
will be fired.

As before mentioned, it is advantageous to have the lines of
mines all directed on one point (A). The mines of the second
^nd third lines are connected to the station B precisely as are
those of the first line. In the case of a vessel passing through
an interval of any two mines of the first line, at such a distance
as to be out of the radius of destructive effect of either of them,
as, for instance, at the point Y, between 3 and 4, it is easily seen
that at the moment of passing the first line of mines, wlien the
observer at A would have his key down, she would not be on
the prolongation of any of the visual lines from the station B to
any of the first line of mines, and as the observer at B would
not under such circumstances press down any key, she would
pass on to the second line and run upon the mine at H, which
would be exploded as just explained. Instead of having the
wire and key at A, as above explained, an ordinar}^ signal flag
anay be used for transmitting preconcerted signals. This, how-

'«•.

452 FIRING.

ever, would require the obsei^er at B to have an assistant to*
look out for the flag, and is altogether inferior to the former
method. It likewise has tlie disadvantage of informing the
enemy of the position of the lines of mines.

As in many cases it would not be practicable to have a station
on such a position as A, so far advanced towards the point of
attack, with the corresponding danger of being cut off by an
enemy, another combination becomes necessary ; this is shown
in Fig. 2, Plate 16.

. Two stations, A and B, well within the defensive works, are
selected in such a position that the lines passing from them over
the mines shall intersect in such a manner as to give a large
angle. When the mines were placed in position, accurate bear-
ings were taken to each from both of these stations. The gal-
vanic battery is placed at A, one pole being connected to eartli,
while tlie other is connected with a centre from which radiate
a series of contact keys. From the contact points of these
keys a series of cables, corresponding in number to the numbers
of tlie mines, pass to the similar contact points of a like set
of keys at station B, and from the pivots of the keys at B
an electrical cable passes to each charge. In this case, there-
fore, each mine has a separate key at station A as well as at
station B, each perfectly distinct from any other and well in-
sulated therefrom, but the whole culminating at A in the single
battery C. In each circuit, cori-esponding to any particular
mine, there are, therefore, two breaks, one at its particular con-
tact key at station A, and the other at its corresponding key at
statio!! B, and till these breaks are bridged over, by pressing
down the contact keys simultaneousl3^ the circuit of the battery
will not be closed and the mine will not be fired. In this way
it is easily seen that if key N'o. 1, for example, is put down at
station A, and key No. 2 at station B, there still remains a break
in each of these circuits; in ciituit No. 1 at B and in circuit No.
9- at A, and neither of these mines will be fired. The object of
xhis arrangement is seen by trafeing the course of the vessel (X)
approaching the line of mines. She first arrives on the line of
5 from station A and simultaneously on that of 1 from station B ;
the observer at A puts down key No. 5 and the observer at B
key No. 1, without, of course, firing any mine. Again, as she
reaches the position Y, the observer at A puts down key No. 4
and the observer at B key No. 2, without any circuit being closed.
When she arrives at 3 both observers put down keys No. 3 simul-
taneously, and the mine is fired and the vessel struck.

""In carrying out the system above described, it has been
found that with a series of very small wooden pickets, placed in

FIRING. 453>

a radiating form from a central point of observation, at a dis-
tance of about 20 feet, and with pieces of twine passing from
the centre over the picl^ets in tlie direction of the mines to
indicate the bearings more accurately, very good practice has
been obtained. The observer, with liis e3^e at the central picket
and his hand on the contact keys, puts the corresponding one
down as the object passes the bearings of each. A man soon
learns bj'' practice the distance he may allow on one side or
other of the bearing line, and with ordinary care and nerve is
soon able to make contact at the right moment.

^-'In using the keys, it is necessar}'- to press them firmly down
and hold them firmly, in order to insure good contact at tlie
proper moment.

'*'To work efficiently, it does not seem desirable that more
than six keys should be intrusted to the management of anyone
man.

^'The sj^stem of pickets above described for giving the bear-
ings might probably be used efifectually up to half a mile, but at
greater distances a more accurate means of obtaining the inter-
sections becomes necessary; the pickets have, moreover, the
disadvantage of being easily disturbed and difficult to replace
in an accurate position if once moved. In order to obviate as
far as possible these defects, an instrument has been devised-
having a telescope, with cross-wires, mounted in connection with
a series of contact points and a movable key, as shown in Fig. 3^
Plate 75. It consists of a iieavy cast-iron stand (a), on which is
placed an iron upright (6) arranged to carry the telescope (c),
allowing it a horizontal motion around the upright; it has also
a vertical motion. Concentric with the upright is a circular arc
(f?), described with a radius of about 18 inches. On this arc are
arranged the contact points for the cables running to the mines-
or to the other station. Attached to the upright, below the tel-
escope, is a horizontal arm (e), which moves around with the
telescope. To this arm is attached a contact key (/*), adjusted'
to touch the contact points on the arc. The arc is graduated
into divisions, by means of which the position of the contact
points may be registered, so that in the event of their being
accidentally displaced they may again be fixed in true relative
position with facility."

To place the instrument in position, a point from which the
lines of mines are clearly distinguishable should be chosen. ThiS'
point should be as far as possible from heavy guns and have a^
solid foundation. The iron stand of the instrument having beert
leveled by means of leveling screws, the telescope is directed on-
some fixed and well-defined object, and the number of the:

454 MECHANICAL CIRCUIT-CLOSERS.

-division under the spring of tlie lever registered. The telescope
is then directed on each buoy marking the mines of each line,
in succession, and one of the contact ai-rangements brought
into proper position for each and l^eyed firmly up, and the num-
ber of the mine and the number of the division on the gradua-
tion are registered. This having been done at both stations, the
buoys marking the positions of the mines are removed. The
points w^here the leveling screws of the iron stand rest should
be carefully marked, so that the whole may be placed in the
same position if accidentally disturbed.

The observations are made through the telescopes, and when a
vessel comes in range with any mine, as indicated by the regis-
tered degree, the corresponding key is put down, the operation
being in every other respect as before described.

691. Mechanical circuit- closers. These are arrangements
by which submarine mines are fired electrically by the vessel
herself closing the circuit.

They are of two classes, one being that in which the charge
.and the circuit-closer are in the same case, and the other is
where the circuit-closer is in a separate case, but connected with
the charge of the mine by an electrical cable. In botli ways,
the conducting cable is electrically charged from the battery on
shore up to the circuit-closer; when this latter is closed by con-
tact with a hostile vessel, the current passes through the fuse in
the charge and the mine is exploded. A great rmmber of differ-
ent forms of both classes have been invented, all of which are
more or less complicated and require special description and
study to understand.

To render mines thus provided with circuit-closers harmless to
friendly vessels passing, it would be necessary only to detach the
firing battery — an operation usually performed by the operator
dimply removing a small plug. In this case the circuit-closer, if
strongly made, may be struck time and again without injury.
This power to resist heavy blows is essential to the efficiency of any
form of circuit-closer, as, when in position in a channel through
which there is much traffic, they are always liable to be struck
with considerable force by blades of screws, floats of paddles,
and other hard and sharp bodies. Another especial considera-
tion is, that the appai-atus for closing the circuit shall not be set
in action by agitation of the water, but only by impact with a
'floating body. The circuit-closer must furthermore have suffi-
cient size to give the required amount of inertia. When the
circuit-closer and charge are combined in the same case, this is
assured ; but when they are separate, it is effected by inclosing
the mechanism in buoys made of wood or metal. The greater

MECHANICAL CIRCUIT-CLOSERS. 45^

the size and weio^ht of the ch-cuit-closer, the greater will be the
chances of the effective worlving of the apparatus.

The destructive power of a mine decreases rapidly as the dis-
tance from it increases. The circuit-closer should not, there-
fore, be beyond the effective range of the mine. Forty to fifty"
feet should be the maximum distance for the heaviest charges.

692* The arrangement of a system of submarine mines in
lines possesses the disadvantage that if the enemy has once as-
certained the position of one mine of a line, whether by explo-
sion or by any accidental circumstance, he would know within
what limits the others were to be looked for. In order to obvi-
ate this disadvantage, it would always be necessary to scatter a.
few mines in irregular intervals in front of the advanced line —
to set them as skirmishers, retaining the line formation for the^
main defense. These advanced mines might either be simply
electro-self-acting, or arranged for ignition on the same principle
as those of the main system, as circumstances required. As it is
not advisable to expend heavy charges against small boats, these
advanced mines should be comparatively small, so as to be used;
against the boats of an enemy seeking for the mines and circuit-
closers.

"The first object of an enemy would be to clear a passage of
sufficient width through the system to enable him to pass freely
in; and for this purpose he would probably employ drifters^
with or without dragging grapnels, for the purpose of either
firing some of the charges by striking the circuit-closers, or grap-
pling and destro3ing the electrical cables and other gear, These-
drifters may be boats allowed to float in with the tide or wind.
In order to stop such a sj^stem of attack, a light boom or strong,
fishing-nets would be useful, and should be employed whenever
circumstances permit. To stop drifters with dragging grapnels,,
it is a good plan to lay three or four heavy chain cables at inter-
vals across the channel, in advance of the system of mines. The
grapnels would catch in these, and the weight of the chains
would be suflScient to bring up the drifters before arriving at
the mines.

"The night would unquestionably be the safest time for the
enemy to carry on operations of this nature, and it would be
necessary to employ Ijoats to row guard in order to watch his
proceedings. The mode of communication with these boats is
a matter of considerable importance, and some means of rapidly
transmitting intelligence is absolutely necessary. This can. o£
course, be done by the system of flashing signals, but the lights
in such case would be a disadvantage, as they would indicate to
the enemy the position of the guard-boat. In order to obviate:

456 TESTING.

this, a system has been devised by vvliich a boat rowing guard
'Can be put in electrical telegraphic communication with a fort or
guard-ship, by simply paying out an insulated wire attached to
a telegraph instrument in the fort or ship, and carrying a second
instrument on board the boat. Should the guard-boat be pursued,
it would only be necessar}^ to detacli the electric cable from the
instrument and throw it overboard, with a buoy and line at-
tached to it, and pull awaj'.

""Several systems have been devised for illuminating chan-
nels at night by means of the electric light, the Drummond
light, magnesium light, <&c., and there is no doubt that, when
practicable, such devices should alwa3'^s be used."

693. Testing. In the electrical-room of the fort are kept
iihe instruments for testing the electrical cables of the mines, for
the puipose of seeing that they are in condition to perform their
work efficiently. The most essential instruments are the test-
table and galvanometers. With these the cables are, from time to
time, examined to ascertain if their insulation is effective, and
if they have a sufficient amount of electricity ; if the firing bat-
teiy is in a condition to insure certain ignition; if the electrical
connections of the circuit-closers are correct; if the electrical
resistance of the fuse is such as to indicate certainty of ignition,
and other similar information.

A separate galvanometer should be used for each mine, and
a special battery, distinct from the firing battery, employed in
connection with the testing circuits ; thus obviating the necessity
of detaching tiie firing battery while testing, — an important mat-
ter likely to occur at the critical period when vessels are attempt-
ing to break through the lines.

Should a leak be discovered in a cable, the extent of it is shown
hy the galvanometer ; and if considerable, the defective cable is
detached from the battery and the fault repaired. When a mine
is tired, it is important that its cable should be disconnected at
once from the firing battery, to prevent loss of powei- through
the broken end of the conductor.

When a separate galvanometer is supplied for each cable of a
system of a mines, it furnishes a constant indicator to point out
the fact of a circuit-closer being struck by a ship, and in many
cases it may be convenient, or even necessary, to perform the
operation of tlirowing in the firing battery without the aid of a
personal operator. A self-acting apparatus has been devised
for doing it. By making the apparatus purely self-acting, all
•chances of error consequent upon the inattention or want of dex-
terity of fehe man in charge is, of course, eliminated. No mine
or circuit-closer can be tampered with by an enemy without the

TESTING. 467

fact being instantly Ivnown in the testing-room, and precisely
what mine.

As it is of importance to be assured of the condition of the
charge in the mine, whether dry or wet, an apparatus for this
purpose has been devised, and it is of easy application. The use
of it obviates tlie necessity of the great labor, time, and trouble
that would be required to raise each mine and, by opening it,
ascertain in that way the condition of the charge.

*' The firing battery should be suited to the nature of the fuses
employed, and should possess considerable excess of power in
order to overcome accidental defects ; such as increased resist-
ance in the communications, or defective insulation in the elec-
tric cable in connection with the mine. A battery just suffi-
ciently powerful to fire a fuse on shore, with the electric cable,
&c., in circuit, but not submerged, would not be unlikely to fail
after the cable has been submerged in sea-water. In such a case
it is recommended that the battery power determined by such
an experiment on shore be doubled for actual work. For all
practical purposes this test can be made by firing a fuse of known
quality through a resistance equivalent to that of the cable.
Double the number of cells necessary to effect this would be re-
quired for the submerged cables, &c.

'* When a system of mines is to be laid, each component part
should be tested before being placed in position and, afterwards,
as the parts are successively combined in the form in which they
are to be used before submersion, and the whole should again
be tested immediately after submersion.

''As a preliminaiy to all electrical testing, it is necessary to
ascertain if the instruments, battei-ies, &c., used in making the
tests are themselves in good working order; otherwise defects
which exist in the testing instruments may produce results which
might be mistaken for defects in the apparatus under trial."

The cases are tested at the time of manufacture to ascertain
if they are thoroughly water-tight and capable of bearing the ex-
ternal pressure to the extent required, according to the depth to
which the)" are to be submerged. A very practical test for this
is to close the case with its proper mouth-piece as for service,
and then submerge it to a depth somewhat exceeding that at
which it is eventually to be used. After remaining thus sub-
merged for about forty-eight hours, it is lifted, opened, and care-
fully examined to see that it has remained perfectly dry inside.

A careful record should be kept of the results of all electrical
tests applied, as by preserving tlie electrical history of any com-
bination a defect in its electrical condition maybe readily dis-
covered, and the nature, position, and extent of such defect
29 a

458

SURFACE CURRENT OF HARBORS.

indicated with a considerable de^^ree of accuracy, without the
necessity of raising the mine out of water, or in any way dis-
turbing the arrangements employed.

The foregoing will suggest to officers charged with harbor
defenses the capabilities of submarine mines as an auxiliary to
land defenses. It also furnishes an idea of the kind and quan-
tity of material required for establishing a system of mines, and
indicates the method of applying and using it.

Dexterity in the use of testing instruments — in fact, all the
electrical manipulations connected with submarine mines — is to
be acquired only by practice, with the aid of treatises on such
subjects. Experience has proved that, with persons of good
intelligence, the necessary qualifications may be acquired in a
period of six months.

694. The following table gives the maximum surface current
for some of the principal harbors upon the Atlantic sea-board. It
will be useful in determining the kind of moorings necessary for
securino; submarine mines in these channels :

Locality.

Portsmouth, N. H., in the channel off Fort Constitution.
Boston Harbor, Mass. :

1. Boston Light-house bearing N., distant }^ mile ;
depth of water 33 feet

2. Broad Sound Channel, Long Island Light-
house bearing S. by W., distant K mile ; depth
of water 58 feet

Entrance to Narragansett Bay, main channel

New York Harbor, Narrows ; Fort Lafayette bearing
N. E., distant H mile; depth of water 90 feet

Delaware Bay, in the channel abreast of Brandywine
Shoal. (No observations were made near Fort
Delaware)

Hampton Roads, Ya., Old Point Comfort Light-house
bearing N. M E., distant H mile; depth of water 78
feet

Beaufort, N. C, Fort Macon wharf bearing S., distant
% mile; depth of water 26 feet

Cape Fear River, west entrance, Fort Caswell bearing
N. W., distant J<j mile ; depth of water 30 feet

"Winyah Bay, S. C, Georgetown Light-house bearing
S. E., distant 2 miles; depth of water 24 feet

Charleston Harbor, Fort Sumpter bearing "W., distant
% mile ; depth of water 29 feet ~

Savannah River, G-a., Tybee Knoll Light- vessel bear-
ing west, distant H mile ; depth of water 16 feet

St, Mary's River, Fla., Fort Clinch wharf bearing S.,
distant J^mile; depth of water 26 feet

Maximum ve-
locity of sur-
face current
in miles per
hour.

Ebb.
1.00

1.6

Flow.
1.5

1.5

1.1

0.5

1.1

0.4

1.2

1.8

1.4

1.3

1.7

1.9

2.8

3.0

1.4

2.4

2.1

2.5

1.4

1,6

2.1

\uvt Witntlu

'OUTLINES OF THE aENEKAL PROPERTIES OF
PERMANENT WORKS.

Plate 77.

The term permanent fortification belongs to that branch of the
■art oj" fortification where means of a durable character are used
to streno^then a position. Permanent differs from temporary
fortiflcation, not only in the character of the means used, but
also in offering a more formidable obstacle to the enemy from
the greater strength of its profile.

Permanent works may be divided into two general classes,
fortresses and forts. The term fortress is applied to fortified
towns alone, and the term fort to a work containing only a gar-
rison.

The character of the fortification is the same in both classes,
consisting in its most simple form of an elevated and wide mound
of earth, termed the rampart, which incloses the space fortified;
of an ordinary parapet surmounting the rampart, and of a wide
and deep ditch which surrounds the whole.

These parts of the profile serve the same purposes as the cor-
responding parts in the profile of a field-woi'k ; the most striking
difference between the two consists in the rampart, which, from
its height, gives a very commanding position to the parapet, and
greatly increases the obstacle presented to the enemy.

To give both strength and durability, the scarp and counter-
scarp are reveted with walls of masonry which sustain the press-
ure of the earth, protect it from the effects of the weather, and
by their height and steepness present an insurmountable obstacle
to an assault by storm.

