LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
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MANUAL 
 
 TOR 
 
 ENGINEER TROOPS; 
 
 CONSISTING OP 
 
 PART I. Ponton Drill, 
 
 PART II Rules for Conducting a Siege, 
 
 PART III. School Of the Sap, 
 
 PART IV. Military Mining, 
 
 PART V. Construction of Batteries, 
 
 BY CAPT. J. C. DUANE, 
 
 CORPS OP EXOIXEERS U. 8. ARMY. 
 
 THIRD EDITION. 
 
 NEW YORK: 
 D. VAN NOSTRAND, 192 BROADWAY. 
 
 1804 
 
vv .%v %%**>" . 
 
 " 
 
 Entered according to Act of Congress, in the year 1862, 
 BY D. YAN NOSTRAND, 
 
 la the Clerk's Office of the District Court of the United States, 
 for the Southern District of Xew York. 
 
 O. A. ALVORD, 8TERKOTYPER AND PRINTJEB. 
 
8 
 
 PEEFACE. 
 
 THE following Manual is a compilation from English, 
 French, and Austrian Military Authors, with such al- 
 terations, as appeared necessary to adapt the work to 
 our service. 
 
 In the instruction for the Pontonier, it has been at- 
 tempted to devise a drill applicable to the various Pon- 
 ton Trains now in use in our Army. 
 
 The first part of the instruction for the Sapper is, with 
 a few alterations, a reprint of General Pasley's Rules 
 for conducting the Practical Operations of a Siege. The 
 second is a translation of the French Sapper Manual. 
 
 That part which relates to Military Mining is taken 
 from the English and French Aides Memoire. 
 
PONTON DRILL 
 
"HE 
 
 UNIVERSITY 1 
 
 I. 
 
 PONTON DRILL. 
 
 CHAPTER I. 
 
 PASSAGE OF RIVERS. 
 
 WHEN an army in the field finds its march interrupted by 
 a river, it may effect the passage of this obstacle either by 
 fording, by ferrying in boats, rafts or flying bridges, or 
 by military bridges. 
 
 The selection of the place and means of crossing a river, 
 is determined by a reconnoissance, which should be as de- 
 tailed and extensive as circumstances will permit. 
 
 Forl. 
 
 A river with a moderate currrent may be forded by in- 
 fantry when its depth does not exceed three feet, and by 
 cavalry and carriages when its depth is about four feet. 
 
 The requisites for a good ford are, that the banks are low 
 but not marshy, that the water obtains its greater depth 
 gradually, the current moderate, the stream not subject to 
 freshets, and that the bottom is even, hard and tenacious. 
 
 In mountainous countries, the bottom is frequently covered 
 with large stones, rendering the passage of carriages nearly 
 or quite impracticable. 
 
8 MANUAL FOE ENGINEER TROOPS. 
 
 In level countries, the case is often still worse, the bottom 
 being either of mud or quicksand, rendering it impassable 
 for both men and carriages. Sometimes the bottom is com- 
 posed of fine sand, which is hard enough, but by the action 
 of the hoofs of animals is stirred up and washed away, in- 
 creasing the depth until it is unfordable. 
 
 The best bottom is coarse gravel. 
 
 Fords are usually found in the wider and more rapid parts 
 of the river. 
 
 Their position may be determined by sending a number 
 of mounted men across wherever there is a probability of 
 the river being shallow enough. 
 
 The most certain method is to float down the stream in a 
 boat, keeping it in the swiftest part of the current, where 
 the stream is usually the deepest. Over the stern a sounding 
 line of the proper length is hung ; when this touches bot- 
 tom the river is sounded across. 
 
 When the ford is discovered, the remarkable objects on 
 the shore should be noted, that the ford may be easily recog- 
 nized, and a picket planted at the water's edge, in order that 
 uny variation in the height of the water maybe ascertained. 
 
 Rivers which are not fordable may sometimes be rendnvl 
 so, when the only obstacle is a too great depth of water 
 over an extent of eight or ten yards, by filling in this por- 
 tion of their bed with fascines loaded with stones, or with 
 stone and gravel. " 
 
 When the water is sluggish, or muddy, a ford may be im- 
 proved by covering the bottom with bundles of coarse grass, 
 rushes or twigs. 
 
 There have been instances of rivers rendered fordable by 
 diverting a portion of the water from its natural course. 
 
 When the river is wide and rapid, the ford must first be 
 carefully examined and staked out. The troops pass in column 
 of platoons, with sufficient interval to avoid choking the 
 current. 
 
PASSAGE OF RIVERS. fl 
 
 When boats are to be had, a few should be stationed be- 
 low the ford, to assist those who may be carried down by 
 the current. 
 
 When boats are wanting, this duty may be performed by 
 mounted men, or a life-hue may be stretched across, sup- 
 ported on casks or other floats. The force of the current 
 may be broken in a measure by stationing cavalry in tho 
 stream above the ford. 
 
 After a freshet, the ford should be re-examined, lest some 
 alteration may have taken place in the bed of the river. 
 
 In marching in retreat, it is frequently advisable to destroy 
 a ford after having used it. This may be effected by dig- 
 ging trenches across it, or filling in the deepest part with 
 harrows, teeth up, plank filled with spikes, crow's feet, &c. 
 
 Ice. 
 
 In high latitudes, during the winter, rivers are frequently 
 covered with ice of sufficient thickness to sustain the heavi- 
 est loads. This means of communication should be used 
 with great circumspection. A change of temperature may 
 not only suddenly destroy this natural bridge, but render 
 the river impassable by any method for a considerable time, 
 in consequence of the floating ice. 
 
 The thickness of ice should be, to allow the passage of 
 infantry in single file, on a line of planks and two yards 
 apart two inches; cavalry, or light guns, with intervals, 
 four inches ; 12-pounder field-pieces, unlimbered and on 
 sleds, five inches; 12-pounder field-pieces, limbered and 
 drawn by horses, with intervals between pieces, six to seven 
 inches. Ice when ten to twelve inches thick, bears the heavi- 
 est loads. 
 
 Two tracks of planks laid on the ice, for the carriage- 
 wheels to run on, may be employed when there is any doubt 
 as to its strength, or the wagons may be transformed into a 
 
 sort of sled by fastening two planks under the wheels. 
 1* 
 
10 MANUAL FOR ENGINEER TROOPS. 
 
 The thickness of the ice may be increased, when the 
 temperature is low enough, by throwing water on it. 
 
 AVhen the river is frozen on each side, but open in tlu- 
 middle in consequence of the velocity of the current, a boom 
 stretched across the open space will often check the veloci- 
 ty sufficiently to cause the ice to freeze. 
 
 Passage oil Boats, Rafts, &c., &c. 
 
 The point of passage being selected, all the boats that 
 can be procured will be collected in default of a sufficient 
 number of boats, lumber, casks and other material suitable 
 for rafts and the rafts constructed without delay. The 
 banks, if too steep, will be cut down ; the landing on the 
 opposite shore should be further down the stream than I lie 
 point of embarkation, as the loaded boats will drift with the 
 current. The boats will be arranged along the shore ac- 
 cording to size, and numbered ; the rafts moored below the 
 boats. 
 
 The infantry will be divided into sections, depending in 
 size upon the capacity of the boats in which they are to 
 embark ; each section is provided with the number of its 
 boat ; great care must be taken not to overload the boats or 
 to crowd the boatmen. 
 
 The soldiers will enter the boats one by one, alternately 
 against the right and left gunwale ; they will be cautioned 
 not to stir from the places assigned them, and above all, not 
 to spring up when the boat lurches ; they will disembark in 
 the same order, i. e., one by one. 
 
 When the river is shallow near the shore, the boat must 
 not approach the bank near enough to ground as it fills with 
 men. 
 
 In the passage of artillery, it is usually necessary to dis- 
 mount the piece. 
 
 Cavalry are not often passed over in boats. When boats 
 of sufficient size can be obtained, their bottoms must b*> 
 
PASSAGE IN BOATS, RAFTS, ETC. 11 
 
 covered over with plank, the horses placed crosswise, facing 
 alternately up and down stream, otherwise they may be 
 thrown down by the rolling of the boat. 
 
 The passage of all arms may be facilitated by construct- 
 ing a floating bridge formed of two boats, covered with a 
 platform constructed as follows : 
 
 From five to seven beams of the same thickness are laid 
 across the two boats, the interval between the beams equal, 
 and such that the covering plank extends one foot beyond 
 the extreme beams. 
 
 The interval between the boats allows the beams to ex- 
 tend two feet beyond the outer gunwales. The beams are 
 lashed to the boats ; the covering planks are kept in place 
 by two side-rails laid directly over the outer beams, and 
 lashed down to them ; the extreme planks are nailed down. 
 
 The size of the beams is regulated by the load, and inter- 
 val between the boats. With seven beams 27' long and 5" 
 square, and covering plank 1" thick, a 24-pounder may be 
 carried. 
 
 Not only artillery and cavalry may be transported by this 
 moans, but infantry may be, in much greater numbers than 
 by using the boats separately. 
 
 The raft can be manoeuvred by oars with nearly the same 
 facility as a boat. 
 
 The same rules apply to the passage of troops on rafts as 
 in boats, attention being paid to the following circumstances : 
 that rafts drift more than boats, consequently the landing 
 on the opposite shore will be further down stream ; and 
 as the embarkation is easier, there is more danger of over- 
 loading the rail, and of confusion in embarking. Infantry 
 enter by the flank, and occupy first the middle of the raft, 
 through its entire length ; a rank is then added alternately 
 on the up and down stream side, until the raft is loaded. 
 
 Artillery and heavy carriages are placed in the centre, 
 and cavalrv as in fl1 ^ v,o+" 
 
12 MANUAL FOE ENGINEER TROOPS. 
 
 Rafts possess these advantages, viz.: the embarkation and 
 landing of all arms is easier. 
 
 They carry large numbers at each trip. 
 
 They are not easily injured by the fire of the enemy. 
 
 They draw little water. 
 
 They cannot, however, be navigated with the same facili- 
 ty as boats, and move much more slowly through the water, 
 thus keeping the troops a longer time under fire when in 
 presence of an enemy. 
 
 They cannot be directed with certainty on a fixed point, 
 when the stream is rapid, and in this case it is often impos- 
 sible to bring them back against the current to the starting 
 point. 
 
 Finally, the length of time required for their construction 
 forbids their use when the passage is to be effected secretly. 
 
 When the material is limited in quantity, the passage will 
 be executed more readily by means of the rope ferry, trail 
 or flying bridge. 
 
 The first, which is used in streams with sluggish currents, 
 consists of a floating support, either raft, floating bridge (as 
 described above) or a wide scow. This support is provided 
 with two forked uprights, one near each end of the up-stream 
 side. The forks support a strong rope, stretched across the 
 stream, and securely fixed at each bank. The raft is caused 
 to traverse the stream by men on its deck hauling on the 
 cable. 
 
 The trail bridge is employed on streams of not more than 
 one hundred and fifty yards in width, and with a current 
 whose velocity is not less than one yard per second. The 
 rope must be maintained above the surface of the water, 
 consequently must be drawn very tight by means of wind- 
 lass, blocks and falls, or similar expedients, also raised at 
 each bank some distance above the water. 
 
 The raft or boat is attached to a pulley which runs on a 
 sheer line, and by means of a rudder, is given such a position 
 
TEAIL, OR FLYIXQ BRIDGES. 13 
 
 that its side makes an angle of about 55 with the direction 
 of the current. 
 
 The force of the current exerted on the side of the float 
 may be divided into two components, one perpendicular to 
 the sheer line, which is destroyed by the resistance of this 
 line, the other parallel to it, which causes the float to cross 
 the stream with a velocity depending on the strength of the 
 current. 
 
 The most suitable float for the purpose, is one composed 
 of two long narrow and deep boats, with the sides nearly 
 vertical, the interval between the boats, such that the cur- 
 rent shah 1 act on the sides of both through their entire length, 
 when they form the proper angle with it. 
 
 When timber rafts are used, they should have the form 
 of a lozenge, whose acute angle is 55. When two sides are 
 parallel to the current, the up-stream side will be in the most 
 favorable position for the passage. 
 
 When the river is more than one hundred and fifty yards 
 in width, the strain on the sheer-line would be very great ; 
 it is therefore usually replaced by a cable, one end of which 
 is attached to the float, the other anchored in the stream, 
 thus forming a flying bridge. 
 
 The cable is supported by several floats, either small boats, 
 barrels, logs, &c. 
 
 When an anchor is used, the first float should be as near 
 it as possible, without danger of tripping it; the others 
 should be so arranged as to maintain the cable above the 
 water. The cable is anchored in the middle of the stream, 
 when the current is stronger there ; but when stronger near 
 one shore, it must be anchored nearer the other. If no floats 
 for the cable are used, it must be passed over a gallows-frame 
 on the raft to keep it from dragging in the water. 
 
 This bridge is manoeuvred in the same manner as the trail 
 bridge. The rope-ferry, trail or flying bridge, furnish the 
 means of passing any stream, and may be' advantageously 
 
14 MANUAL FOR ENGINEER TROOrS. 
 
 employed in many cases. They may be established without 
 difficulty in a short time with limited material, and such as 
 can often be found in the vicinity. They permit the passage 
 of all arms, and the heaviest loads. 
 
 They are not liable to injury from floating bodies, and the 
 flying bridge does not interrupt navigation. 
 
 Bridges. 
 
 When a river is more than four feet in depth, or when its 
 bottom is of mud or quicksand, recourse must be had either 
 to ferrying, by means of boats, rafts, &c., or to military 
 bridges. The latter method is always to be preferred, when 
 circumstances will permit their establishment. 
 
 Military bridges are composed of a road-way and its 
 supports; the first consists of beams, or balks, reaching 
 across the adjacent supports, and covered with plank, called 
 chess. 
 
 The supports, from which the bridge takes its name, may 
 be either fixed, as trestles, gabions, carriages, piles ; or float- 
 ing, as pontons, boats of commerce, rafts, <fcc. 
 
 Ponton bridges are preferable to all others when the pas- 
 sage by main force or surprise is to be undertaken. 
 
 They may be constructed on any stream of sufficient 
 depth. 
 
 Pontons may be replaced by rafts, when the velocity of 
 the stream does not exceed 6' per second. In swifter cur- 
 rents, rafts are unmanageable, drag their anchors, and are 
 liable to destruction from floating bodies. 
 
 Trestle bridges may be constructed in rivers whose depth 
 does not exceed 9', and whose velocity is not more than 6'. 
 
 They may be employed with advantage in rivers of mod- 
 erate depth and gentle current, with hard even bottoms; 
 when the bed of the river is uneven, the adjustment of 
 the trestles to the bottom is very tedious, and when the 
 current is rapid, almost impossible ; when the bed is of 
 
BEIDGES. 15 
 
 mud or fine sand, the settlement of the legs is liable to be 
 irregular. 
 
 Gabion bridges are used over marshes and shallow 
 streams ; they consist of gabions constructed in the ordinary 
 way, and of a height necessary to give a level road. These 
 are placed in rows perpendicular to the axis of the bridge, 
 filled with stones or gravel, and capped with a piece of tim- 
 ber, on which the balks rest. 
 
 Pile bridges are superior, in point of stability, to all other 
 military bridges, but require much labor and time in their 
 construction, and are usually employed in securing the com- 
 munication in rear of the army. 
 
 Military bridges being gnerely temporary expedients, the 
 same solidity is not required in them, as in permanent 
 bridges. It is sufficient to give them the strength required 
 to support the weight of the heaviest loads which accompany 
 an army, and to resist the action of the current, which has a 
 tendency to tear away the supports. 
 
 The first requisite is attained by giving sufficient volume 
 to the supports, if they are floating, vertical strength if fixed, 
 and using balks and chess of the proper dimensions, taken 
 in connection with their length between bearings. 
 
 To resist the action of the current; a good system of 
 anchorage, the greatest possible distance between supports, 
 and by placing these supports exactly in the direction of tho 
 current. 
 
 An intimate connection between the parts of the road-way, 
 and between the road-way and its supports, is also a groat 
 assistance in resisting the current ; sufficient play must how- 
 ever, be left, to allow the bridge to accommodate itself to 
 the action of a heavy load passing over it, and the action of 
 the waves when the water is rough, otherwise, however 
 firm the fastenings may be, they will soon work loose. 
 
 The interval between the supports is regulated not only 
 by the length of the balks, but by the cross section and the 
 
1C MANUAL FOR ENGINEER TROOPS. 
 
 buoyant power of the support. The duties of an officer 
 charged with the construction of a bridge are, to discover 
 and collect all the material disposable for the purpose ; to 
 examine carefully the position chosen for the bridge, ascer- 
 tain the width and velocity of the stream, and the nature of its 
 bottom and banks. He can then determine the composition 
 of the bridge, calculating so as to reserve sufficient material 
 to repair damages, and lengthen the bridge in case of a rise 
 in the water. He will then divide his force into detach- 
 ments, assign to each its task, and require each to labor at its 
 own task without attempting to interrupt or assist that of 
 any other. 
 
 During the progress of the work, he will not allow any 
 unnecessary person to approach the working parties, or step 
 upon the bridge. 
 
PONTON AND TRESTLE BRIDGES. 17 
 
 CHAPTER II. 
 
 CONSTRUCTION OF PONTON AND TRESTLE BRIDGES. 
 
 THERE are four methods of constructing a bridge when 
 pontons or boats of commerce are employed. 
 1 st. By successive boats. 
 2d. By rafts. 
 3d. By parts. 
 4th. By conversion. 
 
 The modified French Bridge Equipage, 
 
 Prate 1, 
 
 Consists of 34 Ponton Wagons, each loaded as follows, 
 viz. : 
 
 7 long balks ; 1 ponton, inside of which are placed 12 balk 
 lashings; 7 rack lashings ; 7 rack-sticks; 6 row-locks; 2 
 spring-lines; 5 oars; 2 boat-hooks; under the rear axle is 
 lashed 1 anchor. 
 
 22 Chess wagons; load of each, 41 chess; 2 cables. 
 
 4 Trestle wagons ; load of each, 2 trestle caps ; 4 legs ; 4 
 shoes; 4 chains; 14 short, or claw balks. 
 
 4 Abutment wagons ; load of each, 2 abutment sills ; 1 
 trestle cap ; 2 legs; 2 shoes ; 2 chains ; 14 short balks. 
 
 4 Tool wagons; loaded with carpenter's and intrenching 
 tools, spare cordage, &c.; 2 travelling forges. 
 
18 
 
 i 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 Recapitulation of Equipage. 
 
 Ponton wagons 
 
 34 
 
 Pumps 
 
 5 
 
 Chess " 
 
 - 22 
 
 Buckets 
 
 - 10 
 
 Trestle " 
 
 8 
 
 Pickets 
 
 24 
 
 Tool " 
 
 - 4 
 
 Rack-sticks - 
 
 - 240 
 
 Forge " 
 
 2 
 
 " collars 
 
 48 
 
 Trestles complete - 
 
 - 12 
 
 Cordage. 
 
 
 Balks, long 
 
 - 238 
 
 Cables - 
 
 - 44 
 
 " short (claw) 
 
 - 118 
 
 Spring-lines 
 
 128 
 
 Chess 
 
 - 902 
 
 Lashing balk 
 
 - 720 
 
 Sills (abutment) 
 
 - 8 
 
 " side-rail 
 
 - 360 
 
 Row-locks 
 
 - 200 
 
 Sheer-lines 
 
 2 
 
 Oars 
 
 - 192 
 
 Sets double blocks, 
 
 large 6 
 
 Boat-hooks 
 
 - 100 
 
 U (I U 
 
 small 6 
 
 Scoops - 
 
 - 70 
 
 
 
 [Discharge of Material. 
 
 The ponton is removed from the wagon by twenty men. 
 The wagon is brought near the river bank, the pole toward 
 the stream, and unlimbered. A double row of chess is laid 
 from the carriage to the water. The lashings are removed, 
 and the boat is allowed to slide gently into the water. The 
 balks are piled on the left of the entrance to the bridge. 
 Two balks are laid on the ground parallel and 18 feet apart; 
 on these is a layer of balks nearly in contact with each other, 
 then two more directly over the first set. Then a second 
 course, &c., until the pile is about 5 feet high. 
 
 The chess are piled on the right of the bridge, as follows : 
 three balks are laid on the ground parallel, and 5 feet apart ; 
 on these a course of ten chess not quite in contact ; on these 
 a second course often chess, &c., until the pile is 5 feet high. 
 Other articles, as trestles, cables, &c., are in separate piles 
 on the right of the chess. 
 
BRIDGES OVER KAVINE6. 
 
 19 
 
 Construction of Trestle Bridge over Dry Ravine. 
 
 Plate 4. 
 
 Sections. 
 No. of 
 
 Duty. 
 
 Non-Com. 
 Officers. 
 
 Men. 
 
 
 1st 
 
 Abutment Section 
 
 1 
 
 8 
 
 Construct abutments, &c. 
 
 2d. 
 
 Trestle Carriers' " 
 
 1 
 
 8 
 
 Brine; first trestle, then go for another. 
 
 8d. 
 
 " Builders' " 
 
 1 
 
 8 
 
 Erect the trestle and adjust the balks 
 
 
 
 
 
 upon the caps. 
 
 4th. 
 
 Balk 
 
 1 
 
 10 
 
 Carry balks by right side to end of 
 bridge, front men give ends to tres- 
 tle builders, take rear ends and as- 
 
 
 
 
 
 sist in placing. Go back for more 
 
 
 
 
 
 by left of bridge. 
 
 6th. 
 
 Chess " 
 
 1 
 
 24 
 
 22 carry chess by right of bridge to 
 
 
 
 
 
 other two who" place them. Keturn 
 
 
 
 
 
 by left 
 
 6th. 
 
 Side-rails " 
 
 1 
 
 8 
 
 Bring side-rails, and lash them down. 
 
 Dismantled by reverse process. 
 
 The pontoniers are divided into detachments, in which 
 each rank is numbered from the right, so that the front and 
 rear rank men of each file have the same number. 
 
 The first section is composed of one non-commissioned 
 officer and eight men, whose duty is to prepare a convenient 
 entrance to, and exit from the bridge, and to place the abut- 
 ment sill. 
 
 For the latter purpose there will be required picks, shov- 
 els, a maul, one sill and pickets, the number and size depend- 
 ing on the nature of the soil. 
 
 A trench one foot in depth is excavated to receive the sill, 
 which is placed in a direction exactly perpendicular to that 
 of the bridge, and firmly fixed in position by pickets eight 
 inches from each end in front and rear ; as soon as the balks 
 are in place, a chess is arranged against their ends, its upper 
 surface coinciding with that of the chess forming the road- 
 way, and retained by pickets. 
 
 The approach to the bridge is then rendered easy by cut- 
 ting down and levelling the bank, if necessary ; the abutment 
 
20 MANUAL FOR E^GDTEER TROOPS. 
 
 for the other extremity of the bridge is then arranged in the 
 same manner. 
 
 Trestle Carriers. 
 
 2d Section. 1 chief of section and 8 men. Nos. 1 and 1 
 and Nos. 2 and 2 carry the cap, passing rack-sticks through 
 the suspension rings; Nos. 3 and 3 the legs and false legs; 
 Nos. 4 and 4 the chains, shoes and wedges. The section is 
 then formed and marched back to the trestle depot. 
 
 To Construct the Trestle. 
 
 3d Section. 1 C. S. and 8 men. No. 1 inserts the leg in 
 the cap and adjusts the chain ; No. 2 the false leg and 
 wedge ; No. 3 the shoe. No. 4 is stationed at the foot, to 
 prevent it slipping. 
 
 The C. S. lays off the distance from the sill or last trestle, 
 at which the new trestle is to be placed ; he also measures 
 the height the cap is to be above the ground, and from this 
 estimates the distance the legs are to be thrust through the 
 caps. 
 
 Nos. 1, 2 and 3 raise the trestle. No. 4 prevents the foot 
 from slipping. Nos. 3 and 4 hold the trestle erect, whilst 
 Nos. 1 and 2 adjust the balk which they receive from the 
 balk carriers. 
 
 When the cap is so high that it cannot be reached from 
 the ground, the manoiuvre is performed as indicated in 
 plate 4. 
 
 Balk Carriers. 
 
 4th Section. 1 C. S. and 10 men. C. S. commands "lay 
 hold," "raise," "shoulder," "forward;" each file seizes a 
 balk, raises it ; the front rank to the rigfit, and the rear 
 rank to the left shoulder. The section marches in line to 
 the entrance of the bridge, the balk carriers on each flank 
 then p-recede the others, all keeping as close as possible to 
 
BRIDGE OVER DRY RAVIXE. 21 
 
 the right-hand side of the bridge ; on arriving at the bridge 
 head they come into line, the front rank pass their end of 
 the balks to the trestle section, step back and relieve the rear 
 rank, and assist in placing the balks. The section is then 
 formed' in two ranks on the left side of the bridge, and 
 marched off by the flank. 
 
 Chess. 
 
 5th Section. 1 C. S. and 24 men (22 carriers and 2 cov- 
 erers). 22 carry chess ; each man carries a chess under the 
 right arm, the forward end raised well np in the air ; he 
 marches on the right side of the bridge, delivers the chess 
 to the coverers, then passes back to the pile of chess, by the 
 left side of the bridge. The coverers stand on the balks to 
 be covered (one on the 1st and 2d, the other on the 4th and 
 5th balks), facing to the rear ; they receive the chess and 
 place them. 
 
 Side-Rails. 
 
 Gth Section. 1 C. S. and 8 men. Nos. 1 and 1 carry side- 
 rails for np-stream, Nos. 2 and 2 for down-stream side of 
 bridge. They are carried in the same manner as balks, and 
 one laid on each bay as soon as the coverers have left it. 
 Nos. 3 and 3 lash up-stream, Nos. 4 arid 4 down-stream 
 rails. 
 
 The side-rails are placed immediately over the outer balks, 
 and lashed by passing a rope around the balk and rail, tying 
 it loosely, then twisting it up tight with a rack-stick ; three 
 lashings are placed on each rail. 
 
 REMARKS. The greatest attention should be given to 
 placing the abutment. * 
 
 The stability of the bridge depends, in a great measure, 
 on that of the abutment sill. 
 
 AVlien, after raising a trestle, the cap is found not to be 
 on proper level, it is better to lower the trestle to the ground 
 
22 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 to correct the error, than to attempt doing so whilst it is 
 standing. 
 
 To Dismantle Bridge. 
 
 The sections remain the same as in the construction, oper- 
 ating in an inverse order 6th section remove the side-rails ; 
 5th section the chess ; 4th section the balks ; 2d and 3d 
 sections overturn, dismember, and carry off the trestles; 1st 
 section remove the abutments. 
 
 Construction of Trestle and French Ponton Bridge 
 I>y succesive Ponton over Watercourse. SUMMARY. 
 
 Plates 6 and 7. 
 
 1 No. of 1 
 | Sections. | 
 
 Duty. 
 
 Non-com. 
 Officers. 
 
 d 
 
 8 
 3 
 
 ~ 
 
 
 1st 
 
 Abutment Section, 
 
 2 
 
 
 Construct first abutment, take material for sec- 
 
 
 
 
 
 ond across river and construct it 
 
 2d. 
 
 Trestle, 
 
 2 
 
 8 
 
 Construct r:ift of two pontons, load it with sepa- 
 rate trestles, caps mid legs. &c.. take raft to its 
 
 
 
 
 
 place, put trestle together, right it, put claws 
 of balks to caps, haul on cables, drop 1. 
 
 
 
 
 
 engage raft. 
 
 3d. 
 
 Up-Stream Anchor, 
 
 2 
 
 8 
 
 Two half-suctions.' Boats with up-stream an- 
 
 
 
 
 
 chors are above abutment two half ft 
 
 
 
 
 
 cuter two boats, row to placv for and. 
 
 
 
 
 
 it drop boat to place in bridge and go ashore 
 
 
 
 
 
 for another boat. If boat is to bo moored, 
 
 4th. 
 
 Down-StreamAnchor 
 
 2 
 
 8 
 
 down-stream anchor is also placed in stern. 
 Two half-sections. First with boat take anchor 
 
 
 
 
 
 from boat already in bridge, drop down and 
 cast it; second half-section bring pontons 
 
 
 
 
 
 with no anchors into bridge and give them to 
 
 
 
 
 
 balk lashers. 
 
 5th. 
 
 Balk Carriers, 
 
 1 
 
 10 
 
 Brinj: balks by right side of bridge, pass front 
 
 
 
 
 
 end to trc.-tfr men or ponton la.-lu-rs. men at 
 
 
 
 
 
 front ends take rear ends and assist in placing 
 
 
 
 
 
 them for a ponton, the balk carriers pu.-h it oil' 
 
 
 
 
 
 and give their end to lashers, all go tor more. 
 
 6th. 
 
 Balk Lashers, 
 
 2 
 
 17 
 
 Four men alternate by twos in fixing spring- 
 lines; two attend up-stream cablo. one down- 
 
 
 
 
 
 stream; in placing ponton, ten (rive in alter- 
 
 
 
 
 
 nate pontons) receive bulks and lash them 
 
 
 
 
 
 down. t 
 
 7th. 
 
 Chess, 
 
 1 
 
 22 
 
 Twenty men bring chesses by right of bridge to 
 other two, who 'face to rear 'and place them. 
 
 8th. 
 
 Side-Rails, 
 
 1 
 
 8 
 
 Bring side-rails and lash them down. 
 
 When more than seventeen boats are employed, the 3d 
 and 4th sections should be doubled. 
 
BRIDGE OVER WATERCOURSE. 23 
 
 When the current is very rapid, the 3d section must be 
 increased. 
 
 "When the bridge is composed of twenty bays or more, 
 there should be two sections for balks alternating ; the same 
 for the chess. 
 
 To Contruct a Bridge over a Watercourse. 
 
 Plate 5. 
 
 The axis of the bridge should be as nearly as possible per- 
 pendicular to the direction of the current of the stream. This 
 direction is determined by throwing a floating body into 
 the stream where the current is the strongest, and as it floats 
 down, mark (with two boat-hooks) a line as nearly perpen- 
 dicular to this as can be determined by the eye. The wag- 
 ons are unloaded as has already been described ; the pon- 
 tons launched. 
 
 At the command " Construct the Bridge" 
 
 1st Section construct the first abutment, as in the pre- 
 vious chapter ; then embark in a ponton with the material 
 for second abutment ; pass over the river, determine its po- 
 sition by sighting at the two boat-hooks marking the axis ; 
 construct this abutment and the road leading from it. If 
 no trestles were used, they would plant pickets thirty paces 
 above and below, and three and one-half paces above and two 
 and one-half below the 1st for anchoring cables, the 2d for 
 spring-lines. 
 
 2d Section construct a raft (Plate 5) with two pontons, 
 (I) two balks, (bb) lashed firmly to the gunwales ; a deck 
 is formed of chess (hh) covering part of first ponton, and 
 the interval between the two. 
 
 The different members of the trestles are embarked, the 
 caps and legs are laid alternately on the balks over the sec- 
 ond ponton, the chains on deck over the first, the false legs 
 and shoes in the bow and stern of first ponton ; the raft is 
 brought opposite the abutment. 
 
24 MANUAL FOR ENGINEER TROOrS. 
 
 The corresponding files in front and rear rank of the sec- 
 tion have the same numbers. The rear rank performs the 
 same operations for the down-stream part of the bridge that 
 the front rank does for the up-stream side ; No. 4 holds the 
 raft in position by the guys or shore lines until they receive 
 cables from the anchor detachment; Nos. 1, 1 and 2, 2 bring 
 forward a sill, lay it on its side, the bottom toward shore ; 
 Nos. 1, 1 introduce the legs in the mortices of the sill, Nos. 
 2, 2 the false legs and chains, Nos. 3, 3 place and secure the 
 shoes. 
 
 The C. S. commands "raise" the trestle is righted; Nos. 
 1, 1 step on the trestle and hold the legs to keep them from 
 sliding down. Nos. 2, 2 adjust the ends of the balks, which 
 are passed to them by balk carriers; the raft is then 
 pushed off by the balk carriers pushing on the shore end of 
 the balks until the proper distance is attained. 
 
 The Nos. 4, 4 are directed by the C. S. to haul or slacken 
 their cables as circumstances may require, until the trestle is 
 in its true position. Nos. 1, 1 then thrust down the legs, 
 pressing them firmly into the bottom of the river ; Nos. 2, 2 
 hook the chains, Nos. 3, 3 drive in the wedges ; C. S. com- 
 mands " disengage" All lift on the cap of the trestle just 
 placed, in order to sink the ponton sufficiently to disengage 
 the balks (bb) from under this cap. 
 
 3d Section is divided into two half sections, for casting 
 up-stream anchors. The pontons which nre to receive up- 
 stream anchors are moored above the abutment. If the 
 ponton is to be anchored down stream, a second anchor and 
 cable are placed in the stern. Each half-section embarks in 
 a ponton with an anchor. The anchor is placed in the bow, 
 the flukes projecting over, the cable coiled immediately be- 
 hind it. No. 1 front rank attends the cable ; No. 1 rear 
 rank steers ; Nos. 2, 2 row. The line on which the anchors 
 are to be cast is marked by two boat-hooks, placed about 
 twenty paces apart, on shore. Arriving on this line, and 
 
BRIDGE OVER WATERCOURSE. 25 
 
 opposite the position which the ponton is to have in the 
 bridge, the C. S. commands " cast anchor" No. 1 throws 
 over the anchor and pays out the cable until the boat arrives 
 at its place in the bridge, the cable is made fast, and the 
 ponton brought, with the boat-hook and oar, along the bridge 
 head ; the short balks, supports, block and sill are arranged, 
 and turned over to the cable detachment, the anchor detach- 
 ment passing to the shore by the bridge after another ponton. 
 
 The distance of the anchors above the bridge should be at 
 least ten times the depth of the stream, otherwise, when a 
 strain is brought on the cables, the anchors will trip. 
 
 In ordinary circumstances, an up-stream anchor is required 
 for the alternate pontons, and an anchor down-stream for 
 every fourth ponton. 
 
 When the river is not over seventy or eighty yards wide, 
 or the current is gentle, a sheer-line may be used in place of 
 anchors. 
 
 The sheer-line is a cable stretched across the river sixteen 
 or twenty yards above the bridge, to which the pontons are 
 attached by lines. As the strain on this line is generally 
 very great, the points of attachment on the shore must be 
 secured with great care. An arrangement similar to the 
 abutment sill may be used, or if the soil is firm, an anchor 
 buried in the ground. 
 
 4th Section. Two half-sections. First half-section cast 
 down-stream anchor ; half section embark in a ponton 
 moored below the bridge ; proceed to the first ponton in 
 the line of the bridge, which lias an anchor on it. No. 1 
 holds the two pontons together, whilst Nos. 2, 2 remove 
 the anchor and cable to the anchor boat, having previously 
 made the end of the cable fast to the ponton. The anchor 
 boat is then allowed to float down to the line of anchors, 
 No. 1 paying out the cable. The anchor is then cast, and 
 the boat hauled back to the bridge by means of the cable 
 of the anchor just cast. 
 2 
 
26 MANUAL FOR ENGINEER TROOPS. 
 
 The boat proceeds to the next boat having a down-stream 
 anchor. Second half-section brings into line those pontons 
 which are not provided with anchors. 
 
 These pontons are brought into their proper places and 
 held alongside the nearest ponton between thein and the 
 bridge, until the cable men are ready to take charge. The 
 detachment then passes ashore by the bridge. 
 
 5th Section Balk Carriers. Duty the same as 4th sec- 
 tion in chapter 2d, except that the front rank push off the 
 ponton before giving the balks to the balk lashers. 
 
 6th Section. Balk Lashers. When the French train is 
 used, an additional section is required to lash the balks to 
 the gunwales of the ponton. 
 
 This section is composed of two non-commissioned officers 
 and seventeen men. 
 
 Four men alternate, two and two, in fixing the spring-lines, 
 which connect the pontons bow and stern, and are made fast 
 to the mooring-posts ; three men at the cables two for the 
 up-stream and one for the down-stream cable ; ten balk lashers. 
 The five front-rank men enter the first ponton, station them- 
 selves opposite the lashing hooks, facing down stream. They 
 receive the ends of the balks from the balk carriers, lay them 
 in their places on the outer gunwale, and overlapping it by six 
 inches. They then throw their weight on the balks to keep 
 them in place whilst the boat is being pushed off. In the 
 mean while, the rear rank lash the shore ends of the balks to 
 the abutment sill, if claw balks are not used, and pass over into 
 the second ponton. When the second ponton is pushed off, 
 the lashers in the first ponton receive the ends of the second 
 set of balks from the carriers, place them on the gunwales of 
 the ponton in contact with the first set, and overlapping the 
 inner gunwale six inches, lash them firmly to both gunwales, 
 then pass over to the third ponton. 
 
 7th Section. Chess Carriers. The same as 5th section, 
 chapter 2d. 
 
DISMANTLING BRIDGES. 27 
 
 8th Section. Side-Rail Carriers. The same as 6th sec- 
 tion, chapter 2d. 
 
 dismantling Bridge over Watercoure. 
 
 8th Section Remove the side-rails. 
 
 7th Section Remove the chess. 
 
 6th Section Act on spring-lines and cast them off, tend 
 cables, and unlash balks. 
 
 5th Section Remove the balks. 
 
 4th Section Two half-sections remove the pontons with- 
 out anchors ; take up the down-stream anchors ; the anchor 
 boat is brought up to the ponton ; sufficient cable is taken 
 into the boat to allow it to drop down the stream to the 
 line of anchors ; the anchor is raised, and the anchor boat 
 hauled back to the bridge. This operation is repeated until 
 three anchors are weighed, when the anchor boat returns 
 to the shore. If the cable to the up-stream anchor is long 
 enough, the readiest way is to allow the ponton to drop 
 down stream by this cable, coiling the down-stream cable 
 until the ponton arrives at the lower anchor line ; the anchor 
 is then weighed, and the ponton hauled by the up-stream 
 cable to the upper line of anchors ; when the upper anchor 
 is weighed, the anchor boat is then dispensed with. 
 
 3d Section Weigh the up-stream anchors, and take 
 the boats to the second shore. The section is divided into 
 two half-sections, which enter the first two pontons. "When 
 the boat is anchored up stream, it is hauled up to trip its 
 anchor by its cable. Boats are taken to shore below bridge. 
 
 2d Section Take up trestles by the reverse of the pro- 
 cess used in placing them. 
 
 1st Section Take up the abutments. 
 
28 MANUAL FOB ENGINEER TROOPS. 
 
 Construction of a Bridge by Parts* 
 
 Plate 8. 
 
 The parts are composed of two or three pontons. 
 
 If the velocity of the stream is less than two yards per 
 second, they are constructed above the abutment; if greater, 
 below. 
 
 The abutment and each bay is formed as in the case of 
 successive pontons, and at the same time. The parts are 
 formed by sections of one C. S. and twelve men, each part 
 as follows : a ponton is moored bow and stern to the shore; 
 a second ponton (No. 2) is brought alongside ; chess are 
 laid from the shore to No. 1, for the pontoniers to walk on ; 
 seven balks are brought ; five are placed as for an ordinary 
 bridge, one on the bow and stern; No. 2 is pushed off; a 
 third ponton is brought alongside of No. 2, and is treated in 
 the same manner. 
 
 The construction is indicated in the plate. 
 
 m m, crossed spring-lines ; //, balks ; d c7, chess to form 
 the junction with the next part. 
 
 When the part is above the bridge, it is conducted to the 
 line of up-stream anchors, drops its anchor, then floats down 
 to its place in the bridge ; a line is thrown to the bridge; it 
 is hauled up to the head of the bridge ; the balks are put in 
 place, and the part pushed off, the chess and side-rails lashed. 
 If the construction is from below, the part is towed to it$ 
 place, where it receives one or two cables of up-stream an- 
 chors, as may be necessary, from another boat. 
 
 To Dismantle by Parts. 
 
 1st Section Take up the abutment from the shore of de- 
 parture, and the balks, chess, <fcc., of the first bay, and pile 
 the material on the first part. The 2d section take up the 
 balks, chess, <fcc., uniting the first and second parts, pile 
 them on the second part, and the same for the other section ; 
 
CONSTRUCTION BY KAFTS. 29 
 
 as soon as the parts are disconnected, the down-stream ca- 
 bles are attached to a buoy and cast adrift ; each part is 
 then hauled up by the up-stream cables, the upper anchors 
 weighed, and the parts rowed or poled ashore and disman- 
 tled. If necessary, the up-stream anchors may be buoyed. 
 
 Construction by Rafts. 
 
 Plate 9. 
 
 Abutment is constructed as in the previous case, each part 
 as follows : 
 
 No. 1 ponton is brought up and moored bow and stern ; 
 chess are laid to it from shore. No. 2 ponton brought along- 
 side ; five balks are laid resting on both gunwales of each 
 ponton, lashed and covered with chess; ponton No. 3 brought 
 alongside No. 2, and treated in the same manner; side-rails laid 
 and lashed ; cross spring-lines ; two spare balks are carried 
 on each part ; the parts are conducted to their places as in 
 previous case. The parts are united by lashing the adjacent 
 pontons bow and stern, and laying the spare balks over the 
 joint formed by two adjacent side-rails, lashing these balks 
 firmly, either with rope or rack collars. The extreme chess 
 in each part should be nailed to the balks. 
 
 Dismantling. 
 
 The parts are disconnected by removing the lashings and 
 balks that unite the different parts. The parts are then 
 brought ashore and dismantled as in the bridge constructed 
 by parts. 
 
 Bridge by Conversion. 
 
 Plato 10. 
 
 The position of the bridge having been determined, and 
 
 the width of the stream accurately measured, a suitable 
 
 * place at some distance above the position of the abutment 
 
 is selected for the construction of the bridge. The place of 
 
30 MANUAL FOR ENGINEER TROOPS. 
 
 construction may be at a considerable distance from that 
 which the bridge is to occupy, and is frequently on some 
 tributary of the stream to be bridged, out of sight of the 
 enemy's shore. 
 
 The bridge is constructed parallel to the shore, side-rails 
 are lashed on all except the extreme bays. The balks, chess, 
 <fcc., for the abutment bay, are embarked on the next to the 
 last bay of the bridge.; a ponton is lashed to the last pon- 
 ton in the bridge ; this contains, in addition to the arti- 
 cles necessary for constructing the abutment, two strong 
 pickets. The up-stream anchors are deposited in the bows 
 of the boats on the wheeling flank; ten or fifteen yarde 
 of their cables coiled, the remainder stretched along the 
 bridge. Two strong lines are extended and lashed, the one 
 over the bows, the other over the sterns of all the pon- 
 tons; these lines should be considerably longer than the 
 bridge, and the ends coiled on the platform. The bridge is 
 then allowed to float down to within fifteen yards of the 
 first abutment. 
 
 The material for the first abutment and bay is brought 
 down in a ponton, two strong pickets are planted at A and 
 B to fasten the spring-lines, and one to fasten the line which 
 is coiled on the next to the last ponton. 
 
 The wheeling flank is pushed off, men are stationed in the 
 bow and stern of each ponton with oars and boat-hooks to 
 increase or retard the progress of the ponton, as may be 
 necessary. A detachment is stationed at the first abutment 
 to manoeuvre the spring-lines, another to prevent the pivot 
 flank from touching shore ; a turn of the shore line is taken 
 around the mooring-bar of the ponton, and this line is eased 
 off, as the case may require. The anchors are cast as the pon- 
 tons in which they are carried come in the proper places, 
 and their cables are brought to the pontons to which 
 they are attached. The progress of the bridge is checked 
 when it arrives opposite the abutments, which should be 
 
DISMANTLING BY CONVERSION. 31 
 
 constructed during the conversion of the bridge, if the 
 force is strong enough. The down-stream anchors are 
 cast by the spare pontons, as in the bridge of successive 
 pontons. 
 
 Dismantle by Conversion. 
 
 This manoeuvre is rarely executed except by an army in 
 retreat, closely followed by the enemy. 
 
 The abutment bays are dismantled, the spring-lines are fas- 
 tened to A and B ; buoys are attached to the down-stream 
 cables, which are cut off, the up-stream cables are lengthened 
 out with spare cables. A strong line is passed from the 
 next to the last ponton to the shore. The bridge is allowed 
 to swing around, the up-stream cables are eased off, alsojthe 
 upper spring-line. When about half the wheel has been com- 
 pleted, the pontons form such an angle with the current that 
 the tendency of the bridge is no longer toward the required 
 direction, but to move obliquely toward the other shore. 
 The strain on the lower spring-line is very great, and the 
 shore line must be used to haul in. 
 
 After the wheel has been effected, the bridge is floated 
 down stream behind an island, or to some other place shel- 
 tered from the enemy's fire, and then dismantled. 
 
 Advance-Guard Bridge Equipage, 
 
 Plate 11, 
 
 Consists of 
 
 29 Ponton Wagons. Load of each 7 claw-balks, 1 tres- 
 tle complete, 1 canvas ponton, 4 oars, 2 boat-hooks, 
 
 ]5 Chess Wagons. 41 chess, 12'xl2"xiy, 1 anchor 
 and cable. 
 
 1 Abutment 4 abutment sills, 7 balks, 2 anchors and cables. 
 
 1 Wagon 1 sheer-line, 6 anchors and cables, spare cordage. 
 
 1 Wagon 7 anchors and cables, windlass, blocks and falls. 
 
 1 Wagon Carpenter's tools and picks, shovels, &c. 
 
32 MANUAL FOR ENGINEER TROOPS. 
 
 The pontons are of the Russian pattern (plate 11), viz.: 
 two side-frames, twenty-one feet long, and two feet four 
 inches deep. These are connected by movable transoms. 
 The whole made of four-inch pine scantling. 
 
 To equip the ponton, the transoms are inserted in the side 
 frames, and then firmly united by rack-lashings. A canvas 
 cover is then stretched over the frame and secured by lash- 
 ings. 
 
 When employed in the bridge, the balks may be lashed 
 to both gunwales, as in the French bridge r or the trestle 
 cap may be placed in the axis of the boat, with its upper 
 surface six inches above the gunwales. It is supported in 
 this position by two transoms let into the stanchions of the 
 side frames, about five feet from the bow and stern. The 
 claw-balks rest on this cap, as in the Austrian bridge. 
 
 As the number of trestles in this train is equal to the num. 
 ber of boats, either of these classes of supports may be used 
 to the exclusion of the other ; in either case forming a 
 bridge about two hundred yards in length. 
 
 Construction of the Bridge by Successive Pontons 
 when the Balks are not Lashed. 
 
 2f. a 
 
 Officers. Men. 
 
 Ibt 
 
 2 
 
 3 
 
 Abutment Construct the abutment, drive the shore-line pickets, 
 
 
 
 
 attach the shore linos, embark with second abutment 
 
 2d. 
 
 2 
 
 8 
 
 Raft. Construct a raft embark trestles, caps, legs, kc. 
 
 
 
 
 Construct trestles. 
 
 8d. 
 
 2 
 
 8 
 
 Boat. Up-stream divided into half-sections, which alternate In 
 
 4th. 
 
 
 S 
 
 bringing up-stream boats and casting anchors. 
 Boat Down-stream two half-sections first half-section bringg 
 
 
 
 
 down-stream boats, second cast down-stream anchors. 
 
 5th. 
 6th. 
 7th. 
 
 1 
 
 1 
 1 
 
 10 
 22 
 8 
 
 Balk Carriers. Bring the. five balks for each bay. 
 Chess Carriers. Twehtv bring chess,two receive and place the chess. 
 Side-Rails. Two half-sections; first bring side-rails second lash 
 
 
 
 
 side-rails. 
 
 When more than seventeen boats are -employed, the 3d 
 and 4th sections should be doubled. 
 
BRIDGE BY PONTOXS. 33 
 
 When the current is very rapid, the 3d section must be 
 increased. 
 
 When the bridge is composed of twenty bays or more, 
 there should be two sections of balk carriers, alternating. 
 The same for the chess. 
 2* 
 
34: MANUAL FOE ENGINEER TROOPS. 
 
 CHAPTER IH. 
 
 FLYING BRIDGES BRIDGES OF RAFTS TRESTLES 
 
 AND BOATS PRESERVATION OF BRIDGES. 
 
 
 
 Flying Bridge. 
 
 Plate 12. 
 
 THIS term is applied to any floating support anchored to 
 a fixed point (usually in the stream), and driven from 
 shore to shore by the oblique action of the current on its 
 sides. 
 
 Although these bridges do not afford a continuous com- 
 munication, yet they possess some decided advantages, viz. : 
 
 They are readily established over even the most rapid 
 streams. 
 
 They, require but little material for their construction. 
 
 They may be worked by very few men. 
 
 They permit the passage of troops of ah 1 arms, and the 
 heaviest carriages. 
 
 The entrance to and exit from them is easy. 
 
 They do not interrupt navigation, and are not liable to be 
 injured by floating bodies which, either by accident or de- 
 sign, are carried down stream by the current. 
 
 The current should not be less than one yard per second. 
 
 Construction. 
 
 The raft is formed of six pontons (plate 12). Two pon- 
 tons a a, are lashed stern to stern, and to these a third b y 
 breaking joints. A second set similar to the above, are 
 
FLYING BRIDGE. 35 
 
 placed at a distance from the first, of twenty-six feet from 
 Bet to set. The two sets are connected by^ix balks c, over 
 which four courses c?, are lashed. Then fifteen balks e, in a 
 manner suitable for receiving the chess. The extreme chess 
 are nailed down, and the outer courses secured by side- 
 rails. 
 
 The length of the cable should be at least one and a half 
 times the width of the river. One, two or three anchors are 
 used, depending on the strength of the current. 
 
 The cable is supported by pontons. 
 
 The boat nearest the anchor is the largest ; the distance 
 between the boats should be such that the cable shall not 
 touch the water between the first boat and the raft ; each 
 boat is fitted with a staging, composed of two short balks 
 and a supporting block, on which the cable rests, and to 
 which it is lashed. 
 
 The cable is also connected with the bow of the boat by 
 a line of such length that the boat is allowed to turn just 
 enough to keep parallel with the raft. 
 
 After the raft is attached to the cable, it is passed from 
 shore to shore once or twice, until the anchors are firmly 
 imbedded, and the cable stretched ; the two abutments are 
 then constructed ; these do not differ from the first bay of 
 the ordinary bridge. 
 
 If the strongest current is nearer one of the shores, the 
 anchor must not be cast in the middle of the stream, but 
 nearer the other shore. 
 
 The proper angle of the axis of the boat with the current 
 is about 55. 
 
 This angle is gradually increased on nearing the shore, 
 until the way of the raft is diminished sufficiently to prevent 
 it fVom striking the abutment with a shock. 
 
 The raft should be provided with spare cables and anchors 
 ready to cast, in case the cable by which it is moored should 
 part. 
 
MANUAL FOR ENGINEER TROOPS. 
 
 When the river is not more than one hundred yards wide, 
 a sheer-line may be used in place of the anchor and cable ; 
 the sheer-line must be taut enough to keep above the 
 water. See plate 16. 
 
 If the banks are not high enough, the sheer-line should be 
 elevated at each shore by passing it over a frame formed of 
 three poles, arranged like an artillery gin. A capstan, or 
 blocks, will be required to tighten the line from time to 
 time as it stretches. Upon this line a pulley is fixed, so that 
 it can run freely from shore to shore ; through the eye of 
 the pulley block a line is passed, one end of which is attached 
 to the bow of the first, and the other to the bow of the 
 second boat forming the raft. This is a trail bridge. 
 
 "the raft is manoeuvred as in the case of the flying bridge, 
 or two pulleys may be used on the sheer line ; a line from 
 one is attached to the bow of the first boat ; a line from the 
 second pulley is passed through a pulley block fastened to 
 the stern of the same boat. 
 
 The required direction may be given to the raft by haul- 
 ing in, or slacking the stern line. 
 
 Rhine Flying Bridge. 
 
 Two boats are required ; they should be long, narrow, and 
 deep, that they may expose as much surface as possible to 
 the action of the current. Those in use on the Rhine are 
 usually ninety feet long, twelve feet wide, and five feet six 
 inches deep. Each boat is provided with a trestle, formed 
 of a bottom sill resting on the ribs directly over the keel. 
 Stanchions connect this with a cap sill, which should be on 
 the same level as the gunwales. 
 
 The boats are connected by a series of balks, whose num- 
 ber and size depend on the load to be carried. These balks 
 should be long enough to give such an interval between the 
 boats, that both may be freely acted upon by the current. 
 
RHINE FLYING BRIDGE. 37 
 
 The beams are spiked to the trestle and gunwales. The 
 flooring planks are nailed on. 
 
 The platform extends over the waists of the boats, and a 
 small forward after-deck is formed between the boats for the 
 accommodation of the crew. 
 
 Each boat is provided with a mast, passing through the 
 deck and firmly stepped. 
 
 The masts are connected by two horizontal beams, the 
 lower being the stronger, between which a block pierced 
 with a hole slides freely. 
 
 The whole frame is stayed by guys. This frame is placed 
 about one-third of the length of the boats from the bows, 
 and is from twenty to thirty feet high. 
 
 A bean} is fastened across the bows of the boats, to pre- 
 vent the cable from catching under them. 
 
 Each boat is provided with a rudder, the tillers of which 
 are coupled by a bar, so that both may be worked by one 
 man. 
 