A fortification thus constituted would be sufficient for the pro-
tection of troops within it, but would not admit of exterior oper-
ations, because it affords no shelter beyond the ditch. There-
fore, to procui-e the facility of manoeuvering on the exterior, a low
work, in the form of a glacis, is thrown up a fev/ yards in front
•of the ditch, and completely enveloping it. The space between

(458 a)

458b main work,

this work and the ditch is termed the covered-wayy because it is-
covered from the enemy's view.

The simplest form, then, of an effective profile for permanent
fortification, consists of a covered-way ; a wide and deep ditch,
with a scarp and counterscarp of masonry ; and a rampart, which,
from its height and width, will orive a commanding position to
the parapet, and sufficient room behind the parapet for the nec-
essary manoeuvres of the troops whilst in action.

The problem presented for the solution of the engineer con-
sists in making such a disposition of his works that no point
within the range of their cannon shall afford a shelter to the en-
emy; that thej^ shall inclose the greatest space w^uh the smallest
perimeter, without sacrificing the reciprocal protection of tlie
parts, afibrded by a flanking arrangement within the medium
range of arms ; that no defensive dispositions which can be de-
stroyed by the enemy's distant batteries, shall be exposed to
their fire ; and finally, tiiat the works shall be secure from an
attack by storm.

To satisfy these conditions, the space to be occupied must nec-
essarily be inclosed by a series of bastions connected by curtains ;
that the line of fortification must be contiiuious, and consist of
a wide and deep ditch, and a high and steep scarp of masonry,
to be perfectly secure from an escalade ; and that the masonry
of the scarp, which is the only pai-t that can be destroyed by a
distant fire, must be covered from this fire by the glacis of the
work which forms the covered-way.

From the range of the fire-arms that are used in the defense,
the distance between the salients of the bastions should not
exceed six hundred yards, and that for a reciprocal flanking
arrangement, the length of the curtains should not be less than
twelve times the absolute relief. (See par. 611.)

To secure the work from escalade, experience has fully proved.
tliat the scarp wall should not be less than thirty feet high, and
that the top of it should not be above the crest of the glacis.

The width of the terre-plein^ or that part of the top of the
rampart behind the parapet, is, for the accommodation of mod-
ern artillery, about thirty-five feet, and its height should give
the parapet a command of at least twenty feet over the exterior
ground.

The dimensions of the parapet are the same as those for the
profile of field-works of the strongest class. {See par. 596.)

The fortification by which the space fortified is immediately
enveloped, is termed the bodij of the place., or the enceinte. It is-
seldom tliat a permanent work consists simplj^^ of an enceinte,,
with its ditch and covered-way, particularly if some of its points

OUTWORKS. 458 c

:are, from their locality, weaker than tlie rest. Other works are
^usually added to strengthen these weak points; tliey are termed

outworks when they are enveloped by the covered -way, and
detached or advanced works when placed beyond it.

The object of these works is to lengthen the defense by forcing
the enemy to gain possession of them before he is able to make
a breach in the enceinte.

The principal outwork is one in the form of a redan, termed
the demi-lune^ which is placed in front of the curtain. This
work adds to the main defense hy a cross-fire on the bastion sa-
lients, whicli are tlie weak points of the enceinte, and when there
are demi-lunes on adjacent curtains, the bastions between them
are placed in strong reenterings, thereby forcing the enemy to
gain possession of the demi-lunes before he can penetrate, with-
out great labor and loss of life, into these reenterings. The main
•entrances to the work are usually through the curtains, which,
being the most retired parts, are also the most secure ; the demi-
lunes also serve to cover these entrances, and to guard them from
a surprise.

The ditch of the demi-lune is sometimes on the same level with
the main ditch; sometimes it is higher, but in all cases the com-
munications between the two, and also with the demi-lune itself,
are arranged so as to be easy and secure.

Situated between the two flanks of the bastions, and directly
in front of the cuitain, a small low work, termed the tenaille^
serves to mask the scarp-wall of tlie curtain and flanks from the

enemy's batteries. This mask is of very great importance, since,
by preventing the enemy from making a breach in either the
flanks or curtain, it will force him to make it in the face of the
bastion ; the flanks will thus be preserved for the defense of the
breach, and the enemy will not be able to turn the temporary
or permanent works, which may be constructed within the bas-
tion to prevent him from gaining possession of the main work,
by an assault of the breach, which he would be able to do could
he ettect a breach at the same time in the curtain or flanks.

Tiie covered-ways of the bastion and demi-lune form a strong
reentering at their point of junction, of which advantage is taken
to arrange a small redan whose faces flank the glacis of the two
covered-ways. Tiie space inclosed b}'- this woi-k, which is a part
of the covered-way itself, is termed the reentering place of arms.

The parts of the covered-ways in front of the salients of the
bastion and demi-lune, are termed the salient places of arms.

The places of arms are so called because they serve for the
^assemblage of bodies of troops who are to act on the excerior.

Small permanent works, termed redoubts, ai'c placed within

458d communications.

the demi-lune, and the reentering place of arms, for the purpose
of strengthening those works.

It is a received militarj'- principle, that the garrison of a work
is no longer in safety, when it can be carried by storm, unless
they are provided with a secure point of retreat. It is to effect
this purpose that redoubts are constructed. The one in the re-
entering place of arms secures the covered-w\ays from an attack
by storm ; and that in the demi-lune forces the enemy to advance
gradually, and with the greatest precaution, to gain possession
of the breach in the demi-lune ; and being provided with flanks,
which, from their position, have a reverse fire on the breacli in
the bastion face, tlie enemy is forced to make himself master of
it before he can venture to assault the breach in the bastion.

Works, termed interior retrenchments y which have the same
properties as a redoubt, are constructed within the bastion.
When the interior retrenchment is sufficiently elevated to com-
mand the exterior ground, it is termed a cavalier.

The protection afforded by a redoubt to another work, is not
by offering a place of safety into whicli the garrison of the work
can retire when driven out of it, but in covering the retreat of
the garrison by a warm fire, which will check the advance of the
enemy, and enable it to retire behind the redoubt, and there re-
form to resist further advance of the enemy into the works.

The crest of the glacis is broken into an indented line for the
purpose of obtaining a flank and cross fire on the ground in front
of the places of arms.

Traverses are placed at intervals along the covered-ways ; they"
serve to intercept the projectiles which enfilade the covered-ways,
and also to defend them foot by foot, enabling the troops to re-
treat from one part of the covered-way behind the traverse under
the protection of its fire.

Tiie principal communications consist of ramps^ stairs^ pos--
ierns^ gateways^ bridges^ and, for wet ditches, sometimes dikes.

Ramps for the use of artillery, or other vehicles, have a width
Dn top of 10 to 15 feet, and an inclination from \ to -^.

Stairsy except for tempoi'ary purposes, are constructed of stone,
and are usually placed along the counterscarp and gorge walls
of the outworks, forming a communication for infantry only,
between the ditch and the terre-plein of the work to which they
lead. They are also used within the enceinte in positions where
there is not sufficient room for ramps.

Posterns are arched bomb-proof passage-waj^s, constructed un-
der tiie ramparts, forming communications between the parade
and the main ditch, or between the ditches and the interior of
the outworks.

BRIDGES. 458e

For artillery, the width is usnallj' 10 feet and the height 8 feet.
For infantry, these dimensions may be much less. A strong
wooden door is placed at each end of the postern. These doors
should be loop-holed for musketry.

Gateways. In works with large garrisons, where the means
of frequent communications with the exterior are required, pos-
terns are constrncted of sufficient width to admit of at least a
single carriage-road witii a narrow foot-path on each side.

An arched chamber is generally placed on one side of the pos-
tern, and the wall between is loop-holed, so as to secure a mus-
ketry fire on the doorway of the postern. The arched chamber
serves as a guard-room. As a further precaution against sur-
prise, a machicoulis defense is sometimes arranged at the top
of the scarp-wall just above the doorway of the postern.

Bridges. The communication across the main ditch leading
from the gateway to the country is usually an ordinary wooden
bridge. The bay of this bridge at the gate is spanned by a draw-
bridge of timber, which, when drawn up, closes and secures the
gatewa}'. A barrier, termed a portcullis^ which can be lowered
or raised vertically by machinery, is sometimes added to secure
the passage-way from surprise.

In recent works, the portcullis, and even the doors preceding
them, have been constructed of a strong lattice-work of wrought-
iron bars. This is a great improvement, both as to diu-ability
and defense. All passage-ways should be placed in the most
secure part of the works, and under such flanking arrangements
as to cover them with close musketry tire, or with that from
machine guns.

With regard to tlie relief of the outworks, as a general princi-
ple those most advanced should be commanded by those most
retired. This principle is applied in all the works, except the
tenaille and the redoubt of th(i reentering place of arms. The
former must not mask the lire of the bastion flanks along the
main ditch, and the latter must not mask the fire of the bastion
faces upon the glacis of the demi-lune covered-way. To satisfy
these conditions, the two works must be commanded by the demi-
lune, which is more advanced than either of them ; but, by the
process of defilement, they are both so arranged that the enemy
will not have a plunging tire into them from the demi-lune.

All the fortification comprehended between the capitals of two
adjacent bastions and the glacis, is termed a front of fortifica-
tion., or simply a front. It is taken as the unit in permanent
fortification.

The usual method of eff"ectually protecting any point, is by a
flank fire ; but, owing to the locality, or to some other cause, it

458f casemates.

may not be practicable to make a flanking arranoement. To
snpplj^ its place, dispositions, termed counterscarp galleries^ are
made behind the counterscarp, with loop-hole defenses for a
reverse fire. This arrangement approximates the nearest to the
military solution of the problem to see witJiout being seen, since,
from the position of these galleries, tlie enemy will not be able
to bring his batteries to bear on them, whilst they will present
a formidable impediment to all of his operations in the ditches.

For sea-coast defenses, embrasui-es are made through the scarp-
wall, and the artillery is protected from shells by an arcl>ed
bomb-proof covering overhead. This arrangement is termed a
defensive casemate. This method of defense is only efficacious
against a sea attack; for on the land side, where the enemy can
approach regularly, casemates would be rapidly destroyed by his
batteries, and the loss of life would be far greater in them than
in an open defense, owing to the fragments of stone which each
shot striking an embrasure would cause.

The arch of the casemate is supported by piers extending back
from the scarp-wall. These piers are usually about six and a
half feet thick, and, a few feet back from the scarp-wall, are
pierced by arched passage-waj^s, which, besides securing free
communication from one casemate to another, gives the gini-
carriage a wider traverse by allowing the rear end to run under
this opening.

The arches of the casemates are of brick, and have a thickness
of three feet exclusive of the roof-shaped capping, which is gen-
erally of rubble and b^ton, and covered on top by the earth of
the rampart and parapet. At least six feet of earth is necessary
to give full security against shells.

Arched recesses are made in the scarp-wall at the embrasure
to permit the gun being well run out to prevent the smoke from
entering the casemate.

Tiie embrasure is in the centre of the recess, the sole being at
the proper height for the easj^ service of the piece.

In some casemates, flues for ventilation and carrying ofl" rapidly
the smoke of discharge run from the top of the carriage recess
through the masonry of the scarp-wall, and have their outlet in
the top of the wall outside. In others, the flues run from the
casemate arch to the top of the scarp-wall.

Beneath the embrasure, a recess, termed the tojigue-hole^ is
made to receive the tongue of the chassis. The tongue is con-
flned in its place, and the chassis traversed around a pintle,
which is received into t\\Q. pintle-hole made at the centre point of
the throat of the embrasure, and extending into the masonrj'
below the tongue-hole. When the casemate serves also as quar-

MAGAZINES. 458g

ters for the garrison, the rear, towards the parade, is closed by a
rausonry wall, which forms tlie front of the quarters. A brick
partition wall separates the quarters from the gun-room.

Built up with this wall are fire-places, with flues extending to
the parapet above.

The front or parade end of the quarters is suitably finished,
with doors and windows.

In contracted situations, wiiere it is desirable to secure greater
fire in a fixed direction than can be had from a single tier of
casemates, one or more tiers are added, the parapet being re-
tained as before. The arclies of the top tier are alone bomb-
proof; those of the lower tiers being of sufficient strength to re-
ceive the armament and admit of the service of the guns with
safety.

Mortars being placed behind the ramparts or traverses to secure
them against horizontal fire, are protected from vertical fire by
arches covered with earth, as in the preceding case. The arch
rises towards the front to give room for the sliell in its flight.
The front end of the casemate is walled up to a height of about
six feet. This permits the mortar to be firied over the wall, and
the interior of the casemate is protected to a great degree from
falling shells and splinters.

Casemates are also used simply as bomb-proof shelters for the
troops and material. These vn'Aj be constructed in the ramparts
of land fronts, where guns are used onlj'- in barbette.

Upon land fronts, where it is important to have the masonry
covered by earth from the fire of stationary batteries, embrasures
are made in the parapet after the manner prescribed in par. 634.
The arch of the casemate is united to the interior slope-wall, as,
in the preceding case, it was to the scarp-wall. Its covering of
earth extends down in front, forming the merlons of the parapet,
thns covering all the masonry except that of tfie embrasure.
The front portion of the arch of the casemate is conoidal, and
descends down to the top of the embrasure.

Magazines (see pars. 569, 637) for permanent works are con-
structed usutdly in connection with the enceinte, being placed in
the most secure part of tiie work. They are built with strong,
full centre bomb-proof brick arches, supported on heavy masonry
piers, which form the outward walls. The arches are covered
with not less than eight feet of earth.

The interior of the magazine, the floors, and the doors and
^vindows are built with a view to security from fire, and to pre-
serve the powder from dampness by a good system of drainage
^around the foundations, and of ventilation by means of air-holes

458h detached works.

made throiio^h the piers and panels of copper pierced with small
holes placed in the doors.

No iron or steel is allowed in any part of the structure, bronze
being used where it is necessary to employ metal.

The exterior openings for air-holes are covered with copper
mesh-work to prevent combustible material or rats or mice pene-
trating to the interior of the magazine.

Heavy guns are usually placed in pairs, with a traverse be-
tween each set of pairs. In this traverse is built the service
magazine for the adjacent pieces.

Advanced works are those placed bej'ond the outworks, and
are so under the fire of either the main work or the outworks a&
to have the ground in advance of them swept by this fire ; their
ditches flanked hj it, and their interior so exposed to it. that if
the work were seized by the enemy he could be driven from it
by tliis fire.

Detached works are those which, although having an important
bearing on the defense of the main work, are so far from it as to
have to depend solely on their own strength in case of assault.

Explanations of Plate 77.

Plan of a regularly fortified front :

A A . . A is the enceinte, or body of the place.

BB, the bastions.

CC . . C, the main ditch, or ditch of the enceinte.

DD . . D, the bastion and demi-lune covered-ways.

E E, the reentering places of arms.

FFF, the salient places of arms.

G, tiie demi-lune.

H, the demi-lune ditch.

J, the demi-lune redoubt.

LL, the'ditch of the demi-lune redoubt.

MM, the redoubts of the reentering places of arms.

a a . . a, traverses of the covered-way.

o, the tenaille.

Fig. A shows a section of the enceinte, main ditch, and cov-
ered-way.

A is the rampart; of which a 6 is the slope, and he the

terre-plein.
B is tiie parapet ; of which cdegh is the outline.
C is the main ditch.

D, the scarp wall.

E, the counterscarp wall.

F, the embankment of the covered-way; of which mn is

the terre-plein, n op the outline of the banquette,,
interior slope, and glacis.

iart mmntU.

SALUTES AND CEREMONIES.

This subject is introduced under the following authority :

Navy Department, Washijstgton, Nov. 20, 1879.
Sib : Referring to your letter of the 30th ultimo, transmitting^ the mantt-
script of a "Chapter on Artillery Salutes in G-eneral," by Major Tidball^.
of the United States Army, I have the honor to inform you that the officeris
of the Navy to whom it was submitted report that it confonns to naval
usage and the conventions with foreign powers with respect to the etiquett©'
of visits and salutes.
The manuscript is herewith returned.

Yery respectfully,
(Signed) R. W. THOMPSON,

Secretary of the Navy.
Hon. GrEORGE "W. McOrary, Secretary of "War. ,

Approved :

By order of the Secretary of "War.

(Signed) JOHN TWEED ALE,

Acting Chief Clerk.
War Department, Nov. 26, 1879.

695. A salute with cannon is a certain number of guns fire^"
in succession with blank cartridges, in honor of a person, to-
celebrate an event, or to show respect to the flag of a country..

Tiie i-apidity with which the pieces are discliarged depends
upon their calibre. Field guns sliould have intervals of five
seconds between discharges; siege guns, eight; and guns of
heavier calibre, ten.

The minimum number of pieces with which salutes can be
fired is two for field, four for siege, and six for sea-coast guns.

Mortars, as a rule, are not used for saluting purposes.

696. Personages entitled to salutes, if passing a mihtary^
post, as also foreign ships-of-war, are saluted with guns of heavy
calibre, the most suitable being the 10-inch smooth-bore.

When trooi)s are drawn up for the reception of a dignitary,,
and it is practicable to have a battery of field guns on the
ground, a salute from it should form part of the ceremony;;
otherwise guns in position are used.

The national salute, and minute-guns upon funeral occasions,,
are, when practicable, fired from heavy pieces.

( 459 )

-460 SALUTES AND CEREMONIES.

697. The pieces used for a salute should, if possible, be of
the same or equivalent calibre; and when the number on the
front of a work admits of it, the entire number required, and
two or tliree over, should be loaded and made ready previous to
commencing the salute; the detachments are then dispensed
with, and a single cannoneer at each piece discharges it at the
proper time. When the number of pieces is insufficient for the
entire salute, as many as possible should be used, so as to avoid
frequent reloadings.