 The cable, after passing through the cat, is made fast to a 
 windlass. 
 
 The cable should be, in length, about one and a half times 
 the width of the river. 
 
 The cable is attached to one or more anchors. 
 
 With boats of the size above stated, the best arrangement 
 is to cast a large anchor about five hundred pounds weight, 
 with its shank in the direction of the current ; two others 
 of about half this weight are cast, with their shanks in the 
 direction which the cable takes when the bridge is at either 
 shore. 
 
 The cables of the three anchors are united near the first 
 supporting boat. 
 
 The cable is supported by small boats. 
 
 The first, which should be the largest, must be at a dis- 
 tance from the anchors, at least three times the depth of the 
 Btream. 
 
38 MANUAL FOR ENGINEER TROOPS. 
 
 The remaining boats should be near enough to prevent 
 the cable from dragging in the water their number in- 
 creasing with the length of the cable, and diminishing with 
 the strength of the current. Near the bow of each boat is 
 a short mast, forked at the top to receive the cable ; a short 
 line or bridle connecting the cable with the bow, prevents 
 the boat from turning too far. The length of the bridle is 
 regulated so as to allow the boat to take position parallel to 
 that of the boats in the raft. 
 
 Any floating body may be, in accordance with the above 
 principles, used as a flying bridge ; rafts of timber, casks, or 
 wagon bodies, are frequently employed. 
 
 When plank can be obtained, a scow either with or with- 
 out ribs, may be constructed by any of the troops who are 
 at all accustomed to the use of carpenters' tools. When 
 plank cannot be found, a rough frame of poles covered with 
 stout cotton canvas may be employed. W'hen a single boat 
 or raft is used the position of the bridge is regulated by a 
 stern line attached to the cable, instead of a rudder. 
 
 When the river is less than one hundred yards wide, a 
 sheer line may be employed, as in the flying bridges, com- 
 posed of pontons. 
 
 When the velocity of the current is not sufficient to work 
 the boat or raft as a flying bridge, it may be propelled as 
 follows : 
 
 On the up-stream side near the bow and stern, standards 
 are erected, the tops of which are forked to receive a sheer 
 line which is stretched across the river, and the boat is 
 caused to pass from shore to shore, by men hauling on the 
 cable. 
 
 Bridges Constructed of Boats of Commerce. 
 
 The same principles are applicable in this case as in that 
 of ponton bridges. 
 
 The following precautions, however, must be observed. 
 
BRIDGES OF BOATS OF COMMERCE. 39 
 
 As the boats are not usually of a uniform size, the length 
 of the balks for each bay should be so arranged with refer- 
 ence to the capacity of the boat that sustains them, that the 
 bridge will not be endangered, even when the bay is cov- 
 ered with as many men as can be crowded on it. 
 
 The boat next to each abutment to be strong and large. 
 
 The boats selected for the strongest part of the current, 
 to be large, so that they may be as much separated as pos- 
 sible. 
 
 The bridge will then offer less obstruction to the current ; 
 and will also be in less danger from floating bodies. 
 
 The intermediate boats should increase or diminish in size, 
 gradually, to avoid a sudden change in the level of the road- 
 way. 
 
 The gunwales of the boats should be brought to the same 
 level, or as nearly so as possible. This is effected by cutting 
 down the larger boats, or loading them until they are suffi- 
 ciently deep in the water. 
 
 This latter expedient increases the strain on the cable, 
 and should not be resorted to in a strong current. 
 
 In the smaller boats the gunwales must be raised, 
 
 Or a trestle, composed of a bottom and cap sill, united by 
 stanchions of the proper length, is placed in the axis of the 
 boat, and kept vertical by braces. 
 
 The balks, when timber of sufficient dimensions can be 
 procured, should be lashed over both gunwales of the two 
 boats on which they rest. If the timber is not sufficiently 
 long to admit of this arrangement, the following course is 
 adopted. The balks of the first bay rest on both gunwales 
 of the first boat ; in the second bay the odd-numbered balks 
 rest on both gunwales of the first, and on one gunwale of 
 the second; the even-numbered balks on one gunwale of 
 the first, and on both of the second boat ; the odd numbers 
 of the third bay on both gunwales of the second, and one 
 of the third boat, &c. 
 
4:0 MANUAL FOR ENGINEER TROOPS. 
 
 If the bridge is subject to the action of the waves, the 
 oscillating motion produced will soon loosen the balk-lash- 
 ings and destroy the bridge. In this case, it will be neces- 
 sary to make use of a sill and short balks, as in the ponton 
 bridge. When anchors of sufficient size can be procured, 
 the anchoring of this species of bridge does not differ from 
 that of the ponton bridge. 
 
 When this is not the case, some of the following expedi- 
 ents may be resorted to : 
 
 First Anchoring paniers (Plate 3). These are conical 
 gabions, closed at both ends, a pole passing through the 
 axis, and a hole in the side of the cone. Through this hole 
 the panier is filled with stones ; the hole is then closed with 
 twigs, a cable is attached to the end of the pole . furthest 
 from the panier. It is cast in the same way as an ordinary 
 anchor. 
 
 A strong box filled with stones or gravel may be employ- 
 ed. A common harrow loaded with stones forms a good 
 anchor. The best anchorage is formed by driving a row 
 of piles above the bridge. This method possesses the ad- 
 vantage of bringing a horizontal instead of a downward 
 strain on the cable, and protecting the bridge from injury by 
 floating bodies. 
 
 Timber Rafts/ 
 
 Plate 14. 
 
 The buoyancy of a raft depends on the volume and specific 
 gravity of the timber employed. 
 
 The volume may be found approximately, by the follow- 
 ing formula : V = 0.785 C 8 L. V= Volume. C = circum- 
 ference at middle of log, L = length. To find the specific 
 gravity, take a piece of the timber of convenient length 
 and of uniform even section, stand it vertically in the water, 
 retaining it in this position by three stakes so driven as to 
 allow it to float freely ; mark the depth to which it sinks. 
 
TO CONSTRUCT A RAFT. 4:1 
 
 Let I = the length of the part above the surface of the 
 water ; L = the whole length of the stick ; then 
 
 -j x 62J Ibs. weight of a cubic foot of the timber, and 
 
 -j-62i = weight which a cubic foot will sustain in the water, 
 in addition to its own weight, or the buoyant power of the 
 
 In the calculation due allowance must be made for the 
 loss of buoyancy which the logs will sustain after immersion, 
 from absorption. This loss will depend on the kind of tim- 
 ber used, being least in resinous varieties, such as pine, 
 and may be retained by^mearing the ends of the logs with 
 pitch. 
 
 To Construct a Raft. 
 
 Plates 13 and 14. 
 
 Select the longest and largest timber ; ach stick must be 
 at least thirty-five feet long. The timber is thrown into the 
 water and moored to the shore at a suitable place for build- 
 ing the raft, and where the current is not rapid. After the 
 position which the stick naturally assumes in the water has 
 been ascertained, the end which is to be up stream when in 
 the raft is drawn up on the shore, and the lower side bevelled 
 in a whistle shape, so as to present less obstruction to the 
 action of the current. 
 
 The timber is then arranged in the position it is to have 
 in the raft the butts" alternately up and down stream the 
 up-stream ends forming a right angle, salient up stream. 
 
 Employ the largest and longest timber, giving at least 
 thirty-five feet length to the raft. Shorter than this, it will 
 not have sufficient stability, but will be subject to dangerous 
 oscillations, especially in a rapid stream. 
 
 Squaring the timber will be worse than useless. Any 
 
42 MANUAL FOE ENGINEER TROOPS. 
 
 irregularities, such as branches and knots, should be trimmed 
 off. The raft must be built in the water. Select a place 
 where there is little current, and where the bank slopes 
 gently to the water. 
 
 Take the case of a raft, to be composed of twenty logs 
 forty-seven feet long and averaging twelve inches in diam- 
 eter. 
 
 The first log is brought alongside the shore, and the end 
 of a plank or small trunk of a tree (a a) is spiked to it 
 about 3' from each end ; it is pushed off a little, and a second 
 log is brought up under the transoms, and in close con- 
 tact with the first. 
 
 The second log is spiked as the first, and so for each of 
 the remaining logs, care being taken to alternate the butts, 
 placing the whistle ends up stream, with the bevel under- 
 neath, and to spike the transoms perpendicularly to the logs. 
 "When the current of the river in which the raft is to be used 
 is very gentle, the up-stream ends may be on a line parallel 
 to the transom ; bat if rapid, they should form a right angle 
 salient up stream, the vertex being in the middle log. 
 
 When the bank is too steep to admit of this construction, 
 the trees may be floated into their proper positions, lu^lu'd 
 together, and the transoms spiked on ; if the logs are nearly 
 of the same size, the centre of gravity will be near the cen- 
 tre of the raft. 
 
 Two additional traverses are spiked at equal distances 
 from the centre of gravity of the raft, and at a distance 
 apart equal to the width of the roadway or platform. 
 
 The traverse should be about 8" wide by 6" high. If 
 square timber cannot be had, saplings 7" or 8" in diameter 
 may be used. 
 
 They should have a bearing on all the logs forming the 
 raft. To effect'this the larger logs should be cut down with 
 an adze, and those too small be blocked up to the traverse. 
 
 The four traverses may be fastened to the logs either with 
 
 \ 
 
TO CONSTRUCT A BAFT. 43 
 
 spikes or wooden pins, or each log may be -lashed by pass- 
 ing a rope around it and the traverse and twisting it tight 
 with a rack-stick. 
 
 When a platform is to be constructed on the raft, inter- 
 mediate transoms are laid, and at a distance apart depend- 
 ing on the strength of the planking. 
 
 The size of this platform must be regulated by the buoy- 
 ant power of the raft. A single course of logs will not have 
 sufficient power to sustain troops enough to cover its whole 
 surface. 
 
 When this is required, several courses of timber are em- 
 ployed, each perpendicular to that below it, the whole firm- 
 ly united with pins as lashing. 
 
 When the raft is to be used in a bridge, the two interme- 
 diate transoms are separated by a distance a little less than 
 -the length of the chess, and at equal distances from a point 
 somewhat astern of the centre of gravity of the raft, in order ' 
 to correct the downward action of the cable on the bow. 
 
 On these traverses, three supports d d d, are spiked to 
 receive the balks. A piece of plank/, is nailed on the bow 
 to prevent the cable from getting entangled in the raft. 
 
 When the logs are less*than thirty-five feet in length, the 
 following construction is employed. See plate 14. 
 
 The small ends of half the trees are bevelled ; then a raft 
 is formed with the butts all down stream ; in other respects 
 similar to that described above. 
 
 The remaining trees are then brought butt to butt with 
 those in the raft, and fastened to them with iron clamps 
 or dogs, or by spiking a piece of plank across the two. A 
 traverse c is spiked on the stern. The traverses h and L 
 as in the preceding example. The traverse g a little for- 
 ward of the centre of gravity of the partial raft A, and the 
 traverse Jc a little astern of the centre of gravity of the par- 
 tial raft C. Two strong timbers d d, extend over the four 
 interior traverses. These timbers support the balks and 
 
44 MANUAL FOB ENGINEER TKOOPS. 
 
 diffuse the load ever the entire raft, without tending to dis- 
 unite the partial rafts. 
 
 For use as support in a bridge, a raft should be able to sus- 
 tain at least fifteen thousand pounds. The same expedients 
 are employed for the anchorage of rafts as for boats. It must, 
 however, be borne in mind, that a raft offers a much greater 
 obstruction to the current than a boat, and that the strain 
 on the cables is proportionally greater. 
 
 Rafts are sometimes constructed for flying bridges, in the 
 form of a lozenge, the acute angle being about 55, so that 
 when two of the sides are parallel to the direction of the 
 current, the up-stream side, which in this form is the only 
 one acted on by the current, is in the most favorable posi- 
 tion. 
 
 A raft of casks may be constructed, by forming a frame 
 of timber to contain the casks. See plate 15. 
 
 The frame consists of four longitudinal pieces, halved into 
 four transoms. The long pieces must be at least twenty 
 feet long ; their distance apart a little less than the head di- 
 ameter of the casks. The under edges are bevelled so as to 
 give them a good bearing on the casks. 
 
 In default of square timber, poles may be used in the con- 
 struction of the frame. The string pieces and transoms may 
 be spiked or lashed at their intersection. 
 
 The four exterior casks in the raft should be lashed to the 
 frame, otherwise they maybe carried off by the current when 
 the raft lurches. 
 
 Trestles. 
 
 Plate 15. 
 
 A trestle is composed of a cap about 15' x 9" x 9", four legs, 
 two lower and two upper traverses, four braces. 
 
 The cap is notched 1 8" from the end, to receive the legs ; 
 the notch is five inches wide and one inch deep. 
 
 The legs should be from five to six inches square ; a 
 
TRESTLE BRIDGE. 45 
 
 shoulder is made to fit the notch in the cap ; the spread 
 is quarter the height. The inclination in the other direction 
 about one-sixteenth. The leg is spiked, pinned or bolted 
 to the cap. The lower traverse is 5'xl^*, dovetailed 
 into the legs at about one-quarter their height from the 
 ground. 
 
 The upper traverse, which is nailed on the inside of the legs 
 and against the cap, is six inches wide, five inches thick. 
 
 The braces are four inches wide, one and a half inches 
 thick, spiked to the cap and legs. 
 
 The above dimensions, and method of construction, are 
 not absolute, but given as a guide to be followed as closely 
 as circumstances will permit. 
 
 The trestle may be made of round timber, care being 
 taken to level the upper surface of the cap. 
 
 When the trestles are to be placed on a soft bottom, a flat 
 sill may be spiked under the legs of each side. 
 
 Trestle Bridge. 
 
 Plate 15. 
 
 "When the water is less than four feet deep, the trestles 
 may be carried to their places, by men wading in the stream ; 
 an abutment is formed as for an ordinary bridge ; the tres- 
 tles are placed with their caps parallel to the abutment 
 sill, and about I'd' apart. 
 
 But when the water is too deep or too cold to allow this 
 method to be pursued, the bridge may be constructed as 
 follows : 
 
 The abutment sill being placed, the first trestle can usual- 
 ly be placed by hand ; the balks are laid and covered with 
 chess to within one foot of the trestle ; a roller is laid on the 
 bridge, on this are laid two beams from 30' to 40' long, 
 and 6* or 7" square. The trestle is placed upright with its 
 cap resting on these beams, to which it ifr firmly lashed. 
 The pontoniers bear down on the other ends of the beams, 
 
46 MANUAL FOE ENGINEER TROOPS. 
 
 at the same time pushing until the trestle is rolled out to 
 the proper distance, they then suddenly let up on the beams, 
 dropping the trestle into its place. 
 
 If the trestle does not stand firmly, or if the caps are too 
 much inclined in consequence of the unevenness of the bot- 
 tom of the stream, a man must walk out on the beams, and 
 sound with a pole the depth of water where each leg is to 
 be placed ; having thus determined the required length of 
 the legs, the trestle is hauled on to the bridge, the legs cut 
 down to the proper length, and the trestle replaced. The 
 flooring balks are slid out on the two beams, adjusted, and 
 covered with chess. 
 
 When a boat or raft can be procured, the trestles are 
 placed with much less labor. 
 
 The boat is brought alongside the last trestle placed, two 
 balks are laid from the bridge, and resting on the outer gun- 
 wale of the boat, the trestle is laid on the balks, its legs ex- 
 tending over the outer gunwale of the boat. The boat is 
 pushed off by means of the balks, until it arrives at the 
 proper position for placing the trestle. 
 
 The trestle is righted. If it has not a good bearing on 
 the bottom, it is hauled into the boat, and the legs cut to 
 the proper length. 
 
 The bridge may be entirely built of round timber. 
 
 The caps should be from 10" to 12" inches in diameter, 
 the legs at least 6". The balks 7" or 8" inches, and faced 
 on the lower side, where they rest on the trestles, so as to 
 bring their upper surfaces on the same plane. 
 
 The covering may be of strong hurdles. 
 
 Preservation of Bridges. 
 
 When the current is rapid, the bridge is protected from 
 the shock of %>ating bodies by establishing a guard of ob- 
 servation above the bridge, to arrest these bodies ; by placing 
 
PRESERVATION OF BRIDGES. 47 
 
 a stockade obliquely across the stream, or by construct- 
 ing the bridge by rafts, and withdrawing that part of the 
 bridge which is menaced, and allowing the body to float 
 past. 
 
 The guard o observation is stationed about one thousand 
 yards above the bridge. It is provided with boats contain- 
 ing cables, anchors, grapnels, hammers, &c. These boats 
 are stationed at different points across the stream. 
 
 As soon as a floating body is observed that may endanger 
 the bridge, a boat hastens toward it, fastens the end of a 
 line to it, and endeavors to tow it ashore. If unable to do 
 so, the line is made fast to an anchor, which should be so 
 cast that the first strain on the cable will be in an oblique 
 direction with the current. The body will then swing around 
 and lose part of its momentum, thus relieving the cable of 
 apportion of the strain. 
 
 The boats should also be provided with chains and grap- 
 nels, to tow burning bodies. 
 
 The floating btockade is constructed of trees united by 
 chains, and forming a continuous barrier to floating objects. 
 Its direction should form an angle of about 20 with the 
 current, which will require its length to be 24 the width of 
 the river. 
 
 Each piece is formed of one, two, or three trunks lashed 
 together. 
 
 As a stockade is not a reliable protection, it should be 
 established some distance above the bridge. 
 
 A guard should be at the bridge, from which a sentinel is 
 posted at each extremity ; and, if the bridge is long, at inter- 
 mediate points. 
 
 These sentinels should turn out the guard when the bridge 
 is in danger from any cause. 'They will see that tlie troops 
 march at the route step ; that the cavalry dismount ; that the 
 troops and carriages halt when %.e bridge commences to 
 oscillate dangerously ; that two heavily loaded carriages do 
 
48 MANUAL FOR ENGINEER TROOPS. 
 
 not enter the bridge ; that not more than five or six head of 
 cattle enter at the same time. 
 
 The officer in charge of the bridge will frequently inspect 
 the cables to see that they are not chafing, and that the 
 anchors do not drag. He will cause the rack lashings to be 
 tightened when they work loose, and the pontons that have 
 leaked or shipped water to be bailed. 
 
 There should be formed on the shore, near the entrance 
 to the bridge, a depot of spare balks, chess, cordage, &c., 
 by means of which any injury the bridge may sustain can 
 be promptly repaired. 
 
French Ponton & Carriage 
 
 Pl.l. 
 
Birag-o's 'I 1 res tie 
 
 PI. 2. 
 
or THE Y 
 UNIVERSITY 
 
Trestle Hrid i -ie ovor Water course. 
 
 PI. 3. 
 
 Anchoring pannier 
 
 ttalk Iftxhing 
 
Trestle lirid<_>e over 
 
OF THE 
 
 UNIVERSITY 
 
Trestle Hriilvjo over Water course. 
 
 
 PI. 5. 
 
Bridge bv -successive Pontons. 
 
 PI. 6. 
 
Trostlc S- I'oiitoius combined . 
 
 Pi. 7 
 
Uridi$e const moled by parts 
 
 r r r r r r r 
 
Britlyo roust rucU'd by Rafts. 
 
 PI 9. 
 
 JTH-IH, , 
 
\ a R A 
 
 OF THE 
 
 UNIVERSITY 
 
 /:RM\h- 
 
-BrirUo by Conversion 
 
 PI 10. 
 
 Continuation of Bridge a.h. 
 
Canvas l\mton.s. 
 
 Pl.1t. 
 
 I 4 4 
 
Flyiny Bridge. 
 
 PI. 12. 
 
imber Hafts X" 
 
Timber Rafts ' 
 
 I'l.l't . 
 
Trestles -"Raft of Casks. 
 
 PI. IS 
 
*CT*R**> 
 
 OF THE 
 
 UNIVERSITY 
 
Pi. 16. 
 
RULES FOR CONDUCTING 
 
 THE 
 
 PRACTICAL OPERATIONS OF A SIEGE 
 
 A S L E Y. 
 
PRACTICAL OPERATIONS, ETC. 
 
 1. Or Preparing Timber and Brushwood for Mili- 
 
 tary Purposes. 
 
 1. OF THE LARGE TIMBER REQUIRED IN A SIEGE OR 
 CAMPAIGN. 
 
 IN the siege of a fortress situated on the sea-coast, plat- 
 forms, timbers for powder-magazines, mine-cases, &c., may 
 be forwarded by sea ; but in inland operations, it is often 
 necessary to cut materials for those purposes in some adja- 
 cent wood, if they cannot otherwise be obtained. In a cam- 
 paign, abatis, stockades, palisades and chevaux-de-frise, are 
 often required to strengthen positions, and temporary pow- 
 der-magazines and bridges are also necessary for field-works. 
 Bridges of trestles, or even floating bridges, as a substitute 
 for pontons, may likewise be necessary in the field. All 
 these services require large timber, or young trees ; the for- 
 mer to be cut into regular scantling and planks, the latter 
 either to be well squared, roughly squared, split down the 
 middle or left round, according to circumstances. 
 
 2. OF THE TOOLS, ETC., REQUIRED FOR CUTTING TIMBER FOR 
 
 MILITARY PURPOSES. 
 
 The felling axe for cutting down large trees. 
 
 The cross-cut saw is necessary for cutting large trees trans- 
 versely, after being felled ; the handsaw is more convenient 
 for small ones. 
 
 The pitsaw is of indispensable necessity for preparing 
 large trees into scantling and planks, fit for platforms, bridges, 
 
52 MANUAL FOR ENGINEER TROOPS. 
 
 mine-cases, sheeting, &c.; also for sawing them down the 
 middle, if considered larger than necessary, for stockades or 
 palisading. Dogs, iron implements for securing the trees 
 while being sawed, and cant-hooks, for turning over, or drag- 
 ging them, are useful. 
 
 The carpenter's broadaxe is the most useful tool for rough 
 squaring. The adze may answer the same purpose, but it 
 is more particularly adapted for cutting concave curves, when 
 necessary. 
 
 Wherever saws are used, setters are necessary; one to 
 each saw, if detached, one to several saws, when working 
 together. One kind of setter is used for the pit and cross- 
 cut saw. Another, of a smaller size, for the handsaw ; and 
 to every individual saw files are required, in a proportion not 
 less than a dozen to each, even for the shortest service. 
 
 Where cutting tools are used, a grindstone is necessary, 
 to which a proportion of rubstones may be added. The 
 latter may serve in lieu of a grindstone, but not so conve- 
 niently. Ragstones (or whetstones) are also necessary. 
 
 Recapitulation of tools for cutting and preparing large 
 timber into scantling and planks. 
 
 Felling axes. Cross-cut saws. 
 
 Topping axes. Files for ditto, dozens of. 
 
 Pitsaws. Setters for ditto. 
 
 Files for ditto, dozens of. Handsaws. 
 
 Setters for ditto. Files for ditto, dozens of. 
 
 Chalk lines and chalk. Setters for ditto. 
 
 Plumb bobs. Carpenters' broadaxes. 
 
 Squares, iron, 2-feet (divided). Adzes. 
 
 Compasses, 6-inch. A grindstone. 
 
 Dogs. Rubstones. 
 
 Cant-hooks. Ragstones, or whetstones. 
 
 Pickaxes and shovels are necessary for forming sawpits in 
 the field. Ropes or chains would also be required for mov- 
 
PRACTICAL OPERATIONS OF A RIEGE. 53 
 
 ing the trees. Handspikes, rollers and wedges, may be cut 
 in the wood. If you should wish to raise your timber on 
 trestles in sawing it, in preference to making a pit, wo-inch 
 socket chisels and mallets, with half-inch spike bits, and spikes, 
 will be required for making the trestles, in addition to the 
 carpenter's tools before mentioned. 
 
 3. OF THE SMALL TIMBER, OR BRUSHWOOD, REQUIRED IN A 
 SIEGE OR CAMPAIGN. 
 
 A great number of fascines, gabions and pickets, are in- 
 dispensable in a siege, and are often necessary in field-works. 
 
 For this purpose, brushwood, not exceeding from one and 
 a half to two inches in diameter at the butt end, is most 
 suitable. The thicker pieces are usually called poles. The 
 smaller ones are called rods. 
 
 When brushwood is not to be had, branches of trees may 
 be used for the same purpose : and the pickets in particular 
 may always be split out of large timber. 
 
 4. TOOLS, ETC., REQUIRED FOR CUTTING BRUSHWOOD. 
 
 For this purpose no tool is so efficient as the hand-hatchet,* 
 with which the great body of men employed on this duty 
 ought to be supplied. A very small proportion (say one in 
 ten) of topping axes may be used for the larger poles, or 
 young trees, when such, are required. 
 
 A grindstone or rubstones, and ragstones or whetstones, 
 are, of course, absolutely necessary. 
 
 * Formerly a two-edged bill-hook was used in the service, calculated to 
 act both as a hand-hatchet and bill, or to chop as well as cut. Recently 
 this complex and loss efficient instrument has been abolished, and a bill- 
 hook of the Kentish pattern, a largo curved knife, with the edge on the 
 concave side, has been adopted in lieu of it. In making hurdles, wood- 
 men sometimes use a block-bill for capping pickets, which has a straight 
 edge, with a small hook at the back: but, bj a little management, the 
 common bill will chop as well as cut, and it is not worth while to use two 
 tools for military purposes. 
 
54: MANUAL FOK ENGINEER TROOPS. 
 
 RECAPITULATION OF TOOLS, ETC., FOR CUTTING BRUSH- 
 WOOD. 
 
 Bill-hooks. A grindstone. Ragstones or whetstones. 
 Topping axes. Rubstones. Gloves. Hatchets. 
 
 5. DETAIL OF MEN FOR CUTTING BRUSHWOOD. 
 
 When troops are ordered for this duty, it will be most 
 convenient to tell them off in divisions of twenty-five men 
 each. These must be subdivided into squads, in proportion 
 to the number of non-commissioned officers present, each of 
 whom will be responsible for the work of his own squ.-id, 
 but corporals, as rank and file, are not exempted from their 
 share of personal labor, unless it should be considered that 
 they may be more usefully employed in superintending. The 
 men must be drawn up in single rank, and in extended order, 
 not less than three yards apart ; and if there be not room for 
 the whole of the divisions employed, to work in one line, 
 they may either commence in several parallel lines, at inter- 
 vals of about thirty yards apart, or on different sides of the 
 wood. The brushwood must be made up into bundles, 
 loosely bound together by withes ; the size and weight of 
 each to be such as a man can conveniently carry to the rear. 
 In wood that has attained the proper age, a bundle may con- 
 tain from twenty to forty rods. The average weight of 
 those made by military working parties will scarcely exceed 
 forty pounds. On commencing the work, all the men should 
 cut ; afterward a few should be told off to bind and carry. 
 After the first day's work, the whole may be tasked to clear 
 a certain extent of ground. 
 
 If the men have to march^ur miles to the wood, a task 
 involving five hours' labor onTne spot, will probably be suf- 
 ficient for each relief or party of men. If the wood should 
 be nearer to the camp, their task may be increased. 
 
PRACTICAL OPERATIONS OF A SIEGE. 55 
 
 II. Rules for Making Fascines. 
 
 6. FASCIXES DESCRIBED. 
 
 FASCINES are a superior kind of fagot, which being built 
 in courses, with a moderate slope, and secured by pickets 
 driven into an earthen parapet, form a revetment useful in 
 field-works. 
 
 A Fascine, when the term is used without further speci- 
 fication, implies one about eighteen feet long and nine inches 
 in diameter, such as is used in reveting batteries, &c., and 
 which can be cut to any shorter length, as may be required, 
 during the execution of the field-work in which it is used. 
 To make fascines thicker than the above dimension would 
 be a waste of materials. 
 
 Trench Fascines, six feet long, are used for crowning a line 
 of gabions in a sap. These are formed by merely sawing the 
 common long fascine, or Battery Fascine, into three parts. 
 
 In like manner, nine-feet fascines, which are useful for cover- 
 ing blinded galleries, and for other purposes, are formed by 
 sawing the common long fascine into two equal parts. 
 
 7. DETAIL Or MEN. 
 
 The men employed in making fascines must be divided 
 into squads of five men each, besides which there must be 
 spare men in the proportion of one to every three or four 
 squads, to prepare pickets. One private in each squad is 
 appointed to direct, but not without taking his share of the 
 labor. One non-commissioned officer has the charge of sev- 
 eral squads. 
 
 8. TOOLS, ETC., FOR EACH SQUAD. 
 
 ' 5 Pairs of stakes for trestles, or more if the brushwood 
 
 be bad. 
 
 5 Lashings, or withes, for ditto. 
 1 Fascine choker. 1 Fid of hard wood, 
 
1 Bill-hook, 
 
 each man. 
 
 56 MANUAL FOR ENGINEER TROOPS. 
 
 1 Maul. 1 Six-feet rod. 
 
 1 Handsaw. 1 Gauge for the bands. 
 
 8 Bill-hooks, ) at the rate of one cutting tool per 
 
 2 Gabion knives, ) man. 
 
 For the spare Men making Pickets. 
 
 1 Chopping block, j" 
 
 For several Squads. 
 
 1 Grindstone, or several rubstones. 
 
 Ragstones, or whetstones. 
 
 REMARKS. The size of the common handsaw is con- 
 venient, but its teeth are rather too large for sawing brush- 
 wood expeditiously. If regular six-feet rods cannot be is- 
 sued to every squad, let a rod eight feet long, cut out of the 
 brushwood, be used as a measure for each squad that is de- 
 ficient. Two lengths of this rod will mark the distance 
 between the extreme trestles. The fids of hard wood should 
 be about nine inches long, one inch in diameter, and pointed 
 at one end. The gauges are pieces of wood about fifteen 
 and a half inches long, also cut out of the brushwood. 
 Chopping blocks it is needless to describe ; but if large tim- 
 ber is not to be had, stout stakes driven into the ground, 
 and standing about two feet above the surface, will answer 
 the purpose. If a lower block be used, the man must work 
 kneeling. 
 
 9. METHOD OF PREPARING FASCINE TRESTLES. 
 
 Fascines are made in a cra- 
 dle composed of a certain 
 number of trestles, placed at 
 intervals not exceeding four 
 feet apart. 
 
 Each trestle consists of a 
 couple of stakes about six 
 and a half feet long, and not 
 
PRACTICAL OPERATIONS OF A SIEOE. 57 
 
 less than from two and a half to three inches in diam- 
 eter, driven obliquely into the ground, touching each other, 
 and crossing at right angles, or nearly so, in the form of 
 a St. Andrew's cross. The upper part of the cross should 
 stand at the perpendicular height of about two feet six 
 inches above the ground, with the ends of the stakes pro- 
 jecting obliquely about two feet beyond it, as in the forego- 
 ing figure. 
 
 At the centre of the cross, the trestle may be secured by 
 a lashing six feet long, consisting of a piece of spun-yarn 
 or tarred line, of the size of tracing line, or a very little 
 larger. This is done by applying the middle of the lashing 
 to the two stakes, and passing the ends 
 horizontally round both until some three or 
 four turns are taken. The ends are then 
 crossed vertically round the centre of 
 those turns, in the space between the 
 two stakes, and hauled taut; and after 
 taking two or three turns in this new di- 
 rection, as shown in the annexed figure, 
 the ends are tied together with a reef- 
 knot. The turns last taken are techni- 
 cally termed flapping turns, and by straining the first part 
 of the lashing, keep every thing tight. A withe or twisted 
 rod may answer the same purpose when lashings cannot be 
 procured. 
 
 When one trestle is thus fixed, another is always placed 
 at the distance of sixteen feet from it. The intermediate 
 trestles, which may be three in number when the brushwood 
 is good, making five in all, are then placed at equal intervals 
 of four feet apart, between these two. When the brush- 
 wood is bad, that interval will be too great, and therefore 
 six or even seven trestles may be used instead of five. The 
 head of the squad directs the placing of the trestles, assisted 
 by two men of his party, whilst the others collect brush- 
 3* 
 
58 MANUAL FOR ENGINEER TROOPS. 
 
 wood. After the first two trestles are properly fixed, he 
 aligns the others by the eye, looking along the upper side 
 of each stake, on the same principle as in profiling. 
 
 'REMARK. At this establishment we sometimes use stakes 
 of fir, of regular scantling, about two and a quarter by three 
 inches square, shod at bottom and hooped at top with iron, 
 like small piles, and connecting each pair by an oak pin pass- 
 ing through holes cut for the purpose in the centre of the 
 cross. Although these make very good fascine trestles, one 
 would scarcely recommend using them on service. 
 
 10. FASCINE MAKING DESCRIBED. 
 
 When the trestles are fixed, straight rods and branches, 
 not exceeding about one and three-quarter inches in diame- 
 ter, are laid over them, with their ends projecting about sev- 
 enteen or eighteen inches on each side, beyond the extreme 
 trestles. The leaves must be stripped off entirely, as well as 
 the refuse ends of the thin branches. When the branches 
 grow out of the stem, with irregular or clumsy bondings, 
 they should be first separated by the bill-hook, as all very 
 crooked parts injure the fascine ; but straight and flex- 
 ible branches may be laid in along with the stem, cutting 
 them half through or not, as may appear necessary. The 
 men piling the brushwood should endeavor to lay the stout- 
 er rods outside, and the smaller stuff near the heart of the 
 bundle. When the cradle is nearly full of brushwood, it 
 will be time to prove the diameter of the proposed fascine, 
 in several places, which is done by the fascine choker ; and 
 more stuff is added in those parts which require it. The 
 fascine is then finished by binding it with withes prepared 
 for the purpose. This is done by four men, two of whom 
 choke, or compress the brushwood near the spot where the 
 other two bind. The first band is applied near the extreme 
 end of the fascine, about six inches from the first trestle. 
 The second is applied about fifteen and one-half inches from 
 
PRACTICAL OPERATIONS OF A SIEGE. 59 
 
 the first, and others are successively added at the same cen- 
 tral intervals, until the whole number of thirteen bands -are 
 completed. The fascine is then removed from the trestle, and 
 the rough ends sawed off. It is to be observed that these 
 ends should be laid as regular as possible in piling the brush- 
 wood, and no more should be cut away than is necessary, al- 
 though the length of the finished fascine should, in this case, 
 prove to exceed the standard of eighteen feet. In regulating 
 the central distance from band to band, the gauge-rod is used 
 as a measure. If the brushwood be very bad, or withes of the 
 desirable length cannot be obtained, the intervals may be 
 diminished to twelve inches, which will increase the num- 
 ber of bands to seventeen, and in this case a twelve-inch 
 gauge must of course be used. 
 
 Strictly speaking, four men are sufficient for making a fas- 
 cine, when all the materials are at hand, but the fifth may be 
 usefully employed in preparing withes, which is the most 
 difficult part of the work. 
 
 11. METHOD OF PREPARING AND USING THE WITHES. 
 
 For Withes (or Gads as they are also called) to bind fas- 
 cines, very straight rods must be selected, which when after- 
 ward cut to the proper length of about five feet, should not 
 be less than about three-eighths of an inch in diam- 
 eter, nor greater, if possible, than about three-fourths 
 or seven-eighths of an inch at the big end. In choos- 
 ing them, therefore, let no part be smaller than your 
 little finger, or much thicker than your thumb. All 
 the small branches must be lopped off, not close to, 
 or cutting in upon the stem, but so as to leave a 
 small stump projecting about one-eighth of an inch 
 above it ; otherwise the rod will be liable to break 
 at each knot. 
 
 In preparing them for use, you must put the thick 
 end under your left foot, and twist the rod with 
 
60 MANUAL FOR ENGINEER TROOPS. 
 
 your hands, from the top downward, with your right hand 
 toward the end of the rod, which you will move in the 
 same manner, nearly, as if working at a winch, so as to turn 
 the rod in the direction technically called " with the sun.'** 
 Great care must be taken to avoid making kinks in the 
 wood, which unpractised persons are apt to do,^as these 
 spoil the withe. 
 
 After the rod is well twisted at the small end, and mod- 
 erately so downward, you will form a loop about nine inches 
 long, near the small end of it, by taking a half-hitch with 
 the end of the rod round the. body, or standing part of it, 
 as in the foregoing figure. 
 
 You wih 1 then give the loop a couple of twists 
 in the contrary direction, so as to plait the double 
 part of the rod, and form an eye, or smaller loop 
 at the top o/ it, as in the second annexed figure. 
 At the part where this eye is formed, the rod should 
 not be less than half an inch in diameter. 
 
 Lastly, the end of the rod must be pointed, after 
 which it will be ready for the use of the fascine ma- 
 kers. In this state it should be at least four feet 
 long, which, after preparing one or two, a man may 
 easily judge of by the eye. 
 In binding the fascine, two men assist, standing on oppo- 
 site sides. They pass the withe under the brushwood, then 
 bring the ends together above it, and pass the big end of the 
 rod through the eye. One man sets his foot upon the eye, 
 and forces it home, it being at this time some inches lower 
 than the top of the fascine. At the same time he hauls upon 
 the end of the rod, turning it with his hands, until the part 
 within the eye is more completely twisted, but, of course, 
 in the same direction of the fibres as before. He then hands 
 * ""With the sun," and "against the sun," are in reference to the appa- 
 rent motion of the sun, as observed by a man standing in the northern 
 hemisphere and looking toward the south. 
 
PRACTICAL OPERATIONS OF A SIEGE. 61 
 
 over the end of the rod thus twisted to his comrade, who 
 bends it back, so as to form a, new loop engaged within the 
 former, like two links of a chain, after which he (the second 
 man) passes the end of the rod from 
 left to right, under the standing part on 
 his own side, over it again, and then 
 under it a second time ; whilst the first 
 man assists with the fid, in disengaging 
 the standing part, which at this time 
 is, of course, jammed close to the body 
 of the fascine. After the second turn, 
 the superfluous part of the rod is cut 
 off; and then the two ends appear exactly alike, excepting 
 that the thicker part has not got a half-hitch at the extremity 
 of it, like the other part. The band when finished accord- 
 ing to this process, is represented in the foregoing figure, 
 in which the fascine supposed to be embraced by it, is 
 omitted. 
 
 12. METHOD OF CHOKING A FASCINE. < 
 
 The instrument called a fascine-choker, consists of a stout 
 chain, attached to a couple of ashen levers, each of which is 
 four feet long, and cut out of one and three-quarters by two- 
 inch scantling, the section of the wood being an oval. The 
 chain is four feet long, between the levers, which it embra- 
 ces by means of a couple of iron sockets. It is fixed at the 
 distance of eighteen inches from one end of each lever, from 
 whence they taper to both ends. There are two small rings 
 attached to the chain, one on each side of the centre, at the 
 distance of twenty-eight and two-sevenths inches apart, which 
 corresponds with the circumference of a nine-inch fascine. 
 In choking the bundle of brushwood, which is done by two 
 men standing on contrary sides of it, the centre of the chain 
 is first brought under the brushwood, and then the ends of 
 it, together with the levers, are brought over and crossed ; 
 
62 MANUAL FOE ENGINEER TROOPS. 
 
 the men handing over the opposite levers to each other, with 
 the long ends uppermost. 
 
 The levers and chain will then appear as in the annexed 
 figure, in which the chain is supposed to have made rather 
 more than one complete turn round the fascine. The small 
 rings are also represented, which do not yet meet, as the 
 chain is supposed to be slack. The short ends of the levers 
 press against the contrary sides of the fascine. Commen- 
 cing at this position, the two men press down the long ends 
 of their m spectivc levers, and thus by degrees tighten the 
 chain, until the brushwood is choked, or compressed into as 
 small a space as possible, when it assumes the form of a per- 
 fect circle, or nearly so. At this period the long ends of the 
 levers should be depressed below the horizontal line,* and 
 the two rings, which at first were several inches apart, 
 ought to meet at the top of the fascine. 
 
 * Hence, if fascines were made of different thicknesses, the length of 
 the chain of the fascine-choker used, should vary according to the diame- 
 ter of the proposed fascine. Five and a half times the diameter is a good 
 pi-oportion. 
 
PRACTICAL OPERATIONS OF A SIEGE. 63 
 
 As soon as each band is finished, the men employed in 
 choking disengage their levers and chain, and commence at a 
 new place. If any part of the fascine has been pinched in 
 choking, it may be turned over when finished, and the bands 
 or fascine beat with a picket, to render the latter quite cylin- 
 drical. 
 
 13. REMARKS* In making fascines, the officers and non- 
 commissioned officers superintending, must be very strict, 
 in regard to dimensions and neatness ; more especially in 
 seeing that the withes are properly selected, well twisted, 
 particularly at the eyes, and in every respect made accord- 
 ing to rule, for upon these, the strength of the fascine almost 
 entirely depends. * 
 
 When good withes cannot be had, spun-yarn may be used 
 in lieu of them, which must be cut into lengths of six; feet. 
 In binding with spun-yarn, the centre of the piece of rope is 
 laid upon the fascine, and the ends are passed under, so as 
 to make one complete round^ turn ; they are then hauled 
 taut, by the two binders pulling against each other ; after 
 which they are brought together at top, and crossed so as 
 to form the first part of a reef-knot. The two men again 
 haul taut, by pulling in contrary directions, after which one 
 man presses down the joint of the spun-yarn with his finger, 
 until the other has taken the necessary turns, for completing 
 
 * \Vo tried experiments with green willow cut a month before it was 
 used, to ascertain the strength of fascine bands of different kinds, by apply- 
 ing progressive weights, until the withes broke. Eyes formed according 
 to rule, at a part of the rod not exceeding half an inch in diameter, re- 
 quired an average weight of more than four cwt. to break them ; but in 
 some few instances, the standing part broke before the eye. Under the 
 supposition of sucli eyes being the weakest part, another method of forming 
 a fascine band was suggested, in which the thick end of the rod was not 
 ! through the eye, but round it, on the principle of what is called the 
 midshipman's hitch in knotting with ropes; but on trial the round turn 
 thus taken with the thick end, unexpectedly proved to be the weakest 
 part, and invariably broke under an average weight of two cwt. only. 
 
64 MANUAL FOB ENGINEER TROOPS. 
 
 the reef-knot. Thus the band passes twice round the fas- 
 cine, before the knot is tied. 
 
 If proper chokers are not to be had, a couple of stout 
 stakes, and a rope doubled by splicing, or rather by tying 
 the ends together, will answer the same purpose. The 
 length of the rope must be equal to that of the chain and 
 sockets, in lieu of which it serves. After the rope is passed 
 round the fascine, and crossed, the ends of the levers are 
 pushed through the bights of the rope, and the operation of 
 choking is then performed in the usual manner. 
 
 14. TIME REQUIRED FOE MAKING FASCINES, WEIGHTS, ETC. 
 
 Every squad of five men may finish fascines at the rate of 
 one in an hour, after a few days' practice.* The average 
 weight of an eighteen-feet fascine, is one and a quarter cwt, 
 or one hundred and forty pounds, after the wood has been 
 cut some weeks. 
 
 15. OF FASCINE PICKETS. 
 
 The men employed in cutting pickets must provide them 
 in the proportion of six or seven to each fascine, and should 
 make them up in bundles of twenty-five. They should not 
 be less than three feet six inches long, including the 
 points, but four feet is better. A sharp triangular 
 point is considered the best way of finishing the 
 picket, and this form penetrates a stout fascine 
 with great ease. The top should also be pointed, 
 but very obtusely, as in the annexed figure ; for if 
 it be cut perpendicularly across, so as to form a 
 plane surface, the picket will be liable to split, in driving. 
 All the branches must be cut off quite close to the stem. 
 Fascine pickets should not exceed one and three-quarter 
 
 * Expert men may make fascines much quicker when tasked, but it 
 would not be prudent to calculate on making greater progress, with the 
 common military working parties in a siege. 
 
PRACTICAL OPERATIONS OF A SIKGE. 65 
 
 inches in diameter at the thick end, but from one and a quar- 
 ter to one and a half inch is a better proportion. After a 
 little practice, a man's eye is the best guide for judging of 
 the proper thickness. When the stuff much exceeds two 
 inches in diameter, pickets must be formed by splitting it 
 into two or more parts, according to its size. 
 
 16. TIME REQUIRED FOR MAKING FASCINE PICKETS, 
 WEIGHT, ETC. 
 
 After a few days' practice, a man may cut and make up 
 fascine pickets into bundles, at the rate of. one bundle (or 
 twenty-five pickets) in an hour. 
 
 A couple of withes, or of pieces of spun-yarn, must be used 
 for binding each bundle. 
 
 The average weight of a bundle of well-sized pickets, 
 three and a half feet long, is about thirty pounds, after the 
 wood has been some weeks cut. 
 
 17. OF TRACING-FASCINES. 
 
 The tracing-fascines, five or six feet long, recommended 
 in all the elementary writers on the attack of fortresses, 
 being of no use whatever, except to measure the task of each 
 workman, in opening the .trenches in a siege ; and it beiog 
 evident, that almost every other mode of effecting this meas- 
 urement, that can be suggested, would be simpler than the 
 above, the use of tracing-fascines has been abolished ; they 
 were made four inches in diameter, in order to waste as little 
 brushwood as possible. 
 
 18. OF COVERING-FASCINES. 
 
 Covering-fascines are those made of stout picket stuff, not 
 less than one inch thick, without any mixture of sin nil brush- 
 wood. They may be used in place of planks for the super- 
 structure of wooden bridges ; and may also be used, if no 
 stout planks or spars are to be had, for the roofs of field 
 
66 MANUAL FOE ENGINEER TROOPS. 
 
 powder-magazines. They maybe made of the usual diame- 
 ter of nine inches. Their length will depend upon the special 
 purpose for which they are intended. The withes should be 
 particularly good.* 
 
 19. OP SAP FAGOTS. 
 
 A sap fagot is a short but very strong fascine, about 
 three feet long, and nine inches in diameter, composed also 
 of stout picket stuff; which may be used, instead of sand- 
 bags, for filling the interstices between the gabions, at the 
 head of a sap. One picket usually projects five or six inches 
 from the end of the sap fagot, and is driven into the ground 
 to keep it steady, when set upright, in which position it is 
 always placed. Sap fagots are also sometimes used for 
 filling the gabions themselves, to hasten the progress of a 
 sap, under peculiar* circumstances. 
 
 20. OF TRACING- PICKETS. 
 
 These are short pickets eighteen inches long, and about 
 one inch in diameter, which are useful in marking out the 
 details of field-works. When they are to be used in the 
 dark, the bark should previously be stripped of 
 
 They may be made rather more expeditiously than fascine 
 pickets, and should be tied up in bundles of twenty-five each. 
 Every bundle weighs about eight pounds when the wood is 
 dry. 
 
 * A covering-fascine, made of willow, twelve feet long and nine inches 
 diameter, was found by experiment to be equal to the calculated strength 
 of a piece of Riga fir, about two inches and nine-tenths square. Conse- 
 quently covering-fascines, although strong enough to bear the weight of 
 any military carriage or wagon, if supported by proper beams, not more 
 than four fe6t apart, are not quite so strong as common three-inch planks. 
 The strength of a common fascine of the same diameter, was about five- 
 eighths of that of the covering-fascine. 
 
PRACTICAL OPERATIONS OF A SIEGE. 67 
 
 III. Rules for flaking Gabions and Hurdles. 
 
 21. OF GABIONS. 
 
 Gabions are cylindrical hampers, open at top and bottom, 
 which, being filled with earth, form a revetment useful in 
 field- works, but more especially in a siege, in the construction 
 of batteries, and in the operations called the regular and 
 flying sap. 
 
 Light gabions are a species of basket-work,. and it requires 
 greater skill and care to make them than is necessary in 
 making heavier ones, which may be compared to hurdle 
 work. 
 
 22. DESCRIPTION AND DIMENSIONS OF GABIONS. 
 
 For many years past we have made all our gabions of the 
 same size, namely, two feet in exterior diameter, and two 
 feet nine inches high in the web, but averaging three feet in 
 height when used for the revetment of a trench or field- 
 work, in consequence of the projecting ends of the pickets. 
 Hence when the term GABION is used, without further specifi- 
 cation, it implies one of the above dimensions, and no other. 
 
 To make larger gabions than the above would be useless, 
 for we ascertained by repeated experiments, that two-feet 
 gabions formed as strong and durable a revetment as those 
 of greater diameter ; which result was the more conclusive, 
 having been contrary to our expectations ; and we also found 
 that there was no advantage in using smaller ones.* 
 
 The batteries being of greater importance than most of 
 the other works of a siege, it is proper to finish them in the 
 most substantial manner, and therefore we use the strongest 
 and heaviest gabions, made of the thickest brushwood, for 
 
 * At one time we used not only two-feet gabions, as above described, 
 but also twenty-one inch gabions. The latter, being employed exclusively 
 for tho regular sap, were called sap-gabions, to distinguish them. 
 
68 MANUAL FOR ENGINEER TROOPS. 
 
 this purpose. In other respects there is no difference be- 
 tween Battery- Gabions and Trench- Gabions. 
 
 23. BASKET-WORK DESCRIBED. 
 
 Before we describe the method of making gabions, a few 
 technical terms and observations on basket-work will be in- 
 troduced. 
 
 The upright parts are called Stakes or Pickets. The 
 'Wailing, or Web, is composed of Hods, the thick end of 
 which is the Butt, the small end is the Tip. It is a rule 
 that the rods shall always be a little smaller than the 
 pickets. 
 
 In working with a single rod, 
 which is called randing, an odd 
 number of pickets must always be 
 used. The rod is alternately passed 
 round one picket, and within the 
 next, and thus commencing at the 
 bottom, it goes round in a kind of 
 spiral, until the body of the basket 
 or gabion is finished, as in the annexed figure, which repre- 
 sents the plan of the commencement of the work, the pick- 
 ets being denoted by small circles. 
 
 Sometimes two or three rods are 
 worked round together, precisely in the 
 manner above described, and still using 
 an odd number of pickets. 
 
 This is called slueing. The appear- 
 ance of the work so finished is shown 
 in elevation, in the annexed figure. 
 
 Neither randing nor slueing ought 
 
 ever to be allowed in making gabions. They are both very 
 weak, especially the latter ; so that the strength of baskets 
 made in this manner, depends entirely upon the top and 
 bottom, which are always finished with greater care. 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 69 
 
 "Working with two rods together, when braided or plaited, 
 is called pairing. 
 
 In this case, the two rods are separated by one picket. 
 That which is to the rear is passed over the other rod, 
 round one picket, and within the next. The second rod, 
 which is now to the rear, is passed over the first rod, and 
 also round one picket, and within the next. 
 
 Thus the two rods cross each 
 other alternately, over and under, 
 as in the annexed figure. In this, 
 and in all the succeeding methods, 
 it is of no consequence whether the 
 number of pickets be odd or even.* 
 Working with more rods than 
 two is called waling. 
 
 In waling with three rods, they are first placed with the 
 butts inward, and tips outward, each being separated by one 
 picket, as in the annexed figure. Then the first rod, which is 
 to the rear, is passed over the other two rods, round two 
 pickets and within one. The second rod, which will then be 
 to the rear, is also passed over the other two rods, round 
 two pickets, and within one. The third rod is next treated 
 in the same manner. Hence each rod will alternately come 
 to the front in its turn, and they will always be separated 
 * This is the method usually practised in our service. 
 
70 MANUAL FOR ENG^EER TROOPS. 
 
 from each other by one picket, as in the second annexed 
 figure ; and thus in winding spirally round the pickets, the 
 rods will be braided into the form of a three-stranded rope. 
 
 Basket-makers sometimes wale also with four or five ro>l , 
 in a manner which I forlrear to describe, as it is not appli- 
 cable to military purposes.* 
 
 In passing a rod from the outside round the inside of any 
 picket, and out again, the basket-maker does not move it 
 all round by the top, in the way that an inexperienced per- 
 son would naturally do. Holding the rod in his left hand, 
 with the tip pointing upward, he passes the fore-finger and 
 thumb of his right hand into the inside of the gabion, be- 
 tween those two pickets, through which the end is to come 
 out, after making the required turn, and with these bent 
 backward, he grasps the middle of the rod, and pulls it out 
 with a jerk, between the said pickets. 
 
 In circular waling, the rods should always pass round 
 more pickets outside than inside.f In straight work, with 
 the same number of rods, this is not necessary. 
 
 When the rods for basket-work, or for withes, are to be 
 used any length of time after they have been cut, they must 
 previously be steeped in water to restore their flexibility^ 
 
 The only basket-maker's tool applicable to gabion making, 
 is the knife ; which, for gabions, ought to be like a stout 
 pruning-knife. The Iron, used by basket-makers for beat- 
 ing down their rods, may be superseded by a common picket, 
 and the Cleaver, a steel instrument for cleaving a rod into 
 
 * The best method for a young officer to learn waling, is to provide 
 some wires as pickets, which he may fix on a large pincushion, using 
 pieces of the small round cord called bobbin, as a substitute for the rods. 
 In this way very neat models of gabions may be made. 
 
 f Because it is desirable that the inside of a gabion, or basket, shall be 
 as nearly circular as possible. But if several pickets be passed inside by 
 each rod, the interior outline will assume the form of a small polygon. 
 
 J It has also been recommended to heat green withes over a fire, before 
 twisting them. 
 
PRACTICAL OPERATIONS OF A SIEGE. 71 
 
 three parts, may be dispensed with altogether ; for, in the 
 process of gabion making, if any of the rods should be con- 
 sidered too large, .it will be sufficient to split them into two 
 parts, instead of three, which may be done by the bill-hook. 
 
 24. DETAIL OF MEN FOR GABION MAKING. 
 
 The men employed in making gabions may be divided 
 into squads of three men each, of whom one prepares pick- 
 ets, rods and withes, whilst the others level the ground, and 
 afterward work at the gabion. In some cases two men may 
 suffice. One private has charge of each squad, under tho 
 non-commissioned officers, who superintend several. 
 
 25. TOOLS FOR EACH SQUAD. 
 
 1 Bill-hook. 
 
 2 Gabion knives. 
 
 1 Four-feet rod, or three sticks cut as gauges, one for 
 the height, and one for the diameter of the proposed 
 gabion, and one for the length of the pickets. 
 1 Chopping block, or stake. 
 1 Piece of line, about three feet long. 
 The following tools are useful when heavy gabions are to 
 be made, otherwise they may be dispensed with : 
 1 Handsaw.* 1 Mallet. 
 
 Implements for several squads. 
 1 Grindstone, or several rubstones. Whetstones. 
 When a party of men are sent to make gabions, pickaxes 
 and shovels should be taken to the ground, if necessary. 
 
 When wooden bottoms are used in gabion making, the 
 proportion is one per squad. 
 
 26. METHOD OF MAKING LIGHT GABIONS. 
 
 The pickets must be from three feet four to three feet six 
 
 * Even in making heavy gabions, the handsarw may be dispensed with, 
 if the men are expert at the bill-hook. 
 
72 MANUAL FOR ENGINEER TROOPS. 
 
 inches long ; and their proper thickness is from five-eighths 
 to seven-eighths of an inch. 
 
 The rods for the web should be from five-sixteenths or 
 three-eighths, to three-quarters of an inch in diameter. 
 Those for the withes should be a little thicker, and the most 
 perfect that can be selected. 
 
 The number of pickets used in working with brushwood 
 of the above description should not be less than fourteen. 
 
 Gabions are usually made by driving the pickets into the 
 ground, and therefore in hard or rocky soil small pits about 
 two and a half feet in diameter, and nine inches deep, must 
 be dug at proper intervals, and filled with loose earth, ex- 
 cluding stones and large gravel. 
 
 A circle of the proper diameter must then be traced, with 
 a piece of string made fast to two short pickets, one fixed 
 into the ground as a centre, the other moving round to mark 
 the circumference. 
 
 The diameter of the circle thus traced should be one inch 
 less than that of the proposed gabion. Hence the proper 
 radius for a two-feet gabion is eleven and a half inches. 
 
 When this is done, the circumference must be divided into 
 as many equal parts as there are pickets to be used in the 
 proposed gabion. When twelve pickets are to be used, the 
 best way is to divide it first into four equal parts, and af- 
 terward to subdivide these portions into three each. A 
 small piece of stick may be used as a measure. 
 
 All the pickets must next be driven, so 
 as to touch the internal circumference, as 
 shown in the annexed figure, and it is 
 proper to place them alternately with 
 the large and small ends upward. 
 
 The rods prepared for the web must be 
 entirely stripped of leaves and twigs ; no 
 part of any one single rod being used 
 double, although in joining a new rod to the tip of one that 
 
PRACTICAL OPERATIONS OF A SIEGE. 73 
 
 is coming to an end, these two may be laid together for a 
 few inches. 
 
 The most approved method of forming the web of light 
 gabions, is by waling with three rods, as described in the 
 foregoing observations; but it will be best not to place all 
 the butts, or thick ends, the same way. 
 
 If the stuff be larger than usual, pairing with two rods 
 may be allowed, but this method must be confined to the 
 body of the gabion only. Five or six inches of the bottom, 
 and as much of the top, must always be waled with three 
 rods. 
 
 Very thin short rods should not, in any case, be used at 
 the top or bottom of a gabion ; for, unless these portions of 
 the work are finished with more than usual care, they are 
 liable to separate from the remainder of the web, whilst the 
 gabions are carried or thrown about. These portions may 
 be formed of twisted withes, instead of common rods.* 
 
 In making the gabion, the web must continually be pressed 
 down with the foot or hand, or beat with a stout picket ; 
 and the greatest care must be taken to preserve the proper 
 diameter, for which purpose a couple of rods may be cut as 
 gauges, which may be placed transversely across the finished 
 part and inside of it, pressing against two opposite pairs of 
 pickets. 
 
 27. METHOD OF FINISHING GABIONS. 
 
 When the web is completed to the proper height of two 
 
 * Twisted withes, braided or plaited, are used in preference to common 
 rods, for all very open wicker-work, as they are less liable to separate from, 
 or slip up and down the pickets with which they are connected. In 
 gabions this is not absolutely necessary. 
 
 Iron wire may bo substituted for withes in the construction of fascines 
 and gabions. This material is superior both in strength and durability 
 to the withe. When used, a pair of pincers must be added to the list 
 of tools for each party. The wire should be annealed, by heating it rod- 
 hot. 
 
 4 
 
74: MANUAL FOR ENGINEER TROOPS. 
 
 feet nine inches, it must be bound from top to bottom, with 
 withes, previously well twisted, in four distinct places, and 
 these should be applied, so as to secure the ends of the ex- 
 treme rods, in preference to the middle of them. 
 
 The centre of the withe being laid over the top of the web, 
 the ends are passed through it, in contrary directions, a few 
 inches from the top ; near to each other, but not between 
 the same two rods. Two men haul upon them, till they are 
 quite taut. They then pass them again through the web, a 
 few inches lower down, in contrary directions, and haul taut 
 a second time ; and thus they proceed by double stitches, as 
 they may be called, like those of shoemakers, until the ends 
 of the withe arrive at the middle of the web. The gabion, 
 being thus secured by four withes from the top downward, 
 disposed at equal distances apart, is pulled out of the ground, 
 and turned upside down ; and an equal number of withes are 
 used, to bind the remaining part of the web, in the same 
 manner, so that the two sets of withes used shall meet, or 
 cross each other, about the centre of the gabion. The ends 
 must be neatly secured, but in what manner is of little con- 
 sequence. The stitches of these bands should be rather 
 close, but not so as to embrace fewer than two spirals, of 
 the original waling of the web. 
 
 Before the gabion is pulled out of the ground, the tops 
 of all the pickets must be cut off about an inch above the 
 web. This is usually done by a handsaw, but the expert 
 woodman cuts off the heads of pickets by his bill-hook, intro- 
 ducing a stout stake between two of the pickets, which he 
 uses as a movable chopping block, in striking at one of 
 the two. 
 
 After the gabion is turned upside down, the points which 
 originally stood in the ground may also be cut off, accord- 
 ing to the same rule, if judged necessary ; we always leave 
 them, which appears to be rather^ an advantage than other- 
 wise. 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 28. METHOD OF MAKING GABIONS OF VERY SMALL 
 BRUSHWOOD. 
 
 Lighter gabions than those described in the preceding 
 article are not to be recommended, otherwise than as a mat- 
 ter of necessity on service ; or of economy, where very small 
 brushwood is often used, in order that nothing may be 
 wasted. 
 
 For example, when none of the brushwood runs larger 
 than about five-eighths or three-quarters of an inch, the pick- 
 ets will not of course exceed from one-half to three-quarters 
 of an inch, and the tods may vary from one-quarter of an 
 inch, or even less, to about one-half, or at the utmost, five- 
 eighths of an inch. 
 
 In this case, the number of pickets used must be increased 
 from fourteen to sixteen, or even twenty, using the greatest 
 number to the smallest brushwood ; and the making of 
 gabions with such very light materials, requires more than 
 usual dexterity and attention. In other respects the method 
 is the same as in making the common gabion before de- 
 scribed. 
 
 In gabions made of very small brushwood, the ends of the 
 pickets should always be cut off, after drawing them out of 
 the ground ; otherwise they are liable to break. This is 
 done by the gabion knife, not by the saw or bill-hook. 
 
 After finishing one gabion, and drawing it out of the 
 ground, the same picket holes will answer for commencing 
 a second gabion, without describing a new circle. 
 
 29. OF WOODEN CIRCLES FOR GABION MAKING. 
 
 In making gabions, wooden circles are sometimes used, 
 consisting of plank leclged together so as to form a circle 
 like the head of a cask. Notches are cut on the circumfer- 
 ence to receive the stakes. The circle is laid on the ground, 
 the stakes driven around it and in the notches, the circle 
 
76 MANUAL FOR ENGINEER TROOPS. 
 
 raised a foot, and the stakes bound firmly into the notches by 
 means of a rope and rack-stick. The gabion is then wattled 
 above the circle, and withed, turned over the circle removed, 
 and the remaining portion wattled. I am informed that this 
 facilitates the operation, and saves time, when inexperienced 
 men are employed ; but I conceive that no extra implements 
 of this description that can possibly be dispensed with, ought 
 to be used on service. 
 
 30. METHOD OF MAKING GABIONS OF THICK BRUSHWOOD. 
 
 Sometimes thicker brushwood than usual must be em- 
 ployed for making gabions, as a matter of necessity. Some- 
 times stronger gabions may be desired for some special pur- 
 pose, such as reveting the embrasures of a battery, or for 
 the interior of a field powder-magazine, in which case the 
 thickest parts of the brushwood are selected. 
 
 The pickets for strong two-feet gabions, need not exceed 
 from seven-eighths to one inch, or, at the utmost, one and a 
 quarter inch in extreme thickness. The rods for the web 
 should not be less than one-half or five-eighths of an inch, 
 and need not exceed one inch in thickness, the best being 
 selected for the withes. 
 
 On account of the greater strength of the brushwood used, 
 the pickets may be reduced to eight or ten for gabions of 
 the above diameter ;* and the whole of the web may be 
 formed, by pairing with two rods only. In other respects, 
 the same method is followed, as in working with smaller 
 brushwood. 
 
 METHOD OF MAKING IRON GABIONS. 
 
 Describe a circle two feet in diameter on a wooden plat- 
 form. Divide the circumference into six or eight equal 
 
 * The proper number of pickets for gabions made of strong brushwood, 
 is in the proportion of one picket to every two and a half or three inches 
 of diameter. 
 
PRACTICAL OPERATIONS OF A SIEGE. 77 
 
 parts (half the number of stakes to be used in the gabion) ; 
 at each of these points insert wooden pins about five inches 
 long. Wrap the hoop iron tightly' around the pins, thus 
 forming a polygonal hoop. The point where this hoop is 
 to be riveted must be marked before it is removed from the 
 form, so that all the hoops may be of the same size. The 
 hoop is then punched and riveted. As the iron used is 
 usually one inch wide, thirty-three of these hoops will be re- 
 quired for a gabion. 
 
 The stakes are usually made from pine plank one inch 
 thick ; their cross section being a triangle, with three or four 
 inches base and one inch altitude. 
 
 This is the best form, although round stakes may be used. 
 
 To set up the gabion, place a 
 hoop on the ground, and a 
 second directly over it, the first 
 as represented by the dotted, 
 the second by the full lines in 
 the figure. Insert a stake in 
 each of the triangular spaces, 
 then place the remaining hoops 
 alternately over the first and 
 second. Drive nails in four of 
 the stakes over the exterior 
 hoops to keep them from coming off. This gabion is much 
 stronger and more durable than those made of brushwood, 
 and is peculiarly adapted to the construction of the cheeks 
 of embrasures, as it is not injured by the blast of the piece. 
 
 CORRUGATED IRON GABIONS. 
 
 For this purpose, the corrugated sheet should be six feet 
 long, thirty-three inches wide, and of iron weighing three- 
 quarters of a pound to the square foot. 
 
 The corrugations running transversely, the sheet is easily 
 bent into a cylindrical form, in which it is retained by two 
 
78 MANUAL FOE ENGINEER TROOPS. 
 
 clamps, the holes for which are punched near the corners ot 
 the sheet. 
 
 The chief advantage claimed for the corrugated over the 
 hoop gabion is, the readiness with which it can be put to- 
 gether on the field. It is also rather more portable, and 
 stakes are dispensed with ; but it is inferior to the latter in 
 stiffness. 
 
 31. TIME REQUIRED, WEIGHT, ETC. 
 
 The time required for making gabions, by common mili- 
 tary working parties, after some days' previous practice, may 
 safely be estimated as follows, observing that it increases in 
 direct proportion to the number of pickets and sniallness of 
 the rods used. 
 
 TIME. Three men will finish a gabion, with eight or ten. 
 pickets, and of large brushwood, in two hours: they will 
 finish a common gabion, of fourteen pickets, and of smaller 
 brushwood, in three hours ; but they cannot finish properly 
 a very light gabion, of from sixteen to twenty pickets, and 
 of the smallest brushwood that can be used, in less than from 
 four to five hours.* 
 
 WEIGHT. The average weight of gabions may be esti- 
 mated at thirty-six pounds, and they scarcely much exceed 
 forty pounds, even when made of large brushwood. 
 
 32. OF SAP-ROLLERS. 
 
 Finding, by experiment, that a stuffed gabion, six feet 
 long and four feet in diameter, if filled with small brush- 
 wood, was not musket-proof; but that, if filled with pickets, 
 it was perfectly unmanageable ; the sap roller was adopted 
 by us in preference. 
 
 The sap-roller is a hollow cylinder, formed by making 
 two concentric gabions, each six feet long, one of four feet 
 
 * In 1839, the men of tho eighth company, who had learned gabion 
 making the year before, finished their gabions in three and a half hours. 
 
PRACTICAL OPERATIONS OF A SIEGE. 79 
 
 in diameter, but the other about two feet six inches in diam 
 eter only, so as to leave a clear interval of nearly eight inches 
 all round between these two, which is afterward stuffed with 
 strong six-feet fascines of a diameter suited to the above in- 
 terval, and with rods not less than about one inch in thick- 
 ness. The larger gabion of these two should have more 
 than the usual number of withe-bands, in proportion to its 
 diameter. 
 
 As we found it difficult to procure pickets of brushwood 
 long enough, and at the same time perfectly straight, for our 
 sap-rollers, we have often used pickets split out of deal, and 
 about an inch by an inch and a half square. For the larger 
 gabion of the sap-roller, we generally used twenty such 
 pickets, and for the smaller gabion, fourteen. 
 
 Sap-rollers serve as a substitute for mantlets. In the 
 single sap one sap-roller is used. In the serpentine double 
 sap, two sap-rollers of the ordinary size are used, with one 
 of a smaller size. The latter may be only three and a half 
 feet long, and rather less than four feet in diameter. In the 
 direct double sap, three ordinary sap-rollers and two short 
 ones are required. 
 
 To prevent the sap-rollers from losing their shape, at one 
 time we introduced internal wheels made of plank ; but re- 
 cently we have adopted the simpler expedient of driving 
 three pairs of strong pickets, not less than about an inch and 
 a half thick, through the large sap-roller, and two pairs of 
 such pickets through the small one, arranging every two 
 pickets at right angles to each other, and cutting off the 
 ends flush with the external surface of the roller. 
 
 33. TIME, "WEIGHT, ETC. 
 
 To make the inner gabion of a large sap-roller requires 
 about six hours, and to make the outer one, nine hours ; to 
 which must be addad about two hours for stuffing and com- 
 bining them into a finished roller. 
 
80 MANUAL FOR ENGINEER TROOPS. 
 
 The average weight of the large sap-rollers now used by 
 us at this establishment, and stuffed with fascines and pickets, 
 is six and a quarter cwt. When the wood was green they 
 must have weighed more: and it must be evident that if 
 they were of any other form than round, such a weight 
 would be perfectly unmanageable. 
 
 The small, or rather the short sap-roller before described 
 may be finished in about two-thirds of the above time, and 
 weighs nearly two-thirds of the former; their respective 
 lengths being nearly as two to three, and all other particulars 
 the same. 
 
 34. OP HURDLES. 
 
 Hurdles consist of strong wicker-work, of a rectangular 
 form, and as they may occasionally be useful in a siege, the 
 mode of making them shall be described. 
 
 The best size for military purposes is six feet long, and 
 two feet nine inches high. The same kind of pickets will 
 therefore answer, as in making very strong gabions ; and, 
 generally speaking, the rods for hurdles should not be much 
 less than an inch in diameter. An even number of pickets 
 must always be used : and I consider ten a good proportion 
 for a six-feet hurdle, although the woodmen in this neigh- 
 borhood generally employ only eight for a hurdle of that 
 length.* 
 
 In preparing to make a hurdle, it is necessary to Describe 
 an arc of a circle on the ground, with a radius of about 
 eight feet, making the length of the arc six feet. This space 
 must be divided into nine equal parts. A picket is then 
 driven into the ground at each end of it, and others into 
 every intermediate point of division, making ten in all. 
 Then the watling is begun, on the same principle nearly as 
 
 * The hurdles made by the Kentish woodmen are either eight feet lonp, 
 with ten pickets, or six feet long, with eight pickfts, and are usually three 
 feet high. 
 
PRACTICAL OPERATIONS OF A SIEGE. 81 
 
 in gabion making, excepting that you do not work round a 
 circle, but in a continued line ; and therefore when you come 
 to one of the extreme pickets at either end, you must twist 
 part of your rod like a withe, and bend it round the picket, 
 after which you must work in the contrary direction. 
 ' The woodmen assert that hurdles intended to be straight 
 must always be made curved in the first instance, as above 
 directed, in order to prevent them from being crooked when 
 pulled out of the ground, which they say that those made 
 in a straight line invariably become. And in hurdle making 
 they use a wooden sleeper, moderately curved, with holes 
 for the pickets on its upper surface, which they lay flush 
 with the level of the ground; but it would not be worth 
 while to make use of such sleepers in the field. The an- 
 nexed figure is the plan of a hurdle made in a curve, accord- 
 ing to the above rule. 
 
 
 In commencing a hurdle, the men work from the bottom 
 upward, as in gabion making, but the first rod is not pressed 
 down close to the ground, excepting hi the centre. Both 
 its ends are raised about nine inches above the ground, and 
 there bent round the extreme pickets by twisting. Thus 
 the first rods used form an arc of a circle, concave on the 
 upper side. The second and third rods are bent round the 
 extreme pickets, as close to the ground as possible, at each 
 end of the hurdle, but in the centre they rise higher than 
 the first rods used ; and thus the first three or four rods, or 
 rather courses of rods, composing the web of the hurdle, 
 are interlaced in such a manner, by crossing each other tow- 
 ard the centre, as to prevent the separation of that part of 
 the web from the,pickets. 
 
 The ends of the rods are kept in their places, by pressing 
 4* 
 
82 MANUAL FOR ENGINEER TROOPS. 
 
 against a picket, which jams them, and they are cut off about 
 an inch in rear of it. It is not good workmnnship to com- 
 mence or finish with a rod, by cutting it ojf.in this manner, 
 close to either of the extreme pickets, as the twisted joint 
 formed by bending the middle of a rod round those pickets, 
 evidently gives greater firmness to the work. 
 
 After having commenced as described, the remainder of 
 the web is worked up in parallel horizontal courses, until it 
 reaches the top of the pickets; and at this part one or two 
 of the uppermost rods, after being twisted round the extreme 
 pickets, are passed diagonally downward in an oblique di- 
 rection, toward the centre of the hurdle, passing through 
 and between one or two of the pickets. This arrangement, 
 which is also sometimes adopted about half-way up, as v, vll 
 as at the top, prevents the upper part of the web from sep- 
 arating from the pickets. The annexed figure represents a 
 hurdle in elevation, just finished. 
 
 In making hurdles for civil purposes, it is usual to work 
 by randing, or with single rods only, for the thick brush- 
 wood generally used in this process is so stiff, that it requires 
 an effort to separate it from the pickets. But as military 
 hurdles would be exposed to greater strains than those used 
 in husbandry, it is better to pair the rods in making them, 
 which may either be done throughout the whole of the web, 
 
^ PRACTICAL OPERATIONS OF A SIEGE. 83 
 
 from the bottom upward, or at least for several courses at 
 the bottom, middle, and top ; for this undoubtedly gives 
 greater firmness to the work. But the precautions before 
 described for interlacing the lowest, and finishing the upper- 
 most courses of the web, render it unnecessary to use verti- 
 cal withes for binding it, as in gabion making.* 
 
 35. NUMBER OF MEN, TOOLS, TIME AND WEIGHT. 
 
 The men and tools to be nearly the same as for gabion 
 making, but with more bill-hooks and knives, and with a 
 line ten feet long. 
 
 The probable time for making a six-feet hurdle would be 
 about three hours ; I do not speak with certainty, having 
 made very few ; and it weighs about fifty pounds when the 
 wood is dry. 
 
 V. 
 
 IV. Rules for Tracing and Commencing the First 
 Parallel, and the Approaches Connected with it. 
 
 36. METHOD OP TRACING THE WORK. 
 
 In opening the trenches in a siege, the workmen should 
 be drawn up in single rank, and each ought to have a task 
 assigned him, which should be six feet in length. Hence if 
 the Hue marked out be divided into portions of fifty yards 
 each, a working party of twenty-five men may be allotted to 
 each portion. 
 
 The trenches in a siege are traced by pieces of white tape, 
 previously rolled up into balls, the above color being chosen 
 
 * The following method has been advantageously employed in construct- 
 ing hurdles, viz. : a stick about seven feet long and five inches hi diam- 
 eter is notched at intervals, corresponding with the spaces between the 
 hurdle stakes. This stick is laid on the ground, and the stakes driven op- 
 posite each notch ; it is then raised horizontally about eighteen inches, 
 and the stakes lashed firmly into the notches, and are thus retained iu 
 place, whilst the upper half is wattled. The hurdle is then reversed, the 
 stick removed and the remaining half finished. 
 
84: MANUAL FOE ENGINEER TROOPS. 
 
 as the most conspicuous by night. Each tape is one hundred 
 and fifty feet in length, and is marked at intervals of six feet 
 by pieces of the same sort of white tape sewed to it,* which 
 should not be less than six inches long ; besides which it has 
 a short piece of tracing line added at each end, for the pur- 
 pose of making it fast to the pickets or otherwise. 
 
 When the proposed trenches are extensive, they may be 
 traced in several portions, and by several engineer officers. 
 
 When two officers are employed in tracing a parallel, they 
 may commence from the same central point, and work out- 
 ward. The mode of proceeding is as follows : each officer 
 will draw up the sappers who are to assist him, in single 
 rank, and will number them from right to left. Every man 
 is to be prepared with a ball of tape, and a white picket. 
 One or two supernumerary men may act as orderlies ; a ser- 
 geant will assist. 
 
 In tracing part of a parallel, the officer, followed by his 
 party marching in file, will advance upon a point therein 
 previously fixed, where he will order the leading man to 
 halt, and will take his tape from him, and march on with it, 
 in the alignment of the proposed parallel, previously turn- 
 ing to the right or left, as may be necessary. The other 
 men will follow the officer. As soon as this tape is expend- 
 ed, the second tape-bearer will halt at the end of it, and 
 deliver over the end of his own tape to the officer, who will 
 march on with it as before, in continuation of the proposed 
 parallel. When this is expended, the third tape-bearer will 
 halt, and deliver the end of his own tape to the officer, who 
 will proceed in the same manner until all the tapes are ex- 
 pended. 
 
 The annexed figure represents this movement, in which 
 the party first advance upon the parallel, in the direction 
 A B, by filing in single rank. On arriving at the point B, 
 in the proposed parallel, they distribute themselves from 
 
 * This improvement was suggested by Captain Jebb, when adjutant. 
 
8765432 
 
 1 
 
 c 
 
 B 
 
 thence along the proper alignment B C, in regular 
 succession, and in extended order. The portion 
 of parallel represented in the figure is supposed *jj 
 to be four hundred yards in length, and to have * 
 been traced by eight tapes. In this operation every *A. 
 tape-bearer, after halting and delivering the end of 
 his tape to the officer, drops the ball on the ground, and lets 
 the tape slip through his fingers. Both parties must keep 
 the tape near to the ground in windy weather, and take care 
 that it be not pulled entirely away from the tape-bearer, 
 when nearly expended. The ends of adjoining tapes must 
 be tied together. Tffe tape-bearers, who are now to act as 
 markers, will place themselves on that side of the white line 
 which is nearest to the fortress, and will face toward the 
 point from which the tracing commenced, as soon as they 
 have taken post opposite to their respective marks ; and if 
 the ground be soft enough, they will fix their pickets into 
 it without knocking, and make fast the ends of the small 
 line to the pickets. They are not to move on any account, 
 before the working parties are properly distributed along 
 the whole line. 
 
 37. METHOD OP ARRANGING THE WORKING PARTY, AND 
 COMMENCING THE PARALLEL. 
 
 Whilst one engineer officer is tracing, another must direct 
 the working party, who will assemble at the engineers' de- 
 pot, at least one hour and a half before sunset, and form in 
 close column, of divisions of twenty-five men, drawn up in 
 single rank. 
 
 If the extension is to be made to the left of the first point 
 marked in the proposed parallel, the column must be drawn 
 
86 MANUAL FOR ENGINEER TROOPS. 
 
 up right in front ; but if the extension is to take place 
 to the right of that point, the column must be drawn up 
 left in front. Each division should be commanded by a 
 captain or lieutenant, assisted by a due proportion of offi- 
 cers and non-commissioned officers ; and every battalion 
 furnishing the working parties should also send superior 
 officers in proportion, one to command the whole, others to 
 superintend several divisions. 
 
 After having formed in single rank, a non-commissioned 
 officer or private of sappers, with a six-feet rod, will be 
 placed on the reverse flank of every division, who is after- 
 ward to assist in extending it ; and every man of the work- 
 ing party will now take up or receive a shovel, which he is 
 to carry in his right hand, and a pickaxe, which he must 
 carry in his left hand. 
 
 To expedite this arrangement, a fatigue party should pre- 
 viously lay out the tools in such order as to suit the column ; 
 the several sets of tools being placed in successive lines of 
 twenty-five pairs each, at the clear distance of about four 
 feet apart, so as to allow room for the men of each division, 
 when in single rank, to form in rear of their respective tools 
 for the purpose of taking them up. 
 
 The divisions of the working party, formed as above di- 
 rected, must be regularly numbered, and when all the men 
 are provided with tools, each division must successively be 
 marched off by files from its own right, if the column was 
 formed right in front, or from its own left, if the formation 
 was left in front. 
 
 Whilst this movement is in progress, the remaining divis- 
 ions are to wait until each preceding division has moved on 
 in the aforesaid order. As every division is successively 
 faced to the right or left, and put in motion, the sapper on 
 the reverse flank of it will lead. The engineer officer must 
 be at the head of the first division, to guide the working 
 party to that point in the parallel where the first marker is 
 
PRACTICAL OPERATIONS OF A SIEGE. 87 
 
 stationed, and from which the proposed extension is to be- 
 gin. On reaching this point, the whole of the working party 
 must be made to form line to the* left or right, in extended 
 order, in rear of the white tape, each man's place being regu- 
 lated by the non-commissioned officer or private of sappers 
 who marched with the division. In so doing, the sapper 
 will be in front of the white tape, that is to say, on that side 
 of it which is nearest to the fortress, and will see that the 
 first man of the working party grounds his shovel parallel 
 to and in rear of the tape, placing the centre of the shovel 
 opposite to the centre of the first six-feet portion marked 
 upon it. He will then see that the second man does the 
 same, opposite to the second six-feet portion of the tape, and 
 thus he will proceed until he shah 1 have arranged all the 
 twenty-five men of whom his division was composed ; who 
 will form up into their proper places behind the white tape, 
 in regular succession, each man marking the centre of his 
 own task by his shovel, when it comes to his turn. 
 
 The engineer officer superintending is to watch over the 
 whole of this measurement and extension with the greatest 
 care, in order to prevent confusion. He must not allow any 
 man of the working party to take post behind the white 
 tape, until the sapper is ready for him ; and he must also see 
 that the latter does not move on until each successive work- 
 111:111 is properly posted. 
 
 As soon as each workman has grounded his shovel in the 
 manner before directed, he must lay his pickaxe in rear of it, 
 and opposite to the centre of it, with the iron to the front, 
 lie will then sit or lie down behind his own tools, so as to 
 be in readiness for work, and waiting the order to begin, in 
 perfect silence. 
 
 The following figure shows the manner in which the tools 
 are arranged in rear of the white tape, which is represented 
 by a dotted line. The large dots show the marks upon the 
 tape by which the tasks of the workmen are regulated. 
 
88 MANUAL FOB ENGINEER TROOPS. 
 
 T T 'T T T 
 
 As soon as the last division is extended on the reverse 
 'flank of the whole line, the men belonging to it will be or- 
 dered to commence work, and this movement must imme- 
 diately be taken up by the other divisions with all possible 
 dispatch ; the commander of each, as well as the sappers 
 attached to it, being on the alert, to watch the movements 
 of the adjoining ones ; and every commander ordering his 
 own men to rise as soon as he observes the men of the next 
 party on his reverse flank in motion. 
 
 8765 48 21 
 
 a -. B 
 
 A 
 
 ""4 5"" 
 
 The annexed figure represents the opera- 
 tion that has been described. The working 
 party are supposed first to be formed in close 
 column in single rank, at A, right in front. 
 From thence they are supposed to move for- 
 ward by filing from the' right of divisions to 
 the point B, when the first division begins to 
 form up into line in extended order, in the 1 
 direction B C, marked by the white tape, 
 
 the other divisions successively wheeling to * 
 
 the left as they reach the point B, until it 
 also comes to their turn to form up in the same 7- ... 
 manner. Every division commences its for- 
 mation as soon as the head of it reaches its own marker. 
 In the figure the first two divisions are supposed to be prop- 
 erly formed: the third is represented in the act of forming. 
 The remaining divisions are coming up by files, in single 
 rank. 
 
PRACTICAL OPERATIONS OF A SIEGE. 89 
 
 If the working parties understand what they have to do, 
 the above extension may be executed with precision and 
 without hurry, at the rate of one division in a minute and 
 a quarter, or of one hundred men in five minutes. Thus it 
 will not require more than twenty minutes to extend four 
 hundred men. It is not desirable that a greater number 
 should be extended from the same point, in the same direc- 
 tion; but in extending from a central point, two distinct 
 working parties may be made to file up together, under two 
 different engineer officers, and in this case the total number 
 employed may be greater, and they will of course advance 
 in double files until they reach the point from whence the 
 extension is to take place. 
 
 It is to be remarked that the extension of the working 
 parties, after the tape is once laid down, is comparatively 
 easy, but that the proper tracing of an extensive parallel the 
 first night that the ground is to be broken before a fortress, 
 may be attended with very great difficulty, apd therefore 
 the officers who are ordered for tlu's duty cannot take too 
 many precautions to avoid error. 
 
 When the working party begins to break ground, each 
 man will seize his pickaxe and cut a hole in rear of and ex- 
 actly opposite to the centre of his own shovel, which he will 
 then take up, and throw the loosened earth over the white 
 tape, until the whole shall form a continued trench of the 
 dimensions prescribed for the first night's task in a siege, 
 which is usually three feet deep, and in that case should be 
 at least five feet wide, measuring from front to rear. The 
 original pickets, driven in to mark the task of every division, 
 should be carefully preserved ; and the officer of infantry 
 commanding it should be held responsible for finishing his 
 trench, according to the prescribed dimensions, throughout 
 the whole extent of the hundred and fifty feet thus marked 
 out. The field officer commanding the working party fur- 
 nished by each battalion, should enforce the proper execution 
 
90 MANUAL FOE ENGINEER TROOPS. 
 
 of the work laid out for the whole of the divisions under his 
 command, he himself being held responsible for the same by 
 the general officer on duty in the trenches. The engineers 
 superintending, and the sappers attached to divisions, will 
 only be responsible for tracing and directing the work, and 
 for measuring it when reported to be finished according to 
 order; but not for the diligence of the men, which must 
 entirely depend upon their own good-will and the zeal and 
 attention of their regimental officers. The sappers will assist 
 in working when they are not more usefully employed. 
 
 38. METHOD OF TRACING THE FIRST APPROACHES, OR THOSE 
 CONNECTED WITH THE FIRST PARALLEL. 
 
 In tracing approaches, the same principle must be acted 
 upon. One engineer officer must be employed to lay down 
 the white tape, and to arrange the markers. 
 
 When any of the angular points of the zigzags does- not 
 coincide with the end of a tape, a spare marker must be 
 placed there with three pickets, one of which he will plant 
 at the angle ; and in order to prevent the tape from moving, 
 it must be passed round this picket, or made fast to it, after 
 which he will cut off about fifteen feet of the tape, from the 
 head of the branch immediately in rear of the angle, and 
 extend-it in continuation of the adjoining branch in front of t 
 it produced toward the rear. The remaining pickets must 
 serve to mark the extremities of the ends of the tape after 
 the angular part has thus been cut.* 
 
 This arrangement, which is represented in the annexed 
 figure, serves to mark the returns, which are necessary at 
 all the angles of the zigzags. The dotted lines show the 
 first positions of the small portions of the tape, that are 
 afterward cut off and moved in the manner that has been 
 
 * In our practice at this establishment, the tapes are not to be cut, as on 
 service. 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 91 
 
 .described. The figures 1,1, rep- 
 resent the positions of the origi- 
 nal pickets, which mark the an- 
 gles. 2 and 3, are the pickets 
 afterward driven to mark the 
 extremities of the branches, after 
 the returns, 18, 13, shall have 
 been tracetl. 
 
 39. METHOD OF ARRANGING THE 
 WORKING PARTY, AND COMMEN- 
 CING THE FIRST APPROACHES. 
 
 Another engineer officer will 
 guide the men of the working 
 party, who will advance by files 
 in single rank, as before direct- 
 ed, until the head of the leading 
 division reaches the tail of the 
 proposed approaches, on the re- 
 verse side of the white tape, that is, on the side farthest 
 from the fortress. The men will then be made to form up 
 in extended order, along the white tape, a non-commis- 
 sioned officer or private of sappers placing them as before 
 directed. 
 
 As soon as they reach the end of the first branch, which 
 is marked by the point 2 in the foregoing figure, the engi- 
 neer who superintends this measurement will lead the next 
 man to the extremity 3, of the return of the branch imme- 
 diately in front of it ; and will cause him and the men who 
 follow, to extend along the reverse side of the white tape, 
 which marks the second branch of the approaches, in the 
 same manner as before directed, but with this difference, 
 that if in extending along the first branch, they formed up 
 to their right, they must now necessarily form up to their 
 
92 MANUAL FOR ENGINEER TROOPS. 
 
 left, and vice versa; and at each succeeding angle of the 
 zigzags the formation must be reversed in the same man- 
 ner. 
 
 40. GENERAL REMARKS ON THE ABOVE OPERATIONS. 
 
 It appears essential toward the proper tracing of a first 
 parallel, that the front of attack of the fortress to be be- 
 sieged shall be well Veconnoitred beforehand, and the dis- 
 tances of certain points, from the most advanced works, ac- 
 curately ascertained, by day ; from which fixed points the 
 engineers who are to trace a parallel should measure for- 
 ward toward the place, until they reach the exact position 
 of the intended parallel, by means of a chain or tape, being 
 the most accurate method, and as expeditious as any other ; 
 unless they have confidence in their own accuracy of pacing. 
 If it be possible to obtain a correct plan of the place, it 
 will of course be of the greatest service, as fortresses are 
 usually surrounded by objects, such as roads intersecting 
 each other, buildings, &c., which cannot be destroyed in 
 such a manner but that traces marking their original posi- 
 tion must remain.* Whatever be the reputation of these 
 plans, they should however ^be verified by actual observa- 
 tion, instead of trusting to them implicitly. If correct, the 
 fixed objects before alluded to furnish the most satisfac- 
 tory data for determining, on the ground, the proper posi- 
 tion of the first parallel and of the approaches connected 
 with it. 
 
 It appears of the most essential importance, that the trac- 
 ing shall be executed before it is dark. Therefore unless 
 the night chosen for opening the trenches is foreseen to be 
 a moonlight night, it is absolutely necessary to commence 
 early, and to have the tracing finished before the end of 
 twilight. If there should be no moon, and a foggy or 
 
 * At the siege of Copenhagen, we obtained a Danish plan of extreme 
 accuracy. 
 
PRACTICAL OPERATIONS OF A SIEGE. 93 
 
 cloudy night, this operation may be attended with the 
 greatest difficulty and confusion, as has been found by ex- 
 perience. The arrangement of the men, on the contrary, as 
 was before observed, is by no means difficult, after once 
 the white line is marked on the ground ; that is to say, pro- 
 vided that they themselves are well inclined, and attentive 
 to the directions of the engineers. 
 
 As soon as the trench and parapet are well defined, which 
 will take place in about an hour after the work has been 
 commenced, the sappers should carefully roll up and take 
 care of the several tapes used in the tracing ; but the pick- 
 ets for marking out the work on the ground should not be 
 removed, and it would be useful for those sappers to pro- 
 vide themselves beforehand, with white banderols, or with 
 bundles of straw or other light-colored objects to be 
 used as such, which should be planted on the reverse of 
 the trench, opposite to the original boundary pickets, for 
 the purpose of preserving the task of each party perfectly 
 distinct in the dark ; and such marks would be very useful 
 even after daybreak. 
 
 41. METHOD OF COMMENCING THE TRACING OF A PARAL- 
 LEL BY THE COMPASS. PRECAUTION USEFUL IN A FOG. 
 
 As the bearing by qompass of an intended parallel may 
 always be ascertained beforehand, it appeared desirable to 
 use this instrument for the purpose of tracing in ^a dark 
 night ; but we had found by previous experience that the 
 common dark lantern could not be employed so as to give 
 light in this operation without being seen from the fortress. 
 Lieutenant Frome* therefore suggested a reading lantern, on 
 the principle of those used in observatories, which is repre- 
 sented in elevation and in section in the two figures an- 
 
 * Then superintendent of the Course of Surveying and Practical As- 
 tronomy, at the Royal Engineer establishment. 
 
MANUAL FOR ENGINEER TROOPS. 
 
 nexed, having air-holes at 
 top and bottom, screened 
 so as not to be seen from 
 the outside, and having 
 its lens inclosed in a tube, 
 which being first horizon- 
 tal and then bent vertical- 
 ly downward, with an ob- 
 lique reflector at the an- 
 gle, throws a strong circle 
 of light upon any object 
 placed below it. Thus the 
 officer in charge of the tracing is enabled to read the bear- 
 ing of a compass fixed in the middle of a six feet or ten feet 
 rod, which rod being thereby laid in the proper direction 
 of the proposed parallel, the white tape is applied to the 
 side of it, and thus the tracing is commenced, and may af- 
 terward be verified, from tune to time, so long as the direc- 
 tion is to remain unaltered, by applying the rod to the tape, 
 and again using the lantern, to see if the same bearing has 
 been preserved. The best sperm oil must be used. 
 
 It has also been found useful in a fog for the officer em- 
 ployed to place three men upon the tape facing toward him, 
 and at a short distance from each other, after he has com- 
 menced his tracing, and then to move on himself as long as 
 he can distinguish them clearly, taking care that he guides 
 his own movement by seeing that they always cover each 
 other. When this is no longer practicable he halts with his 
 foot on the tape, and causes them to advance toward him, 
 preserving their distance from each other, and not deviat- 
 ing from the tape, which will enable him to proceed again 
 with his tracing in the same manner, after the first man 
 shall have reached him. It may be advantageous to have 
 these men dressed in white. 
 
PRACTICAL OPERATIONS OF A SIEGE. 95 
 
 42. RULES FOR ARRANGING THE SECOND AND THIRD RE- 
 LIEFS OF WORKMEN, FOR A FIRST PARALLEL, AND THE 
 APPROACHES CONNECTED WITH IT. 
 
 The engineer will give directions, that after every party 
 of twenty-five men shall have finished their task, each indi- 
 vidual shall lay down his own shovel and pickaxe, close to- 
 gether, in rear of the spot where he worked, on the reverse 
 of the trench, and near to the brink of it. Thus the tools 
 being arranged by pairs, at intervals of six feet apart, or 
 nearly so, will save the trouble of marking out the tasks of in- 
 dividuals a second time. The sappers will take care to pre- 
 serve the original pickets at the end of every one hundred and 
 fifty feet, and if the tools should not be arranged quite regu- 
 larly, one of them, who is to remain on the spot, may employ 
 himself in laying them out better, whilst the other goes to 
 meet and conduct a new party to the same ground. 
 
 The second relief of men of the line will parade at the 
 engineers' depot, at such hour as may have been previously 
 fixed. There a part of the engineer oflicers on duty, and' 
 one sapper from each portion of the trenches, will be as- 
 sembled to receive them. The engineer will tell off one 
 sapper to each division of twenty-five men, as before ; and 
 the whole will be marched by divisions, the sapper of each 
 party leading it, until they reach the ground allotted for 
 the task of that party. 
 
 Preparatory to this arrangement, the several parties being 
 drawn up at the engineers' depot in column, let them be 
 numbered from rear to front, so that the rear division 
 shall now be No. 1, and the front division, if there be six- 
 teen in all, shall be No. 16. 
 
 In this order let them be made to file off, not in a body, 
 but by divisions, singly, and successively, with an interval 
 of some yards between the rear of one division and the 
 head of another, to prevent confusion ; and let each sap- 
 
96 MANUAL FOR ENGINEER TROOPS. 
 
 per, acting as guide, lead his division straight up to that 
 picket, which marks the extreme boundary of the task al- 
 lotted for it. The stationary sappers will remain at those 
 same pickets, ready to assist in distributing the workmen, 
 as soon as they shall arrive, and as the head of each division 
 approaches them, they will each call out their respective num- 
 bers, that the officer commanding the division, as well as 
 the sapper who acts as guide to it, may know whether it is 
 to be halted there or not; which halt will of course take 
 place, as soon as the number of the division shall corre- 
 spond with that announced by the stationary sapper. 
 
 When thus halted and fronted, which orders should be 
 given at the same time, the men of each division will be 
 made to extend over the whole space of fifty yards, allotted 
 as their respective task, by forming them in single rank, if 
 that should not have been done before, and by causing each 
 man, after facing the whole to the rear if necessary, to ex- 
 tend until every pair of tools laid out on the reverse of 
 the trench shall be covered by a workman. 
 
 In this second formation, each party of twenty-five men 
 will begin to work independently, as soon as they shall be ex- 
 tended on their own ground, without waiting for the others. 
 
 It may perhaps appear almost superfluous to observe, that 
 if there should be more reliefs than two required, to com- 
 plete the parallel, the third relief must be formed precisely 
 in the same manner that has just been described. 
 
 If, under peculiar circumstances, any strong reason should 
 exist against leaving the tools in the trenches, the stationary 
 sapper will have time enough to mark out each man's task 
 with tracing pickets, during the interval that must elapse 
 between the quitting of one relief and the arrival of the 
 next ; or, if such pickets are not at hand, the new working 
 party may be made to extend themselves between the ex- 
 treme points with sufficient accuracy, without subdividing 
 the space into six-feet portions at all. 
 
PRACTICAL OPERATIONS OF A SIEGE. 97 
 
 43. TIME OF PARADING THE SECOND AND THIRD RELIEFS OP 
 WORKMEN, FOR A FIRST PARALLEL, AND THE APPROACHES 
 CONNECTED WITH IT. 
 
 In opening the trenches it is absolutely necessary to com- 
 mence at dusk, as the men, having no cover, would be too 
 much exposed to the enemy's fire, if such a thing were at- 
 tempted by daylight. No such necessity, however, exists in 
 respect to the second relief of workmen. If therefore a 
 siege should be conducted, in any country, at a season when 
 the nights are ten hours long or upward, the second relief 
 should be ordered to parade at the engineers' depot, at 
 such time as will admit of all the necessary arrangements 
 being got through, just before daylight, in order that they 
 may commence filing into the trenches with the dawn ; for, 
 considering the number of men usually required at this pe- 
 riod, in a siege of any importance, and the great extent of 
 ground they are to cover, it appears next to impossible to 
 form the second relief of workmen properly in the dark. 
 Indeed the attempt might lead to inextricable confusion, and 
 it is altogether unnecessary; for after cover is once obtained, 
 the work of half a day, even in the short winter days of 
 temperate climates, is better than that of a whole night. 
 Let it therefore be laid down as a rule, that in the formation 
 of parallels and approaches, the second relief of workmen 
 shall never enter the trenches until at or after daybreak : 
 and that the third relief, when three are employed, shall 
 enter them at noon. 
 
 Hence, in the long summer days of northern climates, the 
 periods of relieving the working parties in the course of 
 every twenty-four hours, may always be at equal intervals of 
 eight hours, not otherwise. 
 5 
 
98 MANUAL FOE ENGINEER TEOOrS. 
 
 Y. Rules for Tracing and Commencing the Second 
 Parallel, and the Approaclie connected with 
 it, by the Flying Sap. 
 
 44. OF THE TRACING. 
 
 In commencing the second parallel, one engineer officer 
 must be employed in tracing each portion of it, and another 
 in arranging the workmen on the principle before explained 
 in treating of the first parallel; but there are several variations 
 in the details of the duty; and in the first place it may be 
 remarked that the tracing of the second parallel, and of the 
 approaches connected with it, is a much easier task than that 
 of the first parallel and its approaches. 
 
 For example, if we suppose the first parallel "finished, and 
 that the second parallel is to be established at any average 
 given distance in front of it, such as three hundred yards, it 
 is obvious that the engineers employed in tracing may mark 
 a certain number of equidistant points in the first parallel, at 
 any intervals apart they may judge most convenient, from 
 each of which they may sally out at dusk and measure three 
 hundred yards straight toward the fortress. This will give 
 them an equal number of points in the proposed second 
 parallel, from which they may detach tape-bearers to the 
 right and left, in sufficient number to overlap each other a 
 little when they go to the full extent of their tapes. If they 
 do not meet, let the officer superintending the tracing move 
 backward or forward, when arrived at the extremity of one 
 party thus detached, and he will be sure to find the end of 
 the corresponding tape, which was intended to have been 
 connected with it. Then let him cause one of the parties to 
 move their own tape forward, and the other to move their 
 tape backward, until they meet, and the error will be cor- 
 rected; and the tapes for marking the second parallel may 
 thus be laid out with sufficient accuracy for all practical 
 purposes. 
 
PRACTICAL OPERATIONS OF A SIEGE. 99 
 
 If the second parallel should not be intended to be exactly 
 parallel to the first, it will be obvious that it may be laid out 
 correctly enough, after consulting the plan of attack fixed 
 upon, by measuring unequal distances toward the fortress 
 instead of equal ones, from the points, of departure taken up 
 in the first parallel. 
 
 In pushing out approaches from a first parallel, the point 
 from whence any branch is to commence, as well as the 
 proper alignment of it, may be marked or ascertained in the 
 day time, and such approaches may be traced with white 
 tape at dusk, whilst it is too dark for the enemy to discover 
 this operation, but not dark enough to prevent persons out- 
 side from distinguishing the outline of the extreme works of 
 the fortress, from which the proposed approaches are to be 
 defiladed. 
 
 When the approaches are pushed forward in front of the 
 first parallel, as far as the intended position of the second 
 parallel, previously to the commencement of the latter, which 
 arrangement is very common in a siege, the tracing of the 
 second parallel is of course much facilitated. For in this 
 case all that is to be done will be to connect the heads of 
 the approaches with each other by a line of white tapes, the 
 proper direction of which may be ascertained beforehand, in 
 the day time. 
 
 45. OF ARRANGING THE WORKING 
 PARTY, AND COMMENCING A SECOND 
 PARALLEL BY THE FLYING SAP. 
 
 When a parallel is said to be com- 
 menced by sap, it merely implies that 
 gabions are used. The peculiar ar- 
 rangements and manner of working 
 with them described in this article 
 constitute what is called the FLYING 
 SAP. 
 
100 MANUAL FOE ENGINEER TROOPS. 
 
 The workmen ordered for the duty of commencing, or, as 
 it is also termed, of opening the second parallel, will parade 
 at the engineers' depot to receive their tools and gabions, in 
 divisions of twenty-five men, who must be formed in column 
 in single rank. 
 
 Every man is to carry a couple of two-feet gabions, hold- 
 ing them under his arms, by means of a picket two feet nine 
 inches long, driven transversely through each of them, about 
 fifteen inches from the top, which pickets he grasps in his 
 hands. 
 
 In one of these gabions he also carries a pickaxe, and in 
 the other a shovel, as shown in the foregoing figure. The 
 iron part of the shovel and likewise of the pickaxe, rest on 
 the top of their respective gabions, and are secured from 
 falling, by passing them beyond the picket ends, which pro- 
 ject above the web, whilst their helves hang down inside. 
 In carrying these tools in the gabions, they should be as 
 near to the man's sides as possible. The pickaxe may there- 
 fore come entirely under one of his arms, but the shovel 
 iron standing too high to be carried in this position, must 
 be a little to the rear of his other arm. The transverse pick- 
 ets must not be driven through the centre of each gabion, 
 but nearer to one side of it, namely, that which will touch 
 the man's thighs after he takes it up. (See the more correct 
 figure, afterward given in Article 53.). 
 
 The implements necessary for each division, consisting of 
 fifty gabions, with their transverse pickets, and a shovel and 
 pickaxe fixed in each alternate gabion, must be previously 
 laid out at the engineers' depot, in successive parallel lines, 
 at central intervals of about six feet apart, so as to suit the 
 formation of the column. The sappers employed in this duty 
 must be well acquainted with the proper mode of arranging 
 the pickets and tools, and strictly cautioned to do so with 
 the greatest care, for which purpose they should be on! 
 to lift up each pair of gabions in succession, by way of trial, 
 
PRACTICAL OPERATIONS OF A SIEGE. 101 
 
 after the pickets and tools shall be fixed, shifting them, ii 
 inconveniently placed. If the working party should be so 
 numerous as to occupy an inconveniently great extent ol 
 ground in this order, the depth of the column may be dimin- 
 ished, by laying out one hundred gabions in each parallel 
 line, in two portions of fifty gabions each, with an interval 
 of about ten feet in the centre, between each adjacent por- 
 tion. This arrangement will suit a working party drawn 
 up in grand divisions, instead of single divisions as before 
 explained. 
 
 After receiving their tools and gabions, the whole work- 
 ing party must advance by files, in single rank, to the point 
 from whence they are to extend ; on reaching which they 
 will be formed along the line of white tape, previously laid, 
 as before directed in Article 37, excepting that no marks on 
 the tape 'are necessary in the flying sap ; for the two gabions 
 carried by each workman measure his task. 
 
 As they come up into their proper places on the reverse 
 side of the white tape, the men will successively put down 
 their gabions close together in front of the line, so as to clear 
 it by two or three inches. 
 
 The sapper who assists in superintending the extension, is 
 to correct the position of every successive pair of gabions, 
 which it is difficult for the workman himself to place proper- 
 ly on setting them down. The engineer officer directing 
 will take care to enforce accuracy, and to prevent hurry and 
 confusion. As soon as each workman has got his gabions 
 placed by assistance of the sapper, he will disengage his 
 tools and pickets, as it is useless to waste the latter by 
 leaving them in the gabions. They may be laid down in 
 r-:ir of, and close to the gabions. The tools must be laid 
 down behind the two gabions, which mark each man's task, 
 in the manner before described in treating of the first 
 parallel. 
 
 The following figure represents this arrangement, showing 
 
102 MANUAL FOR ENGINEER TROOPS. 
 
 _| " V I u V 1 u y | u ^_J 
 
 T T T T T 
 
 the position in which the gabions and tools of five workmen 
 are placed, the former in front, the latter in rear of the white 
 tape. 
 
 Whilst the extension of the whole working party is thus' 
 going on progressively, the men first posted will sit doun 
 behind their own gabions and tools, as soon as the latter are 
 properly laid out, and will wait in perfect silence for the 
 order to commence work, which will be passed on from the 
 extreme points of the parallel, as soon as the whole opera- 
 tion shall be completed. 
 
 Every man will then commence digging in rear of his 
 own two gabions, which he will fill with all expedition, pat- 
 ting the earth well down before he throws any part of it 
 over. 
 
 46. OF TRACING AND COMMENCING APPROACHES BY THE 
 FLYING SAP. 
 
 The approaches in front of the second parallel, and some- 
 times even those immediately in rear of it, are commenced 
 by the flying sap. 
 
 The method of tracing them is precisely the same as if no 
 gabions were used, and has already been explained in Article 
 39. The method of extending the workmen, and of commen- 
 cing approaches by the flying sap, is the same as in commen- 
 cing the second parallel. 
 
 In tracing approaches, which are to be executed by the 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 103 
 
 flying sap, it is un- 
 necessary to cut the 
 tape for the purpose 
 of forming a return. 
 Instead of which, let 
 four pairs of gabions 
 be moved from the 
 head of each branch 
 adjoining to an angle, 
 and placed in prolon- 
 gation of the next 
 branch in front of it. 
 Thus, for example, 
 in the foregoing fig- 
 ure, if A B and B G 
 be the original form 
 of an angle of the zig- 
 zags, as traced by 
 the white tape, the 
 four pairs of gabions 
 originally placed at the head of the branch A B, are removed 
 from the position d B to B e, where they arc placed in pro. 
 longation of the advanced branch B C, produced toward the 
 rear, and thus they form the return, at the angle B. 
 
 47. OF THE PROPER TIME FOR PARADING THE SEVERAL RE- 
 LIEFS OF WORKMEN FOR THE SECOND PARALLEL, AND 
 THE APPROACHES CONNECTED WITH IT. 
 