698. The pieces are numbered from right to left, — one, iwo^
'ihree^ and so on, — and each detachment or the cannoneer, as

the case may be, is made to clearly understand the number of
the piece. To insure regularity of intervals, the officer in charge
^of the firing should habituate himself to uniformity in giving the
commands to fire.

At the proper moment the officer in charge commands : Num-
ber one^ Fire, and observing the proper interval, Number two^
Fire, and so on to the left piece, when he returns to the first
and repeats the same commands until the entire number re-
quired for the salute is discharged. In order to preserve regu-
larity in the fires, he will not concern himself with the running
number, but will have a capable person to keep the count and
notify him when the required number of discharges are made.
In giving the command Jire^ he looks towards the piece to be
fired, and gives it in such a pronounced manner, accompanied
'Tjy a signal with his sword, as to be unmistakable; the can-
noneer discharging a piece, when its number is called casts his
eyes to the officer, and, observing the signal as well as the com-
mand, pulls the lanyard with promptness and decision. The
officer will be careful to avoid excitement in himself or to cause
it in the men firing the pieces. Should a piece miss fire, he
immediately commands the next to fire, and allows the piece
that has missed to remain undischarged until its proper turn
-again comes. Immediately after each piece is discharged it is
reloaded and made ready. The cartridges are withdrawn from
the pieces that remain loaded at the conclusion of the salute.

699. Salvos are simultaneous discharges from several can-

Son. They correspond to volleys of musketry, and are fired,
y way of salute, only over the graves of officers at the time of
burial.

The order designating a funeral escort prescribes whether
the fire shall be three volleys of musketry or three salvos of
.-artillerj''.

The following are prescribed salutes :

NATIONAL AND PERSONAL SALUTES. 461.

National Salutes.

I'OO. The national salute is one gun for each State in the-
Union.

The international salute^ or the salute to a national flag, is-
21 guns.

Personal Salutes.
YOl. To civil and diplomatic authorities.

The President of the United States receives a salute,
to be given both on his arrival at and final departure
from a military post or station provided with artil-
lery, of 21 guns..

The Vice-President of the United States 19 guns-
Members of the Cabinet, the Chief Justice, the Speaker
of the House of Representatives, the Governors with-
in their respective States or Territories 17 guns.

A committee of Congress officially visiting a military

post or station 17 gnns»

The Sovereign or Chief Magistrate of a foreign State, to
be given both on ai'rival at and final departure from

a military post or station provided with artillery 21 guns*

Members of the Royal Familj', i. e., the Heir-apparent
and Consort of the reigning sovereign of a foreign

State 21 guns.

The Viceroy, Governor-General, or Governors of prov-
inces belonging to foreign States 17 guns.

Ambassadors Extraordinary and Plenipotentiary 17 guns-
Envoys Extraordinar}' and Ministers Plenipotentiary.. 15 guns.

Ministers Resident accredited to the United States 13 guns.

Ciiarg^s d' Affaires, or subordinate diplomatic agents

left in charge of missions in the United States 11 guns.

Consuls-General accredited to the United States 9 g-uns.

te'

"YO^. To military and naval officers.

The General-in-Chief, Field Marshal, or Admiral 17 guns.

Lieutenant-General or Vice- Admiral...., 15 guns.

Mujor-General or Rear-Admiral 13 guns.

Brigadier-General or Commodore 11 ginis,

Otficers of volunteers and militia, only when in the service o£
the United States, the salute specified for their rank.

Officers of foreign services visiting any military post or station^
provided with artillery, are saluted in accordance with their*
rank.

462 NATIONAL AND INTERNATIONAL SALUTES.

In addition to the foregoing, occasions of a public nature
frequently arise when salutes are both desirable and proper.
Orders will govern in such cases. Personal salutes are, however,
strictly confined to the foregoing, and are fired but once, unless
•otherwise specified herein.

The national color must always be displayed at the time of
firing salutes.

TMie national salute is fired at noon on the anniversary of the
Independence of the United States at each military post or camp
provided with artillery.

7©4. The international salute is the only salute which is re-
turned, and this is invariably done as soon as possible. The
time intervening must never exceed twenty-four hours. The
iailui-e to return such salute is regarded as a discourtesy or lack
•of friendship justifying the other party in asking explanation.

In the presence of the President of the United States, however,
no salute, other than the national salute^ and that specified for
liim, is to be fired.

105. It is the custom for saluting vessels-of-war upon anchor-
ing in presence of a fort, to hoist at the fore the flag of the coun-
try in whose waters they are, and to fire the first salute. A
failure to do so is a proper subject for explanation.

]S"otice of an intention to salute the flag is usually given by
the vessel direct to the fort; but as giving notice involves delay,
vessels frequently salute without it. Vessels mounting less than
ten guns do not fire salutes requiring the guns to be reloaded.
Surveying vessels, store-ships, or transports do not salute.

If there be several forts or batteries in sight, or within six
miles of each other, one of them is designated in orders to return
international salutes. Either of the others receiving notice from
a, saluting vessel of intention to salute the flag, immediately no-
tifies the one designated as the saluting fort, and informs the
vessel of the fact. If a vessel salutes without giving notice, the
fort designated as the saluting fort returns it.

United States vessels return salutes to the flag in United States
waters, only where there is no fort or battery to do so.

United States vessels do not salute United States forts or posts.

Salutes to the flag are in no sense to be considered as personal.

^OQ, The President of the United States, the Sovereign or
Chief Magistrate of a foreign country traveling in a public ca-
pacity, is saluted 'whQw passing m the vicinity of a military post.

A vessel-of-war on which the President of the United States is
traveling displays the national ensign at the main. In the case

OFFICIAL COURTESIES. 463

of foreign sovereigns, vessels display the royal standard of the
sovereign in like manner.

TOT. Personal salutes, in compliment to foreign diplomatic
authorities, are to be fired only for those whose nations pay the
same compliments to United States diplomatic ministers in their
territories.

Personal salutes at the same place and in compliment to the
same person, whether civil, diplomatic, military, or naval, are
never to be fired oftener than once in twelve months, unless such
pei'son shall have been, in the meantime, advanced in rank.

Officers on the retired list, whether military or naval, are not
to be saluted. This, however, does not apply to funeral cere-
monies.

An officer, whether civil, military, or naval, holding two or
more positions, either of which entitles him to a salute, receives
only the salute due to the highest grade. In no event is the
same person to be saluted in more than one capacity.

When several persons, each of whom is entitled to a salute, ar-
rive together at a post, the one highest in rank or position is alone
saluted. If thej'^ arrive successively, each is saluted in turn.

An officer assigned to duty according to brevet rank receives
the salute due to the full rank of the grade to which he has been
assigned.

As a rule, a personal salute is to be fired when the personage
-entitled to it enters the post.

When the troops at a military post are to be reviewed by a per-
sonage entitled to a salute, it is most appropriate to fire the salute
from field guns at the place of review, and at the time, just pre-
vious to the review, when the personage arrives on the ground.

Official Courtesies.

KOS, The interchange of official compliments and visits be-
tween foreign military or naval officers, and the authorities of a
military post, are international in character.

In all cases it is the duty of the commandant of a military post,
without regard to his rank, to send a suitable officer to ofi^er civ-
ilities and assistance to a vessel-of-war (foreign or otherwise)
recently arrived.

After such offer it is the duty of the commanding officer of the
vessel to send a suitable officer to acknowledge such civilities,
and request that a time be specified for his reception by the
commanding officer of the post.

The commanding officer of a military post, after the usual
offer of civilities, is always to receive the first visit without re-
gard to rank. The return visit by the commanding officer of

464 OFFICIAL COURTESIES.

the military post is made the following day, or as soon thereafter
as practicable.

"^09. When a military commander officially visits a vessel-of--
war he gives notice of his visit to the vessel previously thereto, or
sends a suitable officer (or an orderly) to the gangway to an-
nounce his presence, if such notice has not been given. He is
then received at the gangway by the commander of the vessel^
and is accompanied there on leaving by the same officer. The
officer who is sent with the customary offer of civilities is met
at the gangway of a vessel-of-war by the officer-of-the-deck;
through the latter he is presented to the commander of the ves-
sel, with whom it is his duty to communicate.

A vessel-of-war is approached and boarded b}'^ commissioned
officers, by the starboard side and gangway, when there are gang-
ways on each side.

In entering a boat, the junior goes first and other officers
according to rank; in leaving a boat, the senior ^oes first. The
latter is to acknowledge the salutes which are given at the gang-
way of naval vessels.

]N"aval vessels fire personal salutes to officers entitled to them
when the boat containing the officer to be saluted has cleared
the ship. It is an acknowledgment for his boat to '' lie on her
oars" from the first until the last gun of the salute, and for the
officer saluted to uncover, then at the conclusion to '""give way.'^

The exchange of official visits between the commanding officers
of a post and vessel, opens the door to both official and social
courtesies among the other officers.

'710. To a boat with the flag of an admiral, vice-admiral, or
rear-admiral, or the broad pennant of a commodore, boats with
narrow pennants *'lie on their oars" or '■'let fly their sheets,"
and boats without pennants "toss their oars." In both cases^
officers in them salute.

In the case of two boats meeting or passing each other, each
with the same insignia of a commanding officer, the junior is the
first to salute.

Officers of inferior grade to a commanding officer passing him
in a boat, *Mie on their oars" or 'Met fly their sheets," and
salute. All other officers passing each other in boats are to ex-
change salutes, the Junior saluting first.

Cockswains steering boats are, whenever commissioned officers
are saluted, to stand up and raise their caps, and whenever
warrant officers are saluted thej'^ raise their caps only.

The officer or cockswain of a loaded boat, or of boats engaged
in towing, salute a boat with the flag of an admiral, vice-admiral
or rear-admiral, or the broad pennant of a commodore, by
standing and raising their caps.

OFFICIAL COURTESIES. 465

When boats are rowing in the same direction, an inferior is
not to pass a superior in grade unless he i.^ on urgent duty, or
authorized by- the superior.

When boats are pursuing opposite directions, the rule of the
road to prevent fouling is, that both shall "put their helms to
port " — i. e., to pass to the right, circumstances permitting.

When boats are approaciiing the same landing or vessel, an
inferior is always to give way to a superior in rank.

Boats about leaving a ship's side or landing are to give way in
ample time to others approaching.

It is not proper to land over another boat witliout permission,
and only when it cannot be avoided is permission to be asl^ed.

Boats display their ensigns when they shove off, and keep
them flj-ing until their return.

'^'11. To distinguisli officers in boats, commanding officers of
fleets, squadrons, or divisions carry the distinguishing marks of
their rank on the bow of their barges. Flags and pennants dis-
tinguishing rank are also worn at the bows of boats.

An admiral's flag is a blue flag bearing four v^^hite stars ; that
of a vice-admiral bears three stars; a rear-admiral, two stars; a
commodore's pennant, one star, and is a swallow-tailed flag.

The narrow pennant is worn by commanding officers of lesser
rank. In addition, captains in the Navy wear a gilt ball on the
end of their boat staffs, and commanders a gilt star.

To the ships, boats, and officers of the United States Navy, as
well as foreign officers, the foregoing is due; and courtesy be-
tween the land and naval services is indispensable to good order
and discipline, as well as necessary to the national dignity and
honor. Military officers of assimilative rank are entitled to and
should carry the above boat insignia.

Navy regulations require officers and men never to omit, on
any occasion, to extend the same compliments to officers of the
Army as are paid by them to officers of the Navy.

•yiS. When a civil functionary entitled to a salute arrives at
a military post, the commanding officer meets or calls upon him
as soon as practicable. The cominanding officer will tender him
a review, provided the garrison of tlie place is not less than four
batteries of artillery, or their equivalent of other troops.

When an officer entitled to a salute visits a post within his
own command, the troops are paraded and he receives the honor
of a review, unless he directs otherwise.

When a salute is to be given an officer junior to another pres-
ent at a post, the senior will be notified to that effect by the com-
manding officer.

Military or naval officers, of whatever rank, arriving at a mll-
30

466 FUNERALS.

itary post or station, are expected to call upon the commanding
officer.

Under no circumstances is the flag of a military post dipped
by way of salute or compliment.

Funerals.

1'13. When the funeral of an officer entitled, when living,
to a salute, takes place at or near a military post, minute-guns
are fired while the remains are being borne to the place of inter-
ment; but the number of such guns is not to exceed that which
the officer was entitled to as a salute when living. After the
remains are deposited in the grave, a salute corresponding to
the rank of the deceased officer will be fired — three salvos of
artillery, or three volleys of musketry.

In the event of a flag-officer of the N'avy, whether of the
United States or of a foreign country, dying afloat, and the re-
mains are brought ashore, minute-guns are fired from the ship
while the body is being conveyed to the shore. If it be in the
vicinity of a military post, the flag of the latter is displayed at
half-staff, and minute-guns are fired from the post while the pro-
cession is moving from the landing-place. These minute-guns
are not to exceed in number that which the officer was entitled
to, as a salute, when living.

During the funeral of a civil functionary entitled, when living,
to a salute, the flag is displayed at half-staff, and minute-gims
fired as before ; but neither salute nor salvos are fired after the
remains are deposited in the grave.

On the death of an officer at a military post, the flag is dis-
plajT^ed at half-staff, and kept so, between the hours of reveille
and retreat, until the last salvo or volley is fired over the grave,
or, if the remains are not interred at the post, until thej'^ are
removed therefrom.

During the funeral of an enlisted man, the flag is displayed
at half-staff, and is hoisted to the top after the final volley or
gun is fired.

All military posts in sight, or within six miles of each other,
display their flags at half-staff upon the occasion of either one
doing so. The same rule is observed toward a vessel-of-war.

On all occasions where the flag is displayed at half -staff", it is
lowered to that position from the top of the staff. It is after- ^
wards hoisted to the top before being finally lowered.

'^'14. Should it occur that salutes which are due to any for-
eign official or dignitary have not been provided for in the fore-
going paragraphs, he may receive the salutes and honors which
are awarded him in his own country. If time permits, however,
special instructions from the War Department should be sought.

APPENDIX.

All weights and dimensions in tlie foregoing pages are given
In English denominations.

The only legalized unit of weight or measure in the United
States is a troy pounds brought from England, by Captain Kater^
in 1827. This pound is a standard at 30 inches of the barometer
^nd 62° of the Fahrenheit thermometer.

The standard avoirdupois pound is the weight of 27.7015 cubic
inches of distilled water at 30 inches of the barometer and 62° F.
The following table shows the relation between the troy pound
and the avoirdupois pound :

7000 grains troy = 1 pound avoirdupois.
6760 grains troy = 1 pound troy.
175 pounds troy = 144 pounds avoirdupois.
175 ounces troy = 192 ounces avoirdupois.
437.5 grains troy = 1 ounce avoirdupois.

In the United States artillery, tlie troy grain (7000 to the
pound) is taken as the standard.

2240 pounds avoirdupois make a ton (long).

2000 pounds avoirdupois make a ton (short).

The former is used by the English for all purposes.

Both of these tons are in common use in the United States.
Where precision is required, as in making contracts, &c., it is
■customary to state, in pounds, which ton is meant.

A box 16 X 16.8 X 8 inches, contains 1 bushel.
12 X 11.2 X 8 inches, contains ^ bushel.
8 X 8.4 X 8 inches, contains 1 peck.
6 X 6 X 6.4 inches, contains 1 gallon, ^ liquid meas-
4 X 4 X 3.6 inches, contains 1 quart, j ure.

Metric System.

By an act of Congress approved July 28, 1866, the metric
system of weights and measures is made optional in the United
States, and the act provides that the tables in a schedule an-
nexed shall be recognized ''as establishing, In terms of the
weights and measures now in use in the United States, the
equivalents of the weights and measures expressed therein in
terms of the metric system ; and said tables may be lawfully
used for computing, determining, and expressing, in customary
weights and measures, the weights and measures of the metric
system."

(467)

468

APPENDIX.

Schedule annexed to act of July 28, 1866.

MEASURES OF LENGTH.

Metric denom-
inations.

Yalues in metres.

Equivalents in denominations in \

use. .

Myriametre

Kilometre

10000.
1000.
100.
10.
1.
0.1
0.01
0.001

6.2137 miles. ;
0.62137 mile, or 3280 feet and 10 In.
328 feet and 1 inch.
393.7 inches.

39.37 inches. \
3.937 inches. f
0.3937 inch.
0.0394 inch.

Hectometre

Decametre

Metre

Decimetre

Centimetre

Millimetre

25.39954113 millimetres = 1 inch.

0.30479449356 metres = 1 foot.

0.91438348 metres = 1 yard.

1.6093149 kilometres = 1 mile.

MEASURES OF SURFACE.

Metric denominations.

Yalues in
sq. metres.

Equivalents in denominations in use.

Hectare ••

10000

100

2.471 acres.

119.6 square yards.

1550 square inches.

Are ...•........«.•..«•....•«.«•

Centare... ..................

1 square centimetre.
1 square decimetre..

1 square metre

1 square metre ~

1 square inch

1 square foot

1 square yard ,

1 square mile

0.15500591 square inches.
0.107642993 square feet.
10.7642993 square feet.
1.19604326 square yards.
0.0002471 acre.
645.136(39 square millimetres.
0.092899683 square metre.
0.83609715 square metre.
2.58989447 square kilometres.

MEASURES OF CAPACITY.

Metric denominations and yalues.

Equivalents in denominations
in use.

Names.

No. of
litres.

Cubic measure.

Dry measure.

Liquid or wine
measure.

Kilolitre or
stere

1000.
100.
10.
1.
0.1
0.01
0.001

1 cubic metre....

0.1 c. metre

10 c. decimetres.
1 c. decimetre....
0.1 c. decimetre.
10 c. centimetres
1 c. centimetre..

L308 c. yds

2 bus. 3.35 pks.

9.08 quarts

0.908 quart

6.1022 c. inch..
0.6102 c. inch..
0.061c. inch....

264.17 gallons.
26.417 gallons.
2.6417 gallons.
1.0567 quarts.
0.845 gill.
0.338 fluid oz.
0.27 fluid dr'm.

Hectolitre ...
Decalitre . ...
Litre

Decilitre

Centilitre....
Millilitre

METRICAL EQUIVALENTS.

469

1 cubic centimetre (c. c) = 0.0610270515194 c ibic inches.

1 cubic decimetre = 61.0270515194 cubic inches.

1 cubic metre = 61027.0515194 cubic inches.

1 cubic metre = 35.31658074 cubic feet.

1 cubic metre = 1.3080215 cubic yards.

1 cubic inch = 16.3861759 cubic centimetres (c. c.)

1 cubic foot = 0.0283153119 cubic metre.

lcubi<5 yard = 0.7645135 cubic metre.

WEIGHTS.

> Metric denominations and values.

Equivalents in

denominations

in use.

Names.

Number of
grammes.

Weight of what quan-
tity of water at max-
imum density.

Avoirdupois
weiglit.

Millier, or toimeau.
Quintal

1000000.
100000.
10000.
1000.
100.
10.
1.
0.1
0.01
0.001

1 cubic metre

2204.6 pounds.
220.46 pounds.
22.046 pounds.
2.2046 pounds.
3.5274 ounces.
0.3527 ounce.
15.432 grains.
1.5432 grains.
0.1543 grain.
0.0154 grain.

1 hectolitre

Myriagramme

Kilogramme, or kilo

Hectogramme

Decagram.me.. .........

10 litres :

1 litre

1 decilitre

10 cubic centimetres

1 cubic centimetre

0.1 cubic centimetre

10 cubic millimetres

1 cubic millimetre

Gramme

Decigramme

Centigramme

Milligramme

Additional Metrical Equivalents.

1 surveyor's chain in metres = 20.11662 ... log.= 1.3035550

1 metre in surveyor's chain = Q.04971*... log.= 8.6964450

1 square foot in square metres.. = 0.09290*... log.= 8.9680221

1 acre in hectares — 0.40467*... lo^.= 9.6071100

1 square mile in hectares = 258.904 ... log.= 2.4132900

1 square metre in square feet... = 10.76410 ... log.= 1.0319779

1 hectare in acres = 2.47109 ... loo^.= 0.3928900

1 hectare in square miles = 0.00386*... log.= 7.5867100

1 cubic foot in steres = 0.02831*... lo(;.= 8.4520332

1 cord in steres = 3.62445 ... 102^.= 0.5592432

1 stere in cubic feet == 35.31561 .... log.= 1 .5479668

1 stere in cords = 0.27590*.... loo-.= 9.4407568

1 |?rain in grammes = 0.064798*.. log.= 8.8115680

To avoid negative characteristics, 10. has been added to the
logarithms of the numbers marked * in the above table.

470 APPENDIX.

Miscellaneous.

Length. — Gunter's chain = 66 feet = 4 pales = 100 links of

7.92 inches.
1 fathom = 6 feet ; 1 cable-length = 120 fatlioms.
1 hand = 4 inches; 1 palm = 3 inches; 1 span = ^

inches.
Solid. — 1 cubic foot = 1728 cubic inches.

1 cubic j^ard = 27 cubic feet = 46656 cubic inches.
1 reduced foot (board-measure) = 1 square foot X 1

inch thick = 144 cubic inches.
1 perch of masonry = 1 perch (16^ feet) long X 1 foot

high X 1^ foot thick = 24.75 cubic feet ; 25 cubic

feet has generally been adopted for convenience.
1 cord fire-wood = 8 feet long X 4 feet high X 4 feet

deep = 128 cubic feet.
1 chaldron coal = 36 bushels = 67.25 cubic feet.
Paper, — 24 sheets = 1 quire.

20 quires = 1 ream = 480 sheets.

The units of capacity measure are the gallon for liquid and
the bushel foi- dry measure. The gallon is a vessel containing^
58372.2 grains (8.3389 pounds avoirdupois) of the standard
pound of distilled water, at the temperature of maximum den~
sity, (39°.83 Fahrenheit,) the vessel being weighed in air at
62° F., the barometer standing at 30 inches.

The bushel is a measure containing 543391.89 standard grains^
(77.6274 pounds avoirdupois) of distilled water, weighed as above

The gallon is the wine-gallon, of 231 cubic inches, nearly ; and
the bushel, the Winchester bushel, nearly.

WEIGHTS AND VOLUMES OF SUBSTANCES.

471

Weights and Volumes of various Substances.

METALS.

SUBSTANCES.

iirass^2inc 33

Brass, gun-metal

Copper, cast

plates

Iron, cast

gun-metal

wrought bars
Lead, cast

rolled

Mercury, 60°

Steel, plates

soft

Tin

Zinc, cast

rolled

CUBIC

FOOT.

INCH.

Pounds.

488.75

.2829

643.75

.3147

547.25

.3179

543.625

.3146

450.437

.2607

466.5

.27

486.75

.2816

709.5

.4106

711.75

.4119

848.7487

.491174

487.75

.2823

489.562

.2833

455.687

.2637

428.812

.2482

449.437

.2601

WOODS.

SUBSTANCES.

Ash

Cedar

Chestnut

Hickory, pig-nut

shell-bark....
Lignum - vitse

Mahogany, Honduras

Oak, Canadian

English

live, seasoned-
white, dry

upland...

Pine, yellow

Spruce

Walaut, black, dry....

Willow, dry..;

CUBIC

FOOT.

FEET IN A

TON.

Pounds.

52.812

42.414

35.062

63.886

38.125

58.754

49.5

45.252

43.125

51.942

83.312

26.886

5 35.
t 66.437

64.

33.714

54.5

41.101

58.25

38.455

66.75

33.558

53.75

41.674

42.937

52.169

33.812

66.248

31.25

71.68

31.25

71.68

30.375

73.744

472

APPENDIX.

MISCELLANEOUS.

SUBSTANCES.

Air

Brick, fire

mean

Coal, anthracite

bituminous, mean

cannel ,

Cumberland ,

Coke

Cotton, bale, mean

pressed

Earth, clay

common soil,

gravel...

dry sand

loose ,

G-ranite, Q,tiincy

Susquehanna...

Limestone

Marble, mean

Mortar, dry, mean

Water, fresh

salt

Steam

CUBIC

rooT.

Pounds.

137

102

€4

120

137

109

120

165

169

179

167

,075291
.562

^75
,5

!875
,687
,5
,5

625
125
312

75
.75

875

,98

,125

,036747

CUBIC

FJEET IN" A

TON.

16.284

21.961

24.958

21.854

28.

23.609

26.451

35.84

154.48

114.
89.6
18.569
16.335
20.49
18.667
23.893
13.514
13.254
12.462
13.343
22.862
35.84
34.931

Alloys.

Bronze Gun-metal. — 90 copper and 10 tin.

Bell-metal. — 78 copper and 22 tin.

Fine brass. — 2 copper and 1 zinc.

Brass for parts of gun-carriages. — 80 copper, 17 zinc, and 3
tin.

Sheet brass. — 3 copper and 1 zinc.

Silver solder. — 4 silver and 1 copper; or 2 silver and 1 brass
wire.

Hard solder. — 1 zinc and 2 brass.

Plumber'' s solder. — 1 tin and 1 lead.

Tinner'' s solder. — 1 tin and 2 lead.

Fewterer''s solder. — 2 tin and 1 lead.

Fusible alloy. — 2 tin, 3 lead, 5 bismuth ; melts at 197°.

Type-metal. — 11 lead, 2 antimony, and \ tin.

German silver. — 40 J copper, 31 J nickel, 25^ zinc, 2^ iron.

WEIGHT SUSTAINED BY SHEAR SPAR. 473

German silver for casting. — 60 copper, 20 zinc, 20 nickel, 3
lead.

Pewter. — 4 tin and 1 lead.

An alloy that expands in cooling. — 9 lead, 2 antimony, and 1
bismuth ; useful for filling small cavities in cast-iron.

Bahhifs metal, for journal-boxes. — 9 tin and 1 copper.

To ascertain the Weight that a Shear Spar will Sustain With-
out Breaking.

The case is that of a cylindrical beam inclined upward and
supported at each end, the weight applied at a distance m from
one end.

For a square beam in this position the for-
mula will be :

Sld^ P

■VV= X -; in which

m {I — m) c'
W = the weight
S= the value of the fOak S=50
timber for general use, or -J Y. pine S=50

iw.pineS=45
Z= the length between supports in
feet. (A B.)

d = the diameter or side of the beam
in inches. (A E.)

m = the distance in feet from either
point of support to the point where the weight
is suspended.

c = the inclination of the shears or
the horizontal distance between the heel and
upper point of support in feet. (BC.)

For a cylindrical beam the result must be
multiplied by .78124.

~"b C

Example.— R^y'm^ S =» 50, Z = 27^ d = 10% m = 2^, c =10,
SZ3#

then W = X .78124 =

m {l—m) c^

50 X 19683 X 1000 X .78124

2 X 25 X 100

19683 X 7.8124 = 154771. lbs.
This is only calculated for a steady strain ; the result should

474

APPENDIX.

be diminished at least one-half to allow for the surge of the fall
around the capstan, both when hoisting and lowering.

To ascertain the Strain on the Guys and Spars,

From actual measurement of the ground, &c., construct a dia-
gram as follows :

AB. The shears at their ultimate inclination.

AC. The guys.

AD. A vertical line representing the weight suspended.

C ,.""

With any scale of equal parts lay off on the line A D the
distance equal to the number of units of weight ; say, represent
25 tons by 25 inches; through the point E thus found draw E F
parallel to A C. Then, the distance E F measured by the same
scale will represent the strain on the guys, and A F the thrust
on the spars.

Precaution.

In selecting spars for shears, it must be borne in mind that the
strain on the shears is equal to the weight lifted plus the force r&-
quired at the end of the fall to suspend the weight.

Mensuration.

Area of a triangle = base X ^altitude.

Area of a parallelogram = base X altitude.

MENSURATION.

475^

Area of a trapezoid = { "^^^^^ X ^ ^^^ «""^ «* P^^-^"«^'

Area of a tranezium _/ divide into two triangles, an^

Area of a trapezium — ^ ^^^^^ ^^^^^ ^^ ^^^^ triangles.

Circumference of a circle... = diameter X 3.1416.

Diameter of a circle = circumference X .3183.

Area of circle = (diameter) ^ x .7854.

Area of sector of circle :*= length of arc x ^ the radius.

Area ol segment ot circle.. = } '"'tVfif i?';£,T*^ '^'""'^
^ { Jess area of triangle.

{diameter of the two circles X
difference of diameter, and>
that product by .7854.
Side of square that shall J diameter X .8862, or circumfer-
equal area of circle =\ ence X ^282.

Diameter of circle that f
shall contain area of a -j side of square X 1.1284.
given square = (.

Area of an ellipse ={^"'^854. °* ** ''''° '''*'"'"''^ ^

Area of parabola = base x f altitude.

{sum of its sides x perpendicular
from its centre to one of its*

Sarfaceof cylinder ={:"Zdj^,^'-^ '•"'^' ^

Contents of cylinder := area of ends X length.

Surface of sphere = diameter X circumference.

Contents of sphere = (diameter) * X .5236.

Surfaceofpyramidorcone. ={-;—--«.«''>-« >^

^ZTe!L!'L!:I!^^l.Z _{ area of base X J altitude.

c e t*i. t ( sum of circumference at both.

Surface of f nistrum of cone 1 ^^,^^^ , ^.^^ _^ ^^^^

^^•Py^^^«^'^ =1 of both ends. ^

{multiply areas of two ends to-
gether and extract square root^
Add to this root the two areas^
and X i altitude.

476 APPENDIX.

-Contents of a wedge = area of base X ^ altitude.

Contents of a ring ^ftliickness + inner diameter X

^ X square of thickness X 2.4674.

To ascertain the distance to an inaccessible object ; as, for in-
■stance, the breadth of a river : {Fig. 4, Plate 75.)

1st. The line A B (the distance to be determined ) is extended
upon the bank to i>, from which point, after having marked it,
lay off equal distances, CD and C d ; produce B to b, making
Cb = OB; then extend the line db until it intersects the pro-
longation of the line CA at a. The distance a 6 is equal to
A B^ or the width of the river.

2d. Lay off any convenient distance, B C, perpendicular to
AB ; erect a perpendicular, DC, to AC ; note the point D
-where it intersects A B produced ; measure BD ; then —

BC^
AB

BD'

Capabilities of the Horse.

The average weight of a horse is about 1000 pounds; for artil-
lerj^ purposes he should average 1100 pounds. In ranks he 09CU-
pies a front of 40 inches, a depth of 10 feet ; in a stall, from 3.5
to 4.5 feet front.

The load for a light-artillery horse is 700 pounds, including
•carriage ; for heavy field artillery, 1000 pounds, including car-
riage. This is less than that allowed for the ordinary horse in
■civil service, in consequence of bad roads, scant forage, and
frequently forced marches.

Including the weight of carriage, four horses can draw, on
roads such as are considered in America good., 3000 pounds ; six
horses, 4000 pounds; eight horses, 5000 pounds ; and ten horses,
'6000 pounds. This allowance diminishes rapidly as the roads
become bad,

A horse will pack from 250 to 300 pounds, 20 miles per day —
eight hours. Tlie mule is superior to the horse as a pack ani-
mal. An ordinary march is about 15 miles per day of eight
hours, depending upon the state of the roads, condition of the
horses, and various other circumstances. The rate of march,
with liorses starting fresh and resting for a few minutes each
half-hour, would be 2.5 miles for the first hour, 4 miles for the
next two hours, and 8.5 miles for the remaining five hours.

A horse carrying a rider marches, at a walk, at the rate of
■3.75 miles per hour; at a trot, at the rate of 7.50 miles per hour;
;at a gallop (slow), at the rate of 11 miles per hour.

CAST-IRON BALLS.

477

A horse requires, per clay, 4 gallons of water and 12 pounds
of short and 14 pounds of lon^ forage.

Iron.

Strength. The mean strength of American wrought-iron is
55,900 pounds to the square inch; of English, 53,900 pounds.
The working strain is from one-sixth to one-fourth the mean
strength.

The ultimate extension of wrought-iron is ^^th part of its
length.

Test quality. If the fracture gives long, silky fibres of leaden-
gray hue, fibres cohering and twisting together before breaking,
the iron may be considered tough and soft. A medium even
grain, mixecl witli fibres, is a good sign. A short, blackish fibre
indicates badly-refined iron. A very fine grain denotes a hard^
steely iron., apt to be cold-short, hard to work with the file.

Coarse grain, with brilliant crystalline fracture, yellow or
brown spots, denotes a brittle iron, cold-short, working easily
when heated and easily welded.

Cracks on the side of a bar denote hot-short iron.

Good iron is readily heated, soft under the hammer, and throws
out but few sparks.

Steel.

The tensile strength of good steel is 120,000 pounds per square
inch. The properties are ; After tempering, not easily broken ;
welds readily ; does not crack or split; bears a very high heatf
can be hardened after repeated workings; is magnetic, and, as
distinguished from iron, when once magnetized does not lose its-
polarity at ordinary temperatures.

CAST-IRON BALTiS.

DiATvrETER.

"Weight.

Dtatvtrter.

Weioht.

Diameter.

"Weight.

Inches.

Lbs.

Inches.

Lbs.

Inches.

Lbs.

1.09

17.04

69.81

2J$

2.13

22.68

83.73

3.68

29.45

99.40

5.84

6J<S

37.44

136.35

8.73

46.76

181.48

4J$

12.42

57.52

12
15

235.65
450.26

478

APPENDIX.

ROUND CAST-IRON.
Weight of a lineal foot

DiAMETBB.

"Weight.

Diameter.

"Weight.

Diameter.

"Weight.

Inches.

Lbs.

Inches.

Lbs.

Inches.

Lbs.

9.82

61.36

157.08

15.34

5J<$

74.25

177.33

22.09

88.36

198.80

30.07

103.70

245.44

39.27

120.26

298.98

456

49.70

138.06

353.43

552.23

The foregoing tables furnish means of determining approxi-
mately the weight of elongated projectiles, thus : Ascertain from
the second table the weight of the cylindrical portion of the pro-
jectile, and add to it half the weight of a solid shot of corre-
sponding calibre taken from the first table.

APPENDIX 2.

£3397 A. G. 0., 1884.] Headquarters op the Army,

Adjutant-General's Office,
"Washington, July 31sf, 1884.

Lieutenant- Colonel 3 omi C. Tidball, 3(i Artillery,

Commanding U. S. Artillery School, Fort Monroe, Va.

Sir : Referring to your letter of the 27th instant, I have the honor to inform
you that the Lieutenant-General Commanding the Army authorizes the inser-
tion of the enclosed paragraph, from "a" to " p," inclusive, in the new edition
of the " Manual of Heavy Artillery Service," about to be issued by the pub-
lisher of that work.

Very respectfully, your obedient servant,

0. McKEEVER,
[1 enclo.] Acting Adjutant- General.

(A.) For single-rank formations, full detachments will, as a
rule, consist of six cannoneers. A detachment falling short of
this number will be formed as prescribed in^ar. 13, and will be
the left detachment of the battery.