 The proper periods for the relief of the workmen must be 
 regulated precisely on the same principle as those of the first 
 parallel. 
 
 I before named at least an hour and a half before sunset 
 as tin- parade time of the first relief at the engineers' depot. 
 Il is possible that the necessary arrangements may be made 
 in rattier less than this time, but I have doubts on the subject ; 
 
104 MANUAL FOR KXGTNEIOii TROOPS. 
 
 and one thing is certain, that it would be better for the work- 
 ing parties to be kept waiting an hour longer than the time 
 actually required in those preparations, than that they should 
 be ten minutes too late; for if the dark should surprise them 
 before the necessary arrangements are fully completed, the 
 whole night's work may be lost in a scene of inextricable 
 confusion.* 
 
 It is of the most essential importance that every thing 
 shall be completely prepared beforehand at the engineers' 
 depot, so that whatever materials and tools shall be as^i-m-d 
 to each individual of the working party to carry, shall be 
 put together and laid out for him, in good order, without 
 giving him any trouble in what belongs to arrangement. 
 Unless this system be adopted for facilitating the commence- 
 ment of the work, it might take the whole afternoon to get 
 through the preliminary arrangements. 
 
 For the reason before stated (Article 43), the formation 
 and distribution of the second relief of the working parties 
 of men employed in the execution of a second parallel, or 
 of the approaches connected with it, should not be attempted 
 till daylight, when it will be comparatively easy. 
 
 Let it be understood that the same necessity does not ex- 
 ist for waiting till daylight before the second relief are set 
 to work in the other operations of the siege, in which, when 
 the nature of them shall come to be explained, it will be 
 evident that there is much less risk of confusion, for the men 
 are either more concentrated on particular spots, as in the 
 construction of batteries, or more subdivided, at the same 
 time that fewer are employed, as in the execution of the 
 final operations of a siege, most of which are commenced 
 by the regular sap, or by mining. 
 
 * At the siege of Flushing, when I was the executive engineer on duty of 
 the first relief, with my brigade, a night's work of about five hundred men 
 was entirely thrown away from this cause, to my extreme mortification. 
 
PRACTICAL OPERATIONS OF A SIEGE. 105 
 
 48. REMARKS ON THE ABOVE ARRANGEMENTS FOR COM- 
 MENCING THE SECOND PARALLEL, ETC. 
 
 To carry two gabions, with their whole weight, as well as 
 that of the pickaxe and shovel, resting entirely on the hands, 
 may be acknowledged to be rather fatiguing, but there is no 
 means of obviating this inconvenience, except by having 
 shoulder boards and slings, such as are used with milk-pails. 
 But to provide such articles for so temporary a service as 
 the commencement of the second parallel, would not be 
 worth while; and therefore it is best that the working par- 
 ties employed in this operation should submit to the incon- 
 venience for a short time, which cannot bear hard upon 
 robust, able-bodied men like the British iniantry. 
 
 49. OBJECTIONS TO CROWDING THE WORKMEN IN COMMENCING 
 A SECOND PARALLEL. 
 
 If to consult the ease of the workmen in marching from 
 the depot of gabions to the position marked out for the 
 second parallel, each man should be required to carry one 
 gabion only, a much greater evil would follows As every 
 gabion in the flying sap occupies only two feet, it would be 
 absolutely impossible for the whole number of men who 
 carried the gabions to work together properly. Hence one- 
 half of them must either be sent back to the camp after having 
 deposited their gabions, or must get out of the way and re- 
 main idle, thus uselessly harassing or exposing to the ene- 
 my's fire double the number of men that can work to v ad- 
 vantage; for it has been found in field-works, whenever a 
 line of excavators has been crowded into a smaller space 
 than four feet per man, which we consider the minimum 
 pace that ought to be allowed, that instead of expediting 
 the work, it has retarded it; for, being in each other's way, 
 and in danger of being wounded by each other's tools, which 
 has occasionally happened even in working by daylight, :i 
 5* 
 
10G MANUAL FOR ENGINEER TROOPS. 
 
 part of the men have necessarily stood still, and much con- 
 fusion has ensued, which would of course have been con- 
 siderably aggravated had men thus crowded been employed 
 in the dark, and before an enemy. 
 
 50. MODE OF CARRYING ONE GABION ONLY, WITH TOOLS. 
 
 Excepting, however, those em- 
 ployed in the commencement of a 
 second parallel, or of the approaches 
 connected with it by the flying s:ij>, 
 who should carry two gabions, it 
 may not always be necessary to re- 
 quire the workmen in a siege to 
 carry more than one gabion with 
 their tools. In this case the gabion 
 is carried on the left shoulder, with 
 the pickaxe previously attached to 
 it in the manner before described; 
 or, for greater security, with the 
 point of the iron passed between two 
 parts of the web, near the top of the 
 
 gabion, which must always be to the Year; for this being 
 naturally carried a little higher than the front, prevents the 
 pickaxe from dropping out. The shovel is carried in the 
 right hand, at the trail, with the iron to the front, as shown 
 in the foregoing figure. 
 
 VI. Of Arming the Working Parties in si Siege. 
 
 51. WHETHER WORKING PARTIES IN A SIEGE SHOULD BE 
 
 ARMED OR NOT. 
 
 It appears to me that the working parties employed in 
 opening the trenches on the first night of a siege, ought not 
 to carry their arms with them. They must necessarily bo 
 
PRACTICAL OPERATIONS OF A SIEGE. 107 
 
 protected by strong covering parties, destined for the special 
 duty of repulsing sorties. To call upon the working parties 
 also to assist in this service, would only create confusion 
 without adequate benefit; for they are spread over so great an 
 extent of ground, that they could scarcely collect their arms, 
 and form in sufficient time to be of much use ; and if once 
 formed as a military body, no more work could be expected 
 from them. In the event of sorties, therefore, they should 
 remain at their post, if sufficiently protected by the covering 
 parties. If not, let them be ordered to take up their tools, 
 form by divisions, and in that order file independently to the 
 rear, each division being always collected as an organized 
 body, under its own officers, ready to return to its post in 
 the trenches, on receiving orders to that cllirt. 
 
 This remark applies chiefly to the first parallel, and to the 
 approaches in rear of or near to it. But when the operations 
 are more advanced, as in the second parallel, and in other 
 parts usually commenced by the flying sap, the working par- 
 ties being now much nearer'to the fortress, may be allowed 
 to take their arms in order to give them confidence ; but 
 they should carry the musket and bayonet only, without ac- 
 coutrements, because it is impossible for men to work with 
 their accoutrements on ; and if they take them off, they 
 could not put them on again and adjust them in proper time, 
 in the event of a sudden sortie; besides which, the men of 
 the working parties, if provided with accoutrements, could 
 not be distinguished from the guards of the trenches ; and 
 thris lazy or ill-disposed individuals might often have an op- 
 portunity of skulking from their work for a great part of the 
 niu'lit, without detection. The working parties when armed 
 should therefore only carry a few ball cartridges in their 
 pockets or foraging caps, and they should not even be al- 
 lowed to take their bayonet scabbards with them, which 
 might be liable to be lost. 
 
108 MANUAL FOR ENGINEER TROOPS. 
 
 52. METHOD OF ARRANGING WORKING PARTIES WITH ARMS, 
 WHEN THEY COMMENCE A PARALLEL OR APPROACH WITH- 
 OUT GABIONS. 
 
 In all cases when working parties are to carry their arms, 
 they should sling them behind their backs, after the fashion 
 of the old British grenadiers, that is, with the sling all to 
 the front of the body over the right shoulder, and under the 
 left arm, and with the firelock behind, the butt downward* 
 and muzzle upward ; and as accoutrements are not to be 
 carried, the bayonet should previously be fixed in reverse, 
 or pointing downward. In this order they will march to 
 the engineers' depot and receive their tools, which they will 
 be able to carry with ease, as both their hands are at liberty. 
 As soon as the extension shall r/e made behind the line of 
 white tape, which must be done precisely in the same man- 
 ner, whether arms are carried or not, and which was befo're 
 described in Articles 37 and 38, each workman, after laying 
 down his tools in their proper position behind the white tape, 
 will unsling his firelock, and fix his bayonet properly, and 
 afterward, when the ground behind him shall be clear, in 
 consequence of the remainder of the working party having 
 moved on. he will face about and march three full paces to 
 the rear, and ground his arms, in the manner shown in the 
 annexed figure, in which the dotted line represents so much 
 of the line of white tape as is sufficient to mark the ground 
 occupied by five workmen. 
 
 O=D O=o O=o O=^J O=-fl 
 
 T T T T T 
 
PRACTICAL OPERATIONS OF A SIEGE. 100 
 
 53. METHOD OF ARRANGING WORKING PARTIES WITH ARMS, 
 WHEN THEY ARE TO WORK AT A PARALLEL OR APPROACH, 
 COMMENCED BY THE FLYING SAP. 
 
 Case I. When the men are to 
 carry two gabions each, as well as 
 tools. 
 
 In this case the tools and gabions 
 are to be arranged beforehand, by 
 pairs, in the manner before de- 
 scribed in Article 45, a picket being 
 driven through each gabion to carry 
 it by. 
 
 The men of the working party, 
 having their arms slung behind 
 their backs, with bayonets fixed the 
 reverse way, will carry their gabions 
 and tools as shown in the annexed 
 
 figure, and they will place the former and lay down the lat- 
 ter, after being extended, in the manner explained in Article 
 45 ; and when this is done, each man will unsling his firelock 
 and fix his bayonet properly, and afterward ground his arms 
 three full paces in rear of his own tools, as directed in 
 Article 52. 
 
 Case II. When the men are to carry one gabion and 
 their tools, which applies only to the continuation of the 
 work. 
 
 The firelock will be slung and the bayonet fixed, as in 
 the two preceding articles, whilst the gabion and pickaxe 
 attached to it will be carried on the left shoulder, and the 
 shovel trailed in the right hand, as explained in Article 
 50. 
 
 54. FURTHER REMARKS ON THE ARMING OF WORKING 
 PARTIES. 
 
 It was before stated, that the working parties who open 
 
110 MANUAL FOE ENGINEER TROOPS. 
 
 the trenches on the first night of a siege, should not be 
 allowed to take their arms, considering the very extended 
 order in which they are formed for work, and also their dis- 
 tance from the fortress. It is to be remarked, however, 
 that the chief objection to taking their arms is the former 
 circumstance, of their being so much dispersed. But if a 
 greater number of men be concentrated on one spot, as in 
 the construction of large batteries, redoubts, or intrench- 
 ments, the working parties may be allowed to take their 
 arms ; for in this case a considerable body of men may be 
 speedily formed to repulse a sudden attack, who might after- 
 ward resume their work without much confusion, as they 
 would probably be able to maintain their ground, without 
 retiring to the rear. 
 
 The propriety of this arrangement will be obvious, by 
 considering that a ten-gun battery alone might give employ- 
 ment to nearly two hundred men, within a space of about 
 eighty yards, whereas in a first parallel the same number of 
 men would be spread over an extent of four hundred yards. 
 
 Even in this case, accoutrements and bayonet scabbards 
 ought not to be taken, for the reasons before assigned. 
 
 VII. Rulc for Executing tlie First Parallel, and 
 tiic Approaches Connected with it. 
 
 The methods of arranging and distributing the workmen, 
 in commencing the first and second parallels, and the ap- 
 proaches connected with them, in a siege, having now been 
 fully discussed, it remains to explain the nature and execu- 
 tion of those works in detail, which will form the subject of 
 the present and of the following section. 
 
 55. OF THE PROFILE PROPER FOR A FIRST PARALLEL.* 
 
 The profile usually adopted by us of late consists of a 
 
 * This profile is illustrated by the figure afterward given in Article 59. 
 
PRACTICAL OPERATIONS OF A SIEGE. Ill 
 
 trench eleven and a half feet wide at bottom, three feet deep 
 ill front, and three and a half feet in rear, with a reverse 
 slope having a base of three and a half feet, being equal to 
 its height, and with a step of made earth, one and a half 
 feet w r ide at bottom and one and a half feet high, added to 
 the front of the original trench when half finished, which 
 therefore reduces the net width of the sole of the trench 
 from eleven and a half to ten feet. 
 
 The earth of the trench, being thrown forward toward 
 the fortress attacked, forms the parapet of the parallel, 
 which is not rammed. 
 
 A berm of one and half feet is left between the front of 
 the trench and the base of the interior slope of the para- 
 pet, which serves as a banquette, to fire over the parapet, 
 which on being left to take its own form usually proves to 
 be about five feet high, after the trench is finished. The 
 inside of the parapet should then be smoothed, the berm 
 widened if necessary, and any unseemly irregularity in the 
 height of the parapet should be removed, but it is not worth 
 while to cut it generally lower than the form which it may 
 naturally assume; and if therefore its height should be too 
 great to fire over conveniently, let a small narrow step be cut 
 on the interior slope a little higher than the berm, for a man 
 to stand upon whilst firing. 
 
 A regular banquette, like that of more permanent works, 
 is considered unnecessary. 
 
 56. GENERAL REMARKS ON THE TASKING OF MILITARY 
 WORKING PARTIES, IN THE FORMATION OF A FIRST PAR- 
 ALLEL. 
 
 By repeated experiments at Chatham, tried with the ut- 
 most care, it was found that a portion of parallel of the dimen- 
 sions above stated, which involves two hundred and sixty- 
 one cubic feet, or nine and two-thirds cubic yards of exca- 
 vation, may be completed in an average of five hours per 
 
112 MANUAL FOR ENGINEEK TEOOPS. 
 
 man, in soft soil, which requires little or no picking, and an 
 average of nine and a quarter hours per man, in hard soil. 
 
 The most difficult soil that we could possibly find in this 
 neighborhood, which consisted of a concretion of flint- 
 gravel, sand and clay, required an average often and a half 
 hours. In all those experiments, the task of each man was 
 two yards in length ; and we are of opinion, that a shorter 
 portion of trench work ought in no case to be allotted to 
 individual workmen, on the night of opening the trenches 
 in a siege. For, as was before observed, if men be crowded 
 in too small a space, they are liable to wound each other 
 with their pickaxes, and finding that they are in each other's 
 way, a part of them will be tempted to stand still ; and 
 thus by increasing their numbers beyond a certain propor- 
 tion, the casualties from the enemy's fire will of course be 
 increased, without obtaining a proportional increase in the 
 quantity of work performed. 
 
 The sappers employed in those experiments were gener- 
 ally artificers, not previously inured to labor, with the pick- 
 axe and shovel, until they joined this establishment, and 
 not by any means more robust men than the British infan- 
 try usually are. It is evident, that many intermediate qual- 
 ities of soil may occur on service, between the soft soil, which 
 required only an average of five hours' labor, and the very 
 hard soil, that required ten and a half; and of course, in 
 employing workmen of the same physical powers and dex- 
 terity, the time for completing a parallel might vary, between 
 the minimum average of five hours and the maximum of 
 ten and a half hours. In those experiments, the men were 
 tasked individually, and in all cases some got through their 
 task in nearly half the time of others ; but in the very worst 
 soil, the time of the slowest workman did not exceed thir- 
 teen and one quarter hours. 
 
 In tasking a working party of the line on service, the task 
 of fifty yards for each party of twenty-five men ought to be 
 
PRACTICAL OPERATIONS OF A 5IKGE. 113 
 
 general, not individual ; for although a good workman may 
 do twice as much as a bad one in the same time, yet if both 
 do their best, it will be no greater exertion to the one than 
 to the other ; and when a whole party of soldiers are jointly 
 responsible, they will scarcely allow any one man to evade 
 his due share of worfc. 
 
 57. FIRST TASK IN EXECUTING A FIKST PARALLEL BY 
 THREE RELIEFS. 
 
 Considering that the first relief of workmen are more har- 
 assed by preliminary arrangements than the others who 
 succeed them, whilst they cut their trench to the standard 
 length of six feet, let them make it three feet deep in front, 
 three feet three inches deep in rear, and five feet wide from 
 front to rear, as shown in the annexed figure. 
 
 The above will amount. to ninety-three and three-quarters 
 cubic feet, which is nearly but not quite equal to three and 
 a half cubic yards of excavation, which may be executed by 
 able-bodied men, with moderate exertion, in from one hour 
 and three-quarters to three hours and a half, or four hours 
 at the utmost. It really would be trifling with the service, 
 to allot a smaller task than the above to any set of men de- 
 serving of the name. 
 
 58. SECOND TASK IN EXECUTING A FIRST PARALLEL BY 
 THREE RELIEFS. 
 
 In this task, an equal number of men being employed at 
 the standard rate of six feet to each man, as before, let the 
 
MANUAL FOE ENGINEER TROOPS. 
 
 trench f>e widened by cutting it four feet six inches more to 
 the rear, which would make it nine feet six inches wide in all, 
 but for a step of eighteen inches in width in front of the 
 trench, which is formed by this set of men, and which re- 
 duces the net width of excavation at the sole of the trench, 
 to eight feet, as represented in the annexed figure. The 
 depth in rear must be increased to three feet five inches. 
 
 This task involves ninety cubic feet, or three and a half 
 yards of excavation, being a little less than the former, but 
 the distance to throw the earth is greater, and on the whole 
 it is somewhat more laborious than the former task, and is 
 made purposely so for the reason before implied, namely, 
 that the men of the second relief are exempted from those 
 preliminary arrangements that fall to the lot of the iirst 
 working party. 
 
 59. GENERAL DESCRIPTION OF THE THIRD TASK IN EXECUT- 
 ING A FIRST PARALLEL BY THREE RELIEFS. 
 
 In this task, an equal number of men being still employed, 
 at the standard rate of six feet to each man, as before, let 
 the trench be widened by cutting two feet more to the rear, 
 which will complete the sole of the trench, making it three 
 feet six inches in extreme depth. This being done, let the 
 reverse slope of the trench be formed at an angle of fort y- 
 five degrees, making the base of the slope throe feet six 
 inches, being equal to its depth. 
 
PKACTICAL OPERATIONS OF A SIEGE. 115 
 
 3'. 6" 
 
 The quantity of excavation in this task amounts to about 
 seventy-eight and a quarter cubic feet, which is equal to 
 two and eight-ninths cubic yards only, but owing to the 
 great distance that the earth must be thrown to clear the 
 parapet, which cannot be done at one heave, as in the first 
 task throughout, and in part of the second task, and owing also 
 to the necessity of causing this party to make a complete 
 finish of the work, by putting every thing in order, trim- 
 ming the parapet, widening the berm, forming a small step 
 as a banquette on a higher level if required, besides making 
 ools and drains to secure the trench against rain, as will 
 be described in the next article ; I conceive that this task 
 will probably require rather more time than either of the 
 two former tasks to bring it to a conclusion, but it is not a 
 more trying operation, as the men have the advantage of 
 being well covered when they begin. The foregoing figure 
 represents the profile of a finished parallel, such as has been 
 described. 
 
 CO. REMARKS ON PRESERVING THE TRENCHES DRY. THAT 
 THE WORK NECESSARY FOR EFFECTING THIS OBJECT MAY 
 SOMETIMES REQUIRE A SPECIAL WORKING PARTY. 
 
 A VI i en the ground is marshy, it must of course be exceed- 
 ingly difficult to preserve the trenches dry in a siege; but 
 when the evil only arises from heavy and continued rains, 
 the following measures must be adopted, in order to effect 
 that object. 
 
 Let drains be cut from the reverse of the trenches into all 
 
116 MANUAL FOR ENGINEER TROOPS. 
 
 valleys or hollows, which, by being on a lower level, can 
 carry off the water, and let cesspools of about two feet 
 square, and a foot or two lower than the sole of the trench, 
 be made in the reverse thereof, at intervals of about fifty 
 yards ; not however making such cesspools exactly equi-dis_ 
 tant, but in all low points, where the rain-water shows a ten. 
 dency to stagnate. They must be cut entirely in rear of the 
 trench, so as not to diminish its regular width, and the sides 
 sloped, if necessary, to prevent the earth from falling in. 
 
 Cesspools of this description will keep the trenches as dry 
 as can be expected ; but in excessive rains it may be neces- 
 sary to bale out the water occasionally, for which purpose 
 shovels will answer. 
 
 In short the rule to keep a trench dry in rainy weather 
 is, to take such measures as to prevent it from becoming 
 a drain to the neighboring ground which w r ould from time 
 to time convert it into the channel of a torrent. 
 
 Nothing therefore but the rain which falls vertically down 
 upon the trench itself should be admitted, and this surface 
 water, which cannot be excluded, will never annoy the troops 
 in any considerable degree, provided that the above men- 
 tioned precautions, of cutting cesspools at intervals and of 
 occasional baling, be resorted to. The rear of the sole of 
 the trench may also be cut in the form of a small drain, 
 from cesspool to cesspool. 
 
 The arrangements described in this article must generally 
 be made a part of the task of the third or last relief of 
 men, employed in finishing any portion of the trenches, ex- 
 cepting when necessity requires any part of them to be 
 can-lied into effect at an earlier period. The formation of a 
 drain leading into a valley may sometimes require a special 
 working party destined for this object exclusively. 
 
PRACTICAL OPERATIONS OF A SIEGE. 117 
 
 61. FURTHER REMARKS OX THE EXECUTION OF PARALLELS. 
 THAT EACH RELIEF OF WORKMEN SHOULD BE. ALLOWED 
 TO QUIT THE TRENCHES, ON FINISHING THEIR TASK TO 
 THE SATISFACTION OF THE ENGINEERS ON DUTY. 
 
 As a matter of mere labor, it would evidently be better 
 to cut the front step of the trench out of the solid ground, 
 instead of forming it afterward, with loose earth from the 
 rear ; but as the first working parties have to work in the 
 dark, often exposed and always expecting to be exposed to 
 fire, it is of importance to simplify their task as much as 
 possible, which cannot be more effectually done than by 
 the arrangement of leaving the step to be formed afterward, 
 by the second relief, who at this period will have the advan- 
 tage of working by daylight. 
 
 Sometimes we have formed our parallels, with a reverse 
 step, instead of a slope in rear, making this step eighteen 
 inches in width, and equal in height to one foot nine inches, 
 or to one half of the extreme depth of the trench, as shown 
 in the annexed figure. 
 
 This construction, which diminishes the labor of the third 
 task by twenty-one cubic feet, or seven-ninths of a cubic 
 yard, is quite as good as the former, excepting for the 
 passage of carriages, which enter into or issue out of a 
 trench, more conveniently by means of a slope, than by 
 steps. 
 
 When the working parties have a given task allotted to 
 each relief, which in the construction of parallels ai.d ap- 
 
118 MANUAL FOE ENGINEER TKOOPS. 
 
 preaches is the best arrangement, or rather indispensably 
 necessary ; each party of twenty-five men should be allowed 
 to quit the trenches as soon as they shall have finished their 
 task to the satisfaction of the engineer on duty, who must 
 of course previously ascertain this point by actual measure- 
 ment, in which he will be assisted by the sappers of the di- 
 vision ; and in so doing he should be very strict, rather 
 measuring over than under ; for as all the tasks are easy, it 
 would not be fair to throw any part of the labor of the 
 first upon the second, or of the second upon the third relief 
 of workmen. 
 
 In case of any gratuity being promised to the working 
 parties by the general commanding, for the execution of a 
 particular work, it should never be granted without. a cer- 
 tificate in writing from the engineer on duty in the trenches, 
 that they finished their task to his satisfaction.* 
 
 62. ON THE EXECUTION OF THE APPROACHES CONNECTED 
 WITH THE FIEST PARALLEL. 
 
 The rules for tracing the approaches connected with the 
 first parallel, and for commencing the work, have already 
 been explained. It now only remains to treat of the exe- 
 cution. 
 
 The profile of an approach so nearly resembles that of a 
 parallel, and the quantity of labor necessary for the com- 
 pletion of both differs so little, that, generally speaking, 
 the same rules as to the number of relief*, and the pro- 
 portioning of the task of each, may be followed in both 
 cases. 
 
 The only difference in the practice of this establishment 
 is, that we have made our approaches generally a little 
 deeper than our parallels, and we have usually made tlio 
 
 * This rule has generally been followed in our sieges, in which an extra 
 allowance of grog or wine has sometimes been ordered to each man of the- 
 military working parties as a gratuity. 
 
PRACTICAL OPERATIONS OF A 6IEGE. 119 
 
 front steps and berm narrower, a banquette not being so 
 essential in the former as in the latter. We have also 
 usually made the parapets of our approaches a little higher 
 than those of our parallels. 
 
 The reason is, that approaches, being laid out obliquely, 
 require more relief than a parallel, in order to enable them 
 to afford equal protection to the besiegers ; for in the for- 
 mer, a man in the trench is covered by a distant point of 
 the parapet, in an oblique direction, whereas, in the latter, 
 he is covered by that part of the parapet which is near to 
 and perpendicularly in front of him. 
 
 The subjoined figure represents the profile usually adopted 
 by us, in which the trench is eleven feet wide at bottom, 
 three feet six inches deep in front, and four feet deep in 
 rear. The berm and front step are only one foot wide. 
 The latter, instead of being formed with made earth, was 
 cut out of the solid. 
 
 In the above figure the tasks of the three reliefs, as repre- 
 sented by the Roman numerals, I, II, and III, are as follows : 
 
 Each task being six feet in length, the first relief are to 
 cut a trench (I) five feet wide, three feet six inches deep in 
 front, and three feet nine inches deep in rear, which involves 
 one hundred and eight and three-quarters cubic feet, or about 
 f"iir cubic yards of excavation. 
 
 The second relief are to cut the trench four feet six inches 
 wider, and two inches deeper in rear, which involves a task 
 
120 MANUAL FOB ENGINEER TROOPS. 
 
 (II) of ninety-nine cubic feet, being equal to three and two- 
 thirds cubic yards of excavation. 
 
 The third relief are to cut the trench one foot six inches 
 wider, and one inch deeper, which increases the total width 
 of the approach to eleven feet. They will then cut the re- 
 verse slope, giving to it a base of four feet, which is equal 
 to the extreme depth of the trench in rear. This being done, 
 they will cut the front step, making it one foot wide, and one 
 foot nine inches high, or one-half of the depth of the trench 
 in front. These three portions (each marked III, III, III,) 
 amount in all to eighty -five and three-eighths cubic feet, being 
 nearly three and one-sixth cubic yards of excavation. 
 
 The whole of these tasks added together involve two hun- 
 dred and ninety-three and one-eighth cubic feet, or very 
 nearly ten and five-sixths cubic yards of excavation. 
 
 Sometimes an approach is made with slopes only, without 
 having any steps in front, as shown in the annexed figure, 
 which arrangement, however, can make little or no difference 
 in the quantity of labor, or in the tasking of the men. 
 
 63. THAT ALL TRENCHES OR DITCHES SHOULD BE COMMENCED 
 BY VERTICAL EXCAVATIONS, FINISHING THE SLOPES LAST. 
 
 Whenever an approach is formed with slopes in front 
 and rear, as represented in the foregoing figure, the body 
 of the trench is completed first, and both the slopes are 
 cut afterward. And let it be understood that this is a 
 rule which we have invariably followed, not only in forming 
 the trenches of parallels and approaches, but in respect to 
 
PRACTICAL OPERATIONS OF A SIEGE. 121 
 
 the ditches of elevated batteries, and other excavations gen- 
 erally, in field fortification. We always commenced with 
 vertical cuts of .a rectangular section, until the great mass of 
 excavation was finished, doing the slopes last of all. In ex- 
 ecuting these, the crest of each slope should first be marked 
 out on the ground, after which small sections should be cut 
 here and there, according to the proper form of the finished 
 profile. Finally the intermediate earth should be cut away 
 between these small sections, which answer the same pur- 
 pose of insuring regularity in an excavation that wooden 
 profiles erected at intervals do in the' formation of a parapet. 
 If, on the contrary, the slopes be commenced from the first 
 without these precautions, the men will either lose time in 
 attempting accuracy, or will cut them at random, and there- 
 by either disfigure the work or injure its stability. 
 
 Till. Of the Execution of the Second Parallel, and 
 the Approachc connected with it. 
 
 64. RULES FOR EXECUTING A SECOND PARALLEL COMMENCED 
 BY THE FLYING SAP. 
 
 The method of arranging the workmen with their tools 
 behind the line of gabions, so that the space covered shall 
 be at the rate of two gabions, or about four feet per man, 
 has already been explained. In this order the men are rather 
 more crowded than one could desire, but the use of gabions, 
 the size of which is necessarily limited, leaves no alternative. 
 
 When the order is given to commence work, every man 
 will begin digging in the rear of his own two gabions, which 
 he will fill with all expedition, striking the sides of the gabions 
 from time to time with his shovel, and afterward patting 
 the earth at the top, to shake it down and make it compact, 
 before he throws any of it over. When filled, which may 
 be done by good workmen in from seven to fifteen minutes, 
 the line of gabions will be musket-proof everywhere, except- 
 6 
 
122 MANUAL FOR ENGINEER TROCXPS. 
 
 ing at the intervals between the adjacent ones. The engi- 
 neer officers superintending, and the sappers attached to 
 divisions, will take care to instruct the men to force their 
 gabions forward at top, whilst the work is in progress, in 
 order to give them a slope of about one-fourth of their height, 
 which is necessary to their stability, and which may be judged 
 of, with sufficient accuracy, by the eye. This arrangement 
 may be aided by introducing sods under the back of each 
 gabion. The usual berm of eighteen inches must be left be- 
 hind the line of gabions. 
 
 The parapet of a second parallel may be crowned with one 
 or more rows of fascines laid over the gabions, with which 
 it is reveted interiorly. In other respects it does not differ 
 from that of a first parallel, and the trenches of both are 
 exactly alike. 
 
 When fascines are used to crown the gabions in a second 
 parallel, which arrangement however can scarcely be neces- 
 sary under ordinary circumstances, the second and third re- 
 liefs of men ought to take them out with them, each man 
 carrying a six-feet fascine, and two or three pickets. If more 
 fascines and pickets should be required at this period, and 
 generally speaking on any other occasion, when the regular 
 working parties cannot carry a sufficient quantity of mate- 
 rials for their own use, the guards of the trenches may be 
 ordered to call at the engineers' depot for the purpose of re- 
 ceiving materials, which they will deposit on the reverse of 
 the trenches, in such situations as shall be deemed most con- 
 venient. 
 
 65. PECULIAR ARRANGEMENTS FOR CONTINUING AND FIN- 
 ISHING A SECOND PARALLEL, BY THE SECOND AND THIRD 
 RELIEFS OF WORKMEN, AT SIX RUNNING FEET OF TRENCH- 
 1TORK PER MAN. 
 
 Though the workmen who commence the second parallel 
 by tho flying sap, are extended at the rate of only four feet 
 
PRACTICAL OPERATIONS OF A SIEGE. 123 
 
 per man, the same necessity does not exist for thus crowd- 
 ing the workmen of the second and third reliefs, employed 
 in continuing and finishing the same parallel, who should 
 each be required to execute a task of six running feet per 
 man. IJence the number of workmen demanded for the 
 second and third reliefs should only be two-thirds of the 
 number previously employed in commencing the second 
 parallel. Owing to this change in the arrangements, the 
 workmen in the first relief, after finishing their task, must 
 carry all their tools back with them to the engineers' depot, 
 instead of leaving them in the parallel, as suggested in 
 Article 42, which applied to different circumstances. The 
 second relief must therefore bring their tools out with 
 them. 
 
 As the task of a division of twenty-five men is only one 
 hundred feet in commencing the second parallel, but is to 
 be increased to one hundred and fifty feet for the same 
 number of men of the second relief, it will be necessary pre- 
 viously to divide the whole extent of the parallel into spaces 
 of one hundred and fifty feet, which must be marked by 
 pickets or banderols, at their extremities, including seventy- 
 five gabions between each pair of such pickets. This must 
 be done by sappers tinder the direction of the engineers, 
 and when the space allotted for the task of each division of 
 the second relief is marked out, a sapper must be stationed 
 at each picket or banderol, on reaching whom each division 
 of the working party must be halted and fronted, in the 
 manner* before explained in Article 42. When this is done, 
 the men composing each division must be extended over 
 their respective spaces, until the whole of the gabions are 
 covered by a line of men posted behind every third gabion, 
 placing the first man behind the second gabion, the second 
 man behind the fifth, the third behind the eighth, and so on 
 until the whole extension is completed* Every man will 
 then be set to work, each preserving his proper place, and 
 
124: MANUAL FOR ENGINEER TROOPS. 
 
 continuing the excavation of the trench to the rear, along 
 the whole space occupied by his own three gabions. 
 
 If the commanding engineer should deem it convenient, 
 the men of the second relief, before they quit the trenches, 
 may be directed to leave their tools behind every third ga- 
 bion, to mark the proper position and at the same time the 
 extent of task of the men of the third relief, who are to 
 work in equal numbers along the same extent of ground, 
 and may use the same tools. 
 
 The annexed figure is a section of a second parallel, fin- 
 ished with gabions only, not crowned by fascines, in which 
 the tasks of the three reliefs are marked by the Roman 
 numerals, I, II, III. 
 
 The task of the first relief includes also the excavation of 
 the space now occupied by the front step, which is sup- 
 posed to have been added afterward by the second relief. 
 The clear width at the sole of the trench is supposed to be 
 ten feet, being the same as in the first parallel, with which 
 it likewise agrees in all its other dimensions, as was before 
 stated. 
 
 66. STATEMENT, BOTH IN CUBIC FEET AND IN CUBIC YARDS, 
 OF THE QUANTITY OF EXCAVATION IN A FIRST PARALLEL, 
 FINISHED IN THREE TASKS, AT SIX RUNNING FEET OF 
 TRENCH-WORK PER MAN, AS COMPARED WITH THAT OF 
 A SECOND PARALLEL COMMENCED BY THE FLYING SAP, AT 
 FOUR RUNNING FEET ONLY PER MAN, IN THE FIRST TASK, 
 ALL OTHER PARTICULARS BEING THE SAME IX BOTH. 
 
 (Compare the foregoing figure with that in Article 59). 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 125 
 
 COMPAKATTVE EXCAVATION. 
 
 let Parallel. 
 
 2d. Pa 
 
 Cubic 
 Feet. 
 
 ralleL 
 
 Cubic 
 Yds. 
 
 Cubic 
 Feet 
 
 Cubic 
 Yds. 
 
 1st Task (1) 5 feet wide, 3 feet J 
 
 
 
 
 
 deep in front, 3 feet 3 inches deep V 
 
 93f 
 
 H 
 
 621 
 
 n 
 
 in rear J 
 
 
 
 
 
 2d Task (II) 4 feet 6 inches wider, ) 
 
 
 
 
 
 3 feet 3 inches deep in front, 3 feet > 
 
 90 
 
 3} 
 
 90 
 
 H 
 
 5 inches deep in rear ) 
 
 
 
 
 
 3d Task (IH) 2 feet wider at botO 
 
 
 
 
 
 torn, which completes} the sole of 
 
 
 
 
 
 the Trench, making it 3 feet 6 inches 
 deep in rear, and a reverse slope, 
 
 781 
 
 2f 
 
 781 
 
 2 
 
 having a base of 3 feet 6 inches, 
 
 
 
 
 
 equal to its height 
 
 
 
 
 
 Total . . 
 
 262 
 
 t 
 
 
 
 67. RULES FOR EXECUTING THE APPROACHES CONNECTED 
 WITH THE SECOND PARALLEL, AND COMMENCED BY THE 
 FLYING SAP. 
 
 These also differ from the first approaches, only in having 
 their parapets reveted with gabions, or with gabions and fas- 
 cines. In the execution no further difference occurs than 
 what must necessarily arise from the use of gabions, the tasks 
 of the several reliefs of men employed being alike in profile, 
 :md proportional to each other, in the ratio of two to three, 
 in the first reliefs of each, in consequence of the men, who 
 commence by the flying sap, being drawn up at intervals of 
 four feet apart, instead of six feet ; but in the second and 
 third reliefs, the tasks are equal, each man having six feet 
 of trench-work to execute. 
 
 The subjoined figure is the section of an approach of this 
 description, having its gabions crowned by three courses of 
 1-isciiM's, which should be laid at the same slope of one-fourth 
 which was before prescribed in placing the gabions. 
 
 These fascines must be secured by pickets driven through 
 
126 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 them obliquely downward into the earth, at an angle of 
 about forty-five degrees. There should be two such pickets 
 to a six-feet fascine. 
 
 It was before explained in Article 62, that approaches 
 usually require more relief than a parallel ; and for this rea- 
 son it may sometimes be expedient to crown the parapets 
 of approaches commenced by the flying sap, with several 
 courses of fascines, as shown in the above figure ; whereas 
 this precaution might be entirely dispensed with, in a second 
 parallel, situated at the same distance from a fortress of 
 equal command. 
 
 The want of cover in the trenches of approaches is more 
 felt at the angles of the zigzags, than anywhere else ; and 
 therefore it may sometimes be expedient, even in the ap- 
 proaches in rear of the first parallel, which are generally 
 left unreveted, to revet their parapets, for about ten or 
 twelve feet, at each angle "of the zigzags only. It may also 
 be proper for the same reason, to cover out those angles by 
 raising not only their own parapets, but also certain portions 
 of the parapets of the trenches in front of them, and at 
 some distance from them, one or more feet higher than the 
 general level of the adjoining parapets. 
 
 Portions of the parapets thus raised, although for a differ- 
 ent purpose, partake of the nature of trench cavaliers, so 
 far as the construction alone is concerned : and therefore 
 when more than usual height is required, it might be pref- 
 erable to use a couple of tiers of gabions, with one inter 
 mediate row of fascines, instead of gaining the whole height 
 necessary, by crowning one course of gabions entirely with 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 127 
 
 fascines, in the manner represented in the foregoing figure. 
 But as well reveted parapets, which are always essential in 
 gun batteries and trench cavaliers, are only required occa- 
 sionally in approaches, I shall not enlarge further upon the 
 construction of such revetments at present. 
 
 When small portions only of a set of approaches are to be 
 reveted, or when small portions only of the parapets of the 
 trenches are to be raised, it is better to employ extra men 
 for the purpose of executing such details, than to make 
 them a part of the task of any of the regular working parties. 
 
 68. STATEMENT, BOTH DC CUBIC FEET ANI> IN CUBIC YARDS, 
 OP THE QUANTITY OF EXCAVATION IN THE FIRST APr 
 PROACIIES, FINISHED IN THREE TASKS, AT SIX RUNNING 
 FEET OF TRENCH-WORK PER MAN, AS COMPARED WITH THE 
 MORE ADVANCED APPROACHES AFTERWARD COMMENCED BY 
 THE FLYING SAP, AT FOUR RUNNING FEET OF TRENCH- 
 WORK PER MAN, IN THE FIRST TASK, BUT AT SIX RUNNING 
 
 FEET PER MAN, IN THE OTHERS. ( Compare the foregoing 
 figure with the first figure in Article 62). 
 
 1 
 
 COMPARATIVE EXCAVATION". 
 
 First 
 Approaches. 
 
 Advanced 
 
 Approaches. 
 
 Cubiq 
 Foot. 
 
 C-nl)i 
 Yds. 
 
 Cubic 
 Feet. 
 
 Cubic 
 Yds. 
 
 1st Task, 5 feet wide, 3 feet 6 inches ) 
 
 
 
 
 
 deep in front, and 3 feet 9 inches deep V 
 
 1033 
 
 4 
 
 721 
 
 2f 
 
 
 
 
 
 
 2d Task, 4 feet 6 inches wider, 3 ) 
 
 
 
 
 
 feet 9 inches deep in front, and 3 feet > 
 
 99 
 
 3| 
 
 99 
 
 8| 
 
 1 1 inches deep in rear .... ) 
 
 
 
 
 
 3d Task, 1 foot 6 inches wider at ^ 
 
 
 
 
 
 bottom, and 4 feet extreme depth, be- 
 
 
 
 
 
 M<1(!S a reverse slope of 4 feet base, > 
 
 85| 
 
 S 
 
 8*f 
 
 H 
 
 and a front step of 1 foot wide, and 1 
 
 
 
 
 
 
 
 
 
 
 
 Total . . 
 
 2931 
 
 10$ 
 
 
 
128 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 69. THAT TWO RELIEFS OF WORKMEN MAY BE SUFFICIENT FOR 
 FINISHING PARALLELS AND APPROACHES IN EASY SOIL. 
 
 Having kept records of the various periods of time em- 
 ployed by every individual of successive parties under in- 
 struction, in finishing parallels and approaches at Chatham, 
 in all varieties of soil, from the easiest, which required very 
 little picking, to the most difficult, which demanded the con- 
 stant use of the pickaxe, I shall subjoin an abstract of two 
 of these reports of parallels, one of which was finished in 
 the shortest time known at this establishment, and the other 
 in nine and a half hours, in as difficult soil as can be expected 
 to occur anywhere, without coming under the definition of 
 rock. On one occasion, as noticed in article 56, one hour 
 more was occupied in finishing a parallel in the same sort 
 of difficult soil by another party of men, but the report of 
 this latter experiment was not entered in the record book 
 in sufficient detail to make use of it. 
 
 ABSTRACT OF TIME, ETC., IN MAKING A FIRST PARALLEL. 
 
 Date, No. of men 
 employed and 
 
 Soil. 
 
 Tasks, 
 No. of. 
 
 Cubic 
 Feet 
 
 Time of Individuals. 
 
 Avernpe 
 Time of all 
 the men. 
 
 Shortest 
 
 Longest. 
 
 Hours, Min. 
 
 Hours. Min. 
 
 Hours. Min. 
 
 Mar. llth and 
 12th, 1828. 
 20 men. 
 Very difficult 
 soil. 
 
 First . . . 
 Second . . 
 Third . . . 
 
 93? 
 90 
 
 781 
 
 1 10 
 
 2 25 
 2 35 
 
 3 10 
 4 
 4 30 
 
 2 17 
 3 23 
 3 50 
 
 The whole 
 Parallel. 
 
 262 
 
 6 12 
 
 11 55 
 
 9 30 
 
 October 12th 
 and 13th, 1828. 
 30 men. 
 Very easy soil. 
 
 First . . . 
 Second . . 
 Third . . . 
 
 93 
 90 
 
 78{ 
 
 16 
 1 5 
 4 
 
 1 30 
 
 2 40 
 4 
 
 44 
 1 36 
 2 34 
 
 The whole 
 Parallel. 
 
 262 
 
 2 41 
 
 g 4 
 
 4 54 
 
PRACTICAL OPERATIONS OF A SIEGE. 129 
 
 In the various records, it was observed that the individual 
 who was the most expeditious in performing the first task, 
 was sometimes slower than other men, in executing the 
 second and third, and vice versa / but as the whole of the 
 parallel in very easy soil in one of these examples was fin- 
 ished by one very active and zealous workman in two hours 
 and forty-one minutes,* and by the worst workman out of 
 thirty men, in eight hours and four minutes, and as it was 
 executed by the average labor of the whole party in four 
 hours fifty-four minutes, it will be evident, that the number 
 of tasks proper for finishing a parallel in such soil may be 
 diminished from three to two ; but the details of executing 
 a parallel by two reliefs of men only will afterward be ex- 
 plained. A working party of men of the line might not 
 perhaps finish quite so soon, but even if entirely unaccus- 
 tomed to labor, it is not likely that in completing the same 
 task, they would require more than one-third of additional 
 time, over and above the periods stated in the above table ; 
 and even if one-half more, making an average of seven 
 hours twenty-one minutes in all, should be required for fin- 
 ishing the parallel: to do this in two tasks only would not 
 involve a greater personal exertion, than able-bodied men 
 are capable of undergoing without over-fatigue. 
 
 70. OF FLANKING BOYAUS, OR SUCH PORTIONS OF THE AP_ 
 PROACHES, IN A SIEGE, AS PARTAKE ALSO OF THE NATURE 
 OF PARALLELS. 
 
 When a set of approaches are on the extreme right, or 
 on the extreme left of the trenches, in a siege, those branches 
 of them which have their parapets facing outward, are 
 termed flanking boyaus, and may be made to answer the 
 
 * Private Hugh Lanyon, since promoted to the rank of Serjeant, after 
 having been employed for several successive years with a party of R. 
 sappers and miners, at the R. M. College, Sandhurst, in making field-worka 
 for tho instruction of the gentlemen cadets. 
 G* 
 
130 MANUAL FOR ENGINEER TROOPS. 
 
 double purpose of acting also as places of arms, or parallels, 
 for containing the troops destined to repulse the sorties 
 made by the besieged, if such sorties shoitld be attempted, 
 as is most frequently the case, on the flanks of the trenches. 
 
 Thus, for example, if we suppose the first and second 
 parallels, and the approaches from the rear to the second 
 parallel in a siege to be finished, and that an enemy makes 
 a sortie at this period, it will be evident, that if he advances 
 in front, the troops in the parallels will oppose him by a 
 direct fire ; but if he should attempt to penetrate in rear of 
 the second or first parallel by either flank, troops placed in 
 flanking boyaus, will be more conveniently situated than 
 those in either of the two parallels for defeating this object. 
 
 Flanking boyaus, therefore, should never be finished with 
 a front slope, as shown in figure 2, Article 62, nor with nar- 
 row steps ; but with broad steps and a banquette, like a 
 parallel. In other respects, they need not differ from com- 
 mon approaches. 
 
 IX. Modifications in the Construction of Paral- 
 lels and Approaches that may Become Neteary, 
 from Circumstances. 
 
 In the above rules and examples, we have supposed the 
 fortress to be situated on a plain, and to have only that 
 moderate degree of command over the country to which 
 the foregoing profiles are suited, and we have also supposed 
 the soil to be favorable for the works of the besiegers. If 
 the soil were unfavorable, it might be necessary to alter 
 the profiles both of parallels and approaches in the manner 
 about to be explained. 
 
 71. MODIFICATIONS THAT MIGHT BE REQUIRED IN MARSHY 
 OR ROCKY SOIL. 
 
 First, supposing water to be found a few feet below the 
 surface, as in Holland and other marshy countries, it would 
 
PRACTICAL OPERATIONS OF A SIEGE. 131 
 
 not always be practicable to excavate the trenches, in which 
 the troops are to be posted, to the extreme depth of three 
 or four feet as before supposed, without inundating, and 
 thereby rendering them unserviceable. Hence it may be 
 necessary to make shallower and wider trenches, and even 
 to cut a ditch in rear of such trenches and below the usual 
 water level, in order to supply earth for the parapet which 
 in such soil must be raised much higher above the ground, 
 than in dry soil. The subjoined figure represents the sort 
 of profile now alluded to. 
 
 Secondly, supposing rock to be found one or two feet be- 
 low the surface, it would in this case also be necessary to 
 make a shallower trench, and a parapet much higher above 
 the natural ground, than in the regular profile suited to deeper 
 soil, and it might perhaps also be necessary to carry earth 
 from the rear, in sand-bags or otherwise, instead of throw- 
 ing it all forward by shovels. 
 
 Under both of these suppositions, whether of water or of 
 rock below and near to the surface, it may be expedient, in 
 working by night, to obtain earth not only from the rear, but 
 also from the front; and more gabions, fascines, and other 
 materials, will be required than under ordinary circumstances. 
 
 In making the trenches alluded to, in proportion as the 
 depth is diminished the width necessary for the task of the 
 first relief of men should be increased ; and in the second 
 and third reliefs the number of men may also be increased 
 to more than the number proper for more favorable soil: but 
 I would not generally recommend employing more men than 
 usual in the first relief, because it might produce confusion. 
 
132 MANUAL FOR ENGINEER TROOPS. 
 
 72. CONSIDERATIONS TO BE KEPT IN MIND IN RESPECT TO 
 PARALLELS AND APPROACHES ON IRREGULAR GROUND. 
 THAT APPROACHES SHOULD NOT BE MADE DOWN HILL. 
 
 First, if the fortress should be situated on a very com- 
 manding eminence, it is obvious that the trenches must be 
 cut deeper and the parapets raised higher than the profiles 
 before described, which apply to ordinary circumstances, 
 that is, supposing the parallels or approaches of the besiegers 
 to be constructed on level ground. 
 
 But if we suppose the ground on which these parallels 
 and approaches must be made to slope regularly down on 
 all sides, from the commanding eminence crowned by the 
 fortress, this ground being naturally defiladed, is not unfa- 
 vorable, and may not require deeper trenches or higher para- 
 pets than usual. 
 
 Secondly, supposing that there are heights opposite to the 
 fortress, and divided from it by an intervening ravine, at 
 the distance of from five or six hundred yards or upward, 
 these heights should be occupied by the besiegers, as they 
 will be favorable for the construction of parallels or bat- 
 teries; but approaches should not be made from thence down 
 the declivity, because they will be seen and plunged into by 
 the guns of the fortress. 
 
 The reason is, that every branch of an approach being 
 always very oblique, in reference to some part of the works 
 of a fortress of any magnitude, the men in the reverse of the 
 trench are not covered by that part of the parapet of the 
 same branch, which is perpendicularly in front of them, but 
 by some distant part of it, which may be thirty or forty, or 
 even so much as sixty feet lower down the slope. Hence, 
 if we suppose the ground to dip at the rate of one foot in five, 
 the part where the reverse of a descending approach would 
 require to be excavated, may be six or eight, or even twelve 
 feet higher than the other part of the same ground, where 
 
PRACTICAL OPERATIONS OF A SIEGE. 133 
 
 the parapet that ought to cover it from some of the guns of 
 the fortress would be situated. Hence, instead of a total re- 
 lief of about eight feet, which is sufficient for the parapet of an 
 approach against a fortress situated on a plain, which agrees 
 With the profiles before given in articles 62 and 67, it might 
 require the parapet to have a relief of fourteen or sixteen, or 
 even twenty feet, to cover every part of the trench of an 
 approach so situated. 
 
 IP 
 
 These particulars are exemplified in the fbregoing figure, 
 in which the parapet of the parallel P, crowning the sum- 
 mit of a height opposite to the fortress F, from which it is 
 divided by a ravine, affords good protection against the shot, 
 
 1, fired from the fortress; but the parapet of the approach 
 A, on the ground below, sloping toward the fortress, af- 
 fords no protection to the men behind it, against the shot, 
 
 2, of the fortress, nor could it possibly afford such protec- 
 tion unless it were raised to the very inconvenient, or one 
 may say impracticable height, shown by the dotted outline 
 above it. 
 
 In short, approaches should never be carried down the 
 slope of a hill occupied by the besiegers, but should be car- 
 ried round from the rear of the hill, so as to turn the flank 
 of it, which I believe may always be done.* 
 
 * For example, m the attack of Burgos, supposing the hornwork to be 
 taken by the besiegers, the high ground on which it is situated ought to be 
 occupied by a portion of parallel with approaches from the rear, as well as 
 by gun and mortar batteries; but instead of carrying approaches from 
 thence down the slope of the hill, I would recommend the turning of that 
 
134: MANUAL FOE ENGINEER TROOPS. 
 
 I do not think that there is any example of a fortress 
 being situated in a hollow at the extreme bottom of a de- 
 scending slope ; and therefore, except to draw attention to 
 a principle, it may be deemed scarcely worth while to ob- 
 serve, that it would be less objectionable to make approaches 
 down hill against such a fortress. In fact, whenever the 
 path of the Shot fired point blank from the guns of a for- 
 tress, is parallel to the surface of the ground outside, the ap- 
 proaches of the besiegers will not be subject to inconveni- 
 ence, or require any extraordinary relief, whether the ground, 
 on which they are.to be executed, be horizontal, or an as- 
 cending or descending plane. 
 
 To return to the consideration of our former supposition 
 of heights occupied by the besiegers, and separated from 
 the fortress by a valley, it may be remarked, that parallels 
 on the descending slope immediately below such heights 
 are also objectionable, from their requiring a deeper trench 
 and higher parapet than would suffice on level ground, but 
 not in so great a degree as approaches, because^ as was be- 
 fore stated in article 6 2, the men in the reverse of the trench 
 of a parallel are protected by those parts of the parapet 
 which are either perpendicularly opposite to them or nearly 
 so, not exceeding about twenty feet at the utmost. Even 
 this, however, would evidently be a very great inconvenience, 
 if the slope were steep. 
 
 To investigate the farther modifications in the outline or 
 profile of parallels or approaches, that might be required by 
 other varieties of irregular ground not yet noticed, would 
 be superfluous in a treatise of this kind, because the expedi- 
 ents necessary for overcoming or evading the difficulties 
 thereby occasioned, will readily suggest themselves to an 
 intelligent officer, on the scene of action. 
 
 height by going round it, without attempting nny direct communication 
 from thence to whatever works might afterward be executed in front of it, 
 on the ascending slope opposite. 
 
PRACTICAL OPERATIONS OF A SIEGE. 135 
 
 X. Of the Arrangements and Regulations Proper 
 for Military Working Parties in a Siege. 
 
 73. OF THE BEST MODE OF SUPERINTENDING THEM. THAT 
 THE REGIMENTAL OFFICERS OF THE WORKING PARTIES 
 SHOULD BE HELD STRICTLY RESPONSIBLE, FOR THE EXE- 
 CUTION OF THE QUANTITY OF WORK ORDERED TO BE 
 DONE. THAT MIXED WORKING PARTIES, COMPOSED OF 
 MKX OF DIFFERENT CORPS, OUGHT NOT TO BE EMPLOYED. 
 
 The subject of this article is of such importance, that it ap- 
 pears proper to treat of it in some detail, although the general 
 principle about to be developed, might have been inferred 
 from some observations to the same effect, previously made. 
 
 It has already been implied, that the engineers on duty 
 should only be responsible for marking out the several 
 works, for supplying materials and tools, and for making 
 such arrangements and giving such directions, as will enable 
 the working parties of the line to execute their tasks to 
 proper advantage. If the soldiers of the working parties 
 do not exert themselves as they ought to do, let the engi- 
 neers make their representation to the general or field offi- 
 cers on duty in the trenches. 
 
 The regimental officers of the corps which furnish the 
 working parties, should be held solely and most strictly re- 
 sponsible, for the diligence and exertions of the men under 
 their command. The captains, subaltern officers and ser- 
 geants, attached to each division of the working parties 
 should move about continually, to encourage the diligent, 
 and reprove the idle; and the field officers in charge of 
 several divisions should in like manner move about the 
 whole line of workmen under their charge, to see that the 
 men are diligent, and that the officers and sergeants* are 
 
 * It was before mentioned that corporals, as rauk and file, take their 
 of the work in the British service. 
 
136 MANUAL FOR ENGINEER TROOPS. 
 
 doing their duty. These field officers should be held re- 
 sponsible for the diligence of the working parties under 
 their command, by the general officer or officers, on duty in 
 the trenches ; and the latter should be responsible for the 
 proper execution of the operations of each period of twenty- 
 four hours, to the general officer in command of the besieg- 
 ing army. 
 
 It is of the most vital importance to the success of a 
 siege, that this system of responsibility, from the regimental 
 officers of working parties to the general officers on duty 
 in the trenches, shall be established, and fully understood, 
 and inflexibly adhered to ; for which reason the command- 
 ing engineer ought to apply to the commander of the forces, 
 to issue a general order to this effect, previously to the 
 opening of the trenches ; for if this precaution be neglected, 
 it is but too likely that many officers of the working parties 
 will remain perfectly inert, and leave every thing to the 
 engineers, who cannot be expected to keep the workmen 
 diligent, when the latter see that their own regimental offi- 
 cers, who have more influence over them than any others, 
 are either asleep, or grouped together in some corner, in 
 conversation, in a state of apparent indifference to the 
 progress of the work. Such an order is also necessary, to 
 counteract a pernicious and unreasonable prejudice, which 
 appeared to prevail amongst the officers of some regiments 
 of the line, at the commencement of the late interesting 
 wars with France, against being employed on working par- 
 ties at all. Too much pains cannot be taken to prevent the 
 recurrence of a feeling so radically opposed to the success 
 of all siege operations. 
 
 To carry this subject further, it may be considered of great 
 importance in the execution of a parallel, and the same re- 
 mark may generally apply to other works of a siege, that 
 the praise of diligence, and the disgrace of failure shall not 
 
PRACTICAL OPERATIONS OF A SIEGE. 137 
 
 be frittered away by employing mixed working parties ; but 
 that one particular division of the army shall have the whole 
 of the operations of the first twenty-four hours, whether the 
 men be relieved three times or only twice within that period* 
 and that each brigade and battalion of this division shall 
 have its own distinct portion of the work, which no men of 
 any other corps shall meddle with. Thus, if the whole of 
 the work directed to be done in the twenty-four hours should 
 be well executed, the whole division generally will have the 
 credit of it. If the whole should be badly executed, or in- 
 complete, the disgrace will attach to the division as a body ; 
 but if part only should fail, the disgrace will attach to the 
 particular regiment, which either neglected or proved in- 
 competent to its share of the duty. 
 
 In the construction of the first batteries, which are usually 
 commenced the second night, the same system should be 
 followed with a second division of the besieging army, each 
 battalion of which might have its own distinct battery al- 
 lotted to it ; and by pursuing this system, both regimental 
 officers and men would take a strong interest in siege opera- 
 tions, and would feel their own honor and reputation involved 
 in them, which beneficial feeling, by all accounts, has hitherto 
 scarcely ever prevailed amongst the troops in general, in any 
 of the sieges carried on by the British army. Indeed the 
 operations of those sieges, as recorded by Colonel Jones,* in 
 his able and useful work, speak for themselves. When we 
 find that in the sieges of the Peninsula a task of no more 
 than four feet in length, three feet in depth, and three and a 
 half feet in width, being only forty-two cubic feet, or about 
 one and half cubic yards, of excavation, was only executed 
 by each individual of the military working parties as their 
 first night's work, which task we know by experience may 
 be finished by an able-bodied man, with very moderate ex- 
 
 * Now Major-General Sir John T. Jones, K. C. B. 
 
138 MANUAL FOR ENGINEER TROOPS. 
 
 ertion, in twenty minutes,* in easy soil, that requires little or 
 no picking ; and in less than one hour in the hardest and 
 most difficult soil that does not exactly come under the defi- 
 nition of rock ; one cannot but feel mortified and ashamed 
 that the exertions of the British army, on such occasions, 
 should have fallen so miserably short of their brilliant ex- 
 ploits in the field.f It was not so in the royal navy, where 
 officers and men equally disdained to skulk from useful labor 
 as to shrink from danger ; and where the watering of Nel- 
 son's fleet on the coast of Barbary, in an extraordinarily 
 short space of time, just before he proceeded to the West 
 Indies, was regarded with almost as much pride as the mem- 
 orable victory of Trafalgar, that was gained not many months 
 afterward. 
 
 I attach so much importance to having the duty of work- 
 ing parties done by regular divisions, brigades, battalions, 
 and companies, that I am confident that any number of work- 
 men furnished according to this system, will do as much as 
 twice their number of mixed working parties, each com- 
 posed of officers and soldiers of different regiments, fur- 
 nished according to the roster: a system which, in our ser- 
 vice, has been too often carried from the garrison guard- 
 mounting! mto tne camp of the besieging army, and which, 
 
 * Sergeant Lanyon finished his first task of a parallel, nearly one hun- 
 dred and nine cubic feet, in sixteen minutes, iu easy soil (see the note to 
 article 69). At this rate, an active workman might have finished his first 
 night's task in the British sieges in Spain, in seven minutes. 
 
 f Always, however, making an honorable exception in favor of the work- 
 ing parties furnished by his majesty's foot-guards, who did as much as 
 officers and men could do, so that I really do not think that their exertions 
 in making batteries, &c., on service, have been exceeded in our practice at 
 this establishment. I speak to this fact not only from my own observation, 
 but from that of- Colonel (now Major-General) Sir John F. Burgoyue, K.C.B., 
 and other brother officers of much greater experience than myself. 
 
 \ In garrisons in which the duty is regulated by roster each corps fur- 
 nishing a daily detail in proportion to its number, nothing is more com- 
 
PRACTICAL. OPERATIONS OF A SIEGE. 139 
 
 in all cases, more or less injures that organization upon 
 which discipline depends, and to a certain degree converts 
 an army into a mob. 
 
 74. OF T5IE NUMBER OP TIMES THAT THE WORKING PARTIES, 
 GUARDS OP THE TRENCHES, ETC., OUGHT TO BE RELIEVED 
 IN THE TWENTY-FOUR HOURS. 
 
 It must be evident, on a little reflection, that the marching 
 ing backward and forward between the trenches and their 
 camp or cantonments may occasion considerable fatigue to 
 the troops of a besieging army, besides occupying a good 
 deal of 'time. Hence, if the total number of reliefs or changes 
 of men be limited, which is always the case, it follows that 
 the oftener they are relieved in the twenty-four hours, the 
 more harassing it must be to- those men, who might, even 
 by increasing the number of times they were sent on duty 
 within that period, be kept in almost constant movement, or 
 preparation for movement, without due time for rest. 
 
 For this reason the guards of the trenches, who, unless 
 the enemy makes a sortie, are usually in a state of rest, with 
 the exception of pickets or sentinels, or men employed as 
 sharpshooters, are not relieved oftener than once in twenty- 
 four hours ; and the same system is followed in relieving the 
 artillery, whose exertions are not generally of a very labori- 
 
 mon than to see a guard composed of an officer of one regiment, non-com, 
 missioned officers of another, and privates of two or three others. Hence 
 no one regiment or corps can drill to advantage, for no regiment is ever 
 off guard in a body. Thus the discipline of all suffers, and if the duties 
 of such mixed guards involved any serious exertions or responsibility, it 
 is my opinion that the service would be much more likely to suffer through 
 neglect than under the more salutary system of causing each guard to be 
 furnished by officers, non-commissioned officers, and privates of one and 
 the same corps. At the same time I admit that the roster system in gar- 
 risons, if only used occasionally, does good, by destroying a prejudice, which 
 young soldiers are apt to entertain, that they ought only to be commanded 
 by their own regimental officers. 
 
140 MANUAL FOR ENGINEER TROOPS. 
 
 ous nature, because the ordnance in a siege is not fired fre- 
 quently and incessantly, as in battle. 
 
 The working parties, on the contrary, must necessarily be 
 relieved oftener* "for a man cannot work for more than eight 
 hours, without being exhausted ; and if he be stimulated by 
 taskwork four, five, or six hours, at the utmost, of actual ex- 
 ertion will be quite sufficient. 
 
 On the other hand, it may be observed, that to bring a 
 body of men into the trenches, to execute any task involv- 
 ing much less than four or five hours' labor, would really 
 be trifling with the duties of a siege. Now if the soil be 
 of any easy description, requiring little or no picking, and 
 if the whole parallel be divided into three tasks or portions, 
 such as were before described, each party might finish their 
 respective tasks in less than two hours. ^ 
 
 In case therefore of very hard soil, it is proper to divide 
 the execution of a parallel or parallels into three tasks, to 
 be executed by three reliefs of men, the first relief to com- 
 mence their work at dusk, as explained in Article 37, the 
 second at daylight next morning, and the third at noon. 
 But in very soft soil, as was before implied in Article 69, it 
 will be better and less harassing to the troops, to divide the 
 work into two tasks only, and consequently to have no more 
 than two reliefs of workmen in twenty-four hours. We 
 shall now consider the details of this arrangement as ap- 
 plied to a first parallel. 
 
 75. FIRST TASK, IN EXECUTING A FIRST PARALLEL BY TWO 
 RELIEFS, IN EASY SOIL. 
 
 Being drawn up at the usual rate of one man to every 
 six feet of trench-work as before, each man must cut his 
 portion of trench to the width of seven feet six inches from 
 front to rear, making it three feet deep in front, and three 
 feet four inches in rear, which amounts to about one hundred 
 
PRACTICAL OPERATIONS OF A SIEGE. 
 
 and forty-two cubic feet, or rather more than five and a 
 quarter cubic yards of excavation. 
 
 76. SECOND TASK, IN EXECUTING A FIRST PARALLEL BY TTTO 
 RELIEFS, IN EASY SOIL. 
 
 The second relief of men should be marched into the 
 trenches at daylight, and should make the front step, and 
 add four feet to the width of the original trench, which will 
 increase it to the width of ten clear feet at bottom, over 
 and above the base of the said step, and to the extreme 
 depth of three feet six inches in rear ; after which they 
 must finish the trench^ either with a reverse slope, having 
 its base equal to its height, according to the profile before 
 represented in the figure in Article 59 ; or with steps in rear, 
 according to the figure given in Article 61. 
 
 When the parallel is finished with a reverse slope, the 
 task of the second relief amounts to about one hundred and 
 twenty cubic feet, or to four and a half cubic yards nearly ; 
 but when it is finished with reverse steps, the task of the 
 second relief amounts only to about ninty-nine cubic feet, 
 or to three and two-thirds cubic yards. 
 
 In either case, after completing the excavation according 
 to the profile prescribed, the second relief of workmen must 
 make a perfect finish of the parapet, and cut cesspools, <fcc., 
 to secure the trench against the effects of rain, as before di- 
 rected, which will not be a difficult task, as the men have 
 the whole day before them to execute, what would scarcely 
 
14:2 MANUAL FOR ENGINEER TROOPS. 
 
 require more than from two and a half to three hours of 
 active exertion at the utmost. 
 
 The same principle may be applied to the execution of 
 the first approaches, as well as of 'the second parallel and of 
 the advanced approaches connected with it, by two reliefs 
 of men only, in very easy soil. 
 
 Whether three or only two reliefs of men be employed 
 in finishing a parallel or an approach, according to the tasks 
 above specified, the first party may always complete their 
 excavation sooner than the others, after they shall have 
 been fairly set to work ; but the loss of time in preliminary 
 arrangements and the unfavorable circumstance of com- 
 mencing by night, will counterbalance this advantage, and 
 tend to equalize the trouble of all. 
 
 77. OF THE TOTAL NUMBER OF TROOPS NECESSARY IN A 
 SIEGE, TO FURNISH MEN FOR EVERY OPERATION, IN REFER- 
 ENCE TO THE NUMBER OF RELIEFS EMPLOYED IN EACH, IN 
 THE TWENTY-FOUR HOURS. 
 
 When soldiers are employed in military duties, hi the 
 trenches or batteries, in a siege, and are relieved only once 
 in the twenty-four hours, three changes of men may suffice, 
 and even when they are relieved twice in the twenty-four 
 hours the same proportion 'may regulate the total number 
 of men necessary. 
 
 Thus, for example, six thousand infantry, and one thousand 
 and two hundred artillery, might supply daily two thousand 
 men for guards of the trenches, and four hundred gunners 
 to man the batteries in a siege ; as troops employed in the 
 former duty are only relieved once in the twenty-four hours, 
 and the artillery are seldom relieved oftener. 
 
 In respect to the working parties, as these would generally 
 be relieved three times in the twenty-four hours, it is desi- 
 rable that there should be four changes of men in all, by which 
 means each relief would only be on duty once in thirty-two 
 
PRACTICAL OPERATIONS OF A SIEGE. 143 
 
 hours, which would allow ample time for rest, whilst this 
 arrangement would prevent the same men from always com- 
 ing on duty at night, which must necessarily be the case if 
 there were only three changes of men to supply all the 
 three reliefs. If therefore the average number of work- 
 men wanted for constant duty day and night, at the com- 
 mencement of a siege, should be estimated at one thousand 
 and two hundred, it would require four thousand and eight 
 hundred infantry to supply this number in four reliefs, three 
 of which only should be employed within the space of 
 twenty-four hours. This number, added to the two thou- 
 sand before mentioned, would require six thousand and eight 
 hundred men, for all the infantry duties of the siege. * 
 
 In estimating the number of officers and soldiers of the 
 engineer department necessary for a siege, the same rule 
 should be observed which applies to working parties of the 
 line. Hence the number of reliefs would be the same for 
 both, but it has been considered best to relieve the engineers 
 at intermediate periods between the hours of relieving the 
 workmen, in order that the former may get perfectly ac- 
 quainted with every thing necessary before the arrangement 
 of the new working parties, which always occasions some 
 difficulty, shall be thrown upon them. This was the system 
 usually followed in the sieges in the Spanish Peninsula. In 
 respect to the proportion which engineers ought to bear to 
 the working parties of the line, one to twelve appears to me 
 to be desirable, in order to insure proper superintendence 
 and efficiency. 
 
 It is evident that over and above the 'number of soldiers 
 wanted for the daily operations of siege, a certain proportion 
 would also be required on account of casualties, to replace 
 men killed or wounded by the enemy, or disabled by sick- 
 ness, and also to furnish men for the necessary duties of 
 drawing rations, cooking, and for various other little details, 
 which always engross a much greater number of men than 
 
 or 
 
144: MANUAL FOR ENGINEER TROOPS. 
 
 one would suppose on a hasty view of the subject. But it 
 is not my intention to enlarge further at present, on the 
 mode of calculating the proper strength of a besieging 
 army. I shall therefore conclude this article by observing 
 that such estimates should always be made in reference to 
 the number of effective rank and file that can be spared daily 
 for duty, exclusive of soldiers necessarily employed in the 
 various details before alluded to. 
 
SCHOOL OF THE SAP. 
 
PART III. 
 
 THE FULL SAP. 
 
 THE approaches may be carried on by the flying sap until 
 they arrive within close range of small arms from {he cov- 
 ered way, after which the full sap must be employed. 
 
 This is a path executed by sappers, who advance foot by 
 foot, covering themselves from the fire of the place by ga- 
 bions, which are placed and filled in succession, and by a 
 Bap-roller placed at the head of the sap. The sap is called 
 simple when, the fire coming from one direction only, but 
 one gabionade or parapet is required. It is double when the 
 fire, coming in two different directions, requires a gabionade 
 on each side of the trench, which is effected by conducting 
 two simple saps side by side, whose parapets mutually pro- 
 tect each other. 
 
 The simple full sap is executed by a brigade of eight sap- 
 pers, four of whom are especially designated sappers, and 
 are numbered 1st, 2d, 3d and 4th sappers, and four termed 
 ' assistants, who are also numbered from one to four. The 
 duty of the former is to excavate the trench, that of the 
 latter to perfect the work and prepare material. During the 
 operation the men composing the brigade frequently change 
 places, so that every man shall in succession occupy every 
 position. 
 
148 MANUAL FOR ENGINEER TROOPS. 
 
 Sapper No. 1 is placed at the head of the sap. He 
 works kneeling, making an excavation 20" deep and 20" wide 
 at the top* and leaves a berme of 12", giving the side of the 
 excavation toward the gabionade a slope of | in ordinary 
 earth. The opposite side should be vertical, so that the width 
 at bottom may be 15*. The earth thus obtained is sufficient 
 to fill the gabions. In ordinary earth this sapper should fill 
 two gabions before being relieved. The second sapper fol- 
 lows, two gabions and a half in rear of the first ; he also 
 works kneeling. He increases the depth and width of the 
 sap by seven inches, taking the earth from the reverse, and 
 continuing the slope on the other side ; this will leave his 
 form 27* wide at top, 20* at bottom, and 27* deep. The quan- 
 tity of earth excavated by No. 2 is nearly the same as that 
 by No. 1. The third sapper is also two gabions and a half 
 in rear of the second ( 5' 6*). He works on his feet, but 
 stooping. He widens and deepens the sap 7*, leaving it 34* 
 deep, 34* wide at top and 25* at bottom. The fourth sap* 
 per, the same distance in rear of the third, widens and deep- 
 ens the sap 6*; it is then 40* deep, 40" wide at top and 30" 
 at bottom. The excavation in this state, at which it does 
 not arrive until eight gabions are placed, is completed, as a 
 sap. Its parapet, even when formed of earth, which increases 
 considerably in bulk from its movement, is only about 7' 8* 
 thick at base, including the gabion, and 2' 8* high. It is 
 then turned over to the ordinary workmen to be enlarged, 
 and disposed for the reception of the guards of the trenches 
 or for a communication. 
 
 TOOLS. 
 
 Each of the eight sappers should be furnished with a 
 pick and shovel, and each head of sap with two hooks, two 
 forks and one or two drags. 
 
 The sap-hook has two prongs at right angles to each other, 
 each 4" long; the entire length of the fork is 1', of which 4' 
 
THE FULL SAP. 149 
 
 is for the point, 3|* for the body and 4J" for the socket ; the 
 handle is ll/ 8" long, and is fastened in the socket with a 
 rivet ; to the other end is attached a ring 1|" or 1^" in diam- 
 eter. The weight of the entire fork is about 13 Ibs. 
 
 The sap-fork has three points, the two extreme, parallel 
 and 4" apart, the middle at right angles to the plane of the 
 other two, the length of the iron part is 10", of the handle 
 5', the weight 11 Ibs. 
 
 The drag is 8" high, 8" wide at the edge and 2" at the 
 eye ; the handle is 3' 4" or 6' 8" long. 
 
 Each head of sap should be provided with 1 sap-roller, 
 about 30 sap-fagots, and as many crowning fascines, ordi- 
 nary gabions and fascines, levers 10' or 12' long, 4" x 4" crow- 
 bars, sand-bags, wool-sacks 20" or 26" in diameter and 30" 
 or 40" high. 
 
 EXECUTION OF THE FULL SAP. 
 
 The following figure represents a sap in the course of con- 
 struction. 
 
 The four sappers, having the positions indicated, work at 
 
150 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 their respective forms. All the gabions opposite these forms, 
 except the last-placed (which the first sapper is engaged in 
 filling), are crowned with temporary crowning fascines. 
 The joints of the gabion are closed with sap-fagots, as well 
 as that of the last gabion and sap-roller. The latter is 
 placed at the head, and perpendicular to the direction of the 
 sap, in such a manner as to cover at least one foot of the 
 first gabion. The picks and shovels which are not in use 
 are placed on the berme, close to the gabions. One of the 
 hooks is also on the berme, the other, on the reverse, is fixed 
 in the roller, about two-thirds of the height of the roller, 
 above the ground, and 1' from the end ; it is held in position 
 
THE FULL SAP. 151 
 
 by a picket driven through its ring into the ground ; a sap- 
 fcrk lies on the reverse near the first sapper, also two 
 crowning fascines. The assistants are occnpied with re- 
 placing the temporary crowning fascines with ordinary fas- 
 cines, and supplying the head of the sap with all the neces- 
 sary material. They are furnished with two sap-forks, which 
 are placed on the berme, as well as their picks and shovels, 
 which, in case of need, may supply the place of those broken 
 at the head of the sap. 
 
 The sappers and their assistants have neither swords nor 
 cartridge-boxes, their muskets are placed on the reverse, 
 perpendicular to the trench, locks up, opposite their re- 
 spective forms. The chief of sap, stationed a little in rear 
 of the fourth sapper, directs the operation ; the non-commis- ' 
 sioned officer has charge of the assistants. 
 
 TO PLACE A NEW GABION. 
 
 When the last gabion placed is filled and crowned with 
 two small fascines, and the first sapper's form has arrived 
 opposite the middle of the gabion, he warns the chief by 
 crying "Halt" The latter examines the work, and if he is 
 satisfied with it, gives successively the following commands : 
 
 1. "Attention." 
 
 2. " Gabion." 
 
 3. "Hooks." 
 
 4. "Forward." 
 
 5. "Enough." 
 G. "Fagot." 
 
 7. " Commence working." 
 
 At the first command the four sappers cease working, 
 place the tools on the berme, and hold themselves in readi- 
 ness to execute the manoeuvres which the chief is about to 
 command. At the second, sapper No. 1 removes the fagot 
 from the joint of the last gabion and sap-roller, and places 
 it a little in rear on the berme. The second sapper moves, 
 
152 MANUAL FOR ENGINEER TROOPS. 
 
 if necessary, the handle of the hook on the reverse, to allow 
 the passage of the new gabion. The fourth sapper receives 
 a gabion from the assistants, rolls it along the reverse, hold- 
 ing it by the points of its stakes ; it is passed successively to 
 Nos. 3, 2 and 1. The latter places it on its base in the joint 
 of the last gabion and sap-roller. 
 
 At the command "Hooks" sapper No. 2 takes the berme- 
 hook and fixes it in the roller at about half the height 
 of the top of the latter from the ground, and as near 
 the parapet as possible. No. 3 seizes the other hook, and 
 replaces it about the same height from the ground as the 
 first. No. 4 aids No. 2, and the first assistant No. 3, and 
 all prepare to push forward the roller. In this state of things 
 the first and second sappers should be kneeling, and leaning 
 against the berme. Nos. 3 and 1 assist on the side of the 
 reverse, and stooping as much as possible. 
 
 At the command "Forward" the four sappers armed with 
 the hooks push the roller forcibly but steadily forward, with- 
 out abandoning it or deranging its perpendicular direction 
 with respect to the sap. As the roller advances, No. 1 
 pushes the new gabion in the interval left between it and 
 the last gabion, moving it by means of the fork. He indi- 
 cates by the words "more" "too much" and "enough" what 
 the sappers at the hooks must do to bring the roller into the 
 proper position. In the mean while the chief of sap indi- 
 cates to No. 1 whether the gabion is to be pushed nearer the 
 place attacked or driven back, by the words " out" or " in" 
 
 At the command "Enough" the sap-roller is drawn back 
 forcibly against the newly-placed gabion. No. 2 disengages 
 his hook, and places it on the berme; No. 3 leaves his engag- 
 ed, fastening it in its position by driving a picket through 
 the ring with his pick. No. 1 takes the sap-fagot which he 
 placed on the berme, and replaces it in the joint between the 
 first and second, gabions, striking the head of the central 
 picket with the flat of the blade of his pick. 
 
THE FULL SAP. 153 
 
 At the command "Fagot" which follows the last imme- 
 diately, the assistants pass a fagot to No. 4, who passes it 
 through Nos. 3 and 2 to No. 1 ; the latter places it in the joint 
 of the first gabion and roller by means of his fork. The 
 assistants also pass to No. 2 two crowning fascines, which 
 he lays on the reverse near the roller. 
 
 At the command " Commence working" all the sappers re- 
 sume the excavation, No. 1 keeping close to the berme, throw- 
 ing back the opposite shoulder, throwing the earth carefully 
 into the new gabion. When it is filled he crowns it with the 
 two small fascines by means of the fork. The other sap- 
 pers throw the earth in rear of the gabions, and as near to 
 them as possible the second being careful to throw it op- 
 posite the joints of the gabions of his own form. 
 
 CROWNING THE GABIONADE WITH FASCINES. 
 
 The object of crowning the gabions with the small fas- 
 cines, is to increase the cover of the sappers engaged in the 
 excavation, but as they only give the parapet a height of 
 44", and do not bind the gabions together, they are replaced 
 by ordinary fascines, which accomplish the latter object and 
 procure a height of 52" to the parapet. To effect this, as 
 soon as there are in rear of the fourth sapper three gabions 
 not crowned, the chief of sap commands, " Fascines" The 
 first and second assistants, each provided with a fork, draw 
 the temporary crowning fascines from these gabions down 
 upon the berme ; the third deposits them on the re verse ; the 
 fburth brings forward three ordinary fascines ; the first and 
 second take one and place it on the berme, raise it with their 
 forks,' and place it on the rear of the top of the gabions, join- 
 ing it as closely as possible with the preceding, and strike it 
 several blows, to engage it in the points of the gabion stakes. 
 A second is placed in advance of this, and a third on top, 
 and in the joint of the first and second. 
 7* 
 
154: MANUAL FOR ENGINEER TROOPS. - 
 
 TO CHANGE THE POSTS OP THE SAPPERS. 
 
 When the first sapper has terminated his task, which is, 
 ordinarily, filling two gabions, the chief of 'sap commands, 
 " Attention" then " Change." Each sapper falls back one 
 form ; the first assistant takes his musket and passes to the 
 head of the sap, going between the sappers and the reverse. 
 This assistant becomes the first sapper ; the first becomes the 
 second, the second the third, and the third becomes the fourth, 
 the fourth passes to the rear of the brigade, and is fourth 
 assistant. Each of the other assistants advances one number. 
 
 A wounded sapper is replaced by the first assistant ; if he 
 is badly wounded or killed, the sappers in rear deliver him 
 to the assistants, who carry him off, and the work is imme- 
 diately resumed. 
 
 Each brigade should have a reserve, to replace those 
 removed by accidents. A sapper taken from this reserve 
 becomes fourth assistant. 
 
 TIME REQUIRED FOR EXECUTING THE FULL SAP. 
 
 In the schools of practice, when the full sap is executed 
 in ordinary earth, about 15 m. are required to place and fill 
 one gabion, consequently in one hour of uninterrupted labor 
 the sap advances 8' 10". A brigade should be relieved after 
 eight hours' labor ; when this time is exceeded the men be- 
 come too much fatigued to push the sap forward with the 
 necessary rapidity. Experience has proved that although 
 the excavations of the four sappers differ in volume they 
 can be accomplished in the same time, which may be ac- 
 counted for by comparing their tasks with the more or less 
 cramped positions in which they work. But if from any 
 cause one of the three last sappers is retarded, the chief of 
 sap should push him on, and cause him to keep within two and 
 a half gabions of the preceding, as the velocity of the sap 
 should be regulated by the first sapper, and should expe- 
 rience a retardation from him only. 
 
THE FULL BAP. 
 
 155 
 
 OBSERVATIONS RELATIVE TO INCLINED SOIL. 
 
 When the ground over which the sap passes is inclined in 
 any sense whatever, it often happens that gabions placed on 
 their bases simply, have not sufficient stability. The first 
 sapper must endeavor to place them in the most favorable 
 positions. The slope may be so great as to require the ga- 
 bion to be propped with a fagot, sand-bag or sods. 
 
 When the ground is 
 inclined toward the in- 
 terior of the sap, the 
 roller frequently de- 
 scends by degrees in 
 the same direction 
 finally no longer cov- 
 ering the gabionade, 
 and leaving a danger- 
 ous opening. To bring the roller into its true position, the 
 chief of sap gives the following commands : 
 
 1. "Levers. Fagots." 
 
 2. "Hooks." 
 
 3. " Replace the sap-roller." 
 
 At the first command the assistants pass from hand to 
 hand to the first sapper, a well-bound sap-fagot, which he 
 places on the ground parallel to the roller, opposite its mid- 
 dle and near its line of contact with the ground. Nos. 1 
 and 2 receive each a lever, which they engage under the 
 roller, about 1' each side of its middle, resting on the fagot 
 as a fulcrum, and inclining toward the berme. 
 
 At the second command No. 3 takes the reverse and No. 
 4 the berme-hook, the former being fixed in the roller. 
 The first assistant aids No. 3 and the second No. 4. 
 
 At the third command Nos. 1 and 2 weigh down on the 
 levers, bearing them toward the reverse, thus moving the 
 roller in the opposite direction. They should act by succes- 
 
15C 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 sive and sudden impulses, the sappers at the forks pulling 
 strongly to prevent the roller from moving in advance. 
 
 This manoeuvre may be facilitated by first running the 
 roller a little forward by means of the hooks, then engaging 
 the levers and drawing the roller back upon them. As it 
 does not then rest upon the ground, it can more easily be 
 moved in the direction required. 
 
 If there is reason to fear that the sappers will not be 
 sufficiently covered during this operation by the crowning 
 fascines, sand-bags may be placed on the fascines. 
 
 HALF-FULL SAP. 
 
 When the sappers have only a flank fire (coming in a di- 
 rection nearly perpendicular to that of the sap) to fear, the 
 sap-roller may be dispensed with. The first sapper then 
 rovers himself by the last-filled gabion whilst placing and 
 filling the new one. This species of sap, to which applica- 
 tion is sometimes found, is called the half-full sap. 
 
THE FULL SAP. 157 
 
 DOUBLE SAP. 
 
 The details of the double sap are similar to those of the 
 simple. The gabionades which form the two parapets, are 
 13' 4" apart in the clear, taking from this 2' for the two 
 beams, 6' 8" for the width of the saps at top, there remains 
 a bank of earth 4' 8" thick in the middle, which is to be 
 removed by the ordinary workmen. When this is accom- 
 plished, the double sap is 9' 6" wide at the bottom. The 
 depth is usually 40", but when the nature of the ground will 
 permit, it may be greater, in order to facilitate the defile- 
 ment. 
 
 The head of tho double sap is covered by two rollers, 
 placed end to end, each covering one of the lateral gabion- 
 ades ; it is well to engage the fascine with which one is filled, 
 with those of the other ; when this is not the case, their joint 
 is masked with a wool-sack, which the two leading sappers 
 push forward with their forks, after having placed their sap- 
 fagots in the gabionade, keeping the joint always closed. The 
 two brigades execute at the same time the commands of the 
 chief of sap, who stations himself in that one in which he 
 judges his presence most necessary. 
 
 The two heads of sap should always be in the same state 
 of advancement. The chief of sap should not give the com- 
 mand "Attention" until the sappers at the head of each have 
 cried " Halt" The sapper who first fills his gabion contin- 
 ues to enlarge his form until the other is ready. 
 
 This necessity of awaiting for the slowest sapper causes 
 the double sap to advance with less rapidity than the simple. 
 About one-fifth more time is required for the former, that is, 
 eighteen minutes to a gabion. 
 
 When the double sap is pushed directly on the place, trav- 
 erses must be formed from distance to distance to guard 
 against enfilade fire. 
 
 These traverses are said to be u en cremailleres" when 
 
158 
 
 MANUAL FOE ENGINEER TROOPS. 
 
 placed alternately on the right and left of the sap, " tour- 
 n antes" (winding) when left in the middle of the sap, which 
 surrounds them entirely. 
 
 The position of the traverses and returns should be so sit- 
 uated that a man standing in any part of the sap cannot be 
 seen from the place, and that projectiles cannot ricochet on 
 the bottom. 
 
 It therefore varies 
 with the command of 
 the place over the 
 ground on which the 
 | sap is constructed, and 
 as the ground is more 
 or less favorable to ri- 
 cochet. The construc- 
 tion of these traverses 
 involves that of de- 
 bouches, which will be 
 treated of hereafter. 
 
 The inconveniences 
 of the double sap are, 
 1st, length of time re- 
 quired in its construc- 
 tion. 2d, the para- 
 pets have not suffi- 
 cient thickness. 3d, 
 the guard and workmen are too much crowded. 4th, it af- 
 fords less facilities than the simple sap, to be pushed for- 
 ward by the flying sap, when a favorable opportunity offers. 
 5th, its direction exposed to plunging, enfilade and reverse 
 fire. 6th, the head of the sap has no lateral protection 
 against sorties. 
 
THE FULL SAP. 159 
 
 HALF DOUBLE SAP. 
 
 Frequently the double sap is 
 traced over ground so much in- 
 clined, that one sap is exposed 
 to fire passing over the parapet 
 of the other ; this frequently oc- 
 curs in the crowning of the cov- 
 ered way. In this case, when 
 cover cannot be obtained by 
 increasing the depth by a few 
 inches, the half double sap is 
 resorted to. This sap is execu- 
 ted by a single brigade of sap- 
 pers; it has on the side of the 
 berme the ordinary parapet, and 
 on the reverse a provisional par- 
 apet, formed of gabions filled 
 with sand-bags. The two para- 
 pets, which are 5' 8" apart, are 
 formed at the same time by the 
 first sapper. At the command 
 "Gabion" the assistants pass for- 
 ward two gabions, to No. 1, 
 who places the first on the re- 
 verse against the rollers, and the 
 second on the berme in the or- 
 dinary way. ^ At the command 
 " Forward" he first places the 
 gabion on the berme, as in the 
 simple sap, then that on the re- 
 verse in such a manner that one 
 half of it shall be covered by the 
 roller. After the command 
 "Enough" the chief of sap, in- 
 stead of simply giving the com- 
 
160 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 mand " Fagot" commands, " J5a$rs and fagots" Two fagots 
 are passed to No. 1, who places them in the angles of the 
 gabionades and roller. He then receives on his shovel from 
 No. 2 a sand-bag, which he throws into the gabion on the 
 reverse ; he proceeds in this manner until the gabion is filled 
 and the joint with the preceding well closed ; this usually 
 requires ten sand-bags. To avoid having too great a variety 
 of material at the head of the sap, it is better to use sand- 
 bags for crowning the true parapet in the place of small 
 fascines ; four sand-bags are required to crown one gabion. 
 The assistants will therefore pass forward fourteen, which 
 are arranged on the reverse opposite the first sapper form. 
 
 The time required to advance this sap one gabion, is about 
 twenty minutes in the place of fifteen employed in the sim- 
 ple and eighte'en in the double sap. As soon as the sap has 
 advanced so far that twelve provisionally gabions are found 
 in rear of No. 1, the chief of sap causes a small trench to 
 be commenced, perpendicular to the sap, whose parapet 
 shall form a traverse, high enough to cover the sap in rear. 
 
 This trench is but 40" wide, and is executed in the half- 
 full sap by the reserve ; this allows the provisionally gabion- 
 ade in rear to be removed, leaving the head of the sap only 
 encased by two gabionades ; the part in rear can then re- 
 
THE FULL BAP. 
 
 161 
 
 ceive the proper enlargement. Finally, the small traverses 
 are themselves destroyed, after the construction of the large 
 ones, destined to guard against enfilade and reverse fire, both 
 of artillery and musketry. 
 
 CHANGE OP DIRECTION OP THE FULL SAP. 
 
 All the changes of direction of the full sap, both simple 
 and double, are comprised in the following list : 
 
 1. Obliquing to the right or left. 
 
 2. Debouching by the simple or double sap from the end 
 of simple sap whilst in course of construction. 
 
 3. Debouching by the simple sap, from one or both sides 
 of the double sap, in course of construction. 
 
 4. Uniting in one double sap two simple saps meeting 
 each other. 
 
 5. Debouching by the simple or double sap from a sap 
 
 not enlarged. 
 
 6. Debouching by the simple or 
 double sap from a trench of the ordi- 
 nary dimensions. 
 
 Before describing these different de- 
 bouches, it is well to observe that the 
 sap should be well supplied with sand- 
 bags and wool-sacks, and that the chief 
 of sap should conduct the operation 
 with the greatest order and celerity. 
 
 TO CHANGE DIRECTION TO THE RIGHT 
 OR LEFT. 
 
 This change of direction reduces 
 itself to turning the sap-roller until 
 it becomes perpendicular to the new 
 direction to be given the sap. We 
 will suppose the direction is to be 
 changed to the left, the chief of sap 
 
162 MANUAL FOB ENGINEER TROOPS. 
 
 first warns the brigade by the command, "Prepare to change 
 direction" Then 
 
 1. "Levers. Fagots." 
 
 2. "Hooks." 
 
 3. " Change direction." 
 
 At the first^command the assistants pass to the first sapper 
 two sap-fagots and a wool-sack. No. 1 places one fagot 
 perpendicular to the roller and near its interior extremity, 
 the other on the first, near and parallel to the roller, in- 
 clining toward the sap. He then replaces the fagot in the 
 joint of the gabionade and roller by the wool-sack, which 
 he fixes in its position by means of the sap-fork. No. 2 
 receives a lever 12' long, one end of which he introduces 
 between the roller and fagot just placed. 
 
 At the second command No. 3 takes the reverse-hook and 
 fixes it in the roller, in such a manner as to be able to push 
 the roller. No. 4 fixes the berme-hook in such a way as to 
 be able to pull it. The first and second assistants aid re- 
 spectively sappers No. 3 and 4. 
 
 At the third command No. 4 holds the roller against the 
 last-placed gabion, whilst No. 3 pushes the opposite extrem- 
 ity, No. 2 favoring the motion of the roller by weighing 
 down on the lever as the roller advances. ^ No. 1 pushes up 
 the fagot (which is used as a fulcrum for the lever) in order 
 to give No. 2 a better purchase. 
 
 In this way, the direction of the roller may be changed 
 50 or 60 in about fifteen minutes, even on ground ascend- 
 ing toward the place. 
 
 TO DEBOUCH BY THE SIMPLE OR DOUBLE SAP FROM THE EX- 
 TREMITY OF THE SIMPLE SAP IN COURSE OF CONSTRUC- 
 TION. 
 
 FIRST CASTS. BY THE SIMPLE SAP. 
 
 When but five gabions remain to be placed before arriv- 
 ing at the point at which the change of direction is to be 
 
THE FULL SAP. 
 
 163 
 
 made, the chief of 
 sap causes an off- 
 set to be made in 
 the gabionade and 
 berrne, so that the 
 last five gabions 
 I shall form a line 
 parallel to that of 
 the others, and 13" 
 within it. The 
 object of this ar- 
 rangement will be seen hereafter. 
 
 When the fifth gabion is placed, the chief of sap warns No. 
 1 to arrest his form within 20" of the roller, instead of ad- 
 vancing to the middle of the last gabion. When this is 
 filled, the following commands are given. 
 
 1. " Prepare the debouch." 
 
 2. " Prepare to debouch." 
 
 3. "Debouch." 
 
 At the first command 'No. I commences a form parallel to 
 the roller on the reverse ; this form is also 20" wide and 
 deep, but a berate of 20" is left between it and the roller. 
 When he arrives nearly opposite the extremity of the sap- 
 roller he places in its prolongation, by the half-full sap, three 
 gabions, in order to prolong the epau-lement necessary to 
 cover the manoeuvre of debouching. He arrests his form 
 opposite the middle of the third gabion. The other sappers 
 follow, enlarging their forms as usual. 
 
 No. 2 throws his earth in rear of the roller and the first 
 gabion in its prolongation, the others throw the earth be- 
 hind the gabions in rear of the crochet. 
 
 The sap being now in the situation indicated in the above 
 figure, Nos. 1 and 2 commence excavating the retreat, v, oj, 
 y, z ; making it 40" wide and 40" deep at cc, y, and 24" at 
 o, z, they throw their earth in rear of the three last-placed 
 
164 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 gabions. Nos. 3 and 4 also enlarge the extremity of the sap, 
 s, , u, y, until it is 40* wide and deep, throwing the earth 
 in rear of the fifth and sixth gabions. 
 
 At the same time the assistants bring forward a sap-roller, 
 and the fascines necessary to stuff it, also a piece of scant- 
 ling or plank 7' long. 
 
 When Nos. 3 and 4 have finished their excavation, they 
 lay the plank across the sap opposite the joint of the third 
 and fourth gabions, one end on the berme, the other on the 
 reverse. Then, aided by the assistants, they place the roller 
 upon it, and against the parapet of the sap, its extremity 
 6" from the first roller; they then stuff it with the fascines, 
 which operation should be completed about the same time 
 that Nos. 1 and 2 finish their excavation (#, y, v, z). 
 
 At the second com- 
 mand, Nos. 2, 3 and 4 
 place themselves in the 
 retreat, x, y, v, z ; fur- 
 nished with two forks 
 and two hooks, they 
 draw the new roller to- 
 ward them, away from 
 the gabionade ; they 
 place a wool-sack under 
 it to protect their legs 
 from the shot which 
 might pass under the roller after the gabions are removed. 
 No. 1 having a sap-hook, places himself a little in rear of 
 the fifth gabion, in the re-entrant formed in the berme at this 
 point, and holds himself in readiness to overturn the gabions, 
 the first assistant aiding him. 
 
 At the third command No. 1 overturns into the sap the 
 first four gabions, the fascines or sand-bags with which they 
 are crowned and the sap-fagots closing their joints ; he drags 
 them to the rear with his hook, or ranges them on the bot- 
 
THE FULL SAP. 
 
 1C5 
 
 torn of the sap in such a manner as not to interfere with the 
 advance of the new roller, and without displacing the plank 
 over which it is to pass. 
 
 This being accomplished, Nos. 2, 3 and 4 push forward 
 the roller, causing it to pass through the opening thus form- 
 ed, notwithstanding the mounds of earth left on the berme 
 by the overturned gabions. They effect this first by using 
 the forks, afterward the hooks. 
 
 No. 1 then re- 
 pairs to the angle 
 formed by the two 
 rollers, where he 
 places a gabion in 
 the position of the 
 first one, which was 
 overturned ; if the 
 earth left by the 
 latter on the berme 
 impedes the opera- 
 tion, it can be removed with the drag ; after this the sap is 
 executed in the ordinary manner. In ordinary ground this 
 debouche can be executed in an hour and a quarter, from the 
 command '"''Prepare to debouch" to the placing of the first 
 gabion of the new sap. The time required for the different 
 operations is as follows, viz. : 
 
 Executing th.Q form of No. 1 along the first roller, 
 
 and filling the three gabions of the epaulement, 30 min. 
 
 Completing the sap, placing and filling the roller, 34 " 
 
 Overturning the four gabions, 8 " 
 
 Advancing the roller, * 1 " 
 
 Replacing the first gabion, - 2 " 
 
 1 h. 15 min. 
 
 To debouch obliquely from the sap of departure, it is 
 necessary to give the first roller a parallel direction to that 
 
1G6 
 
 MANUAL FOB ENGINEER TROOPS. 
 
 which the new sap is to have, the retreat is then made par- 
 allel to this, and the new roller placed perpendicular to the 
 new direction. The number of gabions to be overturned 
 will depend on the angle made by the two saps. These ga- 
 bions are not all overturned at the same time, but in propor- 
 tion as the roller advances, filling the opening left by those 
 first pulled down. Any opening that may occur between the 
 roller and gabions is closed by a wool-bag. 
 
 An oblique debouche may also be effected by first execu- 
 ting the perpendicular from the sap of departure, then, by 
 successive changes of direction of the roller, obtaining the 
 required direction. This is perhaps the most expeditious 
 method ; but it may happen, that the portion of the new sap 
 which is perpendicular to the sap of departure, is exposed 
 
THE FULL SAP. 
 
 107 
 
 to reverse fire, in which case it will be necessary to make 
 use of the half double sap for this portion. 
 
 SECOND CASE. DEBOUCHING BY THE DOUBLE SAP. 
 
 ii 
 
 I >J 1 
 
 1 I! 
 
 =p 
 
 I ftt 
 
 u 
 
 x 
 
 t*T\ti~ 
 xl-^ 
 
 \ x 
 
 
 
 
 
 Having arrived at the position from which the debouche 
 is to be made, the chief of sap cautions the sappers to throw 
 no earth in rear of the last eight gabions, which are to 
 be overturned, in order to allow a passage for the new roll- 
 In most cases these last gabions can be placed in the 
 
 ers. 
 
 same line with those of the gabionade preceding them, dis- 
 pensing with the crochet used in the former example. 
 The head of the sap having arrived at the last gabion, the 
 
168 MANUAL FOR ENGINEER TROOPS. 
 
 chief of sap commands, " Prepare to debouch by the double 
 sap." The sappers then execute all that has been indicated 
 at the analogous command in the simple sap, and in addi- 
 tion, the first and second assistants of the brigade, or two 
 sappers of the new brigade (necessary to execute the double 
 full sap, excavate a second retreat in the reverse similar to 
 the first, and opposite the Cth *nd half of the 7th gabion. 
 
 Two sap-rollers are then placed on the planks that have 
 previously been laid across the sap. The rollers should be so 
 situated that their outer extremities should be opposite the 
 first and eighth gabions to be overturned. The sap-rollers 
 are moved back on to the reverse. 
 
 The chief of the double sap then causes the first brigade 
 to debouch, replace the first gabion and fill it, then retire. 
 
 The second brigade then advance, debouch with their sap 
 in similar manner, and replace and refill the eighth gabion. 
 The double sap is then conducted by the ordinary commands. 
 It may happen that after the debouche, the two rollers are 
 not in contact ; in this case the opening must be masked with 
 a wool-sack, and the rollers brought together with the levers. 
 
 It requires about one hour and a half to execute the de- 
 bouche, from the command " Prepare to debouch" until the 
 first gabion of the double sap is replaced. 
 
 The following method for debouching from a sap in course 
 of construction, appears to be both of simple and easy exe- 
 cution. A frame is provided, having been previously pre- 
 pared to receive the new roller, also three rollers 4" in diam- 
 eter and 40" long, and a plank 7' long. 
 
 The sap having received its full depth, and the berme being 
 cleared off, the chief of sap commands, " Prepare to de- 
 bouch" No. 1 places a roller across the trench. No. 2 places 
 the plank also across the trench and opposite the third 
 gabion. These two sappers then pass to the rear and 
 receive from the other sappers the frame, which they lay 
 with one end on the small roller, the handles on the plank. 
 
THE FULL SAP. 
 
 169 
 
 2d. Sap-roller." 
 
 At this command an empty roller is passed to the head 
 of the sap by the assistants, placed by the sappers on the 
 frame and against the first roller, then stuffed. 
 
 3d. " Prepare to advance" 
 
 Nos. 1 and 2 leave the sap ; crawl on their bellies along the 
 sap-roller ; No. 1 is charged with pushing the first sap-roller, 
 renewing the rollers under the frame, and giving warning 
 by the words "more" or " too much" of the progress of the 
 new roller which No. 2 holds upon the frame. . Nos. 9 and 
 4, with a sap-hook passing between the gabionade and new 
 roller, hold themselves in readiness to push the first sap-roller 
 forward. The first assistant places himself under the new 
 
170 MANUAL FOR ENGINEER TROOPS. 
 
 sap-roller, the second between the handles of the frame, and 
 the 3d and 4th at the extremities of these handles. 
 
 The chief of sap then glides behind the new roller and 
 commands, " Forward" 
 
 All push (in silence, that they may hear the commands of 
 No. 1). 
 
 When the chief sees that the new roller is unmasked ho 
 commands, "Halt" 
 
 No. 3 disengages the sap-hook, and places a wool-sack in 
 the joint of the new roller and gabionade. 
 
 The second assistant yields his place to the first as soon as 
 the roller has arrived at the end of the trench, and goes to 
 the assistance of sappers 1 and 2. 
 
 "Forward." 
 
 At this command, Nos. 1, 2, and second assistant push the 
 new roller of the frame into the required position. To ef- 
 fect this they should lie flat on the ground, and push with 
 their shoulders, until the command is given, " Enough." 
 
 The second assistant then passes the wool-sack to sapper 
 No 1, who places it in the joint of the two rollers. The op- 
 eration is terminated by the command, " To your posts" 
 Each sapper retakes his place, the frame and small rollers are 
 carried to the rear by the assistant. This method requires 
 not more than five or six minutes, not including excavating 
 the sap to the full depth and stuffing the new roller. It 
 would therefore appear that the process, with some slight 
 modification, would be equally safe and much more expedi- 
 tious than that now in use. 
 
 TO DEBOUCH BY THE SIMPLE SAP FROM ONE OR BOTH SIDES 
 OF THE DOUBLE SAP. 
 
 When the debouche is to be made on both sides of the 
 double sap, the chief of sap will cause the last five gabions 
 of each parapet, to be placed 1' within the lines, and the form 
 of each of the first sappers to stop within 20" of tliu rollers, 
 
THE FULL SAT. 
 
 171 
 
 when in their per- 
 manent position. 
 He will then com- 
 mand, " PrejHire 
 to debouch by 
 tJie simple sap" 
 Each No. 1 
 will then fix his 
 sap roller with 
 ^ pickets. Then 
 \ turning their 
 J forms at right an- 
 P- gles, they will 
 - : move toward 
 each other, mak- 
 ing their excava- 
 tions 40" wide 
 and deep, the pre- 
 ceding portions 
 of the sap are 
 also enlarged to 
 the same dimen- 
 sions. They will 
 I all avoid throw- 
 | ing the earth 
 H against any of 
 ^ the gabions that 
 f are to be over- 
 2 : turned. 
 
 The brigade that first completes this task (that on the 
 right for example) will bring forward an empty roller, place 
 and stuff it, as in the preceding cases. The chief will 
 then command : 
 
 2. u L<'ft In'iffit.th retire. Riyht brigade prepare to debouch." 
 3. 
 
172 MANUAL FOR ENGINEER TROOPS. 
 
 At the second command the left brigade will retire to the 
 rear of the sap, and the right will execute the debouche on 
 the right side of the sap. When they have replaced and re- 
 filled their first gabion, the chief commands : 
 
 4. "Right brigade retire. Left brigade prepare to debouch" 
 
 5. "Debouch." 
 
 The right then retire and the left brigade execute the de- 
 bouche from the left side of the sap, in a similar manner ; when 
 they have refilled their first gabion, the chief will command : 
 
 6. "Might brigade, to your posts." 
 
 The two saps will then proceed in the ordinary manner. 
 About one hour is required to execute the double d'ebourho, 
 which is composed of two successive debouches. If the de- 
 bouche is to be executed on one side only, but forty minutes 
 will be required. 
 
 The processes described in the three preceding articles 
 consume one or two sap-rollers, which remain in their places. 
 As these rollers are of difficult construction, it may be desir- 
 able to withdraw them from these positions to use elsewhere. 
 To eflect this, earth is thrown in rear of the roller to be 
 removed, until a parapet is formed 40" high ; two beams are 
 then laid in front of the roller, upon which it is rolled down 
 into the trench, the position which it occupied is then imme- 
 diately supplied by three or four ordinary gabions, which are 
 filled and crowned. 
 
 TO UNITE TWO SIMPLE SAPS INTO ONE DOUBLE SAP. 
 
THE FULL SAP. 
 
 173 
 
 When the gabionade? of the two saps to be united have 
 approached to within 13' 6" of each other, the chief of the 
 double sap causes their junction by the following commands : 
 
 1. "Prepare to unite in the double sap." 
 
 2. "Lever. Fagots." 
 
 3. "Hooks." 
 
 4. " Change direction." 
 
 5. "Halt." 
 
 6. " Commence working." 
 
 7. "Forward." 
 
 At the first command each brigade prepares to execute 
 simultaneously the manoeuvres which will here b$ described 
 for one of them. Nos. 1, 2 and 3 enlarge their forms, making 
 them 7" wider and 40" deep. No. 1 must not pass beyond 
 the middle of the first gabion, or throw earth behind this 
 gabion. 
 
 The second, third and fourth commands are executed in 
 
174 MANUAL FOR ENGINEER TROOPS. 
 
 the same manner as the same commands in the simple change 
 of direction of the sap, with this exception, Nos. 1 and 4 
 dr:i\v toward the interior of the sap, the end of the roller 
 on the bcrme ; by these means the direction of the roller is 
 changed 70 or 80 ; it should then be entirely within the 
 line of gabions. 
 
 The fifth command is given when the direction is so much 
 changed that No. 2 can no longer act with his lever ; the 
 lever, fagots and forks are then passed to the rear. 
 
 At the sixth command No. 1 commences a form 20" wide 
 and deep in rear of the roller, and as near it as possible ; he 
 works kneeling, and is followed closely by No. 2, who 
 deepens it 12". The earth is thrown on the reverse. 
 