(b.) In battalion formation, when ranks are opened, the post
of a captain is four yards in front of the centre of his battery,
and the line of subalterns is three yards in front of the front
rank.

(c.) When circumstances shall have caused oflScers to take
post in the line of file-closers when the ranks are closed, {see par.
34,) they will, at the command "■ Rear open order^^'' place them-
selves on the right and left of the front rank of their battery,
and at the command '"'■ March^^^ take post in the line of subal-
terns, opposite their original places in line.

(d.) At dress-parade, subalterns, at the command '' Parade is
dismissed^'''' will, after returning swords, step into the line of
captains and then face to the left or right, as their position may
be, for closing on the centre.

(E.) Chiefs-of-detachment, guides, and file-closers will alwa^^^s
execute order arms^Jix and unjix bayonets^ and carry arms. In
rendering honors tliey execute the present^ reverse, and rest on
arms. On drill they execute the support and right shoulder
arms, except the guide of each subdivision in column when
marching in common or quick time, and the guides who mark
the line of battle during its formation. They execute the other
movements of the manual only when specially directed.

(f.) Color-bearers will execute order arms midparade rest with
the colors.

( 478a )

INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Abattis, 397, 644; 398, 645.

to clear away, 406, 654.

Aiming, (see Ranges; Sights; Tiavei-sing,) 59, 20"? ; 80, 330,
Xll; 81, 230, XXIV; 81, 230, XXII; 90, 243;
145, 340.

at moving vessels, 350, 588; 355, 592.

at night, 356, 592.

at unseen objects, 404, 650.

effect of mirage, 58, 206.

of mortars, 63, 212; 63, 213; 64, 213; 148, 342,

343; 149, 343; 163. 365; 167, 372; 170, 378;

356, 593.
Air-cylinders, 68, 218.
Ammunition, 41, 180.

for defense of defiles, 418, 667.

for field service, 93, 255 ; 101, 258.

for field-works and sieges, 316, 568; 390, 637; 410,

660; 411, 662; 413, 666; 416, 666; 418, 667.

for permanent works, 316, 568.

preparation of, 81, 200, XV, XX, XXI, XXVII; 90,

244; 108, 275; 110, 277; 121, 294.

reports of, 413, 666; 414, 666; 415, 666.

Anchors as holdfasts, 264, 521.

for targets, 190. 409.

• mushroom, 436, 677.

Angle of fall, 39, 161 ; 377, 619.

Angle of fire, (see Sights; Range-tables,) 40, 173.

Annual supplies of armaments, 315, 507.

Armament of works, 316, 568; 343, 581.

Armor, artillery against, 347, 586; 353, 590; 354, 591.

Armored vessels, (see Iron-clads,) 348, 587; 351, 589.

' vital points, 351, 589.

Artillery against armor, 347, »586.

( 479 )

480 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Artillery command in defenses, 346, 583 ; 410, 660 ; 411, 661^
411, 663 ; 417, 666.

garrison, sea-coast, and siege distinguished, 1, 4; 1, 5 ;

1, 6; 2, 8.

in connection witli torpedo service, 425, 670.

inconstructinglines, 373, 613; 410, 660; 411 661.

in attacking intrenclied positions, 403, 649; 404, 650;

405, 651-653.

in defense of besieged places, 410, 660.

in defense of defiles, 417, 667; 418, 667.

in defense of river-crossings, 419, 668 ; 420, 668.

in harbor defenses, 343, 581 ; 345, 582.

proportion of, in sieges, 411, 662.

to accompany assaulting parties, 406, 654.

material, annual supply to preserve, 315, 567.

care and preservation of, 293, 551; 294, 555; ^312,

566.

projectiles, 310, 565.

required for sieges, 412, 664 ; 413, 664.

storage of gunpowder, 316, 569.

store-houses, 312, 566.

transportation, 321, 571; 325, 573.

disembarkation, 335, 578.

— railroad, 322, 572.

weight of field battery, 330, 574.

Assault. (See Attack.)

defense against, 410, 660.

Atmosphere, pressure upon projectiles, 57, 206 ; 58, 206.
Attack and defense of positions, 403, 649 ; 405, 652.

advantages of attack, 405, 651.

of defiles, 417, 667; 418, 667.

of river-crossings, 419, 668; 420, 668.

of submarine mines, 455, 692.

selection of point of attack, 409. 659.

Axis, 35, 134.

Backwabd, defined, 201, 419.
Balls, iron, weight of, 477, Appendix.
Barbette batteries, field, 384, 633.

guns, handled with gins, 250, 497.

Barrels, gunpowder, to sample, 46, 182.

Barrow, hand, 260, 512.

Base-line, permanent, for target practice, 189, 409.

INDEX. 481

[Note. — The plain figures refer to the pages of this volnme. The full-
faced figures refer to paragraphs.]

Base of breech, 35, 138.

Battalion, artillery, formation, 28, 116; 29, ll'y-123; 30,
124, 125; 31, 125, 126; 32, 126;

to form, 32, 121; 33, 12':'-130.

Batteries. (See Field Intrencliments.)

barbette, 384, 633.

classified, 396, 642.

commanding defiles, 417, 667; 418, 667.

commanding rivers, 419, 668; 420, 668.

designation in sieges, 413, 665.

dispersion, 344, 581.

distances from, in defense of towns, 376, 617.

elevation of, 347, 585.

embrasure, 385, 634; 396, 641.

intrenched positions, 403, 649.

location of, 364, 600; 366, 603, 604; 373, 613;

388. 635 ; 408, 656.

materials for, 357, 594; 412, 664; 413, 664.

mortar, 397, 643.

pan-couple, 384, 633.

penetration of, 357, 595; 358, 595; 359, 595; 360,

595; 362, 596; 363, 596, 597; 364, 598.

positions of, in attack of intrenched places, 403, 649.

selection of, 371, 612.

strength and composition, 355, 592 ; 411, 662.

to construct, 395, 641.

traverses for, 376, 618; 388, 635.

troops, number for, 345, 585.

Battery, commands in, 8, 31 ; 8, 35 ; 10, 42.

field, weight of, 330, 574.

posts of officers, non-commissioned ofllcers. &c., 7, 24-

30; 24, 103.

siege-gun, composition of, 92, 255.

ammunition for, 316, 568.

siege mortar, Coehorn, 159, 359.

subdivisions of, 6, 19-23; 8, 32-34; 10, 48.

substituted for "company" in foot-drill commands, 34,

130.

to change posts, 27, 1 12.

to form at the pieces, 26, 107, 108.

to form tlie, 8, 37.

- ro leave the pieces, 27, 113; 28, 114, 115.

— to load a, on cars, 324, 572.

482 INDEX.

[Note. — The plain figures refer to the pages of this volume. The fxxOr-
laced figures refer to paragraphs.]

Battery to march to the pieces, 25, 106.

to rest, 27, llO.

to resume the exercise, 27, 111.

wagons for the siege, 100, 358.

what, 6, 19.

Beds for piling projectiles, 311, 565.
Bickforcl's fuse, 422, 669.
Bight, 232, 477.
Blockades, 407, 655.
Block-house, 400, 648.
Blocks, 270, 528 ; 238, 482.

, storage of, 313, 566.

Blowing-charges, 188, 404.

Boats, compUments, 464, 709, 710; 465, 711*

Body of piece, 35, 140.

Bomb-proofs, 394, 639.

Books. (See Records.)

Bore, 35, 132; 36, 144; 38, 153.

inspection of, 300, 561.

record of defects of, 307, 563.

Bottom of bore, 36, 143.
Bouleng^ telemeter, 192, 409-411.
Boyaux, 408, 657; 409, 658.

Brass implements, preservation of, 313, 566.
Breaching earth-works, 361, 595.

walls, 409, 659.

Breech, 34, 137.

Breech sight, 59, 207; 60, 208, 209.
Bridges, covered by t^tes-de-pont, 419, 668.

demolition of, 421, 669; 422, 669; 423, 669.

for disembarkations, 335, 578; 341, 579.

weight of troops on, 341, 579.

Browning of guns, 296, 557.
Budge-barrels, 54, 205.

Buffers. (See Recoil Checks.)

hydraulic, 68, 218; 294, 555.

pneumatic, 69, 219; 135, 320; 294, 555.

Buildings, demolition of, 421, 669.

Bung-stoppers for submarine mines, 444, 683.

Buoys, 445, 685.

Bursting of shells in bore, 298, 558.

Bushing of vent, 36, 142.

Butler projectile, 49, 190.

INDEX. 483

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

•Oables, electric, 443, 682; 445, 686; 446, 686; 447, 686.
to lead into forts, 449, 688, 689.

for bridges, 341, ST'O.

Caissons, for siege-gun batteries, 93, 255.

for siege mortars, 158, 359.

Caked gunpowder, to test, 47, 183.
Calibre, 38, 153.

Calipers, .300, 560.

Camps, intrenched, 364, 601 ; 375, 614, 616; 412, 663.

Canal-boats as lighters, 336, 57'8.

Canals, demolition of, 423, 669.

Canister, 49, 192.

double charges, 131, 318.

Cannon, construction of, 34, 131; 36, 144; 37, 146-150;
38, 154.

marks on, 293, 553.

powder, 42, 180; 43, 180.

to disable, 309, 564.

Cannoneers, in lines of works, 375, 616.
posts of, 81, 230, XXII, XXIII, XXV, XXVI.

reliefs, in service, 82, 230, XXXI.

Canvas muzzle-hoods, 295. 555.

Capstan, 262, 517'; 275, 535; 276, 535; 290, 549.

storage of, 313, 566.

to use a gin as, 262, 518.

Carcass, 40, 194.

Carriages, artillery, in general, 65, 215, 216; 66, 216; 67,
21-7 ;*68, 217, 218; 69, 219-221; 70, 221-
223* 71, 223.

barbette,' described, 1,7; 2, 8 n. ; 67, 21 7 ; 109, 276 ;

115, 286, 288; 119,293; 126, 306; 127, 308.

care of, 295, 555, 557.

casemate, described, 1, 7; 67, 217; 117, 290.

— — platforms, 71, 224.

centre-pintle, 67, 217; 120, 293.

depressing, 69, 221.

8-inch new rifled gun, 135, 320; 136,320; 137,320.

field-gun, platforms for, 74, 226.

flank-casemate, 70, 223 ; 128, 309.

front-pintle, 67, 217; 126, 306.

Catling gun. 0.45-inch, 181, 398.

Hotchkiss gun, 183, 400.

mortar, 1, 7; 2, 8n.; 70,222; 157,357; 158,359.

484 INDEX.

[Note.— The plain figures refer to the pages of this yoltime. The full-
faced figures refer to paragraphs.]

Carriages, mortar platforms, 71, 224; 75, SS-V; 76, 228; 77^
229 ; 78, 229.

recoil checks, 41, \'79; 117, 290.

siege-gun, 1, 'V; 2, 8n. ; 84, 231.

platforms, 71, 224; 72, 225; 73, 225; 84,.

231.

Cars, to load with horses, 322, 572.

siege-guns, guns, or wagons, 324, 5*72.

Cartridge-bags, 47, 185; 154, 354; 298, 558.

preservation in store, 312, 566.

Cartridge-pouch, 55, 205 ; 79, 230, IV. ^

Cartridges, dummy, 83, 230, XXXVII; 104, 262. '

to be filled at depots, 416, 666.

to fill and prepare, 154, 354; 319, 5'yO.

to insert, 80, 230, IX; 88, 240; 151, 346.

to withdraw, 81, 230, XVI; 91, 24t; 117, 289;.

125, 304; 153, 350.
Cascable, 35, 139.
Casemate guns, handled with casemate trucl\S, 257, 506.

gins, 249, 496.

Casemates, iron, field, 400, 648 ; 401, 648.
Casemate truck, 257, 506.

to use, 257, 506 ; 258, 506.

Case-shot, 48, 189, 190; 49, 190, 191.

Cease firing, 81, 230, XVI; 90, 244; 91, 24*:^; 117, 289 f

125, 304.
Chains, iron, weight and strength, 241, 484.
Chamber, 36, 144.
Charge, 36, 144; 131, 318.
Charging shells, 108, 2t5; 165, 368; 298, 558.

blowing charges, 188, 404.

Chase, 35, 141.

Chassis, 67, 21'^.

Cheeks of carriages, 66, 216.

Chocks, 200, 416; 210, 444; 270, 532.

storage of, 313, 566.

Circuit-closers for mines, 452, 691.
Circumvallation, line of, 410, 661.
Coehorn mortar battery, 159, 359.
Collar, for chase, 270, 531.
Combination fuse, 51, 199.

Command of artillery in defenses, 346, 583; 410, 660; 411,
661 ; 411, 663.

INDEX. 486

[Note. — The plain flgiires refer to the pages of this volume. The. full-
faced figures refer to paragraphs.]

Command of artillery in sieges, 346, 583 ; 410, 660 ; 411, 661 ;

411, 663 ; 417, 666.
Commands, 8, 31; 10, 42, 43; 81, 230, XXV; 82, 230,

XXVIII.

''battery" for "company," 34, 130.

"detachments" to replace "fours," 34, 130.

Compressor-bars, 135, 320.

Concussion-fuse, 51, 199.

Conversion of cannon, 34, 131 ; 35, 132; 132, 319.

Cordage, 231, 41'6.

preservation of, 238, 481.

strength of, 237, 481 ; 238, 481.

Counter-hurters, 68, 217.
Countervallation, line of, 410, 661.
Coupling for top-carriage and chassis, 135, 320.
Courtesies, official, 463, 'Y08.

Cradle, 261, 516; 275, 535.

storage of, 313, 566.

Cross-lifting, 203, 427.

Cubical (pellet) powder, 42, 180; 46, 181.
Cutting guns, (mechanical manoeuvres,) 204, 430.
Cylinder-gauge, 300, 560.
Cylinder-staff, 299, 560.

Dainipness of powder. (See Gunpowder tests.)
Defense of besieged positions, 410, 660, 661.

of defiles, 417, 667; 418, 667.

of river-crossings, 388, 636 ; 419, 668 ; 420, 668 ;

425, 670.
Defenses of harbors, 343, 581 ; 388, 636.

distances from towns, (see Submarine Mines,) 376, 617.

number of troops required, 345, 582.

position of batteries, 343, 581.

strength of batteries, 355, 592; 356, 593.

submarine, 346, 584.

Defensive intrenchnients. (See Field Intrenchments.)

distances from towns, 376, 617.

Defilading field-works, 377, 619; 378, 619.
Defiles, 417, 667; 418, 667.

rivers considered as, 419, 668.

Demolition of bridges, 421, 669; 422, 669 ; 423, 669.

buildings, 421, 669.

canals, 423, 669.

■186 INDEX.

[Note. — ^The plain figures refer to the pages of this volume. The full-
faced figures reier to paragraphs.]

Demolition, explosives for, 430, S'V^.
Depots, siege, 413, 666 ; 416, 666.
Depression, 39, 163.
Derricks, described, 288, 548 ; 289, 548.

garrison, gin, 252, 501.

in landing heavy guns, 339, 5t8.

to lower 15-incli gun, 291, 550.

to raise 15-inch gun, 290, 649.

Detachments replace ^'fours'' in commands, 34, 130.

to change posts, 27, lliS.

to form at the pieces, 26, lOt ; 26, 108.

for artillery service, 5, 14-17 ; 6, 21 ; 6, 23 ;

8, S'V; 9, 38-41.

for fatigue, 9, 40.

for leaving the pieces, 26, lOl* ; 26, 108.

for marching drill, 9, 41.

to march tothe pieces, 26, lOT, 108.

to prepare for mechanical manceivres, 201,

419, 420.

wliat, 5, 12 ; 5, 13.

Deviation, 41, 11' V; 56, 206; 57, 206; 58, 206; 59, 206;

186, 402; 192, 409.
Directrix, 41, 179.
Disabling cannon, 309, 564.
Dispart, 37, 145.
Distances, for Coehorn mortar target, 188, 406.

for sea-coast gun targets, 189, 409.

for sea-coast mortar targets, 189, 407; 189, 408.

for siege-gun targets, 184, 402.

for siege-howitzei- targets, 187, 403.

for siege-mortar targets, 187, 404 ; 188, 404.

of defensive woi'lvs from towns, 376, 617.

toascertahi, 184, 402; 191, 409.

by telemeter, 192, 411 ; 193, 411, 412.

Ditches, 378, 620; 400, 648.

Drift, 41, 178.

Drill. (See Manoeuvres, Mechanical; Manoeuvres, Tactical.)

Drop of projectile, table, 404, 650.

Dualine, 431, 675.

Dyer'spointingapparatus, 63, 213; 64,213; 168,372; 170^

378.
Dvnamlte, 431, 675.
-^ in demollLions, 421, 669; 431, 675.

INDEX. 487

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Earth- WORKS, (see Fielrl Tntrenchments,) 357, 594, 595.

penetration of, 358, 595 ; 359, 595 ; 360, 595 ; 362,

596; 363, 596. 59^.

revetments, 362, 596; 363, 596; 377, 618; 379,

622,623; 380,624; 381,625,626; 382,627,
628; 383, 629.

thickness, 362, 596.

to breach, 360, 595 ; 361, 595.

Eccentric rollers, 136, 320.

Eflfect of projectiles, striking, 352, 590 ; 353, 590.

how to be observed, 185, 402.

Electrical submarine mines, 425, 6tl; 426, 6'Yl.

testing-rooms, 449, 689 ; 456, 693.