 When No. 1 has excavated to within 12" or 16" of the 
 further end of the roller, he retires, and when the form lias 
 been sufficiently enlarged, Nos. 2, 3, 4, and first assistant 
 enter it, provided with two forks and two hooks, taking care 
 to keep themselves perfectly covered by stooping. 
 
 At the seventh command these sappers push forward the 
 rollers with their hooks and forks, causing them to enter the 
 interval left between the gabionades. The two brigades 
 will so concert their movements that the two rollers shall 
 be exactly joined, forming thus one roller whose direction 
 is parallel to the sap. 
 
 In the mean while No. 1, stationed at the head of the sap, 
 directs the motion of the roller by warning the sappers who 
 are pushing, and if he perceives that the motion of the 
 roller is hindered by the last gabion of the gabionade (as is 
 almost always the case), he, aided by the second assistant, 
 overturns it in the trench with a sap-hook, and supplies its 
 place with a wool-sack, using a fork to place it. 
 
 Finally, when the two rollers have entered the opening, 
 the c.hief commands, "Gabions;" the two gabions that were 
 overturned are replaced, and the double sap is continued by 
 the ordinary commands. 
 
THE FULL SAP. 175 
 
 In ordinary ground the time occupied in this mano3uvre 
 is as follows : 
 
 Enlarging the two saps about to be united, 25 minutes. 
 Changing direction of sap-rollers 70 or 80, 15 " 
 Excavating forms in rear of sap-rollers, 25 " 
 
 Advancing the rollers, overturning the ex- 
 treme gabions of the two saps, and re- 
 placing them, 15 " 
 
 Total - 1 hr. 20 minutes. 
 
 It must, however, be remarked that No. 1 has to turn his 
 form around the replaced gabion, in order to take the new 
 direction of the double sap, which employs about ten minutes, 
 making the total length of time consumed one hour and 
 thirty minutes. 
 
 If the two simple saps are merely to be united the two 
 rollers which are to form the parapet are united as above, 
 and, if necessary, may be withdrawn by the process before 
 described. In this case the first command is changed into 
 "Prepare to unite the saps" The overturned gabions are 
 not replaced, but the openings left by them closed with 
 fagots or sand-bags. 
 
 TO DEBOUCH BY THE DOUBLE OR SIMPLE SAP, FROM A SAP 
 NOT ENLARGED. 
 
 FIRST CASE. TO DEBOUCH BY THE SIMPLE SAP. 
 
 Let A be the gabion selected as the first of the new gabion- 
 ade. The chief of sap commands : 1. "Prepare to debouch" 
 2. " Commence working" At the first command, No. 1, 
 directed by the chief, traces on the berme and slope of the 
 sap a form 12" to the left of gabion A, 40" wide and deep. 
 He is provided with a pick and shovel. No. 2 places across 
 the sap on each side of this form a plank, one end resting 
 on the benne, the other on the reverse, lie is furnished with 
 
176 
 
 MANUAL FOB ENGINEER TROOPS. 
 
 two drags, one having a handle 3' and thQ other 6' 
 The 3d and 4th sappers pull down the crowning fascines 
 from gabions A, B, C, and D, with their forks. 
 
 The assistants bring forward an empty roller, place it on 
 the planks against the four gabions to be removed, one end 
 opposite the middle of A, and prepare to stuff it. At the 
 2(1 command No. 1, kneeling under the roller, commences 
 
THE FULL SAP. 
 
 177 
 
 to excavate his form. No. 2 draws the earth thus obtained 
 along the bottom of the sap (and to the right), with his drag. 
 Nos. 3 and 4 throw it over the parapet. During this time 
 the assistants stuff the roller and adjust the crowning of the 
 gabions adjacent to the debouche, if they have been dis- 
 arranged. 
 
 As soon as No. 1 has advanced 16" or 20", No. 3 also 
 s under the roller, on the side opposite No. 2, and drags 
 away a portion of the earth excavated by No. 1. The first 
 assistant throws this over the parapet. 
 
 No. 1 pushes his form until he has passed the line of gabions 
 passing under C and B ; he then drags the earth out of these 
 gabions into his form, pulls the gabions themselves through 
 8* 
 
ITS MANUAL FOR EXGIXKFR TKOOPS. 
 
 1lio opening into the trench, overturns gabions A and D, and 
 < I nigs them also into the sap, clears away tlie earth whirh 
 might impede the progress of the roller with his drag. 
 During this operation he is covered from the fire of the 
 place by the mask of earth (about '32" high), which remains 
 in advance of the roller. 
 
 Nos. 2 and 3 move forward the roller until it rests against 
 this mask, closing the openings that may be dangerous l>r- 
 twi'i-u the roller and gabionade witli sand-bags, wool-sacks, 
 fagots, &c. No. 1, under the roller, which is gradually 
 moved forward, continues his form (40" wide and dee})), 
 passing the earth to the rear. Nos. 2 and 3, who work 
 standing, pass this earth to No. 4 and the first assistant. 
 The gabion A should be replaced as soon as there is suffi- 
 cient space for it. 
 
 When the form of No. 1 has attained a length of about 
 5' 4", a second gabion is placed, and the work is continued 
 as in the ordinary sap. It must, however, be remarked that 
 the places of the 2d, 3d and 4th gabions must be prepared 
 with the drag previous to setting them, and that the roller 
 has to be forced over a small mound of earth, the remains 
 of the parapet which has been cut through. 
 
 The time necessary for this debouche, including the crown- 
 ing of the third gabion, is about two hours and a half, viz. : 
 From the commencement until the overturn- 
 ing of gabions, 30 minutes. 
 Overturning gabions, 17 " 
 To advance the roller to the outer surface 
 
 of gabionade, 6 " 
 
 The roller entirely engaged in the gabionade, 32 " 
 First gabion filled, 35 " 
 
 Second " 10 
 
 Third " " crowned, and No. 1 form 
 
 reaches the middle, - 20 " 
 
 Total, - - 2 lirs. 30 minutes. 
 
THE FULL SAP. 
 
 179 
 
 In the case of an oblique debouche the roller is placed per- 
 pendicular to the new direction, and No. 1 excavates in this 
 direction. The operation is similar to that just described, 
 but longer. It is therefore generally preferable to debouch 
 perpendicularly first, and then change the direction, if 
 necessary. 
 
 SECOND CASE. TO DEBOUCH BY THE DOUBLE SAP. 
 
 Two gabions of the gabionade 13' 4" apart, are chosen as 
 the first of the double sap. The chief commands, I. ''Pre- 
 pare to debouch by the double sap" 2. " Commence working." 
 
 Each brigade executes all that has been prescribed above 
 for these commands. The assistants, in stuffing the rollers, 
 should bind them together, causing the fascines of one to 
 project into the other. The earth, inthis case, can only be 
 drawn away on one side of the sap, instead of both, as in 
 the preceding case, which renders the execution somewhat 
 longer. 
 
180 
 
 MANUAL FOR ENGINEER TROOPS. ' 
 
 TO DEBOUCH BY THE SIMPLE OR DOUBLE SAP, FROM A 
 OF THE ORDIN.WIY AVIDTH. 
 
 FIRST CASE. TO DEBOUCH BY SIMPLE SAP. 
 
 Let A be the gabion chosen as the first of the new gabion- 
 ade (on the right of the new sap). The chief commands, 
 1. "Prepare to ikbouch." 2. "Ready." 3. "Debouch." 
 4. "Halt'' 1 At the first command, the assistants brine: for- 
 ward a sap-roller, place it against the reverse, in the trench, 
 and opposite the gabions A, B, C, and D, and if not already 
 filled, fill it. Nos. 1, 2, 3 and 4 are provided with two sap- 
 hooks, two forks, two beams, 10' 6" long, and notched 011 one 
 
THE FULL SAP. 
 
 181 
 
 side, two ropes 30' or 40' long, having a hook at one ex- 
 tremity of each, a long and a short handle drag. 
 
 At the second command, Nos. 1 and 4, each taking a fork, 
 place themselves opposite A, B, C, D (the first on the right), 
 and first take down the crowning fascine, then overturn the 
 into the trench. The same sappers place the beam, 
 one end under the roller, and about 12" from its 
 extremity, the other on the parapet, which has been previ- 
 ously formed into a ramp, by dragging the earth inward 
 with a hoe. Nos. 2 and 3 lay two hooks on the reverse, op- 
 posite and perpendicular to the roller, fasten the hooks of the 
 in roller, and plant two strong stakes on each side of it. 
 
182 
 
 MANUAL FOR ENGINEER TROOrS. 
 
 The assistants are placed two on each side the 1 and 2, 
 provided with forks. At the third command the roller is 
 pushed up to the top of the parapet, first by hand, then with 
 forks ; the sappers having the following positions Nos. 2 
 and 3 assistants near the right beam, acting with the same 
 hook ; Nos. 3 and 4 assistants do the same on the opposite 
 end ; the first and second assistants opposite the middle of 
 the roller, pushing with the forks, and prevent it from rolling 
 back when the hooks are disengaged to take a new hold ; 
 Nos. 1 and 4 at each end of the roller, and outside the 
 beams, also pushing, and in case of need assisting at the hooks. 
 
THE FULL SAP. 
 
 183 
 
 When the roller arrives at tlie crest of the parapet, it is still 
 pushed with the hooks, but the first and second assistants 
 taking the ropes, give them a turn around the pickets (in 
 the bottom of the trench), allow the roller to roll gradually 
 down the exterior slope of the parapet, keeping it parallel 
 to its first position. At the fourth command, which the 
 chief gives when he judges the roller N has nearly reached 
 the foot of the parapet, the ropes are made fast to the pick- 
 ets, and the beams, hooks, &c., taken away and laid on the 
 reverse and berme. The sap is then commenced with the 
 usual command, "Gabion" &c. 
 
184 MANUAL FOB ENGINEER TROOPS. 
 
 It should be remarked, first, That the new gabionade 
 should be so directed that, arriving at the sap-roller, the last- 
 placed gabion shall be at least half covered by it. 
 
 Second, That No. 1, being perfectly covered by the par- 
 apet, having cleared away the earth of the parapet, places 
 the first two gabions on the natural ground, and then com- 
 mences his form in the usual manner, throwing the earth to 
 the rear ; the sappers in the rear fill these two gabions ; No. 
 1 fills the following one, throwing the excess of earth to 
 the rear. 
 
 Third. Any accidental openings are closed immediately 
 with wool-sacks. The time required to execute this debouche, 
 from the command "Prepare to debouch" until seven ga- 
 bions are placed, is about four hours. 
 
 SECOND CASE. TO DEBOUCH BY THE DOUBLE SAP. 
 
 This case is executed in the same manner as the preced- 
 ing. The assistants, in placing the two rollers, take care to 
 bind them well together, that they may not separate in the 
 man<ruvre. That portion of the earth of the parapet be- 
 tween the two saps which does not crumble into the forms, 
 is allowed to remain until the trench is turned over to the 
 ordinary workmen. ^ 
 
 TRENCH CAVALIER. 
 
 The trench cavalier is a mass of earth surmounted by a 
 parapet erected just beyond the range of the hand grenade* 
 of the besieged, for the purpose of obtaining a plunging fire 
 over the salient places of arms of the covered way. 
 
 This construction is ordinarily traced by the full sap. It 
 is included between the prolongation of the branches of 
 these salients, and as nearly perpendicular to them as the 
 sally of the collateral works Will permit. To its extremities 
 are added small ilanks to cover it from enfilade. 
 
 The mass of earth is sustained by several courses of ga- 
 
THE FULL SAP. 
 
 185 
 
 bions, against the interior of which steps arc arranged to 
 ascend to the upper course, which serves as i paifipet. The 
 number of these courses is determined by the condition that 
 tin.; cavalier shall command the crest of the covered way at 
 least 4' 4", so that as each course of gabions crowned with 
 two fascines gives a height of 40"; there will be as many 
 courses plus one required as the difference between the level 
 of this crest and the site of the cavalier contains this num- 
 bering. 
 
 The following is the process for constructing a cavalier 
 three courses high, in an easy soil : 
 
 After having traced the cavalier and its return by the full 
 pup, :ind crowned the gabionade with two fascines, the width 
 of I lie sap is increased by 6' 8", in order to increase the 
 thickness of the parapet and form a step at the foot of the 
 beniHj 20" high, and extending 6' within the gabionade, for 
 the cavalier, and 4' for the flanks. The sappers mount this 
 
186 MANUAL FOR ENGINEER TROOPS. 
 
 step, and with crooked handle-drags equalize the earth of 
 the parapet, thus forming a horizontal platform to receive 
 the second course of gabionsr The width of this platform 
 (including the gabionade) should be 6' for the cavalier, 4' 4" 
 for the flanks. The sappers then, standing on the step or 
 kneeling on the berrne, and stooping to keep themselves well 
 covered, place the second course of gabions 44" from tho 
 first for tho cavalier, and 24" for the flanks. They are 
 placed in position with sap-forks, and filled with earth, which 
 has previously been thrown in the bottom of the trench at 
 the foot of the step. A second step is then made, leaving 20" 
 tread to the first. The latter step has also a rise and tread 
 of 20"; its upper surface is consequently on a level with the 
 berme. The second course of gabions is then crowned with 
 two fascines, and earth thrown in rear until the parapet has 
 sufficient thickness to receive the third gabionade. The 
 necessary earth is obtained by widening the trench. A relay 
 of shovellers is stationed on the second step. A third step, 
 also with 20" rise and tread, is formed on the berme. Aided 
 by this step, and kneeling on the crowning of the first gabion- 
 ade, the sappers prepare a platform for a third, 4' 4" wide, 
 both for the cavalier and flanks. The last course is placed 
 24" beyond the second, by sappers kneeling on the crowning 
 of the first, and provided with forks. These gabions are 
 then filled and crowned with three rows of fascines ; earth 
 is thrown in rear of them to increase the thickness of the 
 parapet. For this purpose men are stationed in relays, the 
 first on the first course of gabions, the second at the foot of 
 the steps, the others 12' apart, to the reverse, where the 
 necessary earth is excavated. When the parapet has at- 
 tained the required thickness, which must be at least 40" at 
 the summit, it is crowned with sand-bags, so arranged as to 
 form loop-holes, and a step is formed between the first and 
 second courses of gabions, to allow the troops to mount the 
 latter. 
 
THE FULL SAP. 
 
 187 
 
 The preceding method has the advantage of consuming 
 the least possible number of gabions. It may be employed 
 when the earth of the glacis is easily worked, and when the 
 fire of the place is not too hot to prevent the sappers un- 
 covering themselves sufficiently to place each course of ga- 
 bions 40" in advance of the preceding. But in case the fire 
 is very active, or the ground difficult, the following method 
 must be resorted to, which, although much slower than the 
 preceding, gives a more solid construction. 
 
 1st. The cavalier is traced by the ordinary full sap, the 
 gabionade crowned with two fastines, and the trench en- 
 larged in width by 40", to thicken the parapet. 
 
 2d. A course of gabions is placed in the bottom of the 
 trench, at the foot of the slope of the berme, which are 
 crowned with two fascines, and earth added if necessary, 
 
188 MANUAL FOR ENGINEER TROOPS. 
 
 until the top has attained the level of the berme. Earth is 
 also thrown against this gabionade, in order that the earth 
 which acquires considerable consistency by the tread of the 
 workmen, may afford it some support. 
 
 3d. A third course of gabions is placed on the berme, in 
 contact with the first. These are filled and crowned in such 
 a manner that the crowning of the two shall be in the same 
 horizontal plane. 
 
 4th. A fourth course is placed over the joints of the first 
 and third. This is effected by sappers kneeling on the 
 second course, and manoeuvring the gabions with their 
 forks. They are filled and crowned like the preceding, and 
 a parapet formed in rear of them, with earth obtained by 
 enlarging the trench. 
 
 5th. When the parapet is elevated to the height of the 
 last-placed gabions, a fifth course is placed against the course 
 on the berme, and consequently on top of those placed in the 
 trench. This course is also filled and crowned. In order 
 to support the first and second course of gabions, a fresh 
 mass of earth is formed against the interior side of these 
 gabionades, as high as the middle of the first course. 
 
 6th. A sixth row is placed in the second stage, and over 
 the joints of the two interior rows of the first stage. These 
 are likewise filled and crowned. 
 
 7th. A seventh row is placed over the joints of the two 
 of the second stage, by means of the fork, as before. These 
 are filled and crowned with three fascines, and the parapet 
 is increased until it reaches the level of this crowning and 
 has acquired a sufficient thickness. 
 
 Finally, loop-holes arc formed by placing sand-bags on 
 this parapet, and the interior is arranged with steps, that 
 the troops may conveniently mount to the upper stage. 
 
 A cavalier composed of three stages, each stage twelve 
 gnbions or 20' in length, with flanks 15' or 20', can be con- 
 structed in twenty-four hours, not including the time re- 
 
THE FULL SAP. 
 
 189 
 
 quired to trace it with the 
 full sap. The number 
 of workmen required, in 
 ground where one pick is 
 required for each shovel, 
 is from 25 to 30 for the 
 first twelve hours, and 30 
 to 36 for the following 
 twelve. 
 
 The shovellers are ar- 
 ranged in files opposite 
 every third gabion, and 
 composed of as many men 
 as there are relays from 
 the reverse of the trench 
 to the summit of the par- 
 apet. Each row of ga- 
 bions can be placed in one 
 minute, and filled in twen- 
 ty, allowing one man to 
 two gabions. 
 
 At the commencement 
 of the work, and while the 
 steps are being construct- 
 ed, a part of the work' 
 men are employed in pre- 
 paring material. 
 
 THE DESCENT INTO THE 
 DITCH. 
 
 The descent into the 
 ditch is effected by a sub- 
 terranean gallery, when 
 the counterscarp has suf- 
 ficient height to allow a 
 mass of oar tli at least 40" 
 
190 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 deep to be left between the terreplein of the covered way 
 and the roof of the gallery. 
 
 This thickness is considered requisite by miners, in earth 
 of ordinary consistency, in order that the work may not be 
 of too difficult construction. It is also useful as a protection 
 against vertical projectiles. 
 
 The height of the descent is from G' to 6' 8" in the clear. 
 Its width varies with the difficulty of the soil. In earth of 
 ordinary consistency the width should be about 6' 8"; in 
 light sandy soil it is prudent to limit it to 4' 4". The fol- 
 lowing figures indicate the form and dimensions of the 
 frames used in the two cases (oak timber being used.) 
 
 hr 
 
 It will be perceived from these dimensions that the height 
 of the excavation must be about 7' G", giving 10' 10" as the 
 minimum distance between the surface of the ground and 
 the floor of the gallery. 
 
 The point of arrival of the descent is ordinarily fixed at 
 40" below the bottom of the ditch, in the case of a dry dit rh, 
 and 16" above the surface of the water in the contrary case. 
 
 The direction should be as nearly straight as possible, 
 
THE FULL SAP. 191 
 
 since a change is of difficult execution, and renders the com- 
 munication incommodious. The slope should not be greater 
 than |", but it is not indispensable that it should be uniform 
 through the whole extent of the gallery. For instance, 
 when the counterscarp is low, that portion which is beneath 
 the terreplein can have a very slight slope, while the pre- 
 ceding part has \". 
 
 The point of departure is fixed in a trench executed in 
 the glacis, to fulfil the preceding conditions. But it should 
 be remarked that the condition of having throughout a 
 mass 40" thick over the roof of the gallery, would oblige 
 the entrance to be placed 10' 10" below the surface if the 
 gallery were commenced at this point. Considerable time 
 and labor would be required to excavate the trench to this 
 depth, particularly as earth rarely has sufficient consistency 
 to sustain itself when excavated to such a depth, with the 
 elope required in the present case. Moreover, the vertical 
 projectiles of the besieged would, by falling into such an ex- 
 cavation, render the approach to the gallery extremely dan- 
 gerous. It is therefore advantageous to commence with a 
 blinded descent, whose point of departure is 20" only below 
 the surface, and not to commence the subterranean gallery 
 until the excavation has attained the depth of 10' 10". 
 
 When the ditch has little depth, advantage may be taken 
 of the traverses in the covered way, under which to execute 
 the gallery. This is effected by debouching into the defile 
 of the traverse (by the blinded gallery) 40" below the terre- 
 plein, and entering the profile of the traverse with the sub- 
 terranean gallery. In this case the sap-roller employed to 
 cover the head of the work, as will be seen hereafter, be- 
 comes superfluous from the depth of the excavation. 
 
 It may also be observed that the debouchc is only 
 covered by the profile of the traverse from direct fire, and 
 may be subject to a flank fire. It is therefore advisable, 
 when near the debouche, to first enter the defilu by a small 
 
192 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 opening similar to a branch gallery, and to place a mask of 
 gabions crowned with fascines in the defile, which may 
 cover the passage into the gallery under the traverse. 
 
 It may also be remarked that the above process gives the 
 means of " descending into the covered way," since having 
 once descended into the defile of the traverse, a debouche by 
 the sap can be effected into the terreplein of this work, in 
 order to establish lodgements. 
 
 Ono hour is required to execute 40" of a subterranean 
 descent, 6' x 6' 8" in ordinary soil. The miners employed 
 should be relieved every six hours. 
 
THE FULL SAP. 193 
 
 BLINDED DESCENT 
 
 Consists of a deep sap, which is covered as it advances 
 with fascines supported by blinds. The dimensions of the 
 latter are so regulated that the width and height in the 
 clear of the descent shall be 6' 8", which requires the width 
 of the sap at the bottom to be 7' 6", in order that the lateral 
 blinds may be easily placed. 
 
 The point of departure is usually in the crowning of the 
 covered way, 5' below the surface of the glacis, a depth 
 which allows the requisite mass of fascines and earth to be 
 heaped on the blinds without projecting above the parapet 
 of the adjacent trenches. The point of arrival is fixed as 
 for the subterranean descent, at 40" below the bottom of 
 the ditch when dry, and 16" above the level of the water 
 when wet. The direction of the descent between these 
 two points should be a right line, and the inclination should 
 not exceed . In case the maximum inclination would be 
 insufficient to cause the descent to debouch at the proper 
 level, the point of departure must be lowered. But this is 
 seldom necessary, since blinded descents are only employed 
 when the depth of the ditch is less than 10' 10". This depth 
 permitting, as has already been stated, the construction of 
 a subterranean gallery. 
 
 The construction is as follows : a debouche by the double 
 sap is executed from the crowning of the covered way, ac- 
 cording to the method previously described, with the ex- 
 ception that bermes 2' in width are left, in order to reduce 
 the width of the trench (when completed) at bottom to 7' 8". 
 This course is pursued until the sap-rollers have nearly clear- 
 ed the parapet of the trench from which the debouche has 
 been effected, which will require the placing of four gabions, 
 if care has been taken to enlarge the sap forming the crown- 
 ing, and to throw no earth in rear of the gabions to be over- 
 turned in debouching. The required depth for the descent 
 9 
 
MANUAL FOB ENGINEER TROOPS. 
 
 is then attained ; the slope given to the sides should be as 
 Bteep as the nature of the ground will permit (1 or | for ex- 
 ample). At the same time a landing is formed in the crown- 
 ing sap at the point 
 of departure of the 
 descent, having the 
 same depth as the 
 latter. This landing 
 is united with the 
 bottom of the trench 
 by slopes. A ver- 
 tical blind is then 
 placed on each side, 
 and connected by a 
 strong batten pass- 
 ing across the trench. 
 A horizontal blind ia 
 then placed, one side 
 ^ resting on the two 
 vertical blinds, the 
 other on two false 
 stanchions placed in 
 advance. Two or 
 three of the vertical 
 blinds are placed 
 when the excavation 
 has sufficiently ad- 
 vanced. The whole 
 is then covered with 
 fascines and the hides 
 of newly-killed cat- 
 tle. 
 
 Shortly after the commencement of the descent a very 
 delicate operation has to be executed, viz. : causing the sap- 
 rollers to descend the interior slope of the covered way. 
 
195 
 
 In order that this operation may be successful, it is essential 
 that previous to debouching the two rollers should be se- 
 curely fastened together. Then, if there are no palisades 
 in the covered way, or if the palisading, torn by the cannon 
 of the besiegers, has little sally above the crest of the glacis^ 
 the rollers may be pushed forward with the sap-hooks and 
 allowed to fall on the banquette, a rope or chain being fast- 
 
196 MANUAL FOR ENGINEER TROOTS. 
 
 ened to each end and the middle, by which the rollers are 
 prevented from rolling off the banquette to the terreplein. 
 If, however, the palisades have preserved their points and 
 then sally above the crest, these points engaging in the 
 watling may impede the* progress of the rollers. In this 
 case the rollers may be slightly raised with levers, and three 
 or four planks slid under their middle and extremities, and 
 placed, one end resting on the glacis, the other on the pali- 
 sading, thus forming a ramp over which they may be rolled 
 untill they fall on the banquette. The same end may be ac- 
 complished by throwing sand-bags into the interval between 
 the palisades and interior slope, heaping them above the 
 points of the palisades. In every case great attention must 
 be paid to the ropes by which the rollers are retained. The 
 same precaution is necessary in descending the banquette 
 elope, lest the roller move too far in advance to cover the 
 head of the descent. If, however, it is sometimes found 
 too far in advance, it will suffice to suspend across the descent, 
 against the upper part of the last-placed blinds, a thick plank, 
 which serves to mask the interior. As to the head of the 
 work, the roller always covers it sufficiently. 
 
 The execution of the descent comprises two operations, 
 
 EXCAVATING AND BLINDING. 
 
 The excavation is accomplished by the double sap, as be- 
 fore mentioned. It is executed by two sappers, who exca- 
 vate to the full width and depth of the descent, throwing 
 the earth in rear of the lateral gabions. If, however, the 
 depth is to be greater than 80", the leading sappers only dig 
 to this depth, and are followed by two others, who complete 
 the excavation, leaving for the first a banquette 40" wide, and 
 throwing the earth into wheelbarrows, in which it is trans- 
 ported to the rear and thrown on the parapet of the crown- 
 ing by the remaining sappers. In case the soil is too loose 
 to allow the excavation to be carried to the depth of 80", 
 
THE FULL SAP. 197 
 
 leaving a slope of ^ ; the leading sappers dig as deep as the 
 nature of the soil will permit, giving the sides a slope of 
 *orf 
 
 When the head of the descent has attained a depth of 80", 
 the leading sappers are sufficiently covered to dispense with 
 the lateral gabionades. They still continue, however, to 
 form parapets, by throwing the earth to the right and left, 
 taking care to move the rollers forward gradually, so that 
 at each partial advance a portioa of the parapet thus formed 
 shall fall forward against them, affording a cover to the sap- 
 pers. On such occasions a quantity of loose earth should be 
 kept in readiness to fill up the gaps formed by the advance 
 of the rollers, as soon as they are made. Finally, as soon as 
 the lateral parapets have acquired sufficient thickness to pro- 
 tect the head of the work, earth is thrown to the rear, on 
 the fascines forming the roof of the blindage, to protect it 
 from the fireworks of the besieged. 
 
 As the excavation advances, pickets are driven at inter- 
 vals of 40", to aid in determining the direction and inclination. 
 
 BLINDAGE. 
 
 When the excavation has advanced 24" or 28" beyond 
 the last vertical blind, a horizontal blind is placed on the 
 latter, and sustained in front by two "false stanchions" 
 These are placed on each side, and about 30" from the axis 
 of the descent ; the foot of each is buried a few inches in 
 the ground, and their height is such as to raise the anterior 
 of the horizontal blind from 4" to 6" above its true position. 
 
 A new lateral blind is introduced when the excavation 
 has advanced 5' from the last-placed vertical blind; for this 
 purpose two holes are made on each side, in the alignment 
 of the lateral blinds, to receive the feet of the new ones, the 
 one 14" deep and 20" from the nearest stanchion of the last 
 blind, the other 4" deep and 40" from the first (in the case 
 where the inclination is \). The lateral blinds are then 
 
198 
 
 MANUAL FOB ENGINEER TROOrS. 
 
 placed, their tops engaged under the horizontal blind, and 
 the false stanchion removed. 
 
 It may be remarked that the lateral blinds should be placed 
 as nearly vertical and in the same alignment as possible, but 
 an attempt to place them with great accuracy would delay 
 the work unnecessarily ; it is sufficient to place the two first 
 on each side carefully to guide the position of the folio wing. 
 
 When the blinds are in position they are covered with 
 blinding fascines, which are 9' long, and 9" in diameter. 
 The two sappers at the head of the work are charged 
 with this operation. They seize the fascines (one at each 
 end), cast them up on the blinds, and arrange them with 
 
THE FULL SAP. 199 
 
 their forks ; three or four courses are thus placed and covered 
 with raw hides. 
 
 The spaces between the lateral blinds and slopes of the 
 excavation are then filled with fascines, for this purpose a 
 great number of fascines from 3' to 5' long and 9" in diame- 
 ter will be acquired. 
 
 TIME. 
 
 In ordinary soil, and with a counterscarp 11' high, about 
 13" of the descent may be executed in one hour. Ten 
 sappers are employed ; the two at the head of the work should 
 be frequently relieved ; they are provided with all the tools 
 necessary for the double sap, as well as those required in 
 executing an ordinary attack by the mine. 
 
 UNCOVERED DESCENT. 
 
 The sap by means of which the descent into a ditch of 
 little depth is efiected, without employing a blindage, is 
 termed an uncovered descent. From the difficulty of defiling 
 them, they usually require to be very narrow, and much 
 deeper than the ordinary sap ; otherwise there is nothing 
 peculiar in their construction, except the difficulty in firmly 
 placing the gabions on the slope of the descent. 
 
 DESCENT INTO THE COVERED WAY. 
 
 This is nothing more than a blinded descent executed by 
 the process already described usually placed opposite a 
 traverse, as previously remarked, and indicated in the figure. 
 When not exposed to a plunging fire, the " uncovered de- 
 scent" may be employed for this purpose. 
 
 PASSAGE OF THE DITCH. 
 
 When the ditch is dry, the passage merely consists of a 
 sap connecting the debouche of the descent with the foot of 
 the breach. But in the wet ditch, a bridge must be con- 
 structed, which, under musketry and artillery fire of the 
 
200 MANUAL FOE ENGINEER TROOPS. 
 
 place, is ordinarily a very difficult operation. The greater 
 part of the experiments in this operation in the schools of 
 practice have led to no satisfactory results. The following 
 is the process given by Vauban in his " Traite de Tattaque 
 des places" 
 
 PASSAGE OF THE MAIN DITCH. 
 
 When the ditch is wet, from 100 to 120 men (according 
 to circumstances) are stationed in line, two paces apart, with 
 their backs to the parapet ; they pass fascines from hand to 
 hand to the head of the bridge ; they are there received by 
 a sapper, who forms an epaulement with them, by piling them 
 on his right or left, as the case may require ; he then advances 
 a few paces and commences the construction of the bridge, 
 by casting the fascines obliquely downward and beneath the 
 water. This operation is continued until the mass arrives at 
 the surface ; he then lays a course of fascines crosswise, and 
 covers them with sufficient earth to sink them. The same 
 operation is repeated until a firm passage is formed, whoso 
 top is a few feet above the surface of the water, and from 
 12' to 14' wide. During this manoeuvre the epaulement is 
 carried on by placing fascines a little in advance, with a fork, 
 and arranging by the most convenient means. The epaule- 
 ment should receive a considerable height, as the fascines 
 always settle a goocl deal. 
 
 When it is perceived that the fascines touch the bottom 
 of the ditch, and the epaulement has sufficient solidity, it is 
 revetted with fascines bound together and picketed. 
 
 NOTE. When the debouche is exposed to a plunging fire 
 from the bastion, the passage must be commenced by form- 
 ing a " mountain" of fascines, from 8' to 10' high, the sap- 
 pers keeping close to this work at the epaulemeut and gallery, 
 continually pushing forward the mountain until out of range 
 of the plunging fire. The fascines of which it is constructed 
 are then withdrawn by degrees and used for the bridge and 
 
THE FULL SAP. 201 
 
 epaulement, continuing to push forward the passage until it 
 arrives at the foot of the breach, which I suppose by this 
 time to be far advanced. 
 
 To guard against this plunging fire, the mountain of fas- 
 cines alone will not be sufficient ; a good strong gallery must 
 also be employed, which is constructed under shelter of the 
 mountain, as above stated, and continued until beyond the 
 range of this fire. 
 
 When the water in the ditch is deep and has a rapid cur- 
 rent, or can be given one, it must be acknowledged that 
 the passage is by far the most difficult operation of the 
 siege, especially when the current can be neither turned nor 
 weakened from without. The utmost care and address will 
 hardly secure success, unless the fire of the place is totally 
 extinguished ; even after that of the faces, flanks, curtain and 
 tenailles is silenced, the work will be very much annoyed 
 by mortars and stone-mortars. 
 
 When all these dangers can be avoided, the operations 
 are carried on in the ditch as elsewhere. But it is ex- 
 tremely difficult to avoid even a part of them, and the dan- 
 ger of the execution is still very great ; the workmen are 
 very badly covered. From the constant danger of being seen 
 a great loss of time and life ensues. 
 
 Let us suppose a place surrounded by a ditch, through 
 which the water passes with considerable velocity, and is 
 supplied either by a river or by a reservoir, from which the 
 water is distributed from time to time through the ditches 
 by means of sluices, giving whatever velocity may be re- 
 quired, as is the case in many of our places. In either case, 
 as there will be either a continuous current, strong or 
 feeble, or one repeated from time to time, the only method 
 of effecting the passage will be by means of a heavy dike 
 across the ditch, having sufficient strength to withstand the 
 current, and a height at least two feet above the level of 
 the water when at its greatest height. 
 9* 
 
202 MANUAL FOR ENGINEER TROOPS. 
 
 For this purpose a mass of fascines well loaded with 
 stones, sods, and earth, must be formed, that they may sink 
 immediately to the bottom. Great width must be given to it, 
 the earth rammed, and stakes driven through into the bot- 
 tom of the ditch. 
 
 In a word, every means must be taken to render it solid, 
 until it arrives within 20' or 24' of the foot of the revet- 
 ment. The current then becomes rery troublesome, and it 
 will be necessary to make use of various expedients to com- 
 plete the passage, such as rolling in large gabions and barrels 
 filled with stones, which filling up the interval will still leave 
 a passage for the water ; trestles loaded with stones, earth 
 and fascines, sinking boats (if any are to be obtained). All 
 this should be accomplished before opening the breaching 
 batteries. After by all these expedients the dike has arrived 
 within 12' or 18' of the scarp, its head well secured, and its 
 upper surface above that of the highest water, the guns of 
 the breaching batteries should commence a lively fire against 
 the foot of the scarp, which being overturned into the ditch, 
 will probably fill up the interval. 
 
 If this is not completely effected, it will be necessary to 
 attach a miner to the portion of the scarp still standing to 
 drive the mine well in advance and opposite the head of the 
 dike, if this does not succeed, workmen must be detached to 
 form a lodgement at the foot of the breach, and working 
 from that side of the ditch contribute to the completion 
 of the dike. 
 
 There is another method which is excellent, but only ap- 
 plicable in narrow ditches with high revetments, which is, to 
 attach two miners, the one to the scarp the other to the 
 counterscarp, directly opposite each other. 
 
 If the mines are sufficiently deep and heavily charged, 
 the ditch may be choked at one blow, particularly if the 
 water has not more than 5' or 6' head. 
 
 It is thus we contemplated passing the ditch at the "porte 
 
THE FULL SAP. 203 
 
 d'Auzin" at Valenciennes, if the place had resisted long 
 enough to compel us to go thus far. 
 
 SAPS CONSTRUCTED WITH SAND-BAGS. 
 
 These saps are principally employed when the ground 
 passed over cannot be excavated, either in consequence of 
 the presence of rock or water. 
 
 The bags are filled at some convenient place near the 
 position where they arc to be used, and out of view of the 
 place attacked. 
 
 The working parties for this purpose are divided into 
 squads, composed of two shovellers, one holder, two tiers, 
 and as many men provided with picks as the nature of the 
 soil may require. Each squad should fill 150 bags per hour. 
 
 The flying sap is constructed as follows : 
 
 A path from the depot of sand-bags to the trench should 
 be selected, and distinctly marked, advantage being taken 
 of the inequalities of the ground to obtain as much cover as 
 possible. The carriers march along this path in single file, 
 each carrying a filled bag on his shoulder ; on arriving at the 
 head of the sap he delivers the sand-bag to the sapper and 
 returns for another. 
 
 Two sappers receive the bags from the carriers and form 
 with them the 1st course of the parapet. The bags are all 
 laid (. e., headers) perpendicular to the direction of the 
 trench and with their mouths alternately out and in. 
 
 When twelve bags have been laid, a second course is 
 commenced, by a second couple of sappers, supplied by a 
 second set of carriers. This course is laid directly over and 
 in the same manner as the first. 
 
 The succeeding courses are added in the same manner 
 until the parapet has attained the required height. When 
 a trench of the usual depth can be dug in the rear of this 
 parapet, six or seven courses of bags will be sufficient. If 
 the trench is but half the ordinary depth, nine or ten courses 
 
204 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 will be required ; and if no excavation can be made, the 
 parapet must be 6' 8" or fourteen bags higher. 
 
 This parapet is executed as follows: the 1st sapper, kneel- 
 ing, places the first four courses (1), 
 the second, also kneeling or stoop- 
 ing, lays the four courses No. 2. 
 
 Sappers Nos. 3, 4, and 5, lay the 
 courses marked 3, 4, and 5 ; No. 6 
 lays the portion marked 6, No. 7 standing on the banquette 
 and passing the bags up to him. 
 
 By a combination of gabions and sand-bags, the parapet 
 may be constructed with greater rapidity and a less number 
 
 of bags. 
 The gabions are placed as in the ordinary flying sap, and 
 
 filled with sand-bags by a party of 
 
 carriers. The bags for this purpose 
 
 should not be quite full, in order 
 
 th.it they may lie closer in the 
 
 gabion. The sand-bags for increas- 
 ing the height and thickness of the parapet are laid in a 
 
 manner similar to the preceding case. 
 
 To give greater stability to the parapet, two rows of 
 
 gabions may be employed, ^^ ^ 
 
 and the thickness afterward 
 
 increased by either throw- 
 ing earth over, joining the 
 
 mound represented by the 
 
 dotted lines, or increasing from the interior by courses of 
 
 sand-bags. 
 
MILITARY MINING. 
 
PART IV. 
 
 PRACTICAL OPERATIONS IN MINING. 
 
 THE essential difference between civil and military mining 
 is, that in the former the works are, for the most part, car- 
 ried on at greater depths below the surface of the earth, 
 and in solid rock; whereas, military mining is what may 
 be termed superficial, and consequently the miner works 
 through the more recent formations of earths and sands, 
 which, from their little tenacity, he has to support, as he 
 advances, with wooden linings. It is in the adjustment and 
 fittings of these linings that the chief art of the military 
 miner consists. 
 
 The excavations made by military miners are, when verti- 
 cal, called shafts ; when horizontal, or when slightly inclined, 
 and exceeding in dimensions three feet by four feet, galler- 
 ies ; when under these dimensions, branches. When galler- 
 ies or branches are inclined, they are called ascending or 
 descending, according to the direction of their inclination. 
 
 The galleries or branches of a system of mines, forming 
 part of the defences of a fortress, are usually reveted with 
 masonry. Their construction and detail will not be included 
 in this part of the subject. 
 
 The following table gives the names and dimensions of 
 galleries and branches employed in mining operations : 
 
208 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 Name. 
 Description of Gallery or 
 Branch. 
 
 Dimrnsions in 
 the clear. 
 
 Scantling of Frames. 
 
 Ground-sill. 
 
 Stanchions. 
 
 Cap-silL 
 
 1. Groat Gallery, 
 2. Principal Gallery, 
 3. Common Gallery, 
 4. Great Branch, 
 5. Small Branch, 
 
 Height "Width. 
 Ft Ins. Ft. Ins. 
 
 6 6 X'7 
 66x36 
 46x30 
 36x29 
 26x20 
 
 Inches. 
 6x3 
 54 x 3 
 
 14 
 
 4x3 
 3x2 
 
 Inches. 
 
 6x6 
 5* x 54 
 5x5 
 4x4 
 3x3 
 
 Inches. 
 
 6 x 84 
 54 x 8 
 5 x 64 
 4x5 
 3x4 
 
 1. Those galleries used for descent into ditches and the 
 passage of cannon. 
 
 2. Those used for descent into ditches and the passage of 
 troops, two deep. 
 
 3. Sufficiently large for all the general purposes of attack ; 
 and as it allows the miner a free change of posture, either to 
 work kneeling on both knees or on one knee, with the right 
 or left foot advanced, he works without feeling cramped, 
 and executes this size more rapidly than any other. 
 
 4 and 5. Too small to work in for a greater distance than 
 ten or twelve feet. 
 
 TOOLS REQUIRED FOR MINING OPERATIONS. 
 
 Pickaxe (common), 
 do. (short-handled), 
 
 Shovel (common), 
 do. (short-handled), 
 
 Push-pick, 
 
 Rake, 
 
 Canvas bucket, 
 
 Windlass and rope, 
 
 Rope-ladder, 
 
 "Wooden wedges and pins, 
 do. pickets, 
 
 Miners' wagon, 
 
 Wheelbarrow, 
 
 Handsaw, 
 
 Mallet, 
 
 Hammer (claw), 
 
 Rough plane (j-inch), 
 
 Chisel, 
 
 Gimlet, 
 
 Two-foot rule, 
 
 Plumb-bob, 
 
 Boring-rods, 
 
 Five-foot rod, 
 
 Bellows (miners), 
 
 Ventilating tube, 
 
 Flexible joints, 
 
PRACTICAL OPERATIONS IN MINING. 209 
 
 Iron candlestick, Needles, threads, and scissors, 
 
 Lamp (miners), Calico for hose, 
 
 Lantern, Hatchet, 
 
 Oil-can, Tin funnel (for fitting hose), 
 
 Measuring-tape, Rammers (short-handled), 
 
 Compass, Helves (spare), 
 
 Universal level, Sand-bags. 
 
 WOODEN LININGS. 
 
 It has already been stated that the military miner, from 
 the loose or made soil in which he generally works, has, as 
 he advances, to support with wooden linings the top and 
 sides of his excavation. In some soils, the earth is of suf- 
 ficient tenacity to require only, that in driving galleries in 
 it, their top should be supported. But in sinking shafts, it 
 is always advisable, unless their depth should be very little, 
 to line them with boarding throughout, or, at least, par- 
 tially. 
 
 In describing the process of driving a gallery, the soil is 
 supposed to be of that nature which renders close casing 
 desirable. 
 
 There are two methods adopted for lining shafts and gal- 
 leries. The first is with mine-frames, which, in appearance, 
 are similar to door-frames, being cut out of scantling, and 
 placed upright or horizontally at certain intervals in the 
 gallery or shaft, as the case may be, and which serve as sup- 
 ports to planks, called sheeting-planks, or sheds, which are 
 placed all around between the frames and sides of the exca- 
 vation. The second is with cases, which, instead of being 
 made from scantling, are formed out of plank, about two 
 inches thick and one foot wide ; these are placed close to- 
 gether, and serve at once for frames or sheeting. The 
 advantage of this latter method in saving excavation, and 
 consequently expediting the work, is at once obvious. Be- 
 sides which, the facility of fixing them up is much greater. 
 
210 
 
 MANUAL FOR ENGINEER TROOP8. 
 
 o 
 
 '* - I J 
 
 u 
 
 Fio. 1. 
 
 Shaft frames are composed of 
 four pieces halved together. The 
 top frame has the same dimen- 
 sions in the clear as the other, 
 but the ends project about one 
 foot in each direction. 
 
 The sheeting for shafts should 
 be of plank, from 1" to 1" thick. 
 The planks are usually chamfered 
 at one end, to admit of their be- 
 Their length will depend 
 
 FIG. 2. 
 
 ing more easily pushed forward, 
 on the distances at which the frames are placed, which, on 
 an average, may be assumed to be four feet ; the planks 
 may therefore be cut in lengths of five feet, which will allow 
 the necessary overlap. 
 
 MEN AND TOOLS REQUIRED TOR SINKING A SHAFT. 
 
 It has been found that one man can work in a shaft not 
 less than four feet in depth, and throw out earth until it is 
 
PRACTICAL OPERATIONS IN MINING. 
 
 211 
 
 eight or nine feet deep ; after which the earth is drawn up 
 in a canvas bag, or bucket, by two men at the top, by means 
 of ropes attached to each of its handles. Should the depth 
 become great, a windlass and bucket must be substituted. 
 
 MEN 
 
 . TOOLS. 
 
 
 
 Picks. 
 
 Shovels. 
 
 
 
 
 
 
 
 
 
 
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 8 
 
 
 
 
 
 
 
 
 
 
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 SB 
 
 
 
 
 
 
 
 
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 ^ 
 
 JU 
 
 d 
 
 ^H 
 
 B 
 
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 Privates 
 
 I 
 
 X 
 
 f! 
 
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 c 
 
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 Measurii 
 
 Mallet. 
 
 Canvas 1 
 
 c. 
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 Windlas 
 
 Miners' 
 
 Ventilat 
 
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 2 
 
 1 
 
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 2 
 
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 2 
 
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 The disposition of the workmen is as follows : 
 
 One man excavates and fills the bag. 
 
 Two men haul up, or work the windlass. 
 
 One man fills the wheelbarrow. 
 
 One man wheels. 
 
 One man spreads, to prevent an accumulation, which 
 might attract observation. Two gauges or rods for the ex- 
 treme dimension of the rectangle of excavation are to be 
 provided. These two rods must exceed respectively the 
 true exterior dimensions of the shaft-frame in length by 
 about six inches (three inches on each side), in order to 
 admit of two thicknesses of sheeting planks being intro- 
 duced all around, between the frame and sides of the ex- 
 cavation. 
 
 The top shaft-frame having, when placed, only one thick- 
 ness of sheeting planks around it, the rectangle of excavation 
 must be marked on the ground rather less than the dimen- 
 sions of the gauges. When the shaft is intended to be sunk 
 with a view to the commencement of a gallery, care must 
 
212 MANUAL FOR ENGINEER TROOPS. 
 
 be taken that the scores on the sides of this rectangle shall 
 agree with the direction of the proposed gallery. 
 
 The distance at which the floor of the gallery is to be 
 placed below the surface of the ground being given, the 
 first thing to be done is to determine the distance to be left 
 between the frames. To find this, let us suppose that a 
 common gallery, four feet six inches high in the clear, is to 
 be driven from the bottom of a shaft twenty-five feet deep. 
 
 Then the height of the gallery, from the floor to the top 
 of the cap-sill being . . . 5 ft. 1 in. 
 
 Thickness of top sheeting, . . " 2 " 
 
 Free space for introduction of sheeting, . " 2 " 
 
 Thickness of shaft frame next above the gallery, " 4 " 
 
 Total, . . . . 5 ft. 9i in. 
 
 The top, therefore, of the frame above the gallery must 
 then be five feet nine and one-half inches from the bottom 
 of the shaft. 'Subtract this from the total depth of twenty- 
 five feet, there remain nineteen feet two and one-half inches. 
 There would then be required four intervals of four feet 
 each, and one of three feet two and one-half inches for the 
 last interval. To find the length of the last set of sheeting 
 planks, the thickness of one frame and one overlap of two 
 inches must be added to 5' 9", making 6' 4". 
 
 An excavation of the size of the rectangle previously 
 marked must then be cut vertically down -to the depth of 
 two or three feet ; after which, one of the top-shaft frames, 
 before described, is placed directly over the excavation, the 
 projecting pieces preventing it from falling down. This 
 frame is generally placed flush with the surface of the 
 ground. The excavation is then continued to the depth 
 of four feet, when a common frame is put together, and 
 laid horizontally at the bottom of the shaft, with its cor- 
 responding sides vertically under those of the upper frame. 
 The excavation at this level must be fully equal to ilie 
 
PRACTICAL OPERATIONS IN MINING. 213 
 
 dimensions indicated by the gauge-rods. A plumb-bob is 
 necessary to preserve the verticality of the excavation, as 
 well as for the adjustment of the successive shaft-frames by 
 means of the notches before noticed. As soon as the second 
 frame is placed, the first set of planks are pushed vertically 
 downward, with their pointed ends foremost, between the 
 earth on each side and the top frame. 
 
 At top, each of these planks is pressecj. home close to the 
 top frame, but at the bottom it is kept out from the lower 
 frame by wedges rather thicker than the plank itself. The 
 two frames are then connected by four ties of wood, which 
 are thin laths, about two inches wide, extending vertically 
 from one frame to the other, being nailed to each. Some- 
 times rope is used, in which case it is made to pass through 
 holes bored in the frames ; and a knot in the rope, or a picket 
 between the strands, immediately under the lower frame, 
 prevents it from falling. 
 
 After the first two shaft frames and one set of sheeting 
 planks are thus placed, and the frames connected, the exca- 
 vation is continued about four feet deeper, when another 
 frame is placed with the same care. A second set of planks 
 is then introduced between the first set and the second frame, 
 after removing the wedges which were before inserted, in 
 order to preserve room for them. These new planks are 
 pushed down to the bottom of the shaft, and are there sep- 
 arated from the lower shaft frame by wedges, as before 
 described. Thus the work goes on until the miner arrives 
 near the level of the top of the proposed gallery, when the 
 last shaft frame must be placed at the calculated interval. 
 This being attended to, the excavation is continued down 
 to the bottom of the intended gallery, when another shaft- 
 frame is placed so as to have its upper surface on a level 
 with the floor of the gallery. Three sides only of this part 
 of the shaft must now be sheeted, and without wedging out 
 the planks which are to rest against the bottom frames. The 
 
214: 
 
 MANUAL FOE ENGINEER TROOPS. 
 
 FIG. 8. 
 
 fourth side of the shaft being le/t clear for the entrance of 
 the gallery on this side, the outline of the gallery is traced. 
 
 DRIVING GALLERIES WITH MINE FRAMES. 
 
 Fig. 3 represents a gallery-frame. 
 The uprights are called stanchions; 
 the top piece, cap-sill; the bottom 
 piece is the ground-sill. The two^ lat- 
 ter pieces are scored at the middle 
 point. 
 
 The scantling for the stanchions of 
 a branch may be 4"; for a gallery 
 three or four feet wide, 5" or G". 
 The cap-sill is usually made of the 
 same width as the stanchions, but 
 somewhat deeper, for the sake of 
 strength, the chief pressure being 
 vertical. In branches and small galleries an excess of about 
 one-fourth will be sufficient ; in the wider galleries, the ex- 
 cess may amount to one-third, or even one-half. The side 
 sheeting of galleries may be of l" or l" plank ; for the top 
 sheeting it should be from 2" to 2i". Great gallery frames 
 have their stanchions of scantling 5" or 6" square, and 
 their cap-sills 8" by 5", or 8" by 6". 
 
 We shall now proceed to describe the method of driving 
 the gallery from the bottom of a shaft ; and we shall con- 
 eider the ground to be such as to render it necessary to 
 sheet the skies as well as the top. The first thing necessary 
 is, to prepare two rods as gauges for regulating the height 
 and width of the excavation. The gauge for the height 
 must allow, beyond the extreme dimensions, for two thick- 
 nesses of plank, and that for the breadth for four thick- 
 nesses of plank two on each side of the frame ; and the 
 latter, i. e., the gauge, must be notched, or otherwise con- 
 spicuously marked, in the centre. It was stated before, 
 
PRACTICAL OPERATIONS IN MINING. 
 
 215 
 
 that in sinking a shaft the scores on 
 the frames must correspond with the 
 direction of the gallery intended to 
 be driven from the bottom. If this 
 has been carefully attended to, the 
 direction of tie gallery will be at once 
 obtained by dropping plumb-lines 
 along the scores, and marking these 
 points at the bottom of the shaft with 
 pickets ; or, the notches on the bot- 
 tom frames, if accurately laid, will be 
 i ; sufficient. In commencing the gal- 
 lery, the excavation may be carried 
 FIG. 4. forward about one or two feet before 
 
 the first frame is placed. The entrance made in the first 
 instance should be less, both in width and height, by the 
 thickness of one set of planks that is, by 1" on each 
 side and 2" on the top. The exact position of the first 
 frame being determined, the ground-sill is imbedded in the 
 ground, outside and against the lower shaft frame. The 
 stanchions are inserted, and the cap-sill set, and the whole 
 frame squared by means of a plumb-bob, and temporarily 
 secured in place by battens. This being completed, the 
 excavation is continued for a distance of four feet, when an- 
 other frame is set up. The ground-sill is first placed exactly 
 perpendicular to, and its score in, the axis of the gallery. 
 If the gallery is to be horizontal, the position of this sill will 
 be verified by a spirit-level and straight-edge. If inclined, 
 a slope-block is used in connection with the above imple- 
 ments. This is a block whose thickness is equal to the rise 
 or fall of the floor of the gallery, in a distance equal to one 
 interval. 
 
 The stanchions are then set up, their lower ends inserted 
 in the notches in the ground-sill. The cap-sill is placed, and its 
 position verified by plumbings from its score to that in the 
 
216 
 
 MANUAL FOR ENGINEER TKOOPS. 
 
 Fio. 5. 
 
 ground-sill. The top- 
 sheeting planks having 
 been introduced over the 
 first frame, with their 
 pointed ends foremost, 
 are now pushed forward 
 until they rest upon the 
 cap-sill of the second 
 frame. Wedges ar e th en 
 introduced, as in sinking 
 a shaft, and the side 
 sheeting is pushed on in 
 an exactly similar manner. 
 