Electric batteries, 450, 689.

cables, 443. 682; 445, 686; 446, 686; 447, 686.

to lead into forts, 449, 688, 689.

fuses, 440, 680.

primers, 51, 201.

in demolitions, 421, 669.

Elevating-arc, 60, 208; 60, 209; 138, 320.
Elevating-bar, 56, 205; 66, 216.

Elevating-screw, 67, 216; 294, 555.

Elevation, 39, 162; 82, 230, XXXIII, XXXIV.

of batteries, 377, 585.

Embarkation of artillery, 321, 511.

horses, 328, 573; 329, 574; 333, 576.

of unsuccessful expeditions, 340, 579.

Embrasure batteries, 385, 634.

Energy of projectiles, 39, 167.

Engineers, functions in besieging positions, 411, 661 ; 411,

663.
Entanglements, 397, 644.

to clear away, 406, 654.

Epaulments, 376, 618.
Equipments, 53, 203.

for officers, 413, 664.

preservation of, 313, 566.

Explosion, 41, 180.

Explosives, (see Dualine ; Dynamite ; Gun-cotton ; Gunpowder;
Lithofracteur ; Nitro-glycerine,)41, 180; 430,675.

Fascines for revetments, 380, 624.
Feeding horses at sea, 328, 573.

488 INDEX

[Note.— The plain figures refer to the *pages of this yolume. The full-
faced figures refer to paragraphs.]

Field-glass for each siege gun, 95, *25'7.
Field-gun platforms, 74, 226.
Field iiitrenchments, 357, 594.

attack and defense, 403, 649.

bastioned works, 369, 611 ; 370, 611 ; 371, 611.

batteries, barbette, 384, 632.

embrasure, 385, 634; 396, 641.

pan-coup6e, 384, 633.

besieging, 407, 656.

block-houses, 400, 648.

bomb-proofs, 394, 639.

camps, to lay out, 364, 601 ; 375, 616.

classified, 396, 642.

defiles, 417, 667; 418, 66'^.

detached works, to lay out, 366, 603, 605 ; 367, 606-

608; 368, 610.

ditches, 378, 620.

entanglements, 397, 644.

fascine revetments, 380, 624.

garrisons for, 367, 609 ; 368, 609 ; 370, 611; 374^

614.

gun batteries, location of, 364, 600 ; 388, 635.

guns and mortars for, 371, 612.

interior arrangement, 384, 630.

lines of battle, to lay out, 364, 602; 372, 613.

lines of works, to lay out, 372, 613; 373, 613; 374,.

613, 614; 375, 614, 615.

magazines, service, 392, 637.

storage, 390, 637.

mortars in, 397, 643.

parapets, ditches of, 378, 620.

form of, 376, 618 ; 377, 618, 619 ; 378, 619.

penetration of, 358, 595 ; 359, 595 ; 360, 595 ;.

362, 596; 363, 596, 597.

slopes of, (tables,) 377, 619; 378, 619; 379,

621.
thickness of, 362, 596; 378, 619.

platforms for batteries, 387, 635; 388, 636; 397,

643.

profiling, 379, 621.

revetments, 362, 596; 363, 596; 377, 618; 379,

622, 623 ; 380, 624 ; 381, 625 ; 381, 626 ; 382,
627, 628; 383, 629.

INDEX. 48^

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Field intrenchments, river-crossings, attacking, 420, 668.
defending, 419, 668.

sea-coast, 388, 636.

splinter-proofs, 393, 631'.

to breach, 361, 595 ; 379, 621.

tracing, 379, 621.

traverses, 376, 618 ; 388, 635 ; 393, 638 ; 394, 638..

Fire, armor against, 347, 586.

curved or vertical, 38. 156; 356, 593.

direct or horizontal, 38, 155; 347, 585.

earth-works, to breach, 361, 595.

kinds, during attack, 406, 654.

magazines, to destroy, 360, 595.

uight repairs, to prevent, 361, 595.

plunging, 39, 159.

rapidity of, 127, 308.

ricochet, 38, 15*^; 347, 585; 350, 581.

rolling, 38, 158.

to, 80, 230, XIII; 90, 243, 244; 91, 247; 115^

286 ; 125, 301 ; 153, 348.

vessels, moving, 350, 588 ; 355, 592.

Fire-ball, 50, 195.

Fire-works, storage of, 317, 569 ; 318, 569.
Firing at night, 356, 592.
mines, 450, 690; 451, 690; 452, 690; 453, 690.

reports of, during sieges, 416, 666.

rules for target, 183, 401.

salutes, 460, 698.

Flag at half-staff, 466, '^13.

never dipped at posts, 466, 712.

Forces acting on projectile, 57, 206.

Formula, cordage, to find strength of, 238, 481.

guys, to find sti-ain, 474, App.

lighters, to find capacity, 341, 579.

parapet, to find number of men for, 345, 582; 367^.

609; 368, 609; 370, 611.

powder, to find charge for bridge demolitions, 421, 669-

projectile, to compute energy,"39. 167.

to compute number in piles, 312, 565.

to find weight of, 478, App.

ranges, to find elevation, 61, 210.

to find for mortars, 154, 354.

• shears, to find strength of, 473, App.

490 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
"jfaced figures refer to paragraphs.]

Forts, bastioned, 369, 611; 370, 611; 371, 611.
command of artillery in, 346, 583.

complements of men for, 345, 582; 367, 60t; 368,

60T; 370, 611; 374, 614.

distances from towns, 376. 61*7.

snbmarine defenses, 346, 584.

Forward, defined, 201, 419.

Friction against bore, influencing projectile, 58, 206.

Friction-bars, 69, 220.

Friction-ppimers, 51, 200.

preservation of, 313, 566.

Front sight, 59, 20t ; 60, 208 ; 60, 209.
Fulminate of mercury, 433, 675.
Funeral honors, 466, 113.
Fuse-block, 55, 205.

Fuse-gauge, 55, 205.

Fuse-hole in elongated shells, 49, 190.

in spherical shells, 48, 188.

Fuse-knife, 55, 205.

Fuse-plug extractor, 55, 205.
Fuse-plugs, 110, 1l'7'7.
Puse-reamers, 55, 205.
;Fuses, 60, 196.
blasting, 422, 669.

combination, 51, 199.

concussion, 51, 199.

electric, 440, 680.

ignition, to secure in mortar, 165, 368.

mortar fuse-plugs, 51, 19'^; 165, 368.

paper time, 51, 197.

percussion, 51, 198.

position in mine charges, 441, 681.

preservation of, 313, 566.

sulphuric acid, 439, 679.

time, 60, 197.

water-cap fuse-plug, 50, 197.

.Fuse-setter, 54, 205.
Fuse-wrench, 65, 205.

Gabion revetments, 381, 626 ; 386, 634 ; 393, 638.
'Gabions, 382, 626.

Garrison gin-derrick, (narrow,) 252, 501.
Harrison trucks, painting and storage, 314, 566.

INDEX. 491

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

GaMing guns. (See Guns, Gatling.)
against assaults, 410, 660.

for block-houses, 400, 648.

not substitutes for artillery, 371, 612.

Gauging bores, 297, 558.

General rules for service of piece, 79, 230 ; 86, 234-236 ;.
87, 238, 239.

for target practice, 183, 401.

for traversing in aiming, 81, 230, XXIV; 145, 340-

Gins as capstans, 262, 518.

as shears, 252, 500.

described, 242, 485.

dimensions, weights, &c., 252, 499.

garrison and casemate, 248, 495 ; 249, 495.

painting and storage, 313, 566; 314, 566.

Piper's, 247, 494.

ropes for, 244, 489.

to lower, 244, 488.

— to move, 244, 488.

to put together, 243, 488.

to raise, 243, 488.

to shift the fall, 247, 493.

with barbette guns, 250, 49 f.

with casemate guns, 249, 496.

with siege guns, 245, 490.

w^ith siege mortars, 246, 492.

Grape-shot, 49, 193.

Grommet, 234, 479.
Gun-cotton, 432, 675.
Gun-lift, described, 279, 539.

storage, 314, 566.

to assemble and raise, 281, 540.

to mount 15-inch gun, 282, 541.

to raise a weight, 281, 540.

Gunner's level, 53, 205; 105, 263; 129, 310; 160, 344;;

161, 362.
Gunner's pouch, 55, 205; 78, 230, IV.
Gunner's quadrant, 53, 204.
Gunpowder, barrels, marks, 44, 180.

sampling, 46, 182.

to open, 319, 570.

caked, to break, 319, 570.
cartridges, bags, 47, 185.

492 INDEX.

[Note.— The plain figures refer to the pages of this volnme. The full-
^aced figures refer to paragraphs.]

Ouiipowder, cartridges, to weigh or measure charges, 188, 404.

charges to destroy vessels, 430, 6 74.

demolition by, 421, 669.

grain, size of, 42, 180; 43, ISO.

granulation irregular, (cannon, mammoth, musket,) 42,

ISO; 46, 181.

regular, (cubical and molded,) hexagonal, 42,

ISO; 45, ISl.

pellet, 42, ISO; 46, ISl.

prismatic, 42, ISO; 46, ISl.

hardness, 43, ISO.

incorporation, 44, ISO.

initial velocity, 43, ISO.

inspection, 44, ISO.

materials, 42, ISO.

moisture tests, 43, ISO.

naval classification, 46, ISl.

preservation, 316, 569.

pressure, 47, 1S4; 147, 341.

pressure-plug, 197, 413.

qualities, 42, ISO.

special, 44, ISl; 45, ISl.

specific gravitv, 43. ISO.

storage, 317, 569; 318, 569; 390, 63t.

strain on guns, 43, ISO.

tests, flashing, 47, 1S3.

of moisture, 43, ISO.

sampling, 46, 1S2.

transportation, 318, 569.

^uns, ammunition for, 316, 56S ; 390, 637; 410, 660; 411,

662; 413, 666; 416, 666.

designation of, in batteries, 82, 230, XXVIII.

for field-works, 371, 612.

location of, 388, 635.

space for, 368, 609.

Gatling, 0.45-inch, description, 170, 379; 177, 390.

carriage, 181, 39S.

nomenclature, 180, 39S.

precautions, 179, 397.

service, 177, 391.

to assemble, 181, 400.

to take apart, 181, 399.

1-inch, description, 170, 379; 171, 379.

INBEX. 493

[Note. — ^The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

<Guns, Gatling, 1-inch, noraenclature, 175, 386.

service, 171, 380.

storage, 314, 566.

to assemble, 176, 389.

to take apart, 176. 388

Hotchkiss, revolving, description, 182, 400.

suitable for block-houses, 400, 468.

in attack of positions, 403, 649 ; 404, 650.

injuries of, 132, 319; 297, 558.

inspection of, 299, 559.

location in field-works, 388, 635.

marks on, 293, 553.

on skids, 295, 555.

Parrott. (See below.)

quantity in sieges, 411, 662.

rifles best against armor, 354, 590.

selection of^ for besieging batteries, 408, 657.

siege, care of, 295, 557'.

space for, in field-works, 388, 635.

to brown, 296, 557.

to disable, 309, 564.

to load on cars, 324, 57!J.

what, 36, 144; 37, 146; 38, 154.

•Guns of U. S. system, 4.5-inch rifle, described, 2, 8 : 83, 231.

carriages, S3, 231 ; 84, 231.

dismount carriage and limber, 222, 459.

from mortar-wagon, 214, 450.

the gun, 212, 448.

with the gin, 246, 491.

with sling-cart, 254, 503.

firing to traveling bed, 208, 441.

forward or backward, 206, 435.

mechanical manoeuvres, 204, 431.

mount on mortar-wagon, 214, 450.

the gun, 210, 447.

with the gin, 245, 490.

prepare for action, 210, 446.

for traveling, 210, 445.

ranges, 84, 231.

remove short roller from under the body, 208,

439.

the chase^ 207, 437.

service of, 83, 231.

494 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Guns of U. S. system, 4.5-inch rifle, shift carriages, 213, 449.
from carriao;e to mortar-wagon, 21G,.

45*2.
from mortar-wagon to carriage, 217^

453.

short roller under body, 207, 438.
under chase, 207, 436.

side-lift carriages, 209, 443.

to limber, 204, 433.

to unlimber, 205, 434.

ti-aveling to firing bed, 208, 440.

10-inch rifled, 2, 8.

12-inch rifled, 2, 8.
13-inch smooth-bore, 2, 8; 2, 8n.

15-inch smooth-bore, 2, 8; 2t 8n. ; 119, 293; 126,
306.

carriages, 119, 293 ; 126, 306 ; 127, 308.

dismount by blocks, 273, 534.

the gun. 274, 535 ; 275, 535 ; 276,

535.

lower with derrick, 291, 550.

mount with gun-lift, 282, 541.

other methods mounting and dismounting, 278,

53T'; 282, 541.
ranges, 119, 293; 126, 306.

raise with derrick, 290, 549.

remove chassis, 277, 536.

replace chassis, 2*77, 536.

service of, 120, 294; 126, 307.

20-inch smooth-bore, 2, 8 ; 2, 8n.

Guns not of U. S. system, but in service, 4.2-inch (30 pdr.) Par-
rott, 2, 8.

6.4-inch flOO pdr. ) Parrott, 2, 8; 115, 288.

ranges, 116, 288.

service of, 115, 288.

8-inch (200 pdr.) Parrott, 2, 8 ; 115, 288.

service of, 115, 288.

8-inch rifled, 2, 8; 132, 319.

carriages, 134, 319; 135 n. ; 135, 320; 137,

320.
— indications of injury, 132, 319.

ranges, 133, 319; 134, 319.

service of, carriage 1, 137, 321.

INDEX. 495

[Note,— The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Guns not of U. S. system, but in service, 8-inch rifled, service of,

carriage 2, 141, 331.

carriage 3, 142, 33'2.

carriage 4, 144, 33S.

8-lnch smooth-bore, 2, 8.

10-inch smootli-bore, 2, 8 ; 108, 276.

barbette carriao:e, 109, l^fG.

ranges, 109, 2t6.

^_^_^^_ ,.„.^^^^__ spi'vicft of 109 2 '7 *7

to dismount, 282, 542 ; 283, 543 ; 284, 544.

— (300 pdr.) Parrott, 2, 8 ; 115, 288.

service of, 115. 288.

Gun-shields, 400, 648; 408, G^K.

Guys, formula to compute strains on, 474, App.

Hammer-wrench, 200, 416; 210, 444.
Hammocks, horse, 332, 576; 334, 577.
Hand-barrows, 260, 512.
Hand-carts, 259, 507.

painting and storage, 314, 566.

Handspikes, 56, 205 ; 86, 235, 236; 93, 256; 200, 417;

201, 417.
Harbors, defenses of, (see Submarine Mines,) 343, 580; 388,

636 ; 389, 636.

arrangement of mines, 428, 673.

lighting, 456, 692.

position of mines, 427, 672.

strength of batteries, 355, 592 ; 356, 593.

submarine mines, 346, 584; 425, 671 ; 426, 671.

table of surface currents, 458, 694.

Harness, care of, 101, 258.

for siege-gun batteries, 93, 255 ; 101, 258.

Hitches, 234, 480 ; 235, 480.
Holdfasts, 263, 519; 263, 521; 264, 521.
Horse batteries, 101, 259.
Horses, capabilities of, 476, App.

care of, at sea, 101, 258.

disembarkations, 338, 578.

embarkations, 328, 573; 329, 574; 333, 576.

feeding, at sea, 328, 573.

for batteries in lines of works, 375, 616.

for siege-gun batteries, 94, 256; 413, 665.

hammocks for, at sea, 332, 576; 334, 577.

496 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Hor.ses, medicines for, siege-gun batteries, 101, 259.

transportation of, by rail, 322, 512.

by sea, 327, ^K^; 330, 51^5.

Hotchkiss. (See Guns, Hotclilviss.)
Howitzers, 5.8-inch, 2, 8 ; 128, 309.

carriage, 128, 309.

dismount carriage, 271, 533.

howitzer, 271, 533.

mount carriage, 273, 533.

howitzer, 272, 533.

ranges, 128, 309; 131, 318.

8-incli, (siege,) 2, 8; 102, 261.

at short ranges, 404, 650.

defined, 36, 144; 37, 141.

doubly charged to repel assaults, 131, 318.

mechanical mancBuvres, 208, 439.

ranges, 103, 261 ; 222, 458.

service of, 102, 261.

shells, to charge, 108, 2 '75.

target practice, 187, 403.

to dismount, 218, 455.

as a mortar, 221, 458.

carriage and limber, 222, 459.

to mount, 219, 456.

as a mortar, 220, 451.

to stand on its muzzle, 218, 454.

uses in ricochet firing, 65, 214.

Hurters, 68, 211.

Hydraulic buffers, 69, 219; 135, 320.

jacks. (See Jacks.)

Ice as bridges, 342, 519.
Impact, effect of obliquity, 348, 586.
phenomena, 352, 590.

to record centre of, 185, 402 ; 186, 402.

Implements, 53, 203 ; 199, 416 ; 200, 416, 411 ; 201, 411-

419.

care of, 295, 555 ; 312, 566.

to replace, 92, 250 ; 81, 230, XXII.

to take to and from the battery, 79, 230, I ; 81, 230,

XXH; 201,419.
Impressions of the bore, 303, 562.
Infantry, cooperation in attack of positions, 405, 653.

INDEX. 497

[Note. — The plain figures refer to the pages of this volume. The full-
^aced figures refer to paragraphs.]

Infantr5% cooperation in defending defiles, 418, GGK,
in constructing lines of works, 373, 613.

in harbor defenses, 345, 582.

Injuries of guns, 297, 558.

of vents, 307, 563.

Inspections, by impressions of bores, 303, 562.

instruments for, 299, 559.

of guns, 299, 559.

of injuries, 297, 558.

of projectiles, 311, 565 ; 312, 565.

of vents, 307, 563.

to be made after target firing, 185, 402.

to record defects, 307, 563.

Instruments for inspections, 299, 559.
Interpolator, Paddock's, 149, 343.
Intrenched camps, 364, 601.

lines of battle, 365, 602.

Intrenching tools, 413, 664.

Intrenchments, (see Field Intrenchments,) 403, 649.

Iron balls, weights, 477, App.

Ii'on-clads, charges to destroy, by mines, 430, 6Y4.

extreme ranges of, 376, HIH.

in defense of river passages, 420, 668.

mortar fire against, 356, 593.

rate of movement, 355, 592.

submarine mines against, 425, 6'?'0; 426, 671; 427,

672; 428, 673; 429, 674.

vital points, 351, 589.

Iron implements, preservation of, 313, 566.
Iron, round, cast, weights of, 478, App.
Iron, strength of, 477, App.

Jacks, hydraulic, 264, 522; 265, 522; 267, 522; 269, 527.
lever, 260, 511.

lifting, 259, 510.

to lift, 268, 525.

to lower, 268, 526.

pulling, 267, 522.

to fill, 267, 524.

to use, 269, 527.

storage of, 314, 566.
valves, 266, 522 ; 267, 522.
weights and dimensions of, 269, 527.

498 INDEX.

[Note. — The plain figures refer to the pages of this Tolume. The full-
faced, figures refer to paragraphs.]

King gun-carriage, 70, 221.
Knots and splices, 231, 476.

Lacquer for guns, 296, 557.

for projectiles, 311, 565; 312, 565.

annually required, 315, 567.

Ladle, 54, 205; 115, 286.
Landing sea expeditions, 339, 5T9.
Lanyard, 55, 205 ; 90, 243, 244.
Launching guns, 203, 430.

Leather equipments, preservation of, 313, 566.

Le Clanch^ electric battery, 450, 689.

Level, gunner's, 53, 205 ; 105, 263; 129, 310; 150, 344;.

161, 362.
Leverage of limbers, 202, 425.
Life of a piece, 38, 154.
Lifting, (mechanical manoeuvres,) 202, 424.

projectiles, 115, 286; 115, 287; 145, 340; 165^

368.
Lighters in disembarkations, 336, 578.

to find capacity, 341, 579.

Line of fire, 40, 172.

Line of metal, 40, 168; 59, 207 ; 60, 209; 154, 354.
Line of sight, artificial, 40, 1 70.

natural, 40, 169.

Lines of works, 372, 613 ; 373, 613 ; 374, 613.

to man, 374, 614; 375, 614.

Lithofracteur, 431, 675.

Load, to withdraw. (See Unload.)

Loading guns, &c., 81, 230, XVI-XXI; 80, 230, VI-X; 82,.

230, XXXIV; 88, 240; 91, 248; 92, 252-

254; 94, 256.
Loading-bar, Piper's, 165, 368.
Loading cars, with guns, 324, 572.

with horses, 322, 572.

with siege guns, 324, 572.

with wagons, 324, 5 72.

Loading for drill, 83, 230, XXXVII; 117, 289; 154, 354;

164, 367.
Location of batteries, 364, 600.
Log levetmenis, 380, 623.
Lorain's trunnion sights, 62, 211; 168, 372.

INDEX. 499

[Note.— The plain figures refer to the pages of this volume. The full-
tfaced figures refer to paragraphs.]

Magazines, care of, 317, 569 ; 318, 569.

classified, 316, 569; 389, 631".

marked, 317, 569.

of earth-works, to destroy, 360, 595.

records, 317, 569.

service, 392, 63 1.

storage, 390, 631.

Mammoth powder, 42, 180; 43, ISO; 46, 181.
Manoeuvres, mechanical, garrison and casemate gins, 248, 495 ;

249, 495.

with barbette guns, 250, 49 "y.

with casemate guns, 249, 496.

— garrison gin-derricks, 252, 501.

gins, 242, 485.

with siege guns, 245, 490.

with siege mortars, 246, 49^.

barbette guns, 15-inch, to dismount by blocks,

273, 534.
to dismount by other methods,

278, 53t.
to dismount the gun, 274,

535; 275, 535; 276,

535.
to lower with derrick, 291,

550.
to mount by other methods,

278,531; 282, 541.
- to mount with gun-lift, 282,

541.
_ to raise with derrick, 290,

549.

to remove chassis, 277, 536.

to replace chassis, 277, 536.

casemate guns, 10-inch, to dismount with blocks,
282, 542 ; 283, 543.

precautions, 284, 544.

siege guns, 204, 431.

forward and backward, 206, 435.

to dismount carriage, 222, 459.

from mortar-wagon, 216, 45 1 .

the gun, 212, 448.

with the gin, 245,

490.

500 INDEX.

[ISTOTB.— The plain figures refer to the pages of this Tolume. The ftill-
faced figures refer to paragraphs.]

Manoeuvres, mechanical, siege guns, to dismount the gun with.

the sling -cart, 254, 503.

to limber, 204, 431.

to mount on mortar-wagon, 214, 450.

the gun, 210, 447.

with the gin, 245^

490.

to prepare for action, 210, 446.

for traveling, 210, 445.

to put short roller under body, 207^

438.

under chase, 207, 436.

to remove short roller from under body,

208, 439.

from under chase, 207, 431'.

to sliift carriages, 213, 449.

from carriage to mortar-wag-

on, 216, 452.

from firing to traveling bed,.

208, 441.

from mortar-wagon to carri-

age, 217, 453.

from traveling to firing bed,,

208, 440.

to side-lift the carriage, 209, 443.

to unlimber, 205, 434.

flank-casemate howitzers, to dismount carriage^

271, 533.

the howitzer, 271, 533.

to mount the carriage, 273, 533.

the howitzer, 272, 533.

siege howitzer, to dismount, 221, 458.

carnage and limber, 222, 459^

the howitzer, 218, 455.

to mount as mortar, 220, 457'.

the howitzer, 219, 456.

to stand on muzzle, 218, 454.

with sling-cart, 254, 503.

8-inch siege mortar, 228, 468.

10-inch siege mortar, to dismount, 224, 464.

from wagon, 227, 468.

to mount, 225, 465.

on mortar-wagon, 225, 466..

INDEX. 501

*oK?fi^-~'^^® ?^^^ flffnres refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Manoeuvres, mechanical, 10-inch sie.i^e mortar, to sling and hoist

with the gin, 246, 492.

to sine, 224, 463.

to stand on muzzle, 223, 462.

to stand on one trunnion, 223, 460.

with sling-cart, 254, 503.

13-inch mortar, to dismount, 228, 469 : 229.

4tO.

to place, with carriage on rollers, 229,

471.

to raise and place on blocks, 229, 472.

to shift from carriage to truck-wag-on,

279, 538. °

~~ ■; to transport on sling-cart, 230, 473.

sling-cart, with siege gun, howitzer, or mortar,

254, 503.

definition, 199, 414.

detachments for, 199, 415.

duties of chief-of-detachmont, 202, 422.

— ' of detachment, 202, 423.

of gunner, 202, 423.

of instructor, 201, 421 ; 231, 475.

- handspikes, and their uses, 200, 417: 201
417. '

- implements, machines, &c., 199, 416: 200,
416; 230, 474; 241, 484.

- leverage by limbers. 202, 425.

- to cross-lift, 203, 427.

- to cut a piece, 204, 430.

- to launch a piece, 203, 430.

- to lift, 202, 424.
to parbuckle, 202, 426.

to pinch, 203, 429.

to prepare for, 201, 419; 201, 420: 231,

475.

— tactical, alignments, 11, 53.

by battalion, 28, 116.

to change posts, 27, 1 12.

— to double rank, 25, 104, 105.

to single rank, 24, lOl, 102.

to close ranks, 11, 52.

" to dismiss, 12, 55.

to halt the line, 12, 57.

502 INDEX.

CNOTE. — ^The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Manoeuvres, tactical, to leave the pieces, 27, 113; 28, 114,
115.

to march bv detachments, 18, SO ; 19, 81-86 ;

*20, 87, 88; 22, 93-96; 23, 91'.

by platoons, 14, 66, 67 ; 15, 68, 69,

16, 73; 17, 75-79.

by the flank, 14, 64, 65.

detachments into line, 20, 89; 21,

90-92.

in columns of files, 14, 64; 16, 73;

17, 74; 23, 99; 24, lOO.

in hne, 12, 56; 23, 98.

in route step, 23, lOO.

obliquely, 12, 58; 14, 65; 22, 96.

platoons into line, 15, 70; 16, 71, 75S.

to the pieces. 25, 106 ; 26, 107.

to the rear, 23, 98.

to open ranks, 10, 49.

to rest, 12, 54; 27. IIO.

to resume the exercise, 27, 111.

to take posts at pieces, 26, 108.

to wheel, 13, 66-63.

Material, artillery, annual supply to preserve, 315, 567.

care and preservation of, 293, 551 ; 294, 555 ;

312, 566.

of projectiles, 310, 565.

required during sieves, 412, 664 ; 413, 664.

store-houses for, 312, 566.

Mechanical submarine mines, 425, 671; 426, 671.

Mensuration, 474, 475, App.

Metrical equivalents, 469, App.

Metric tables, 467, 468, 469, App.

Mines, (see Submarine Mines,) 425, 671 ; 426, 671.

Mortar fuse-plug, 51, 197.

Mortar platforms, 71, 224 ; 75, 227 ; 76, 228 ; 77, 229 ; 78,

229; 155, 355; 158, 357; 159, 360 ; 188, 404.
Mortar powder, 42, 180; 43, 180; 154, 354.
Mortars, 36, 144 ; 37, 148.

against iron-clads, 356, 593.

batteries of, 397. 643 ; 408, 656.

on skids, 295, 555.

penetration of shells, 363, 597.

positions in field-works, 371, 612 ; 388, 635.

INDEX. 503

[Note. — The plain figures refer to tlie pages of tlus volume. The full-
faced figures refer to paragraphs.]

Mortars, tar^^et practice, 188, 406; 189, 4L01f.

to aim, 63, 212, 213; 64, 213; 148, 342, 343;

149, 343; 163, 365; 167, 3'5'2; 170, 3'7S.

to prevent nigiit repairs, 361, 595.

to select shells for, 188, 404.

uses in ricochet firin<y, Qo^ 214.

weighing powder charges, 154, 354; 188, 404.

5.8-inch Coehorn, 2, 8 ; 157, 357.

carriage, 157, 357; 158, 359.

ranges, 157, 357.

8-inch siege, 2, 8 ; 155, 355.

ranges, 155, 355.

target practice, 188, 405.

to manoeuvre, 228, 468.

to sling and hoist, with gin, 246, 492.

with sling-cart, 254, 503..

10-inch sea-coast, 2, 8 ; 165, 369.

carriage, 165, 369.

ranges, 166, 369.

service, 166, 369.

- target practice, 187, 404.

- 10-inch siege, 2, 8 ; 145, 341 ; 146, 341.

- bed or wagon, 146, 341.

- ranges, 146, 341 ; 154, 354.

- service, 147, 342.

- to dismount, 224, 464.

from wagon, 227, 468.

to mount, 225, 465.

on mortar-wagon, 225, 466.

to sling and hoist, with gin, 246, 492.
to slue, 224, 463.

to stand on muzzle, 223, 462.

on one trunnion, 223, 460.

with sling-cart, 254, 503.

ranges, 159. 360.

service, 160, 361 ; 167, 371.

to dismount, 228, 469 ; 229, 470.

to mount, 228, 469 ; 229, 47®.

to place on rollers, 229, 471.

to raise and place on blocks, 229, 472.

to shift from carriage to truck-wagon, 279, 538.

604 INDEX.

P^OTE.— The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Mortars, 13-inch, to transport, on sling-cart, 230, 473.

Mortar-wagons, 261, 515.

Motion of projectiles, 56, 206 ; 57, 206 ; 58, 206 ; 50, 206.

Mounting siege-gun batteries, 101, 258.

Musket ball, penetration of, 363, 59S.

Musket powder. 42, ISO.

Muzzle, 35, 133.

canvas hoods, 295, 555.

IN" AVAL classification of gunpowders, 46, 181.
Night firing, 356, 592 ; 407, 654.
Nitro-glycerine, 431, 675.

Obstructions to channels, 343, 581.

Ofiicial courtesies, 463. f08.

Oils, painting, required annually, 315, 567.

storage, 314, 566.

volatile, storage of, 314, 566.

Ordnance sergeants, 294, 554; 317, 569.
Organization of siege-gun batteries, 92, 255.

Paddock's interpolator, 149, 343.
Paint, annual supply, 315, 567.

brushes, storage, 314, 566.

for siege guns, 101, 258; 295, 557.

storage, 314, 566.

Pan-coupde, 384, 633.
Paper time-fuse, 51, 197.

Parallels, siege, 408, 656; 411, 661 ; 411, 663.
Parapets, forms, 376, 618; 377, 619; 378, 619.

penetration of, 358, 595; 359, 595; 360, 595; 362,

596; 363, 596-598.

revetments, 362, 596; 379, 622, 623.

slopes, 377, 619 ; 378, 619.

thickness, 362, 596; 378, 619.

Parbuckling, 202, 426.

Parcelling, 232, 478.

Parks, location, 375, 614-616; 412, 663.

Parrott guns, 115, 287; 115, 288; 116. 288.

Pass-box, 54, 205.

Pellet gunpowder, 42, 180; 46, 181.

Penetration, action of projectiles, 360, 595; 361, 595^

eftect of revetments on, 362, 596 ; 363, 596.

INDEX. 505^

[Note. — The plain figures refer to the pages of this volume. The full*^
faced figures refer to paragraphs.]

Penetration of armor, 347, 586.

of batteries, 357, 595.

of mortar shells, 363, 597.

of rifle-musket balls, 363, 598.

tables of. 358, 595; 359, 595; 360, 595.

Percussion-fuse, 51, 198.

Pickets for holdfasts, 263, 519.

to draw, 263, 520.

Piece, defined, 5, lO; 34, 131.
Pile-driver, 263, 520.

Piles of projectiles, to compute number of balls, 312, 565.

Plliufv projectiles, 311, 565; 312, 565.

Pinch-bar, 270, 530.

Pinching guns, 203, 429.

Pintle, 67, 217.

Pintle-key, 67, 217.

Pintle-plate, 67, 217.

Piper's gin, 247, 494.

Piper's loading-bar, 165, 368.

Plane of sight, 40, 174; 148, 342.

tables, 187, 409.

Plank revetments, 382, 627.

Platforms, 41, 179; 71, 224; 72, 225; 73, 225; 74, 226;:
75, 227 ; 76, 228 ; 78, 229 ; 84, 231 ; 184, 402 ;.
188, 404; 387, 635; 388, 636; 397, 643.

barbette, 10-inch gun, 109, 276.

centre-pintle, 15-incli gun, 120, 293.

front-pintle, 15-inch gun, 126, 306.

Coehorn mortar, 158, 357.

howitzer, 103, 261.

mortar, 13-inch, 165, 369.

suitable for field-works, 387, 635 ; 388, 636 ; 397^

643.
Platoons, 6, 18-22; 10, 42.
Plotting, results of target practice, 191, 409.
Pneumatic buff'ers, 68, 218.
Pointing. (See Aiming.)
Point of fall, 39, 160.
Pontoons, dimensions, 337, 578; 341, 579.

in disembarkations, 336, 578 ; 338, 578.

weight of troops on, 341, 579.

Port-fire composition, in shells, as carcasses, 50, 194.
Post revetment, 381, 625.

506 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
-faced figures refer to paragraphs.]

Posts of cannoneers, 81, 230, XXII, XXVI.

Powder. (See Gunpowder.)

Powder-measure, 55, 205 ; 154, 354.

Preponderance, 38, 154.

Pressure of gunpowder, 47, 184; 147, 341; 197, 413.

Primers, electric, 52, 201.

friction, 51, 200; 433, 61'5.

Primer-pouch, 55, 205 ; 79, 230, IV ; 86, 234.

Priming, general rules, 80, 230, XI; 82, 230, XXXV; 89,

243 * 92 252
Priming-wire, 54,' 205; 79, 230, IV; 59, 206; 81, 230,

XVI.
Prismatic gunpowder, 46, 181.
Profiling, 379, 621.
Projectiles, action of, against earth-works, 360, 595; 361, 595 ;

362, 596.
amount and proportions required, 316, 568 ; 390, 63*7;

410, 660; 411, 662; 413, 666.

armor penetration, 347, 586.

punching, 354, 591.

Butler, 49, 190.
canister, 49, 192.
carcass, 49, 194.
case-shot, 48, 189.
classified, 37, 150; 47, 186.
cored-shot, 49, 191.
drop of, tables, 404, 650.
effect of, racking or punching, 353, 590.
elongated, 48, 190.
energy of, 39, 16'T.
fire-ball, 50, 195; 154, 354.
forces of gravitation, 57, 206.
forces acting on, 56, 206.

for drill, 83, 230, XXVII; 90, 244; 117, 289.
friction, effect on, 58, 206.
grape-shot, 49, 193.
hollow, 48, 188; 49, 191.
inspection of, 311, 565.
lacquer for, 311, 565; 312, 565.
mortar, penetration of, 363, 597.
packing, 311, 565.
penetration of, in armor, 347, 586.
r_ ill earth, 358, 595 ; 359, 595 ; 360, 595.

INDEX. 507

[Note. — The plain figures refer to the pages of this Toltime. The full-
faced figures refer to paragraphs.]