 MEN AND TOOLS REQUIRED FOR DRIVING A GALLERY FROM 
 THE BOTTOM OF A SHAFT. 
 
 MEN. 
 
 TOOLS. 
 
 Picks. 
 
 Shovels. 
 
 3 
 
 The disposition of the workmen is as follows : 
 
 1 man picks. 
 
 1 fills the truck. 
 
 1 " wheels. 
 
 1 " fills the bucket at the bottom of the shaft, or at- 
 taches the truck to the windlass. 
 
 Five men are employed at the top of the shaft, as stated 
 before. 
 
 For every fifty feet driven, an additional man and truck 
 become necessary, recesses being cut at the sides to receive 
 the empty truck while the loaded one passes. One ad- 
 
PRACTICAL OPERATIONS IN" MINING. 217 
 
 ditional man will also be required at top, to work the venti- 
 lating apparatus. Instead of using a bucket for hoisting 
 up the earth, it is found to be a more expeditious plan to 
 attach the full truck to the windlass. Where the gallery is 
 unconnected with a shaft, the two men working the wind- 
 lass might be struck off. In great galleries the earth may 
 be removed in wheelbarrows. 
 
 Whenever there appears to be any risk of the soil falling 
 in, it is proper, after placing each successive frame and ex- 
 cavating one or two feet beyond it, to remove the wedges, 
 and to introduce the next set of top-sheeting planks, as far 
 as they will go, without waiting for another frame, and to 
 push them forward as the excavating proceeds. Thus the 
 man excavating will always work under cover of these 
 planks. 
 
 INCLINED GALLERIES. 
 
 When the depth required to be reached is not great, it will 
 generally be found more convenient to obtain this object by 
 making a descending gallery in preference to striking out 
 from the bottom of a shaft. A gallery is never made to de- 
 scend more than 1 foot in 2. A descending gallery may bo 
 commenced from behind some bank or natural cover, or 
 from behind a parapet ; as for example, from one of the most 
 advanced parallels or lodgements in a siege. It may not al- 
 ways be convenient to commence a gallery, when required 
 in a siege, from one of the regular parallels or lodgements ; 
 in such cases a small parallel may be made for the purpose, 
 and connected with the nearest trenches by a boyau. When 
 a descending gallery is commenced from a parallel, the 
 trench of the parallel must be deepened at the spot chosen 
 for the entrance of the gallery as much as maybe necessary 
 to allow the top of the excavation of the gallery to be two 
 and a half or three feet below the original surface of the 
 ground. The execution of the gallery is to all intents tho 
 same as that of a horizontal one, except that tho frames are 
 JO 
 
218 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 set up perpendicular 
 to the slope, and the 
 distance between 
 any two must be 
 measured along it. 
 This being attended 
 to, the same sheeting 
 will answer whether 
 the gallery is in- 
 clined or horizontal. 
 The first frame of 
 an inclined gallery 
 ought, as nearly as 
 possible, to be under 
 the terrcplein of the 
 banquette. It is to 
 be observed that the 
 pressure of loose 
 earth acting upon" 
 the roof of a gallery 
 will always tend to 
 overset the mine- 
 frames, unless the 
 latter are placed in 
 
 FIG. e. a direction perpen- 
 
 dicular to the floor of the gallery, or nearly so. 
 
 In changing from a descending direction to a horizontal 
 one, it is necessary to change also from oblique frames to 
 vertical ones, and it becomes also necessary to support the 
 first vertical frame by struts placed parallel to the stanch- 
 ions of the oblique frames in rear of it. Thus the cap-sill of 
 the first vertical frame is as it were supported by two pairs 
 of stanchions, one pair vertical and the other oblique, in 
 order to resist the double action of the loose earth imme- 
 diately above it, which presses vertically upon the top sheet- 
 
PRACTICAL OPERATIONS IN MINING. 210 
 
 ing of the first horizontal bay, but obliquely upon the top 
 sheeting of the last inclined bay of the gallery. 
 
 ^ SINKING A SHAFT IN BAD SOIL. 
 
 Iii soil which has little tenacity, it may*be necessary to 
 provide an intermediate support for the sheeting, during the 
 operation of sinking the interval. 
 
 For this purpose a false frame is employed ; this differs 
 from the ordinary shaft frame, in being a little larger from 
 out to out, and being made of rather smaller scantling. 
 
 It is used as follows, after the excavation has been car- 
 ried about two feet below the frame last placed : the sheet- 
 ing having been driven down as fast as the excavation ad- 
 vanced, the false frame is placed in the same manner as 
 the ordinary frame ; with the exception that no wedges are 
 driven between it and the sheeting, it is connected by bat- 
 tens with the frame above. The excavation is then con- 
 tinued until the full depth of the interval is attained, when 
 an ordinary frame is placed, the wedges driven, and the 
 false frame removed. 
 
 When a common, or branch gallery is to be driven from 
 the bottom of the shaft, the only precaution to be taken in 
 making the last interval, will be to use somewhat thicker 
 sheeting. But when the gallery is to be grand, or principal, 
 the sheeting must be driven on all four sides, instead of 
 three, and an additional frame placed three feet above the 
 bottom. 
 
 To commence the gallery, set up the first frame and secure 
 it in place by battens, then drive down the sheeting that is 
 opposite the cap-sill until sufficient space is gained to enter 
 the top sheeting of the gallery. As soon as this sheeting is 
 entered, in order to prevent the pressure of the earth from 
 forcing down the forward ends, a piece of plank is laid over 
 t lie rear ends and engaged under the shaft-frame directly 
 above. (See fig. 4.) 
 
220 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 Then force down the shaft sheeting above mentioned, one 
 foot further, drive the top sheeting as far as it will go, and 
 enter the upper course of side sheeting. It may be necessary 
 to brace the opposite plank of this sheeting apart, at their 
 inner ends, to counteract the pressure of the earth at their 
 other extremities. Continue to introduce the side sheeting 
 by pairs, forcing down for this purpose the shaft sheeting 
 one foot at a time on reaching the intermediate shaft frame, 
 knock out the side which is against the gallery, and remove 
 the sheeting resting against it, insert all the side sheeting, 
 and push the excavation forward, always driving the sheet- 
 ing in advance of the excavation. Two feet in advance 
 
 of the first frame, the false 
 frame (fig. 7) is set up. This 
 consists of a ground-sill, two 
 stanchions, and a cap-sill, 
 united by mortice and tenons, 
 the cap is rounded on top, the 
 height is the same as the gal- 
 lery frame, the width two 
 inches greater. It is placed in 
 the axis of the gallery, and in 
 such a manner that the cap-sill shall be 2" higher than those 
 of the ordinary frames. In driving the sheeting around it 
 no wedges are used. The excavation is then pushed on, 
 until the place for the second gallery-frame is reached ; this 
 is set up and the wedges driven in the usual manner, and 
 the false frame is removed. 
 
 When the soil is very bad, a mask is employed to pre- 
 vent the earth, above and in front from caving into the 
 gallery. The process is as follows : as soon as the top 
 sheeting is entered and the shaft sheeting forced down 1' 
 as above described, a piece of plank, equal in length to the 
 width of the gallery, is placed directly under the top 
 sheeting and against the earth to be excavated ; this plank 
 
 FIG. 7. 
 
PKACTICAL OPERATIONS IN MINING. 
 
 221 
 
 FIG. 8. 
 
 is held in place by braces on each 
 side to the frame in rear. In the 
 same way the remaining planks of 
 the shield are added in succession, 
 and as soon as the shaft sheeting 
 is lowered enough to receive 
 them, until the entire front is 
 covered, then the top plank of 
 the shield is removed, and the 
 earth excavated until it can be re- 
 placed 8" or 10" in advance, after 
 which each plank is removed in succession, the earth excav- 
 ated, and the plank replaced ; as each partial excavation ad- 
 vances, the sheeting is driven forward. 
 
 BRANCHES. 
 
 In a system of military mines the branches are merely 
 smaller galleries than usual, branching out from the com- 
 mon galleries, hence their name. As the construction of 
 both is so much alike, it is only necessary to notice the cir- 
 cumstances under which a branch proceeding from a gallery 
 may be commenced. 
 
 1. A branch may be excavated in the same direction and 
 in continuation of the gallery itself. 
 In this case the first branch frame 
 must be placed immediately beyond 
 the last gallery frame and close to 
 it ; or, if there be room, it may be 
 placed exactly within it, the centre 
 of both coinciding as in the annexed 
 figure. 
 
 2. A branch may be cut at right 
 angles to the gallery from whence 
 it proceeds> In this case the mode 
 of commencing is the same as ex- 
 
 Fm. 9. 
 
222 
 
 MANUAL FOB ENGINEER TROOPS. 
 
 cavating a gallery from the lower part of one side of a shaft, 
 it being understood that the floor of the branch always com- 
 mences from the bottom of the gallery. The entrance of 
 the branch is of course cut half way between two adjacent 
 gallery frames. 
 
 3. A branch may be commenced obliquely from the side 
 of a gallery. 
 
 In this case, if the soil be good and not wanting much 
 
 support, the first 
 branch frame is 
 placed as near to 
 the side (see fig. 
 10) of the gallery 
 as possible, but 
 at right angles to 
 the direction of 
 the intended new 
 branch. Hence, 
 one stanchion 
 only of the first branch frame can agree with the side of 
 the gallery; the other side will be more or less distant from 
 it in proportion to the degree of obliquity. If, on the con- 
 trary, the ground 
 cannot be trusted 
 the first branch 
 frame must be 
 placed so as to 
 line with the side 
 of the gallery it- 
 self (see fig. 11), 
 and consequent- 
 ly a longer cap- 
 sill than the or- 
 dinary ones will 
 be necessary. 
 
 FIG. 10. 
 
 FIG. 11. 
 
PRACTICAL OPERATIONS IN MINING. 
 
 223 
 
 
 MINING WITH CASES. 
 
 Having described the method of mining with frames and 
 sheeting, it remains now to point out the difference when 
 mine-cases alone are used. These descriptions of cases 
 have long been known under the name of Dutch cases ; 
 
 these consist of four pieces two 
 stanchions, a cap-sill, and ground- 
 sill. For ordinary work they are 
 made out of two-inch deal, and 
 have a three-eighths of an inch 
 round iron bolt driven transverse- 
 ly through the middle thickness 
 of the wood of each piece, about 
 four and a half inches from each 
 end, to prevent them from split- 
 The stanchions have tenons 
 
 Tic,. 12. 
 
 ting. 
 
 2" long by 3" wide at each end, and mortices of correspond- 
 ing dimensions are cut in the ends of the cap-sill and ground- 
 sill to receive the tenons; the most convenient width for 
 the piece would be twelve inches, but this is not a matter 
 of consequence, and they may be made of whatever sized 
 planks, not less than two inches thick, that can most readily 
 be procured. In great galleries which require stronger ma- 
 terials, the stanchions may be four inches thick, the ground- 
 sill three inches and the cap-sill five inches ; notches, as 
 shown in the figure, are cut in the stanchions for the pur- 
 pose of rendering them more manageable, both in putting 
 them up and taking them down ; they also serve for places 
 in which to drive pickets to support the case in a descend- 
 ing gallery. The size in the clear of cases, both for shafts 
 and galleries, is the same as that of frames, and the same 
 precautions and arrangements in their adjustments are 
 necessary. 
 
 In sinking shafts when the excavation has advanced about 
 
224 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 one foot in depth, it becomes necessary to fix the first case, 
 which is done in the following manner : One of the short 
 pieces is first placed in its proper position into the excavation; 
 the tenons of the two long pieces are then fitted into the mor- 
 tises of this, and then the mortise at one end of the fourth 
 side is fitted on its tenon ; but to adjust the corresponding 
 mortise and tenon, it will be necessary to push back either 
 this short piece or the long one full two inches, in order to 
 bring the mortise and tenon together ; and whichever plan 
 is adopted, as little earth as possible should be cut away. 
 The first case being placed the excavation is proceeded with, 
 and the second case is placed close under the first, and in a 
 similar manner, and so on to the bottom of the shaft. This 
 is the mode of proceeding when the soil is so bad as to re- 
 quire close casing ; under ordinary circumstances, how- 
 ever, it will be sufficient to introduce a case at every three 
 or four feet ; and when this is done, it is usual to cut out 
 the earth to the thickness of the plank, so as to admit of 
 the case being placed flush with the sides of the excava- 
 tion. 
 
 When it is intended to push a gallery from the bottom 
 
 r 4-.- .-> of a close-cased shaft, 
 
 it is evident, before 
 proceeding, it will be 
 necessary to remove 
 one side of the cas- 
 ing ; and to do this 
 without causing the 
 adjacent sides to col- 
 lapse, and the casing 
 to tumble in, a frame 
 somewhat similar to 
 a door frame must 
 be introduced its 
 ground-sill being ad- 
 
 
 Fio. 18. 
 
PRACTICAL OPERATIONS IN MINING. 225 
 
 justed so that its upper side may be on a level with the 
 floor of the intended gallery ; the exterior dimensions of the 
 frame must exactly correspond with the width of the shaft, 
 and the interior dimensions may be exactly those of the 
 gallery, or exceed them by an inch or two. When this 
 frame is first put up it should be made to stand about one 
 foot from the side of the casing which is to be removed ; 
 and when this is effected, it must be forced up against that 
 side. These details having been attended to, the casing on 
 the side from which jthe gallery is to start may be removed, 
 commencing with the side of the lowest case ; to remove 
 which Avill be a work of some difficulty, as the earth must 
 be picked away from behind it in order to admit of its 
 being pushed back to clear it of its tenon. It will be neces- 
 sary, in the first instance, to excavate the ground underneath 
 it in order to admit of the introduction of the pick and 
 push-pick, but the removal of each successive side will be 
 easier. In driving the gallery, the mode of using the cases 
 is as nearly similar as possible to that described for shafts, 
 making allowance for the difference of direction; the ground- 
 sill is first placed next the stanchions, and to fix the cap-sill 
 the same mode of proceeding is to be adopted as has already 
 been described for fixing the fourth side of the shaft case ; 
 the space which is necessarily left between the earth and 
 the top of the cap-sill should be filled in before proceeding 
 to place the next case. Close casing will seldom be required 
 in a gallery, but the roofing should in most cases be sup- 
 ported ; this can easily be effected by using pieces of the 
 cases as top sheeting, extending from the top sides of the 
 cases which it may be found necessary to use. 
 
 Great gallery cases are somewhat different from other 
 cases. In order to give greater strength, the stanchions are 
 marie without tenons at their lower ends, which are kept in 
 their places by cleats two inches thick nailed on to the sill ; 
 the mortises in the cap-sills need not be more than two 
 10* 
 
226 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 inches deep. In driving great galleries in loose soil, after 
 setting up the first frame it becomes necessary to support 
 the top-sill, whilst the miner excavates the ground for the 
 ground-sill and stanchions. For this purpose two upright 
 
 FIG. 14. , 
 
 pieces of timber, carrying each a cross-piece, as represented 
 in the annexed figure, are made use of. The upright part 
 rests on the sill of the frame already placed, and is steadied 
 
 by being wedged 
 up. The cross- 
 piece is two feet 
 long, and the part 
 that projects in ad- 
 vance, as will be 
 seen from the fig- 
 ure, is made an 
 inch higher than 
 the rear part, to 
 support the top-sill 
 somewhat higher 
 than its final level. 
 
 FIG. 15 
 
PRACTICAL OPERATIONS IN MINING. 
 
 227 
 
 The rear part of the cross-piece 
 is braced by a piece of iron to 
 the upright. These are called 
 crutches, and the materials of 
 which they are made should be 
 as light as a due regard to 
 strength will admit. 
 
 In working with cases, the 
 direction of a gallery may be 
 easily and gradually changed, as 
 shown in fig. 16. 
 
 If the soil is good, the inter- 
 vals which occur between the 
 cases may be left open ; if bad, 
 they may be filled up with small 
 pieces of wood. When it is 
 necessary to break out from the 
 side of a gallery in a direction 
 perpendicular or oblique to it, 
 the requisite number of cases 
 must be removed, and the roof of the interval lined with 
 pieces of board extending across and supported on the ex- 
 treme cases, as in fig. 17. 
 
 If the soil is very bad,. the stanchions only from the side 
 
 whence the new gallery is to 
 proceed need be removed, and 
 the intervening cap-sills can 
 be supported as in fig. 18. 
 But this method has the in- 
 convenience of lowering the 
 headway, a serious objection. 
 When a gallery branches from another in an oblique di- 
 rection, it will be better to obtain the obliquity gradually, 
 than by introducing an oblique case, like the frame indi- 
 cated in fig. IG. 
 
 FIG. IG. 
 
 s 
 
 FIG. IT. 
 
228 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 Flo. 18. 
 
 When cases 
 are used, the 
 w o r k will ad- 
 vance at nearly 
 double the rate 
 it would with 
 frames and sheet- 
 ing, viz. : great 
 galleries and shafts about one foot an hour ; common gal- 
 leries one foot and a half per hour. 
 
 CHARGING OP MINES. 
 
 The receptacle for the powder is called the chamber, and 
 is usually at the extremity of a branch, either in its pro- 
 longation or on the flank. 
 
 When the charge does not exceed one hundred pounds, 
 the ordinary powder-barrel may be used to contain it. 
 When it is greater a cubical box is constructed in such a 
 manner as to be readily put together in the excavation for 
 the chamber. When the charge is very large, the lining 
 of the chamber is formed with the ordinary mining- frames 
 and sheeting or with mining-cases. When the weight of 
 the charge is given, the size of the box may be determined 
 by allowing thirty cubic inches to -the pound. 
 
 TAMPING MINES. 
 
 The tamping of mines consists in filling up the gallery 
 with solid material for a certain distance from the chamber, 
 with the view of preventing the force of the explosion from 
 expending itself in the gallery, rather than in the direction 
 in which the mine is required to act. 
 
 The tamping should extend from the charge for a distance 
 equal at least to 1 times the line of least resistance ; and if 
 the material used for forming the tamping be not heavy, i- 
 
PRACTICAL OPERATIONS IN MINING. 229 
 
 otherwise but loosely packed, this distance should be double 
 that line. 
 
 The materials usually employed in tamping consist of 
 earth which has been excavated in the formation of the gal- 
 lery, sods, sand-bags, or indeed, of any heavy substance 
 which may be at hand. If the soil be argillaceous, it may be 
 roughly moulded into bricks, which form an excellent mate- 
 rial, and one with which the operation proceeds quickly. 
 The most expeditious mode of tamping is, however, gen- 
 erally considered to be with sand-bags. 
 
 Split or cleft timber, in lengths of four or five feet, and of 
 about 9 inches girt, jammed together in the gallery, is also 
 very applicable, and when mixed with common earth at 
 intervals of 10 or 12 feet, forms a good tamping. Indeed, 
 in the demolition of revetments, by an arrangement of mines 
 in an escarp gallery, it would be found sufficient if both 
 extremities of the gallery were tamped with cleft timber. 
 In tamping wholly with common earth, it is desirable to 
 strengthen the mass by pieces of scantling crossing each 
 other, and placed diagonally in the gallery. These pieces of 
 scantling must be secured in their position by letting their 
 ends into the sides of the gallery, or by simply jamming 
 them. 
 
 In a permanent system of countermines, it is usual to 
 leave grooves in the walls of the galleries, for the purpose 
 of receiving the ends of the scantling above alluded to. 
 
 In a common gallery (4| by 3 feet), the tamping, when 
 executed with, common earth and well rammed, will not be 
 completed at a greater rate than from 2 to 3 feet per hour. 
 
 In proportion as the charge is increased, the value of the 
 tamping diminishes. Experiments were made by Mouze 
 for the purpose of determining in what ratio the charge 
 must >be increased to produce the same effect with a dimin- 
 ished tamping ; and he concluded that when the tamping is 
 diminished by I, the charge should be increased]; when 
 
230 MANUAL FOR ENGINEER TROOPS. 
 
 the tamping is diminished by |, the charge should be in- 
 creased | ; and when the mine is not tamped, the charge 
 should be doubled. 
 
 FIRING MINES. 
 
 Mines are usually fired, or, as it is technically termed, 
 sprung, by a powder-hose, or by Bickford's fuze. 
 
 The powder-hose consists of a tube of strong linen, reach- 
 ing from the chamber to the outside of the tamping. To 
 protect the hose, it is enclosed in a hollow wooden case 
 
 represented in profile as follows : Pp., 
 sions of the case being 3 inches, P~^ 
 
 the exterior dimen- 
 and the interior 1 
 inch. The case is fastened to the side of the shaft or gal- 
 lery by wooden pegs ; and in galleries and branches, after it 
 has been secured, it is usually covered with earth, to pre- 
 vent accidents during the operation of tamping. The mine 
 is fired by a piece of port-fire inserted into the end of the 
 powder-hose, of such length as will give time to the man 
 who fires it to escape before the explosion takes place. The 
 port-fire is then covered all round with moist clay, well 
 kneaded with the hands ; and earth is applied around all, 
 so as to render it impossible for any fire to communicate 
 with the powder-hose till the port-fire shall have burnt out. 
 When if is desired that several mines should explode simul- 
 taneously, being fired from one point, it is necessary that 
 equal lengths of powder-hose should extend from the focus 
 or point of ignition to all the mines. 
 
 To effect this object, the hose of the mines nearer to the 
 focus must be bent more frequently than those leading to 
 the more distant ones, as in the annexed diagram (fig. 19). 
 a Thebendingsofthe 
 
 _ _ 
 
 II . hose retard the pro- 
 
 FMkit - r~ s ress of ig nition 
 
 but only in a small 
 
 degree, so small as to be safely neglected. 
 
PRACTICAL OPERATIONS IX MINING. 231 
 
 Bickford's fuze consists of a train of gunpowder enveloped 
 in the strands of a rope which has been steeped in a pecul- 
 iar composition, and the rope protected by a coat of pitch ; 
 it is not injured by damp, and will burn under water ; it 
 burns at the rate of 12 feet in five minutes. 
 
 The Voltaic battery is a means which may be resorted to 
 for igniting mines ; but the care and attention required to 
 isolate the wires, and the difficulty of arranging securely so 
 great a length of them, render this application of the bat- 
 tery, however desirable, hardly available for military pur- 
 poses. 
 
 The rocket is also employed to fire the charge. Like the 
 powder-hose, it requires a case or hose-trough. Wherever 
 a change of direction takes place in the case, care must be 
 taken that it is not made too quickly. At each angle it is 
 usual to place a fresh rocket, with its quick-match secured 
 round a nail ; the first rocket, arriving at the point where 
 the second is placed, fires it. In order better to secure the 
 first rocket firing the second, a quantity of powder should 
 be strewed about the match of the latter, protected by a 
 triangular slip of deal, nailed to the bottom of the trough ; 
 the first rocket then ignites the powder, and so fires the 
 second, which its rapid motion might otherwise fail to do. 
 
 AVhen by the explosion of a charge of powder in a mine, 
 a conical excavation or crater is formed in the ground. The 
 radius at the surface is called the radius of the crater. The 
 distance from the centre of the charge to the surface is the 
 line of least resistance. The slant height of the cone is the 
 radius of explosion. When the crater radius is equal to the 
 line of least resistance, it is called a one-lined crater, when 
 double a two-lined crater, &c. 
 
 When the crater is two-lined, the mine is called a common 
 mine, when less an undercharged, and when greater an over- 
 charged mine, or globe of compression. 
 The charge of powder necessary to produce these craters 
 
232 MANUAL FOR ENGINEER TROOPS. 
 
 will of course depend on the nature of the soil as well as 
 the depth of the charge below the surface. 
 
 In ordinary soil, the charge to produce a common mine 
 may be found by cubing the line of least resistance taken in 
 feet ; this number divided by ten will give the charge in 
 pounds. For the other classes of mines the charge has not 
 as yet been well determined. 
 
 The following table has been derived from the most relia- 
 ble experiments. 
 
 L L R 3 X aV g ave 1 -lined crater. 
 
 ".2 " 
 LLR 3 Xi " 3 " " 
 
 LLR X4* " 6 " 
 
 The following general rules will give approximate results 
 
 Subtract the given line of least resistance from the radi 
 us of crater; multiply this difference by ,85. Add this prod 
 uct to the given line of least resistance ; the result will givt 
 the L L R of a common mine, requiring the same charge as 
 the globe of compression, which may be determined as be- 
 fore stated by cubing the line of least resistance, and divid- 
 ing by ten. 
 
 The effect of the explosion of the charge in a mine, is not 
 confined to the formation of a crater. The earth in every 
 direction within certain limits, called the radii of rupture, 
 is pulverized and compressed to such a degree as to destroy 
 any gallery that may be within the sphere of action. As 
 one of the principal objects of offensive mines is the de- 
 struction of the enemy's galleries, it is important to ascertain 
 the lengths of the radii for different charges. 
 
 When the charge placed at A is insufficient to form a crater, 
 the effect is, to produce a spherical compression M N O, 
 whose radius will depend on the charge and nature of the 
 soil. This sphere is termed a camouflet. 
 
PRACTICAL OPERATIONS IN MINING. 233 
 
 c O 
 
 FIG. 20. 
 
 When the charge is sufficient to produce a crater, the solid 
 of rupture becomes an elipsoid, a b c. 
 
 When A B = B C, or the mine is a " common" one, a A 
 will be = 1.7 A B, and A b = 1.3 A B. 
 
 In the globe of compression, although the crater radius 
 cannot be increased much beyond three times the line of 
 least resistance A B, yet the radius of rupture may be, al- 
 most indefinitely, by increasing the charge. 
 
 In the case of a six-lined crater, the transverse axis A a'= 
 4| A B, and the vertical axis A 6'=1 A B. It will be ob- 
 served that the radius of rupture increases much more rap- 
 idly in the horizontal than in the vertical direction, with the 
 increase of charge. 
 
 VENTILATION. 
 
 Great attention must be paid to ventilation in driving ex- 
 tensive galleries, as the gases generated by the explosion of 
 gunpowder or contained in the soil, have sometimes suffocated 
 the miner before the extinction of his light have warned him 
 of its presence, and even under ordinary circumstances, the 
 air becomes so much vitiated by the presence of the work- 
 men alone, that branches cannot be safely driven more 
 than about 60 feet ; beyond this distance apertures should 
 therefore be bored, if possible, up to the surface of the 
 ground at intervals, taking care to conceal their position 
 from the enemy. Communications may also be made with 
 adjacent galleries to create a draught. 
 
 Mechanical means are sometimes employed to produce a 
 
234: MANUAL FOB ENGINEER TROOPS. 
 
 circulation, so as to substitute fresh air for that which is im- 
 pure; for this purpose tubes are laid along the galleries 
 through which fresh air may be forced in, or bad air extract- 
 ed. As there may be a large quantity of noxious gas in the 
 soil, ready to supply the place of that extracted, the system 
 of forcing air in is to be preferred. The tubes used for 
 ventilation have ordinarily been made of wood or tin, but 
 vulcanized india-rubber would probably answer the purpose 
 better. 
 
 For forcing the air through the tubes, the fan-blower, such 
 as is used in reverberatory furnaces and forges has been 
 employed advantageously. The ordinary blacksmith's bel- 
 lows may be used where the length of the tube is not 
 great. 
 
 ATTACK AND DEFENCE OF A SYSTEM OF COUNTERMINES. 
 
 When the besieger arrives in the vicinity of the glacis of 
 a countermined fortress, he is obliged to move slowly, and 
 dares not advance on the surface of the ground further than 
 what he may be master of below. He then commences to 
 excavate the earth, in order to try to discover the galleries 
 of the besieged, and to seize them, or else he endeavors to 
 blow them in by firing mines. To accomplish this, in the 
 middle of his third parallel he sinks shafts from sixteen to 
 twenty-one feet deep, he then pushes forward a gallery, tak- 
 ing care to stop working at intervals, to listen if the enemy 
 is coming to meet him. 
 
 Often the besieged, especially when his galleries extend 
 to a great distance, drives a branch almost under the third 
 parallel, and fires one or more mines. The besieger, under 
 this supposition, ought to make a lodgement on the edge of 
 the crater, and sink a shaft, in his own lodgement, This 
 shaft is not sunk from the bottom of the crater, because it 
 would be the reservoir of all projectiles thrown from the 
 place. Care must be taken, however, at the same time, to 
 
PRACTICAL OPERATIONS IN MINING. 235 
 
 clear away the excavation caused by the globe of compres- 
 sion, in order to discover the direction of the branch which 
 joins it, and which necessarily communicates with a main 
 gallery. 
 
 While the besieger is sinking the shaft, he ought fre- 
 quently to listen, for there is not a doubt that he is now in 
 the vicinity of the mines of the besieged ; and when he ar- 
 rives at the depth of eighteen or twenty feet, he commences 
 a branch, breaking out on that side where he imagines the 
 enemy's gallery to be situated. 
 
 When the besieger finds himself sufficiently near to the 
 gallery of the place, a*nd is in danger of being forestalled, he 
 hastens to dig a chamber at the extremity of his branch, in 
 which he places a certain quantity of powder. He then 
 tamps as fast as possible, and endeavors to fire his mine be- 
 fore the besieged can find time to establish one to destroy 
 his works. 
 
 The besieged, on their side, directly they cease to hear 
 the sound of the pickaxe, work with the greatest possible 
 diligence, because they suppose from that instant their ene- 
 my, is engaged in tamping their mine. If they have the 
 good fortune to fall in with the mine, they endeavor to seize 
 the powder, or else to saturate it by an inundation of water. 
 If, on the contrary, they discover a part of the branch al- 
 ready excavated, they ought, without delay, to inundate it, 
 in order to destroy the hose, and so prevent the powder 
 from exploding. These artifices are made use of in like 
 manner by the besieger. 
 
 It sometimes happens that two miners, who are working 
 to meet each other, are only separated by a slight parti- 
 tion of earth. This is an occasion seized upon to give the 
 "camouflot," which is performed in this manner : The most 
 active of the two pierces a hole on the side of his enemy, 
 with borers of different diameter, in order to enlarge it 
 gradually, and to give it a diameter of six inches. He digs 
 
236 MANUAL FOR ENGINEER TROOPS. 
 
 this hole as deep as he can from six to eight feet, for in- 
 stance. He then introduces a large cartridge of the same 
 size, containing from twelve to twenty pounds of powder. 
 He drives in this species of mine with a plug of wood, which 
 he fixes and props up strongly with a piece of wood across 
 the branch. Finally, he fires this little mine, by means of a 
 fuze which goes through the middle of the plug. 
 
 If the gallery of the enemy is but four or five feet from 
 the head of this cartridge, he may be sure that it will be 
 driven in by the explosion. 
 
 To produce the same effect, two or three shells, fixed to- 
 gether, are sometimes employed. But this method requires 
 a great deal of care and attention, in order that one's own 
 labor be not exposed to destruction. 
 
 In subterranean warfare, when two miners are working 
 to meet each other, they take care to try the ground fre- 
 quently with a borer, to find out exactly what distance they 
 are off. In such a case, he who sees the end of his enemy's 
 borer appearing, keeps a strict watch on the moment it is 
 drawn back. He then introduces quickly into the hole it 
 loaves a pistol loaded with ball, and fires it the moment he 
 imagines the hole is clear. This ought to be followed by 
 three or four more ; after which a probe is pushed into the 
 opening, to clear it, and prevent the enemy coming through 
 on that side. 
 
 Vauban recommends the following articles to be provided, 
 in attacks of this description : 
 
 1st. A frame of wood, like a shield, 3" or 4" thick,with 
 a bolt in the middle to manage it with, and to place it against 
 the hole perforated by the probe. 
 
 2d. Smoke balls. They are pushed in through the same 
 hole, when lighted, and care is taken to stop the hole on 
 one's own side, so that all the smoke goes into the enemy's 
 gallery, by which means their miner is driven away for 
 time. During his absence the mine is charged and fired, 
 
PRACTICAL OPERATIONS IN MIXING. 237 
 
 which, by blowing in the gallery, prevents the return of the 
 enemy. If the opening is wide enough, a shell or port-fires, 
 to suffocate, or grenades, may be introduced. The shell is 
 to be preferred, when it can be used, because it destroys the 
 part of the gallery where it falls. *When a thin partition of 
 earth divides the combatants, a petard is used to blow 
 it in. 
 
 Such are a great part of the artifices made use of by 
 miners. To avoid them the besieger should, as soon as ho 
 can, fire a mine to blow in the branches, and even the gal- 
 leries, of the besieged, if within reach. He is sure, by this 
 means, of driving him #way for some days. It is well known 
 that the firing of a mine shakes the ground to a considerable 
 distance, so that if a gallery be within this limit, the gases 
 of the powder penetrate and poison the air with such effect 
 that no one can breathe it. This is not so much felt by the 
 besieger, as he has more air, not being obliged to use such 
 long galleries. 
 
CONSTRUCTION OF BATTERIES. 
 
PART V. 
 
 CONSTRUCTION OF BATTERIES. 
 
 IN the follow- 
 ing pages the 
 t e r m battery 
 is applied to 
 those positions 
 prepared for 
 the reception of 
 artillery in such 
 a manner as to 
 cover the pieces 
 and cannoniers 
 from the ene- 
 my's fire. 
 
 Fig. 1 repre- 
 sents the plan 
 of a battery for 
 six pieces. The 
 covering mass 
 in front is the 
 parapet. That 
 at the side is 
 the epaulement. 
 
 The earth for 
 the construc- 
 tion of these 
 embankments 
 is generally fur- 
 nished from an 
 
 11 
 
 FIG. 1. 
 
242 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 exterior excavation or ditch. In batteries the different slopes 
 of the parapet, ditch, <fcc., are designated in the same man- 
 ner as the corresponding surfaces in field fortifications. 
 
 Embrasures are openings in the parapet through which 
 the pieces are fired. 
 
 The lower surface is termed the sole, the sides the 
 cheeks, and the interior openings the throat of the em- 
 bf UK ure. 
 
 In the interior of the battery the floor, or surface of the 
 ground, is called the terreplein. 
 
 The splinter-proof traverses are mounds 
 of earth sustained by revetments. They are 
 usually placed alternately between the pieces, 
 and are intended to limit the destructive ef- 
 fect of a shell exploding in the battery. 
 
 The first batteries in a siege are usually 
 situated about thirty yards in advance of 
 the parallels. 
 
 The nature of the ground, or danger from 
 sorties, may render it necessary to place 
 them behind or in the parallel. 
 
 Whatever their position may be, it is es- 
 sential that they should be connected with 
 the parallel by well covered and commodi- 
 ous communications, and when in the paral- 
 lel, a trench should be cut in their rear, 
 so that the working parties and guards of 
 the trenches may pass around and not make 
 a thoroughfare of them. 
 
 Batteries are termed elevated when their 
 terrepleins are formed by the natural sur- 
 face of the ground. 
 
 They are half-sunken when the terreplein 
 is lowered 2', and full-sunken when it. is 
 FIG. 2. lowered three feet. 
 
CONSTRUCTION OF BATTEKIES. 
 
 243 
 
 FIG. 8. 
 
 c 9 tp Sole of embrasure, 
 tgp Cheefcf 
 
 &t i t* D. 
 orizontal dlstatoCffT -=-f rertical distance f*tf. 
 
 In the first form the fire of the guns is less liable to be ob- 
 structed by accidents of the ground in front, and the terre- 
 plein is more easily drained. In the latter classes the para- 
 pet has more stability, and their construction is more rapid, 
 as a greater number of workmen can be employed at the 
 same time. 
 
 THE TRACING OF BATTEEIES. 
 
 The ground on which a battery is to be constructed, 
 should be carefully examined, and if possible the direction 
 of the parapet traced before dark. Whenever it is practi- 
 cable, the parapets of direct batteries should be parallel, 
 and of enfilade batteries perpendicular, to the faces they 
 are to attack. 
 
MANUAL FOR ENGINEER TROOPS. 
 
 Before proceeding to trace the battery on the ground, an 
 accurate drawing must be made, showing the direction of 
 the parapet, epaulement and communications, also the posi- 
 tion of the traverses and magazine. 
 
 The tracing on the ground must be made after dark. 
 
 "We will suppose that an elevated six-gun battery is to be 
 constructed, with traverses between the guns. 
 
 ! J*J .? . ? * 
 
 s 
 
 * * 
 
 t> 
 * 
 
 2*- 
 
 + FIG. 4. 
 
 Let a b represent the foot of the interior slope of the 
 parapet, a c that of the epaulement. Lay off a, 1 = 9', 1, 
 2=18'. 1 and 2 will give the positions of the first and second 
 errfbrasures. The next interval is 24' as a traverse which 
 will occupy six feet, will come between the second and third 
 gun. The other intervals are laid off in a similar manner, 
 15' being allowed for the extreme merlon on the side where 
 there is no epaulement. The object of the epaulement being 
 to screen the interior of the battery from oblique fire, the 
 length and direction of the line a c will be dependent on 
 the direction of this fire. The angle cab having been 
 previously determined, may be laid off either with a field 
 level, or by constructing the triangle a e d. 
 
 By inspecting figure 1, the thickness of the parapet at 
 its base will be found 28' and that of the epaulement 20 feet. 
 These distances must be laid off on the perpendiculars, b m, 
 a n t and a 0, cp. Stout pickets are driven at c, a, b, wi, ?i t s 9 
 
CONSTRUCTION OF BATTERIES. 245 
 
 s, 0, and />, and tracing-tape or white cord stretched around 
 them, thus enclosing the ground to be covered by the para- 
 pet. 
 
 The ditch is marked out in a similar manner, giving it a 
 width of -24' in front of the parapet and 20' for the epaule- 
 ments, and leaving a space of three or four feet from the 
 foot of the exterior slope for the berme. 
 
 DISTRIBUTION OF THE WORKING PARTY. 
 
 The working party, provided with tools and reveting ma- 
 terial, are conducted to the site of the proposed battery, 
 as soon as it is dark enough to avoid being seen by the be- 
 sieged. 
 
 The line representing the foot of the exterior slope is 
 divided into intervals of six feet ; for each interval two ex- 
 cavators are placed in the ditch, one shoveller on the berme, 
 one on the parapet, to level and ram the earth thrown in, 
 and one sapper to level the terreplein and prepare the 
 ground fbr receiving the platform. 
 
 When earth has been thrown into the parapet to the 
 depth of two feet, the revetment of the interior slope is 
 commenced ; for this purpose five sappers for each one-gun 
 portion of the battery are required. 
 
 FIG. 5. FIRST NIGHT'S WORK. 
 
 During the first night the terreplein should be pre; arecl, 
 the parapet and revetment carried to the height of the sole 
 of the embrasures, the traverses commenced, and the com- 
 munications finished; the latter are constructed by the flying 
 
 FIG. 6. WORK AT END OF FIRST DAY. 
 
24:6 MANUAL FOR ENGINEER TROOPS. 
 
 sap. As the excavation of the ditch is the most fatiguing 
 part of the work, the men thus engaged change places with 
 thosqjpn the benne and parapet every two hours. 
 
 The working party for the day arrive, just before dawn, 
 bringing with them gabions, fascines, <fcc. The working 
 party for the ditch is the same as before, the excavation 
 being deep enough to cover them from the fire of the place. 
 
 They continue the excavation, throwing the earth on the 
 berme, until no more can be piled there, then dig back toward 
 the counterscarp, throwing the earth against the scarp ready 
 to be passed up as soon as the berme is cleared on the follow- 
 ing night. The shovellers and rammers will be prevented 
 from working on the parapet by the fire of the besieged. 
 They will be employed in finishing the communications, and 
 the excavations for the magazine commenced on the previous 
 night, and bringing up the timber for the platforms. The 
 sappers will continue the revetment if the fire is not too 
 heavy, and work at the magazine. 
 
 The working party for the second night arrive at dusk ; 
 they are distributed as on the first night the shovellers 
 thro whig in the earth accumulated during the day on the 
 berme. The sappers finish the revetment, the platforms are 
 laid, if they have not been during the day, and the battery 
 armed. 
 
 CONSTRUCTION. 
 
 The excavation is commenced 3' from the line marking 
 the crest of the scarp, and is carried down to the depth of 
 3', then toward the counterscarp; as the ditch is intended 
 merely to furnish earth for the scarp, and not as a defensive 
 work, its form is immaterial. That indicated in fig. 5 is 
 generally found most convenient, the step furnishing a plat- 
 form on which the earth from the outer part of the ditch 
 is thrown, and from thence into the parapet by a relay of 
 shovellers. The steps are removed when the parapet is 
 nearly finished. 
 
CONSTRUCTION OF BATTERIES. 
 
 247 
 
 REVETMENT WITH FASCINES. 
 
 The line of the foot of the interior slope is levelled and a 
 trench five inches deep is excavated to receive the first 
 course of fascines for the revetment of the parapet. (The 
 epaulement is not reveted.) The fascines are then laid, 
 n aligned, and fastened down 
 
 with three pickets, one driven 
 through the middle and one 
 18" from each end of every 
 fascine. The earth of the para- 
 pet is levelled up to the top of 
 this course and rammed. The 
 second course is laid, breaking 
 joints with the first and pick- 
 eted, the stakes passing through 
 both courses. The other courses are laid in the same way, 
 the earth always being brought up to the level of the top 
 of each course before another is laid. In order to give uni- 
 formity to the slope of the revetment, it will be convenient 
 to drive guide-stakes having the proper inclination in front 
 of the first course (as soon as they are laid). The withes of 
 the fascines should have their knots toward the parapet. 
 
 The fifth course brings the revetment to the height of the 
 Bole of the embrasure ; these fascines must be anchored. 
 This is effected by making one end of a piece of wire, rope, 
 or withe fast to the fascine, and with the other taking two 
 or three turns around a stake driven vertically into the para- 
 
 Fia. 8. 
 
24:8 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 pet, and three feet from the revetment ; each fascine of this 
 course should have at least two anchoring pickets. 
 
 EMBRASURES REVETED WITH FASCINES. 
 
 FIG. 10. 
 
 The sole of the embrasure is an inclined plane, falling 
 about one foot toward the exterior. To trace the sole, mark 
 the directrix by a cord, u v (fig. 9), lay off u o, and u s = 1 ', 
 v t = vp = 6', op s , is the sole. Along the lines o t and s p 
 excavate a trench about 5" deep to receive the first course of 
 fascines for the revetment of the cheeks ; three pickets are 
 driven through each of these fascines. The three remaining 
 courses, which are required to finish this revetment, are laid 
 
CONSTRUCTION OF BATTERIES. 
 
 249 
 
 so that the cheeks shall be vertical at the throat, and have 
 a slope of one-third on the exterior. Each fascine should 
 be anchored twice, the anchoring pickets being driven 3' 
 within the merlon ; the fascines forming the interior slope 
 overlap those of the embrasures. The revetment is usually 
 terminated 18" below the superior slope, and is connected 
 with it by a slope of 45. The fascines for the embrasures 
 should be bound with wire instead of withes, and the ends 
 toward the throat strengthened by additional bands. 
 
 These 
 
 FIG. 
 
 SPLINTER-PROOF TRAVERSES. 
 
 are rectangular, they are 16' x 6' at the base, and 
 
 14' x 4' at top, a 
 passage 2' wide is 
 left next to the para- 
 pet. The first course 
 of fascines is half 
 imbedded in the 
 ground and secured 
 
 Fro ' ai< by pickets, the earth 
 
 filled in and rammed. The other courses 
 are laid in a similar manner. In every 
 second or third course the opposite fascines 
 of the long sides are tied together with wire 
 or rope, those of the short sides are an- 
 chored. * 
 
 The method of arranging the courses is 
 shown in the figure. 
 
 REVETMENT WITH GABIONS. 
 
 11* 
 
 Fio. 13. 
 
250 MANUAL FOR ENGINEER TROOPS. 
 
 The interior slope is commenced by imbedding a course 
 
 of fascines and securing it 
 by pickets, as in the pre- 
 vious case. The first 
 course of gabions is placed 
 with the points of the 
 stakes up, and the inner 
 edge of the bases resting 
 on the fascines just laid, 
 14t , the ground having been 
 
 previously prepared so as to give the gabions the proper 
 slope. Earth is thrown into and in front of the gabions, 
 and well rammed. When nearly full every second gabion 
 should be anchored to a stake, driven 3' in front of it in the 
 parapet. 
 
 When the gabions are full, a second course of fascines (b) 
 is laid on their inner edges, and driven down with a maul 
 until it is firmly engaged on the points of the stakes. 
 The second course of gabions is placed so that the axis of 
 each gabion coincides with that of one of the lower course. 
 The points of the stakes are down, and driven into the fas- 
 cines of the course (b). The gabions are anchored as in the 
 first course. 
 
 The throats of the embrasures are formed by omitting a 
 gabion and sawing out the corresponding portion of the up- 
 per course of fascines. 
 
 TK A VERSES. 
 
 A course of fascines is em- 
 ployed to form the base of 
 the revetment, as in the pre- 
 vious case. 
 
 Flo> 15 - The arrangement of the ; 
 
 first course of gabions is shown in the figure. When nearly / 
 filled, the opposite rows should be tied together and across 
 
CONSTRUCTION OF BATTERIES. 
 
 251 
 
 FHJ. 17. 
 
 the corners, with wire or rope ; when filled they are crowned 
 with fascines. In the second course there is one less gabion 
 on each side than in the first. The two rows meet at 
 top, where they are tied together. The earth is rounded 
 over the top to the depth of IS". 
 
 EMBBASUEES REVETBD WITH GABIONS. 
 
 Fio. 19. 
 
f252 MANUAL FOR ENGINEER TROOPS. 
 
 The sole is prepared and one course of fascines laid, as in 
 the fascine embrasure. 
 
 The revetment of each cheek is formed as follows : com- 
 mencing at the throat, six gabions are placed in a line, and 
 resting on the fascine abave mentioned. The first gabion 
 is vertical, the last has an inclination given it of , from 
 the directrix. In these positions they are filled and secured, 
 and the intermediate gabions aligned on them at top and 
 bottom. 
 
 All the gabions are securely anchored to pickets driven 
 3' within the merlon. 
 
 The strongest gabions should be selected for this part of 
 the revetment. Those of hoop iron, make the most substan- 
 tial embrasure. Although it is essential that the embrasure 
 gabion should be well anchored 3 they should never be 
 tied to each other. The independence of the parts in this 
 revetment, renders the gabion superior to any other mate- 
 rial, for the upper portion of the battery ; as one portion 
 may be torn away by a shot without endangering the adja- 
 cent parts. 
 
 The merlon is carried about 18" higher than the revet- 
 ment, and its superior slope united to it by a slope of 45. 
 
 SAND-BAG BATTERIES. 
 
 When the presence 
 of rock, water, or 
 other obstacle ren- 
 ders excavation on 
 the site of the battery 
 
 impossible, the work is executed by means of earth brought 
 
 forward in sand-bags, some of which are built into, and 
 
 others emptied on the parapet. 
 
 The bags are filled before dark and are brought as near 
 
 the proposed battery as possible without attracting the ob- 
 
 eervation of the besieged. 
 
CONSTRUCTION OF BATTERIES. 253 
 
 The battery is traced after dark, the%urface to be covered 
 by the parapet is marked by tracing-tape, 
 
 The working party is divided as follows : 
 
 For each one-gun portion twenty-five men to fill and 
 tie, and forty to carry bags ; eight sappers to lay the bags, 
 and two to level and ram the earth. 
 
 The carriers pass from the depot to the battery in single 
 file, each carrying a filled bag on his shoulder. These are 
 received by the sappers, who immediately commence form- 
 ing a mask or wall of bags (a b) extending the whole length 
 of the battery. The lower part of the mask is 40" thick, 
 the remainder 20". The bags are laid alternately, headers 
 and stretchers. The usual height is G' 6", but this may be 
 increased, if it does not afford sufficient protection. It may 
 also be found necessary to carry the mask round into the 
 epauleinent. 
 
 The revetment of the interior slope, which is carried on at 
 the same time, is formed of sand-bags laid in alternate 
 courses of headers and stretchers. The tie of the bag is 
 kept in the parapet. From time to time bags should be an- 
 chored by passing a rope around them and making it fast to 
 a stake driven within the parapet. 
 
 Whilst the 'revetment is going on, a second party of car- 
 riers bring up untied bags of sand, which they empty be- 
 tween the mask and revetment to form the parapet and 
 outside the mask to form the exterior slope. 
 
 The embrasures should be reveted with gabions or fascines, 
 if possible. When sand-bags are employed they must be 
 covered with raw hides, or hurdles, otherwise they are soon 
 destroyed by the blast of the piece. 
 
 About twelve hundred sand-bags are required per gun, 
 for the revetment and mask, and four thousand bags of sand 
 to form the parapet. 
 
 This battery may be constructed in a single night. 
 
 In consequence of the celerity and safety with which the 
 
254- 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 work is executed, lis method may often be employed 
 with advantage, even when the soil will permit the use of 
 the ordinary form. 
 
 HALF-SUNKEN BATTERIES. 
 
 Tina term is applied to those batteries in 
 which the earth to form the parapet is derived 
 partly from a ditch in front, and partly from the 
 excavation of the terreplein. 
 
 To trace the battery, first mark out the base 
 of the parapet and epaulemcnt. Then a line 20' 
 in rear of and parallel to the parapet, which 
 will give the position of the foot of the reverse 
 elope of the terreplein. 
 
 The construction is as follows : taking the 
 case where the terreplein is to be lowered 2'. 
 
 For each one-gun portion, six excavators are 
 placed in the ditch, and six sappers commence 
 the interior revetment by half imbedding a 
 fascine at the foot of the interior slope. Paral- 
 lel to this they commence excavating a trench 
 2' deep and 3' wide, leaving a berme of 18" on 
 the side next the parapet. At, the same time, 
 six men are employed excavating along the rear 
 line of the terreplein, throwing the earth toward 
 the revetters, who pass it into the parapet, where 
 it is levelled and rammed by two sappers, assisted 
 by two workmen. 
 
 The terrepleiu has an inclination to the rear, 
 where it is finished with a trench to carry off 
 the rain-water. If there is no low ground in 
 the vicinity to which this trench can be con- 
 b10 ' 2 ' ducted, it should terminate in a cesspool. 
 The revetment of the interior slope is carried up to the 
 level of the sole of the embrasure with fascines. It may be 
 finished either with fascines or gabions. 
 
CONSTRUCTION OF BATTERIES. 
 
 255 
 
 The method above described is only applicable when the 
 soil is sufficiently firm to stand without revetment in the 
 excavated portion of the interior slope. When this is not 
 the case, a trench is dug at the foot of the interior slope, 
 and to the full depth of the terreplein. At the bottom of 
 this trench the revetment is commenced and carried up, as 
 in the elevated battery. 
 
 Under ordinary circumstances, this battery may be con- 
 structed in eleven hours. 
 
 PIG. 22. 
 
 FULL-SUNKEN BATTERIES. 
 
 In full-sunken batteries the terreplein is low- 
 ered 3'. Sufficient earth is thus furnished for 
 the parapet, and no ditch is required. 
 
 There are two methods employed in their 
 construction: The first is the same as for half- 
 sunken batteries, the whole of the interior slope 
 usually being reveted, and the ditch omitted. 
 
 The second consists in first constructing a 
 trench by the flying sap, 10' in advance and 
 parallel to the interior crest of the proposed 
 battery. The terreplein is traced 20' wide, 
 taking the foot of the interior slope 10' from 
 the gabionade (c). 
 
 The working party is distributed along the 
 trench, and commences excavating from the re- 
 verse (a >), throwing the earth against e d. 
 When the trench has been carried back 3' or 
 4', the revetment (i k) is commenced. This is 
 executed as in the elevated battery. The em- 
 brasures are laid out, and the revetment of the 
 cheeks carried as far as the gabionade (c), which 
 is allowed to remain until the parapet has at- 
 tained its full height, when it is overturned, and 
 the embrasure finished. These batteries may 
 
256 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 be constructed in a parallel, instead of making a trench 
 especially for the purpose. 
 
 In this case, a trench must be cut around, and thirty yards 
 in rear of, the battery, to replace the portion of the parallel 
 thus occupied. 
 
 There is still another method of changing a trench into a 
 sunken battery, which will be described under the head of 
 " Breaching Batteries." 
 
 MORTAR BATTERIES. 
 
 As mortars are fired at an angle of elevation of at least 
 30, greater latitude is allowed in the selection of the posi- 
 tion of their batteries, than for those of guns and howitzers. 
 The least exposed position is on the capitals of the works 
 attacked. Frequently the labor in their construction may 
 be very much abridged, by taking advantage of the irregu- 
 larities of the ground. Thus the greater part of the parapet 
 may often be formed by a natural ridge. 
 
 Under ordinary circumstances they are placed in rear of 
 the second parallel. 
 
 Unless the nature of the soil is unfavorable, these batteries 
 are always sunken. They are without embrasures, and un- 
 less the soil is very light, are not reveted. 
 
 TO CONSTRUCT A BATTERY FOR FOUR MORTARS. 
 
 FIG. 28. 
 
CONSTRUCTION OF BATTERIES. 257 
 
 FIG. 24r SECTION ON p q. 
 
 The intervals between the axes of the mortars should be 
 15'. Six feet is added to the interval in which the traverse 
 occurs. A space of 10' is allowed between the axes of the 
 extreme mortars and the epaulement. The width of the 
 terreplein is 20' at bottom ; its depth, iu front, 3' 6", and 
 in rear, 4'. 
 