Projectiles, penetration of mortar shells, 3G3, 59 T.

preparation of, 81, 230, XVII, XXI, XXVII; 110,

3tT; 165, 368; 188, 404.
preservation of, 310, 565.

resistance of the air, 57, 306 ; 58, 206.

rifle, 49, 191.

ring for, 52, 202.

to be lubricated, 81, 230, XX ; 92, 254.

rifling, resistance of, 58, 206.

sabot for, 52, 202 ; 154, 354.

solid, 47, IS-l; 188, 404.

spherical, best for ricochet, 65, 214.

to ascertain time of flight, 184, 402.

to charge hollow, 108, 275; 121,294; 165,368; 188,.

404.

to compute number in piles, 312, 565.

to determine weight, 478, App.

to lift in loading, 115, 286; 115,281'; 145,340; 165,,

368.

to select, 188, 404.

to withdraw, 91, 24'?'; 117, 289; 125, 304.

Prop, sponge and rammer, 82, 230, XXIII.
Pulley-blocks, storage, 313, 566.
Punching, 353, 590, 591.

QUADBANT, gunner's, 53, 204.

Quartermaster's stores for siege-gun batteries, 102, 260.

Backing, 353, 590, 591.

Kailroad construction corps, 423, 669.

in sieges, 412, 663.

rolling-stock required, 325, 572.

speed, 325, 572.

transportation of artillery, 322, 572.

of guns, 324. 572.

of horses, 322, 572.

of men, 325, 572.

Kammer, 54, 205 ; 82, 230, XXXIII ; 312, 566.
Range, 39, 174.

extreme, 39, 165; 376, 617.

greatest, 39, 165; 376, 617.

of canister, 49, 192.

point-blank, 41, 176.

508 INDEX.

P^OTE. — The plain figures refer to the pages of this volume. The fuU-
^aced figures refer to paragraphs.]

Kange tables, formula to find elevations, 60, 210; 61, 21G.

of guns, 4.5-inch siege, 84, 231.

8-incli rifled, 133, 319; 134, 319.

10-inch smooth-bore, 109, 2'Y6; 117,

290.

15-inch smooth-bore, 119, 293.

100-pdr. Parrott, 116, 288.

of howitzers, 5.8-inch flank casemate, 128, 309;

131 318.
8-inch 'siege, 103, 261; 222, 458.

-: of mortars, 5. 8-inch Coeliorn, 157, 351'.

8-inch siege, 155, 355.

10-inch siege, 146, 341 ; 154, 354.

13-inch sea-coast, 159, 360.

Bear sights, 59, 20'^' ; 60, 20S, 209.

Becoil, 41, 1':'9; 117, 290; 135, 320.

checks, 68, 21^218; 72,225; 74,226; 117,290;

185, 320; 136, 320.
Becord of ammunition, in sieges, 413, 666 ; 414, 666 ; 415,
666.

of artillery, 293, 552.

of defects of bore and vent, 307, 563.

of electric-cable tests, 457, 693.

of firing during sieges, 416, 666.

of gunpowder storage, 317, 569.

Beembarkations, 340, 5K9.

Beliefs, of cannoneers, 82, 230, XXXI.

Beports of ammunition, in sieges, 413, 666; 414, 666; 415,
666.
of firing during sieges, 416, 666.

of target firing, 185, 402.

Beserves for lines of works, 375, 614-616 ; 412, 663.
Betreating after repulse, 365, 602.
Bevetments for embrasures, 386, 634.
for parapets, 362, 596; 376, 618; 377, 618.

of fascines, 380, 624.

of gabions, 381, 626.

of logs, 380, 623.

of planks, 382. 627.

of posts, 381, 625.

of sand-bao-s. 382, 628.

of sods. 379. 622, 623.

for scarps. 383, 629.

INDEX. 509

[Note. — ^The plain figures refer to the pages of this volume. The fuU-
iaced figures refer to paragraphs.]

Hicochet firing, 64, 314; 65, 214; 347, 5S5 ; 350, 58 1.

Rifle projectiles. (See Projectiles.)

Himbases, 34, 136.

River defenses, 388, 636; 419, 668; 420, 668-6'YO.

Rivers, influence on operations, 419, 668.

to attack crossings, 420, 668.

to defend crossings, 419, 668 ; 425, 6tO.

Hodman's pressnre-plng, 197, 413.

Rollers, 93, 256; 200, 416.

storage, 313, 566.

Rolling-stock for railroad transportation, 325, 5Y2.
Ropes for gins, (see Cordage,) 244, 489.

strength of, 237, 481 ; 238, 431.

to man, 201, 411'.

Sabots, 52, 202 ; 154, 354.

Salutes and ceremonies. 459, 695 ; 463, '7 OK.

at funerals, 466, 713.

for boats, 464, t09.

— — for war vessels, 462, 705.
— international, 462, 704.

national, 459, 696 ; 461, 700 ; 462, 703.

personal, civil or diplomatic, 461, 701 ; 462, 705,

706; 463, 707; 464, 709; 465, 712.
militarj'- or naval, 461, 702.

to fire, 460, 698.

Salvos, 460, 699.
Sand-bag revetments, 383, 628.
Sand-bags, 382, 628.
Saps. (See Boyaux.)
Scarp revetments, 383, 629.
Sea-coast mortars. ( See Mortars.)
Searcher, 300, 560.

Service of the piece, general rules, 79, 230 ; 80, 230 ; 81, 230 ;
86, 234-236; 87, 238, 239.

guns, 4.5-inch siege, 84, 232 ; 94, 256.

8-inch rifled, carriage 1, 137, 321.

carriage 2, 141, 331.

carriage 3, 142, 332.

carriage 4, 144, 338.

10-inch smooth-bore, barbette, 108, 276.

casemate, 117, 290.

15-inch smooth-bore, centre-pintle, 120, 294.

510 INDEX.

[Note,— The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Service of guns, 15-inch smooth-bore, front-pintle, 126, 306.

Gatlino-, 0.45-inch, 177, 391.

1-inch, 171, 380.

Parrott, 100-pdr., 115, 281'; 115, 288; 116»

288.

howitzer, 5.8-inch flank casemate, 129, 309.

8-inch sie.:?e, 102, 261.

mortars, 5.8-inch Coehorn, 158, 358.

8-inch siege, 155, 356.

10-inch sea-coast, 165, 369.

10-inch siege, 147, 342.

13-inch sea-coast, 160, 361.

Serving, 232, 418.

Shears, described, 284, 545 ; 285, 545.

formula to compute strength, 473, App.

in landing heavv guns, 339, 518.

to rig, 285, 546 ; 286, 546 ; 287, 546.

to use as a gin, 287, 541; 288, 541; 252, 500.

Shell-hooks, (see Loading-bar,) 55, 205.

expedients for, 115, 286, 281; 145, 340.

Shells, (see Projectiles,) against earth-works, 358, 595; 359,
595; 360, 595; 361, 595.

cartridge-bags for, 298, 558.

coating for interior surface, 298, 558.

ignition, 48, 188, 190; 49, 190, 191; 355, 591.

penetration of mortar, 363, 591.

to charge, 108, 215 ; 110,211; 121,294; 188,404;

318, 569.

to select and weigh, 188, 404.

Shifting-planks, 200, 416; 210, 444.

storage, 313, 566.

Ships, armored, (see Iron-clads,) 348, 581; 351, 589.

vital points, 351, 589.

extreme ranges, 376, 611.

Shot, (see Projectiles,) 37, 150; 47, 186, 181; 65, 214.
Siege guns, (see Battery and Manoeuvres, Mechanical,) ammu-
nition, 316, 568.
batteries, 92, 255.

care of, 295, 551.

carriages, 1, 1; 2, 8n.; 92, 255.

description, 83, 231.

platforms, 71, 221; 75, 221; 76, 228; 146, 341;

155, 355; 387, 635; 388, 636 j 397, 643.

INDEX. 511

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Siege guns, projectiles, packing of, 311, 565.

ranges, 84, S31.

service of. 83, 231.

target practice, 184, 402 ; 185, 402 ; 186, 402.

transportation by rail, 324, 572.

Siege howitzers. (See Howitzers.)
Siege-mortar field batteries, 159, 859.

Siege mortars, carriages, 1, 7; 2, 8n.; 70, 222; 146, 341;
158, 359.

described, 155, 355.

platforms, 71, 224; 75, 22*^; 76. 228 ; 146, 341 ;

155, 355; 387, 635; 388, 636; 397, 643.

ranges, 146, 341 ; 154, 354; 155, 355; 157, 357.

Sieges, 407, 655.

ammunition reports, 413, 666 ; 414, 666 ; 415, 666.

662.

investing works, 407, 656 ; 408, 656, 657.

'■ — proportion of artillery, 411, 662. .

transporting ammunition, 413, 666.

guns, 413, 665.

Sighting of howitzers, 107, 269.

of mortars, 63, 212, 213 ; 64, 213 ; 148, 342, 34% ;

Signals for target practice, 184, 4©2 ; 187, 4©4.
Skids, 200, 416; 270, 528; 273, 534; 295, 555.
Sling for disembarking horses, 338, 578.

for embarking horses, 329, 574.

for horses at sea, 332, 576; 334, 577.

painting and storage, 314, 566.

Sling-chain, 200, 416; 210, 444.
Slopes for parapets, 377, 619.

tables of, 378, 619.

Sluing, 203, 428; 204, 43®; 270, 532.
Smootii-bores in ricochet firing, 65, 214. *
Sod revetments, 379, 623.

512 INDEX.

[Note. — The i)lain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Spars, to compute strains, 474, App.
Spiking guns, 310, 565.
Splicing, 233, 479.

Splinter-proofs, 393, 637; 394, 638-640.
Sponge, 53, 205; 81, 230, XIX; 82, 230, XXXTTI; 92,
253; 209, 444.

bucket. 94, 256.

cover, 54, 205.

preservation. 312, 566.

Sponging, 80, 230, V, VU, VIII ; 81, 230, XVI, XXI ; 82,

230, XXXVI; 88, 240; 94, 256; 294, 555.
Spun-yarn, 232, 476.

Stalls for transports, 330, 575 ; 333, 576, 577.
Standard rule, 300, 560.
Star gauge, 299, 560; 300, 561.
Steel implements, preservation of, 313, 566.

qualities, 477, App.

Store-houses for artillery material, 312, 566.
Store-truck, 259, 509.

Strength of cordajje, 237, 4S1 ; 238, 481.

of gins, 252, 499.

. of horses, 476, App.

7 of iron, 477, App.

'- of spars, 473, App.

St^-iking point of shots, to find, 185, 402; 186, 402; 187,

404; 189, 407-409.
Submarine defenses, 346, 584; 425, 670.

arrangement of, 428, 673; 430, 674.

attack and defense, 455, 692.

bung-stoppers, 444, 683.

buoys, 445, 685.

charges of mines, 429, 674; 430, 674.

circuit-closers, 454, 691.

electric batteries for, 450, 689.

cables, 443, 682 ; 449, 688, 689.

fuses. 440, 680.

ignition of charge, 439, 679; 440, 679.
joints, 444, 684.
junction-boxes, 449, 688.
lines, 438, 678: 451, 690.
of rivers, 420, 668; 425, 670.
positions, 427, 672; 430, 674.
of fuse in charge, 441, 681.

INDEX. 513

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Submarine surface currents, 458. 694.

testing-rooms, 449, 689.

tests of cables, 456, 693 : 457, 693.

to fire, 450, 690; 451, 690 ; 452, 690; 453, 690.

to lay cables, 445, 686.

to plant the mines, 447, 687 ; 448, 687.

Supplies for preserving artillery material, 315, 567.

for siege-gun batteries, 96, 258.

of ammunition for field-works, 316, 568; 390. 637;

410, 660; 411, 662; 413, 666; 416, 666; 418,
667.

of material, 315, 567.

Swimming horses, 338, 578.
Sword manual, 10, 46-48 ; 12, 59.

Tables, metric, 467, App.

miscellaneous, 470, App.

— of alloys, 472, App.

of annual armament supplies, 315, 567.

'■ — of armor penetration, 347, 586.

— of atmospheric pressure, 57, 206.

of drop of projectiles, 404, 650.

of harbor surface currents, 458, 694.

of metrical equivalents, 469, App.

of penetrations of parapets, 358, 595 ; 359, 595 ; 360,

595.
of ranges. (See Ranges.)

of slopes for parapets, 377, 619 ; 378, 619.

of strength of cordage, 237, 481.

of thickness of parapets, 362, 596.

of strength and weight of iron chains, 241, 484.

of strength of cordage, 237, 481.

of U. S. artillery, 2, 8.

of weights and measures, 467, App.

of weights and volumes of metals, 471 App.

— miscellaneous, 471, App.

woods, 471, App.

to obtain centre of impact, 186, 402.

Tackles, 239, 483; 240, 484.

power gained by, 241, 484.

Tactics, (see Manoeuvres, Mechanical, and Manoeuvres, Tactical,)

in battalion formation and skirmishing, 34, 130.
Target practice and targets, 183, 401 ; 191, 409.

514 INDEX.

[Note.— The plain figures refer to the pages of this volume. The full-
faced fig ares refer to paragraphs.]

Target, floating, 190, 409.
guns, Gatling, 192, 410.

sea-coast, 189. 409.

siege, 184, 402 ; 185, 402 ; 186, 402.

horizontal, 185, 402.

howitzers, siege, 187, 403, 404; 188, 405.

mortars, Coehorn, 188, 406.

sea-coast, 189, 407; 189, 408.

siege, 187, 404 ; 188, 405.

• plotting results, 191, 409.

presented by ships, 349, 587; 350, 588; 351, 589.

record of, 185, 402 ; 191, 409; 299, 559.

Teams in sieges, (see Horses,) 413, 665.

Telegraphic communication, importance during attacks, 406,
654.

in defending defiles, 418, 66 '7.

with guard-boats in defending submarine mines, 456,

692.
Telemeters, Boulong^'s, 192, 411 ; 193, 411.

Gautier's, 193, 412.

one for each siege gun, 95, 25'y ; 192, 409.

Telephone. (See Telegraph.)

Tests, flashing, of powder, 47, 183.
of defective guns, 307, 563.

of gunpowder, to sample, 46, 182.

of submarine mines and cables, 449, 689 ; 456, 693 ;

457, 693.
T6te-de-pont^, 416, 667; 418, 668.
Time-fuses 50 197

Time of flight,' to ascertain, 184, 402 ; 192, 409.
Tompions, 294, 555.
Tools, intrenching, 413, 664.
Torpedoes, (see Submarine Mines,) 398, 646.

defined, 425, 670.

r- for bridge demolitions, 422, 669.

fuses, 439, 679; 440, 679.

Towns, distance of defenses, 376, 617.
Toy's fuse, 422, 669.

Trace-rope, 93, 256; 200, 416; 210, 444.

Tracing field-works, 379, 621.

Trains, hauling ammunition in sieges, 413, 666 ; 416, 666.

parking, 412, 663.

Transportation by rail, 322, 572,

INDEX. 515

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraphs.]

Transportation by sea, 321, S*^! ; 325, ^KS.

disembarking, 335. 5'?'8.

horses, by sea, 327, dfS.

ammunition in sieges, 413, 666 ; 414, 666.

stalls, sea transports, 330, SI'S ; 333, 516 ; 333, ^'7'7.

weight of field battery, 330, 574.

Transports, marks, 341, 5'S'6.

Traverses, 376, 618; 388, 635; 393, 638; 394, 638.
Troops, number for harbor batteries, 245, 582 ; 368, 60*7 ;

370, 611; 374, 614.
Trucks, casemate, 257, 506.
garrison, 314, 566. -*

store, 259, 509.

wagon, 260, 514; 277, 536; 279, 538.

Trunnion beds, 66, 216; 294, 555.

chains, 259, 508.

gauge, 300, 560.

rings, 314, 566.

rule, 300, 560.

— sights, 62, 211 ; 168, 372.

squares. 300, 560.

Trunnions, 84, 135 ; 294, 555.

Unload, to, 81, 230, XVI; 91, 247; 117, 289; 125, 304;
153, 350; 164, 366.

Veix)CIty, 39, 166.
Vent, 35, 142; 294, 555.

to inspect, 297, 558 ; 307, 563.

Vent-cover, 79, 230, IV.

gauge, 300, 560.

gimlet. 54. 205.

piece, 36, 142.

punch, 54, 205.

searcher, 300, 560.

stopped, 79, 230, V; 87, 238.

Verification of sights, 60, 208; 62, 211.

Vessels, armored. ( See Iron-clads.)
Vital points of iron-clads, 351, 589.

Wagon, mortar, 261, 515.
Water- cap fuse-plug, 50, 197.
Water caps, preservation of, 313, 566,

516 INDEX.

[Note. — The plain figures refer to the pages of this volume. The full-
faced figures refer to paragraph^.]

Water supply during sieges, 412, 663.
Way-planks, 270, 529.
Weights and measures, 467, App.

and volumes, miscellaneous, 472, App.

of alloys, 472, App.

of elongated projectiles, 478, App.

of iron balls, 477, App. i

of metals, 471, App. I

of round cast-iron, 478, App.

of woods, 471, App.

of field artillery, 330, 5Y4.

of troops on bridges, 341, 51'9.

Wharves, temporary, 335, 5*^8; 341, 51'9.

Windage, 38, 152.

Wind pressure, 57, 206; 58, 206; 192, 409.

Wire entanglements, 397, 644.

Worm, 54, 205 ; 312, 566.

Worming, 232, 4*78.

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(C8481sl0)476B

General Library

University of California

Berkeley

U.C. BERKELEY LIBBABI

coDssastbi

M44844

THE UNIVERSITY OF CALIFORNIA LIBRARY