 TRACE. 
 
 Mark on the ground the line representing the foot of the 
 interior slope, and lay off on this line 71' (the sum of the 
 intervals). From each extremity lay off the epaulements ; 
 their direction will depend on that of the enemy's fire. Par- 
 allel to the first line, and 20' from it, lay off the foot of the 
 reverse slope. Then mark, with tracing-tape, the lines, A, e, 
 g, f t 30' ; outside the lines first laid out. These lines will be 
 the intersection of the interior slopes o*f the parapet and 
 epaulements with the natural surface of the ground. 
 
 The excavation is commenced on the line (a ), by sinking 
 a trench 40" deep and 4' wide.' The earth is thrown into 
 the parapet, and passed forward by a relay of shovellers, to 
 form the exterior slope. When the trench is finished, the 
 excavation is carried back toward the reverse. 
 
 As soon as the parapet has attained its full height on the 
 exterior, the sappers commence building j,he interior slope 
 (e, m), which will be one of f in ordinary soil. The earth 
 required for this purpose is thrown on the bcnric. When 
 the excavation of the terreplein has been carried back to 
 the line (r q), the step (a m p) is cut away, and the earth 
 thrown on the parapet. The earth obtained from theex- 
 cavution of the terreplein is about sufficient for the con- 
 
258 MANUAL FOR ENGINEER TROOPS. 
 
 struction of the parapet. That for the epaulements will be 
 furnished by the ditches (x y) on the exterior. 
 
 The splinter-proof traverse is of the usual form and con- 
 struction. 
 
 When the soil is of such a character as to require the in- 
 terior slope to be sustained, the usual revetments of gabions, 
 fascines, or sand-bags, may be employed. The working 
 party is distributed as follows : 
 
 For each one-mortar portion, 4 picks, 4 shovels, 2 rammers. 
 
 For each epaulement, 9 picks, 7 shovels, 4 rammers. 
 
 For each traverse, two picks, two shovels, two revetters. 
 
 Or, for the four-mortar battery, ninety men, four being 
 added for the increased interval opposite the traverse. 
 
 Fia. 25. 
 
 Portions of a trench or parallel are frequently converted 
 into mortar batteries. To effect this it is only necessary to 
 increase the width of the trench to 20'. The earth thus fur- 
 nished is thrown in front of the parapet, thus giving it the 
 requisite thickness. 
 
 BREACHING AND COUNTER BATTERIES. 
 
 The crowning of the covered way is a trench constructed 
 by the full sap, the crest of the parapet being parallel to 
 and 14' from that of the covered way. In this trench, the 
 breaching and counter batteries are constructed. 
 
 The traverses employed for the defilement of the trench, 
 are usually far enough apart to allow the introduction of two 
 pieces between them. The intervals between the pieces 
 may be reduced to 14'. The line of fire in the broaching 
 battery should be as nearly perpendicular to the scarp to be 
 Breached as possible; if the angle is less than 30 the shot 
 will ricochet and the breach cannot be 
 
CONSTRUCTION OF BATTERIES. 
 
 259 
 
 I./*' 
 
 Fio. 20. 
 
 The profile of the scarp to be breached, and the ditch and 
 covered way in front should be ascertained. This will de- 
 termine the position of the directrices, -and inclinations of 
 the soles of the embrasures. 
 
 The parapets of breaching batteries are 14' thick and 8' 
 high. Those of counter batteries, have the same height, 
 but should be five or six feet thicker, as they are more ex- 
 posed to the enemy's fire. In each the terreplein is 27' 
 wide. 
 
 CONSTRUCTION OP BREACHING BATTERIES. 
 
 During the day all the necessary material is collected, the 
 terreplein excavated and the platforms laid. 
 
 If the trench has been well constructed, and the soil is 
 good, the revetment of the trench may be retained for that 
 of the battery, otherwise a new revetment is formed, simi- 
 lar to those described under the head of full-sunken batteries, 
 
MANUAL FOR ENGINEER TROOPS. 
 
 with this exception, that the upper course of 
 gabions must be crowned with three fascines to 
 bring the parapet to the required height. 
 
 The line marking the reverse of the terreplein 
 is laid out parallel to and 27' from the interior 
 slope. 
 
 The directrices of the embrasures are deter- 
 mined and four pickets driven to mark the posi- 
 tion and height of the corners of the platforms. 
 The excavation of the terreplein is commenced, 
 part of the earth thus furnished is used in form- 
 ing the foundation of the platforms, the remain- 
 der in increasing the height of the adjacent 
 traverses. The figure shows the necessary al- 
 terations, from a trench to a breaching battery. 
 To construct the embrasure, a double row of 
 gabions filled with fascines, is formed along the 
 exterior crest of the parapet, as a mask, or pro- 
 tection against musketry. 
 
 A gabion of the revetment of the interior 
 slope is removed, to form the throat ; into this 
 opening a sapper enters, and commences the ex- 
 cavation of the embrasure, throwing the earth 
 on the merlons, until he has formed a seat for 
 the second pair of gabions of the cheek, which 
 he places, and is then relieved by two sappers, 
 who continue the excavation, throwing the earth into the 
 gabions just placed, until they are full, then on the merlons ; 
 they each place a gabion, forming the third pair in the em- 
 brasure. In the 'same way a third relief places the fourth 
 pair, &c., until six pairs are placed. During this operation, 
 the direction of the cheek and inclination of the sole, are 
 indicated to the workmen by a straight-edge resting on the 
 heads of two pickets, one in the throat of the embrasure the 
 other in the terreplein. 
 
 FIG. 27. 
 
CONSTRUCTION OF BATTERIES. 261 
 
 After the embrasure is finished, the mask is either removed 
 by drawing the gabions into the battery, with sap-hooks, or 
 is left to be blown out by the first discharge of the piece. 
 
 FIG. 28. SECTION ON at a/. 
 
 The parapet of the counter-ba-ttery being five or six feet 
 thicker than that of the trench, which increase is gained on 
 the inside, it will always be necessary to renew the interior 
 revetment. In other respects the construction does not dif- 
 fer from that of breaching batteries. 
 
 MAGAZINES 
 
 Are usually built fifteen yards in rear of the parapet of the 
 battery or communication, sometimes at the end of the 
 batteiy parapet or in that of the communication. 
 
 The figure represents a rectangular magazine in rear of 
 the parapet. An excavation 4' deep receives the five mining 
 frames, each composed of a cap-sill 6' X 8" X 6", two stanchions 
 4' 6"X6"X6", and one ground-sill 5' 6"X6"X3". The in- 
 tervals between the frames are 2' 6". The ground-sills are 
 brought to the same level, and surrounded with sheeting one 
 inch thick, and covered with timber or plank at least 6" thick. 
 The frames for the communication may be of somewhat 
 smaller scantling, that of six inches square will answer for 
 the cap-sills. These frames are 2' 6" wide in the clear, and 
 of the same height as those in the magazine. The sheeting 
 is also the same. 
 
 The roof may be still further strengthened by layers of 
 timber or fascines. The whole must be covered with earth 
 to the depth of 7'. 
 
 As a precaution against moisture, a mound of earth is 
 raised over the magazine, in the form of a roof, and about 2' 
 
262 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 high in the middle, over which a tarpaulin is laid and the re- 
 -2j* mainder of the earth thrown 
 on. 
 
 The earth for this covering 
 is partly furnished by the exr 
 cavation for the magazine, and 
 the remainder from a trench 
 cut around it, leaving a suffi- 
 cient berme to prevent the em- 
 bankment caving in. 
 I 
 
 Fio. 29. 
 
 When the soil is favorable the magazine may with advan- 
 tage be sunk two or three feet lower. 
 
 The magazine is connected with the battery, by a trench 
 4' wide, and 3' 6" deep, whose direction is such as to avoid 
 being enfiladed. 
 
 The entrance to the covered passage should be turned 
 from the enemy. The passage having a return or change of 
 direction, so that there may be no danger of fragments of 
 shell finding their way into the magazine. 
 
CONSTRUCTION OF BATTEKIES. 
 
 203 
 
264 
 
 MANUAL FOR ENGINEER TROOPS. 
 
 FIG. 82. 
 
 When suitable timber cannot be obtained for the above 
 construction, those shown in the following figure may be 
 used, in which the interior revetment is principally of fas- 
 cines and gabions. 
 
CONSTRUCTION OF BATTERIES. 
 
 265 
 
 FIG. 84. 
 
 REMARKS. 
 
 The dimensions given for the preceding constructions 
 are not invariable. 
 
 In ordinary soil, the thickness of parapet and covering of 
 the magazine, are a sufficient protection against the artillery 
 usually employed in the defence of a work. In the case 
 however, of a light soil, or when the enemy is provided 
 with very heavy ordnance, as in the siege of Sebastopol, this 
 thickness may frequently require an addition of six or eight 
 feet. 
 
 The throats of the embrasures must also correspond with 
 the pieces which are to be fired through them. For how- 
 itzers the width should be 2' 6", and when pieces are intend- 
 ed for ricochet firing only, an embrasure of peculiar form 
 may be employed, the sole having a reverse slope, and but 
 two gabions being used in the revetment of each cheek. 
 
 The subject of siege platforms is fully treated in a work 
 on heavy artillery, published by the war department, and is 
 therefore omitted here. 
 12 
 
INDEX. 
 
 PAGK. 
 
 Advance-guard bridge equipage 31 
 
 Anchoring paniers 40 
 
 Approaches, execution of the, connected with the first parallel 118 
 
 executing the, connected with the second parallel and 
 
 commenced by the flying sap 125 
 
 " modifications in the construction of 130 
 
 " on irregular ground 132 
 
 " reliefs of workmen for, in easy soil 128 
 
 " tables of comparative excavation in 127 
 
 Arming working parties in a siege. . . ; 106, 108, 109 
 
 Arrangements for military working parties in a siege 135 
 
 Attack of a system of countermines 234 
 
 Balk carriers 20 
 
 Basket-work described . 68 
 
 Batteries, breaching and counter 258 
 
 " construction of , 241 
 
 " distribution of the working parties in the construction of . . 245 
 
 " fullsunken 255 
 
 " half sunken 254 
 
 " mortar 256 
 
 " remarks on the construction of 265 
 
 " sand-bag 252 
 
 " tracing of 243 
 
 Blindage | 197 
 
 Blinded descent 193 
 
 Boats 10 
 
 " of commerce, bridges constructed of 38 
 
 Branches 207, 221 
 
 " dimensions of 208 
 
 Breaching batteries 268 
 
 Bridge, construction of trestle and ponton by successive pontons over 
 
 watercourse 22 
 
268 INDEX. 
 
 PAC1 
 
 Bridge, to construct a, over a watercourse 23 
 
 " construction of, by parts 28 
 
 " " " by rafts 29 
 
 " construction of a, by successive pontons when the balks are 
 
 not lashed 32 
 
 11 constructed of boats of commerce 38 
 
 " by conversion 29 
 
 " dismantling over a watercourse 27 
 
 " dismantling by parts 28 
 
 " dismantling by conversion 31 
 
 " equipage, modified French 17 
 
 " equipage 18 
 
 11 floating 11 
 
 " flying 12-34 
 
 " gabion 15 
 
 " miUtary 14 
 
 " pile 15 
 
 11 ponton 14 
 
 " ponton and trestle, construction of 17 
 
 " preservation of 46 
 
 " Rhine flying 36 
 
 " trestle, to dismantle 22 
 
 " to construct a, over a'watercourse 23 
 
 " trail -.. 12 
 
 " trestle 14, 45 
 
 Brushwood, detail of men for cutting 54 
 
 - " preparation of, for military purposes 51 
 
 " required in a siege or campaign 53 
 
 " tools required for cutting 53 
 
 Canvas pontons 32 
 
 Carriers, balk 20 
 
 I " trestle 20 
 
 Casks, raft of 44 
 
 Cavalier, trench 184 
 
 Charging of mines 228 
 
 Chess 21 
 
 Construction of batteries 241, 246 
 
 " of breaching batteries 259 
 
 of a bridge over a watercourse 23 
 
 " " " by parts 28 
 
 " " " by rafts 29 
 
INDEX. 269 
 
 PAGB. 
 
 Construction of a bridge by successive pontons when the balks are 
 
 not lashed 32 
 
 of flying bridges 34 
 
 of ponton and trestle bridges 17 
 
 " of a raft 41 
 
 of trestle bridge over dry ravine 19 
 
 of trestle and ponton bridge by successive pontons over 
 
 watercourse 22 
 
 Corrugated iron gabions 77 
 
 Counter batteries 258 
 
 Countermines, attack and defence of a system of 234 
 
 Covered w ly, descent into the 199 
 
 Covering-fascines 65 
 
 Debouche by the simple or double sap from the extremity of the simple 
 
 sap in course of construction 162 
 
 " by the simple sap from one or both sides of the double sap 170 
 
 " by the double or simple sap from a sap not enlarged 175 
 
 " by the simple or double sap from a trench of the ordinary 
 
 width 180 
 
 " by the double sap from a trench of the ordinary width 184 
 
 Defence of a system of countermines 234 
 
 Descent into the covered way 199 
 
 " " " ditch 189 
 
 " time for executing the 199 
 
 Discharge of material. 18 
 
 Dismantling trestle bridge 22 
 
 bridge over a watercourse 27 
 
 " by parts 28 
 
 " constructed by rafts * 29 
 
 " by conversion 31 
 
 Ditch, descent into the 189 
 
 " passage of the 199 
 
 " main 200 
 
 Double sap 157 
 
 " debouching by the 167 
 
 " debouche by the, from a trench 184 
 
 " to debouch by the, from a sap not enlarged 179 
 
 Drag 1 49 
 
 Embrasures 242 
 
 revetted with fascines 248 
 
 " " gabions 251 
 
2 TO INDEX. 
 
 PAGE. 
 
 fepaulement 241 
 
 Equipage, advance-guard bridge 31 
 
 Excavating and blinding 196 
 
 Fascine-choker 61 
 
 Fascine-pickets 64 
 
 " time required for making 65 
 
 " weights of 65 
 
 Fascine-trestles, method of preparing 56 
 
 Fascines described 55 
 
 u detail of men for making 55 
 
 " making, described 58 
 
 " method of choking 61 
 
 " revetment with 247 
 
 " rules for making 55 
 
 " time required for making 64 
 
 " tools for each squad of men, making 55 
 
 " weights of 64 
 
 Firing mines 230 
 
 First approaches, arranging the working party and commencing the, 91 
 ' method of tracing the, connected with the first par- 
 allel 90 
 
 " remarks on commencing the 92 
 
 " rules for executing the 110 
 
 First parallel, arranging the working party and commencing the 85 
 
 " execution of the approaches connected with the 118 
 
 " first task in executing a, by three reliefs 113 
 
 " " " " by two reliefs hi easy soil 140 
 
 " method of tracing 83 
 
 " profile proper for a v 110 
 
 " reliefs of workmen for a, and its approaches 95-97 
 
 " remarks on commencing the 92 
 
 " rules for executing the 110 
 
 " second task in executing a, by three reliefs 113 
 
 " " " " by two reliefs hi easy soil. 141 
 
 tasking of military working parties in the formation of a 111 
 
 " third task in executing a, by three reliefs 114 
 
 Flanking boyaus 129 
 
 Floating bridges 11 
 
 Flying bridge 12, 34 
 
 Flying sap 99 
 
 " executing a second parallel, commenced by the 121 
 
INDEX. 271 
 
 PAGE. 
 
 Flying sap, rules for tracing and commencing approaches by the 102 
 
 Fords -. 7 
 
 French bridge equipage 17 
 
 Full sap 147 
 
 " change of direction of the 161 
 
 " to the right or left 161 
 
 " execution of the 149 
 
 " time required for executing the 154 
 
 Full-sunken batteries 255 
 
 Gabionade, crowning the, with fascines 163 
 
 Gabion bridges 15 
 
 Gabions, corrugated iron 77 
 
 " description and dimensions of 67 
 
 " detail of men for making 71 
 
 " embrasures revetted with 251 
 
 " method of finishing 73 
 
 " method of making light 71 
 
 " " " of very small brushwood 75 
 
 iron 76 
 
 " " of thick brushwood v . 76 
 
 " mode of carrying, with tools 106 
 
 " revetment with 249 
 
 " time required for making 78 
 
 " to place new 151 
 
 tools for each squad of men, making. 71 
 
 " weight of 78 
 
 " wooden circles, for making 75 
 
 Galleries 207 
 
 " dimensions of 208 
 
 ' " driving, with mine frames 214 
 
 " incUned 217 
 
 " men and tools required for driving 216 
 
 " ventilation of 233 
 
 Gallery-frame 214 
 
 Half-double sap 159 
 
 Half-full sap 156 
 
 Half-sunken batteries 254 
 
 Hurdles 80 
 
 " number of men required for making . . 83 
 
 " time required for making 83 
 
 " tools for making 83 
 
272 INDEX. 
 
 PAGE. 
 
 Hurdles, weight of 83 
 
 Ice , 9 
 
 Inclined galleries 217 
 
 I " soil, observations relative to 155 
 
 Iron gabions, method of making 76 
 
 Large timber required in a siege or campaign 51 
 
 Magazines 261 
 
 Marshy soil, construction of parallels and approaches in 130 
 
 Material, discharge of 18 
 
 Men required for driving a gallery 216 
 
 " for sinking a shaft 210 
 
 Military bridges 14 
 
 Mines, charging of 228 
 
 " firing of 230 
 
 " tamping of 228 
 
 Mining operations, tools required for 208 
 
 " practical operations in 207 
 
 " with cases 223 
 
 Mortar batteries 256 
 
 Parallels, commencing the tracing of, by compass 93 
 
 " execution of 117 
 
 " modifications hi the construction of. 130 
 
 " on irregular ground 132 
 
 " reliefs of workmen for, in easy soil 128 
 
 " rules for tracing and commencing the first, and the ap- 
 proaches 83 
 
 " rules for tracing and commencing the second, and ap- 
 proaches, by the flying-sap 98 
 
 " tables of comparative excavation in 125 
 
 " tracing of, in a fog 93 
 
 Parapet 241 
 
 Passage of rivers 7 
 
 " " by fords t 
 
 " " " byice 9 
 
 " " " onboats 10 
 
 " " " on rafts - 10 
 
 Pile bridges 15 
 
 Ponton bridges 14 
 
 " " construction of 17 
 
 Preservation of bridges 46 
 
 Bafts.. 10 
 
INDEX. 273 
 
 PAGK. 
 
 Rafts, construction of 41 
 
 " " " a bridge by 29 
 
 " dismantling bridge constructed by 29 
 
 " of casks 44 
 
 " of timber 40 
 
 Regulations for military working parties in a siege 135 
 
 Reliefs, number of troops necessary to furnish proper, in a siege 142 
 
 " of workmen for the first parallel and its approaches 95-97 
 
 " " second parallel and its approaches 103 
 
 Revetment with fascines 247 
 
 " gabions 249 
 
 Rhine flying bridges 36 
 
 Rivers, passage of 7 
 
 Rocky soil, construction of parallels and approaches in 130 
 
 Rules for executing the first parallel and approaches 110 
 
 " second parallel and approaches 121 
 
 " " making fascines 55 
 
 <; " " gabions and hurdles 67 
 
 ". " tracing and commencing the first parallel and approaches. . . 83 
 " " " " " second parallel and approaches 
 
 by the flying sap 98 
 
 Sand-bag batteries 252 
 
 Sand-bags, saps constructed with 203 
 
 Saps constructed with sand-bags 203 
 
 Sap-faggots ^ 66 
 
 Sap-fork 149 
 
 " hook . 148 
 
 Sap-rollers 78 
 
 " time for making 79 
 
 " weight of , 79 
 
 Sappers, to change the posts of the 154 
 
 Second parallel, arranging the working party and commencing the, by 
 
 the flying sap 99 
 
 " crowding the workmen in commmencing a 105 
 
 " reliefs of workmen for the 103 
 
 " " " " " in executing a 122 
 
 " remarks on commencing the, 105 
 
 " rules for executing the, and approaches, 121 
 
 " " rules for executing a, commenced by the flying sap,. .121 
 
 ' * tracing of,. 98 
 
 Shafts 207 
 
 12* 
 
274 INDEX. 
 
 PAGK. 
 
 Shaft, men and tools required for sinking a, 210 
 
 " sinking a, in bad soil 219 
 
 Side-rails 21 
 
 Siege, arming working parties in a 106, 108, 109 
 
 " arrangements and regulations proper for military working par- 
 ties in a 135 
 
 " practical operations of a 49 
 
 Simple sap 147 
 
 " " debouching by the 162 
 
 " " debouche by the, from a trench 180 
 
 " " to debouch by the, from a sap not enlarged 175 
 
 " saps, to unite two, into one double sap 172 
 
 Small timber required in a siege or campaign -, 53 
 
 Splinter-proof traverses 242, 249 
 
 Stockades 47 
 
 Tamping mines 228 
 
 Terreplein 242 
 
 Timber, large, required in a siege or campaign 51 
 
 " preparation of, for military purposes 51 
 
 " rafts 40 
 
 " small, required in a siege or campaign 53 
 
 Time required for executing the full sap 154 
 
 " " " making fascines '. 64 
 
 " " " " fascine-pickets 65 
 
 " " " " gabions 78 
 
 " " " *" hurdles 83 
 
 " " " " sap-rollers 79 
 
 Tools for each squad of men making fascines 55 
 
 * " " " " " " gabions 71 
 
 " " making hurdles 83 
 
 " mode of carrying gabion 106 
 
 " required for cutting timber for military purposes 51 
 
 11 " " " brushwood 53 
 
 " for the full sap 148 
 
 " required for mining operations 208 
 
 " " sinking a shaft 210 
 
 " " driving a gallery 216 
 
 Trace 257 
 
 Tracing-fascines 65 
 
 Tracing of batteries 243 
 
 Tracing-pickets 66 
 
INDEX. 275 
 
 PAGE. 
 
 Trail bridge 12 
 
 Traverses 250 
 
 Trenches 120 
 
 " preserving the, dry 115 
 
 Trench cavalier 184 
 
 Trestles 44 
 
 " fascin/e, method of preparing 66 
 
 Trestle bridges 14, 45 
 
 " construction of 17 
 
 " bridge over dry ravine, construction of. 19 
 
 " carriers 20 
 
 " to construct the 20 
 
 Troops, number of, necessary in a siege to furnish proper reliefs 142 
 
 Uncovered descent 199 
 
 Ventilation of galleries 233 
 
 Weight of fascines 64 
 
 " " fascine-pickets 65 
 
 " " gabions 78 
 
 " " hurdles 83 
 
 " " sap-rollers 79 
 
 Withes, method of preparing and using 59 
 
 Wooden circles.for gabion making 75 
 
 Wooden linings 209 
 
 Working parties, arming, in a siege 106, 108, 109 
 
 " " mixed 135 
 
 " " relief of ^ 139 
 
 " " regulations proper for military, in a siege 135 
 
 " " superintending 135 
 
 " " tasking of, in the formation of a first parallel Ill 
 
 Workmen crowding the, in commencing a second parallel 105 
 
 " reliefs of, for a first parallel and its approaches 95-97 
 
 " " "for the second parallel and its approaches 103 
 
 " " " in executing a second parallel 122 
 
 " " " in finishing parallels and approaches in easy soil. . 128 
 
CATALOGUE 
 
 OP 
 
 Military, Naval, and Scientific 
 
 BOOKS, 
 
 PUBLISHED BY 
 
 D. VAN NOSTRAND, 
 
 192 BROADWAY, NEW YORK. 
 
 * llc * On receipt of price, copies of any of these Books will be 
 sent by mail, postage paid, to any part of the United States. 
 
D. VAN NOSTRAND, 
 
 PUBLISHER, 
 
 IMPORTER, AND BOOKSELLER, 
 
 192 BROADWAY, NEW YORK, 
 
 would respectfully solicit orders from Public and Private Libraries 
 for the purchase of any Books, Apparatus, or Philosophical Instru- 
 ments, in this country or Europe. From his long experience in the 
 Book Business, he is confident of giving satisfaction in any commission 
 that may be entrusted to him. 
 
 Books imported from London and Paris by every steamer, and at 
 the lowest possible rates, and, for Public Institutions, free of duty. 
 
 Owing to the high rate of Exchange, and the increased tariff, the 
 prices of foreign books have been advanced ; but only sufficient to 
 cover the extra cost of importation. 
 
 A LARGE STOCK OF THE PRINCIPAL 
 
 French, English, and American 
 
 MILITARY, 
 NAVAL, AND SCIENTIFIC WORKS 
 
 ON HAND. 
 
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 Catalogues sent free by mail, on application. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 coTT's MILITARY DICTIONARY. 
 
 Comprising Technical Definitions ; Information on Raising and 
 Keeping Troops ; Actual service, including makeshifts and im- 
 proved materiel, and Law, Government, Regulation, and Admin- 
 istration relating to Land Forces. By Colonel H. L. SCOTT, 
 Inspector-General U. S. A. l vol., large octavo, fully illustra- 
 ted, half morocco, $6; Half russia, $7.50 ; Full morocco, $9. 
 
 " It is a complete Encyclopaedia of Military Science, and fully explains every thing dis- 
 covered in the art of war up to the present time." Philadelphia Evening Bulletin. 
 
 " We cannot Bpeak too much in legitimate praise of this work." National Intelligen- 
 cer. 
 
 " It should be made a text-book for the study of every volunteer. 1 " Harper's Mag- 
 aine. 
 
 "We cordially commend it to public favor." Washington Globe. 
 
 "This comprehensive and skilfully prepared work supplies a want that has long been 
 felt, and will be peculiarly valuable at this time as a book of reference." Boston Commer- 
 cial Bulletin. 
 
 "The Military Dictionary is splendidly got up in every way, and reflects credit on the 
 publisher. The officers of every company in the service should possess it." N. Y. Tablet. 
 
 " The work is more properly a Military Encyclopaedia, and is profusely illustrated with 
 engravings. It appears to contain every thing that can bo wanted in the shape of informa- 
 tion by officers of all grades.'''' Philadelphia Nortfi American. 
 
 "This book is really an Encyclopaedia, both elementary and technical, and as such occu- 
 pies a gap in military literature which has long been most inconveniently vacant. This 
 book meets a present popular want, and will be secured not only by those embarking in 
 the profession but by a great number of civilians, who are determined to follow the de- 
 scriptions and to understand the philosophy of the various movements of the campaign. 
 Indeed, no tolerably good library would bo complete without the work." New York 
 Times. 
 
 "The work has evidently been compiled from a careful consultation of the best author- 
 ities, enriched with the results of the experience and personal knowledge of the author.'' 
 N. Y. Daily Tribune. 
 
 " Works like the present are invaluable. The officers of our Volunteer service would 
 all do well to possess themselves of the volume."^ Y. Uerald. 
 
 u It is a book to be referred to on the spur of the moment, to be consulted at leisure, and 
 to be read with deliberation. It reflects honor on the military service of the United States, 
 and gives new glory to one of the noblest of the names connected with that service." 
 Boxton Traveller, 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 C 
 
 AVALRY; ITS HlSTORY, MANAGEMENT, AND 
 USES IN WAR. 
 
 By J. ROEMER, LL. D., late an Officer of Cavalry in the Service of the 
 Netherlands. Elegantly illustrated, with one hundred and twenty- 
 seven fine Wood Engravings. In one large octavo volume, 
 beautifully printed on tinted paper. Price $5.00. 
 
 SUMMARY OF CONTENTS. Cavalry in European Armies ; Proportion 
 of Cavalry to Infantry ; What kind of Cavalry desirable ; Cavalry 
 Indispensable in War ; Strategy and Tactics ; Organization of 
 anArmy ; Route Marches ; Rifled Fire- Arms ; The Charge ; 
 The Attack ; Cavalry versus Cavalry ; Cavalry versus Infantry ; 
 Cavalry versus Artillery ; Field Service ; Different . Objects of 
 Cavalry; Historical Sketches of Cavalry among the early 
 Greeks, the Romans, the Middle Ages ; Different kinds of Modern 
 Cavalry ; Soldiers and Officers ; Various systems of Training of 
 Cavalry Horses; Remounting ; Shoeing ; Veterinary Surgeons, 
 Saddlery, etc., etc. 
 
 WHAT GENERAL It'CLELLAN BATS OF IT. 
 
 u I am exceedingly pleased with it, and regard it as a very valuable addition to our 
 military literature. It will certainly be regarded as a standard work, and I know of none 
 so valuable to our cavalry officers. Its usefulness, however, is not confined to officers of 
 cavalry alone, but it contains a great deal of general information valuable to officers of the 
 other arms of service, especially those of the Staff, 
 
 " With the hope that it may find a large circulation in our armies, I am, very truly yours 
 
 "GEO. B. MCCLELLAN, Maj-Gen. U. 8. A." 
 
 "We can truly say that, from no single volume have we obtained so much information 
 on the art of war as from this." Phila. Press. 
 
 " Beading, culture, and practical experience united, give this work a value and impor- 
 tance that will cause it to be regarded as a standard authority." Saturday Eve. Gazette. 
 
 "By far the best treatise upon Cavalry and its uses in the field, which has yet been 
 published in this country, for the general use of officers of all ranks, is this elaborate and 
 {Interesting work. Eschewing the elementary principles and tactics of cavalry, which may 
 be learned from any hand-book, the author treats of the uses of cavalry in the field, of 
 strategy and tactics, and of its general discipline and management. The range of the work 
 includes an admirable treatise upon rifled fire-arms, a historical sketch of cavalry, embod- 
 ying many interesting facts, an account of the cavalry service in Europe and this country 
 and a treatise on horses, their equipment, management, Ac. The work is copiously illus- 
 trated and elegantly printed. It is interesting not alone to military men but to the gen- 
 eral reader, who will gain from its pages valuable historical facts and very clear ideas of 
 pome branches of the art of war, such as the employment of spies, gaining information in nn 
 enemy's country, advance movements and other strategical maneuvrcs. Boston Journal' 
 
B 
 
 D. VAN NOSTRAND'S PUBLICATIONS. 
 
 ENfir's MILITARY LAW. 
 
 A Treatise on Military Law and the Practice of Courts-Martial, by 
 Capt. S. V. BENT, Ordnance Department, U. S. A., late As- 
 sistant Professor of Ethics, Law, &c., Military Academy, West 
 Point. 1 vol., 8vo, law sheep. "$3.50. 
 
 "This book is manifestly well timed just at this particular period, and it is, -without 
 doubt, quite as happily adapted to the purpose for which it was written. It is arranged 
 with admirable method, and written with such perspicuity and in a stylo so easy and grace- 
 ful, as to engage the attention of every reader who may be so fortunate as to open its pages. 
 This treatise will make a valuable addition to the library of the lawyer or the civilian ; 
 while to the military man it seems to be indispensable." Philadelphia Evening Journal. 
 
 "Captain Bene"t presents the army with a complete compilation of the precedents and 
 decisions of rare value which have accumulated since the creation of the office of Judge- 
 Advocate, thoroughly digested and judiciously arranged, with an index of the most minute 
 accuracy. Military Law and Courts-Martial are treated from the composition of the latter 
 to the Finding and Sentence, with the Eevision and Execution of the same, all set forth in 
 a clear, exhaustive style that is a cardinal excellence in every work of legal reference. That 
 portion of the work devoted to Evidence is especially good. In fact, the whole performance 
 entitles the author to the thanks of the entire army, not a leading officer of which should 
 fail to supply himself at once with so serviceable a guide to the intricacies of legal military 
 government" IT. Y. Times. 
 
 " This volume has been carefully prepared by the author in order to present in a col. 
 lectcd form, the able decisions issued from the War Department since the establishment 
 of the office of Judge- Advocate of the Army, and the opinions given by the Attorneys- 
 General on points requiring legal interpretation. It is full of information for military men, 
 founded on the authority of these decisions and opinions, and is a valuable contribution 
 to the science of military law." Providence Journal. 
 
 JtTDGE-AnVOCATE GENERAL'S OFFICE, ) 
 
 October 18, 1862. f 
 
 * * * So far as I have been enabled to examine this volume, it seems to me carefully 
 nd accurately prepared, and I am satisfied that you have rendered an acceptable service to 
 the army and the country by its publication at this moment In consequence of tho 
 gigantic proportions so suddenly assumed by the military operations of the Government, 
 there have been necessarily called into tho field, from civil life, a vast number of officers, 
 unacquainted from their previous studies and pursuits, both with the principles of mili- 
 tary law and with the course of judicial proceedings under it To all such, this treatise 
 will prove an easily accessible storehouse of knowledge, which it is equally tho duty of tho 
 eoldier in command to acquire, as it is to learn to draw his sword against the common 
 enemy. The military spirit of our people now being thoroughly aroused, added to a 
 growing conviction that in future we may have to depend quite as much upon the bayonet 
 as upon the ballot-box for the preservation of our institutions, cannot, fail to secure to 
 this work an extended and earnest appreciation. In bringing the result- of legislation :md 
 of decisions upon tho questions down to so recent a period, tho author has added greatly 
 to the interest and usefulness of the volume. Very, respectfully, 
 
 Tour obedient swvaut, J. HOLT. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 E 
 
 LEMENTS OF MILITARY ART AND HlSTORY. 
 
 By EDWARD DE LA BARRE DUPARCQ, Chef de Bataillon of Engineers in 
 the Army of France ; and Professor of the Military Art in the 
 Imperial School of St. Cvr. Translated by Brig-Gen. Geo. W. 
 CULLUM, U. S. A., Chief of the Staff of Major-Gen. H. W. HAL- 
 LECK, General-in-Chief U. S. Army, i vol., octavo, cloth. 4. 
 
 " I read the original a few years since, And considered it the very best work I had seen 
 upon the subject Gen. Cullum's ability and familiarity with the technical language of 
 French military writers, are a sufficient guarantee of the correctness of his translation." 
 
 U. W. HALLECK, Major-Gen. U. S. A. 
 
 " I have read the book with great interest, and trust that it will have a large circulation. 
 It cannot fail to do good by spreading that very knowledge, the want of which among our 
 new, inexperienced, and untaught soldiers, has cost us so many lives, and so much toil 
 and treasure." 
 
 M. C. MEIGS, Quartermaster-General, U. 8. A. 
 
 "I have carefully read most of General Cullum's translation of M. Barre Dnparcq's 
 'Elements of Military Art and History.' It is a plain, concise work, well suited to our 
 service. Our volunteers should read and study it I wish it could be widely circulated 
 among our officers. It would give them a comprehensive knowledge of the different arms 
 of the service, and invite further investigation into the profession of arms which they have 
 adopted. A careful study of such works will make our officers learned and skilful, as well 
 as wise and successful ; and they have ample time, while they arc campaigning, to improve 
 themselves in this regard." 
 
 S. K. CURTIS, Major-Gen. U. 8. A. 
 
 "Barre Duparcq is one of the most favorably known among recent military writers in 
 France. If not the very best, this is certainly among the best of the numerous volume* 
 devoted to this topic. Could this book be put into the hands and heads of our numerous 
 intelligent, but untrained officers, it would work a transformation supremely needed. 
 "We can say, that no officer can read this work without positive advantage, and real pro- 
 gress as a soldier. Gen. Cullum is well known as one of the most proficient students of 
 military science and art in our service, and is amply qualified to prepare an original text- 
 book on this subject" Atlantic Monthly. 
 
 " That Gen. Cullum, Chief of Staff to the Commanding General, should have chosen to 
 translate and edit his work, rather than to prepare an original one himself, gives tho 
 highest professional testimony to its value. The work contains a History of the Art of War, 
 as it has grown up from the earliest ages; describes the various formations which have 
 from time to time been adopted; and treats in detail of the several arms of tho service, and 
 the most effective manner of employing them for offensive and defensive purpose.". It is 
 fully illustrated with diagrams, displaying to the eye the formations and evolutions which 
 find place in ancient and modern armies. Though the book is especially designed for tlie 
 instruction of oflicers and soldiers, the non-professional reader cannot fail to perceive the 
 clearness of its statements and the precision of its definitions." Harpers" Monthly. 
 
B 
 
 D. VAN NOSTRAND'S PUBLICATIONS. 
 
 ENTON'S ORDNANCE AND GUNNERY. 
 
 Course of Instruction in Ordnance and Gunnery; compiled for 
 the use of the Cadets of the United States Military Academy, 
 by Capt. J. G. BENTON, Ordnance Department, late Instructor 
 of Ordnance and Gunnery, Military Academy, West Point. 
 Principal Assistant to Chief of Ordnance, U. S. A. Second 
 Edition, revised and enlarged, l vol., 8vo, half morocco, cuts. 
 $5 oo. 
 
 " TTo cannot commend this work too highly, both for the substance it contains, and th 
 highly finished manner in which it has been issued by the publisher. There is no one 
 book within the range of our military reading and study, that contains more to recommend 
 it upon the subject of which it treats. It is as full and complete as the narrow compass 
 of a single volume would admit, and the reputation of the author as a scientific and prac- 
 tical artillerist is a sufficient guarantee for the correctness of his statements and deduc- 
 tions, and the thoroughness of his labors."^. Y. Observer. 
 
 "The present edition is the second one, and is revised and enlarged, being rendered al- 
 together invaluable, not only to the student, but as a standard book of reference on the 
 subject of which it treats. Apart from its great merits as a treatise, it is as respects bind- 
 ing and printing, a truly splendid work." Louisville Journal. 
 
 "A GREAT MILITARY "WORK. "We have before us a bound volume of nearly six hundred 
 pages, whii-.h is a complete and exhaustive ' Course of Instruction in Ordnance and Gun- 
 nery, 1 as its title states, and goes into every department of the science, including gunpow- 
 der, projectiles, cannon, carriages, machines, and implements, small arms, pyrotechny, 
 science of gunnery, loading, pointing, and discharging fire-arms, different kinds of fires, ef- 
 fects of projectiles and employment of artillery. These severally form chapter heads and 
 give thorough information on the subjects on which they treat. The most valuable and 
 interesling information on all the above topics, including the history, manufacture, and 
 use of small arms is here concentrated in compact and convenient form, making a work of 
 rare merit and standard excellence. The work is abundantly and clearly illustrated." 
 Boston Traveller. 
 
 "This work is designed for a standard work, not only for the soldier and the sailor, or as 
 a vade mecumfor reference on the quarter-deck and in the officer's tent, but from its plain 
 and forcible diction and familiar illustrations, must interest the general reader in the na- 
 ttiro and effects of 15-inch Columbiads, and all kinds of artillery, down to a signal rocket. 
 All who desire a work of reference upon the subject at large, will find this book a useful 
 nd interesting informant." C/ycago Journal. 
 
T 
 
 D. VAN NOSTRAND S PUBLICATIONS. 
 
 HE ARTILLERIST'S MANUAL: 
 
 Compiled from various Sources, and adapted to the Service of the 
 United States. Profusely illustrated with woodcuts and engrav- 
 ings on stone. Second edition, revised and corrected, with 
 valuable additions. By Gen. JOHN GIBBON, U. S. Army, i 
 vol., 8vo, half roan. $5. 
 
 This book is now considered the standard authority for that particular branch of the 
 Service in the United States Army. The War Department, at "Washington, has exhibited 
 its thorough appreciation of the merits of this volume, the want of which has been hither- 
 to much felt in the service, by subscribing for 700 copies. 
 
 "It is with great pleasure that we welcome the appearance of a new work on this sub- 
 ject, entitled "The Artillerist's Manual,' byCapt John Gibbon, a highly scientific and mer- 
 itorious officer of artillery in our regular service. The work, an octavo volume of 500 
 pages, in large, clear type, appears to be well adapted to supply just what has keen hereto- 
 fore needed to fill the gap between the simple Manual and the more abstruse demonstra- 
 tions of the science of gunnery. The whole work is profusely illustrated with woodcuts 
 and engravings on stone, tending to give a more complete and exact idea of the various 
 matters described in the text. The book may well bo considered as a valuable and impor- 
 tant addition to the military science of the country." New York Herald. 
 
 H 
 
 AND-BOOK OF ARTILLERY, 
 
 For the Service of the United States Army and Militia. New, re- 
 vised, and greatly enlarged edition. By Maj. JOSEPH ROBERTS, 
 U. S. A. 1 vol., i8mo, cloth. $1. 
 
 " A complete catechism of gun practice, covering the whole ground of this branch of 
 military science, and adapted to militia and volunteer drill, as well as to the regular army. 
 It has the merit of precise detail, even to the technical names of all parts of a gun, and how 
 the smallest operations connected with its use can be best performed. It has evidently 
 been prepared with great care, and with strict scientific accuracy. By the recommenda- 
 tion of a committee appointed by the commanding officer of the Artillery School at Fort 
 Monroe, Va., it has been substituted for ' Burns 1 Question and Answers,' an English work 
 which has heretofore been the text-book of instruction in this country." ITeic York 
 Century. 
 
 The following is an extract from a Report made by the committee appointed at a meet- 
 ing of the staff of the Artillery School at Fort Monroe, Va., to whom the commanding 
 officer of the School had referred this work : 
 
 * * * "In the opinion of your Committee, the arrangement of the subjects and the 
 selection of the several questions and answers have been judicious. The work is one 
 which may be advantageously used for reference by the officers, and is admirably adapted 
 to the instruction of non-commissioned officers and privates of Artillery. 
 
 " Your Committee do, therefore, recommend that it be substituted as a text-book in 
 place of ' Burns' Questions and Answers on Artillery.' " 
 
 (Signed,) I. VOGDES, Gnj*. \st ArfiBtry. 
 
 (Signed,) E. O. C. ORD, Capt 3d ArtiUcry. 
 
 (Signed,) J. A. HASKIN, Btt. Maj. and Capt. lt Artillery. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 T 
 
 HE AUTOMATON REGIMENT; OR, INFAN- 
 TRY SOLDIERS' PRACTICAL INSTRUCTOR. 
 
 For all Regimental Movements in the Field. By G. DOUGLAS BREWER- 
 TON, U. S. Army. Nearly put up in boxes, price $1 ; when 
 sent by mail, $ 1 . 40. 
 
 The "Automaton Regiment" is a simple combination of blocks and counters, so 
 arranged and designated by a carefully considered contrast of colors, that it supplies thy 
 student with a perfect miniature regiment, in which the position in the battalion of each 
 company, and of every officer and man in each division, company, platoon, and section, ia 
 clearly indicated. It supplies the studious soldier with the means whereby he can con- 
 sult his " tactics," and at the same time join practice to theory by manoeuvring a ininiio 
 regiment. 
 
 HEAD-QUARTERS, MILITARY GOVERNOR, ) 
 
 Department of the South, 
 Beaufort, South Carolina, Oct. 21st, 1SC2. ) 
 
 I hereby certify that I have examined the "Automaton Regiment," invented by G. 
 Douglas Brewerton, late of the U. S. Regular Army, and now serving as a Volunteer Aide 
 upon my military staff, and believe that his invention will prove a useful and valuable 
 assistant to every student of military tactics. I take pleasure in recommending it accord- 
 ingly. K. SAXTON, 
 
 .- General Volunteers. 
 
 T 
 
 HE AUTOMATON COMPANY ; OR, INFAN- 
 TRY SOLDIERS' PRACTICAL INSTRUCTOR. 
 
 For all Company Movements in the Field. By G. DOUGLAS BREWER- 
 TON, U. S. A. Price in boxes, $1.25 ; when sent by mail, $1.95. 
 
 T 
 
 HE AUTOMATON BATTERY; OR, ARTIL- 
 LERISTS' PRACTICAL INSTRUCTOR. 
 
 For all Mounted Artillery Manoeuvres in the Field. By G. DOUGLAS 
 BREWERTON, U. S. A. Price in boxes, $1 ; when sent by 
 mail, $1. 40. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 QYSTEMS OF MILITARY BRIDGES, 
 
 In Use by the United States Army; those adopted by the Great Eu- 
 ropean Powers ; and such as are employed in British India. With 
 Directions for the Preservation, Destruction, and Re-establish- 
 ment of Bridges. By Brig.-General GEORGE W. CULLUM, Lieut.- 
 Col. Corps of Engineers, United States Army, i vol., octavo. 
 With numerous Illustrations. $3.50. 
 
 " It is a trito remark that of all the operations of war none is more difficult and hazard- 
 ous than the passage of a large river in the presence of a bold and active enemy. The 
 importance to this country of such a work as the present, when our armies have to pass 
 so many great rivers, cannot be over-estimated. We have no man more competent to pre- 
 pare such a work than Brigadier-General Cullum, who had the almost exclusive supervi- 
 sion, devising, building, and preparing for service of the various bridge-trains sent to our 
 armies in Mexico during our war with that country. The treatise before us is very com- 
 plete, and has evidently been prepared with scrupulous care. The descriptions of tha 
 various systems of military bridges adopted by nearly all civilized nations are very inte- 
 resting even to the non-professional reader, and to those specially interested in such subjects 
 must be very instructive, for they are evidently the work of a master of the art of military 
 bridge-building." Washington CJironide. 
 
 M 
 
 ILITARY AND POLITICAL LlFE OF THE 
 EMPEROR NAPOLEON. 
 
 By BARON JOMINI, General-in-Chief and Aide-de-camp to the Emperor 
 of Russia. Translated from the French, with notes, by H. W. 
 HALLECK, LL. D., Major-General U. S. Army. 4 vols., Royal 
 octavo. Fully Illustrated by Maps and Plans. In press 
 
 D 
 
 ELAFIELD'S REPORT. 
 
 Report on the Art of War in Europe in 1854, 1855, and 1856. By 
 Col. R. DELAFIELD, Corps of Engineers U. S. A. i vol. folio, 
 cloth. With maps and views. $5. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 A UTHORIZED U. S. INFANTRY TACTICS. 
 
 For the Instruction, Exercise, and Manoeuvres of the Soldier, a Com- 
 pany, Line of Skirmishers, Battalion, Brigade, or Corps d'Armee. 
 By Brig.-Gen. SILAS CASEY, U. S. A. 3 vols., 241110. Cloth, 
 lithographed plates. $2.50. , 
 
 VOL. I. School of the Soldier ; School of the Company ; Instruc- 
 tion for Skirmishers. 
 
 VOL. II. School of the Battalion. 
 
 VOL. III. Evolutions of a Brigade; Evolutions of a Corps d'Armee. 
 
 The manuscript of this new system of Infantry Tactics was carefully examined by Gen- 
 eral MCCLELLAN, and met with his unqualified approval, which ho has since manifested by 
 authorizing General CASEY to adopt it for hia entire division. The author has retained 
 much that is valuable contained in the systems of SCOTT and HARDEE, but has made many 
 important changes and additions which experience and the exigencies of the service re- 
 quire. General CASEY'S reputation as an accomplished soldier and skilful tacticiau is a 
 guarantee that the work he has undertaken has been thoroughly performed. 
 
 "These volumes are based on the French ordonnancea of 1831 and 1845 for the manoeu- 
 vres of heavy infantry and cJidftseurti & pied : both of these systems have been in use in 
 our service for some years, the former having been translated by Gen. Scott, and the latter 
 by CoL Hardee. After the introduction of the latter drill in our service, in connection 
 with Gen. SCOTT'S Tactics, there arose the necessity of a uniform system for the manoeu- 
 vres of all the infantry arm of the service. These volumes are the result of the author's 
 endeavor to communicate the instruction, now used and adopted in the army, to achieve 
 this result." Boston Journal. 
 
 "Based on the best precedents, adapted to the novel requirements of the art of war, and 
 very full in its instructions, Casey's Tactics will be received as the most useful and most 
 comprehensive work of its kind in our language. From the drill and discipline of the in 
 dividual soldier, or through all the various combinations, to the manoeuvres of a brigade 
 and the evolutions of a Corps D'Arm<io, the student is advanced by a clear method and 
 steady progress. Numerous cuts, plans, and diagrams illustrate positions and movements, 
 and demonstrate to the eye the exact working out of the individual position, brigading, or- 
 der of battle, &c., &c. The work is a in<JGel of publishing success, being in three neat 
 pocket volumes." New Yorker. 
 
 "WAR DEPARTMENT, "WASHINGTON, August 11, 1862. 
 
 The System of Infantry Tactics prepared by Brig.-Gen. Silas Casey, U. S. A., having 
 been approved by the President, is adopted for tho instruction of the Infantry of the Ar- 
 mies of the United States, whether Kegular, Volunteer, or Militia, with the following modi 
 fications, viz. : 
 
 Fir^ That portion which requires that two companies shall be permanently detached 
 from the battalion as skirmishers, will be suspended. 
 
 Second, In Title First, Article First, the following will be substituted for Paragraph C, 
 viz.: 
 
 " A regiment is composed of ten companies, which will be habitually posted from right 
 in left in tho following order; first, sixth, fourth, ninth, third, eighth, fifth, tenth, seventh, 
 wi-i.iicl, according to tho rank of Cuptain." EDWIN M. 8TANTON, 
 
 /Secretary of War. 
 
A 
 
 RMY OFFICERS' POCKET COMPANION. 
 
 Principally designed for Staff Officers in the Field. Partly translated 
 from the French of M. DE ROUVRE, Lieutenant-Colonel of the 
 French Staff Corps, with Additions from standard American, 
 French, and English Authorities. By WM. P. CRAIGHILL, First 
 Lieutenant U. S. Corps of Engineers, Assist. Prof, of Engineer- 
 ing at the U. S. Military Academy, West Point. 1 vol., i8mo, 
 full roan. . $1 50. 
 " I have carefully examined Capt CRAIGIIILL'S Pocket Companion. I find it one of the 
 
 very best works of the kind I have ever seen. Any Army or Volunteer officer who will 
 
 make himself acquainted with the contents of this little book, will seldom be ignorant of 
 
 his duties in camp or field.'' 
 
 H. W. HALLECK, Major-General U. S. A. 
 
 " I have carefully examined the ' Manual for SUiff Officers in the Field. 1 It Is a most in- 
 valuable work, admirable in arrangement, perspicuously written, abounding in most useful 
 ma' ters, and such a book as should be the constant pocket companion of every army officer, 
 Regular and Volunteer." 
 
 G. W. CULLUM, Brigadier-General TJ. 8. A. 
 Chief of General Halleck's Staff, Chief Engineer Department Mississippi. 
 
 M 
 
 ANUAL FOR ENGINEER TROOPS. 
 
 Consisting of 
 
 Part I. Ponton Drill. 
 
 II. Practical Operations of a Siege. 
 
 III. School of the Sap. 
 
 IV. Military Mining. 
 
 V. Construction of Batteries. 
 
 By Major J. C. DUANE, Corps of Engineers, U. S. Army. 1 vol., 
 I2mo, half morocco, with plates. 82. 
 
 " I have carefully examined Capt. J. C. Duane's l Manual for Engineer Troops,' and do not 
 hesitate to pronounce it the very best work on the subject of which it treats." 
 
 H. W. HALLECK, Major-General, U. 8. A. 
 
 " A work of this kind has been much needed in our military literature. For the army'* 
 sake, I hope the book will have a wide circulation among its officers." 
 
 G. B. MCCLELLAN, Major-General, U. S. A. 
 
 V 
 
 IELE'S HAND-BOOK. 
 
 Hand-Book for Active Service, containing Practical Instructions in 
 Campaign Duties. For the use of Volunteers.' By Brig. -Gen. 
 EGBERT L. VIELE, U. S. A. I2mo, cloth. $1. 
 
E 
 
 D. VAN NOSTRAND'S PUBLICATIONS. 
 
 VOLUTIONS OF FlELD BATTERIES OF AR- 
 TILLERY. 
 
 Translated from the French, and arranged for the Army and Militia 
 of the United States. By Gen. ROBERT ANDERSON, U. S. A. 
 Published by order of the War Department. l vol., cloth, 32 
 plates. $1. 
 
 WAR DEPARTMENT, Nov. 2d, 1859. 
 
 The System of " Evolutions of Field Batteries," translated from the French, and arrang- 
 ed for the service of the United States, by Major Robert Anderson, of the 1st Regiment of 
 Artillery, having been approved by the President, is published for the information and gov- 
 ernment of the army. 
 
 All Evolutions of Field Batteries not embraced in this system are prohibited, and those 
 herein prescribed will be strictly observed. 
 
 J. B. FLOYD. Secretary of War. 
 
 "This system having been adopted by the "War Department, is to the artillerist what 
 Hardee's Tactics is to the infantry soldier; the want of a work like this has been seriously 
 felt, and will be eagerly welcomed." LoitArriUe Journal, 
 
 OTANDING ORDERS OF THE SEVENTH REGI- 
 MENT, NATIONAL GUARD. 
 
 For the Regulation and Government of the Regiment in the Field 
 or in Quarters. By A. DURYEE, Colonel. New Edition, flex- 
 ible cloth. 40 cents. 
 
 "This, which is a new edition of a popular work, cannot fail to be eagerly sought after 
 &s presenting clearly and succinctly the principles of organization and discipline of a most 
 favorite corps. An appropriate index facilitates reference to the matter of the volume." 
 New Yorker. 
 
 L 
 
 IGHT INFANTRY COMPANY AND SKIRMISH 
 DRILL. 
 
 The Company Drill of the Infantry of the Line, together with the 
 Skirmish Drill of the Company and Battalion, after the method 
 of General LE LOUTEREL. Bayonet Fencing ; with a Supple- 
 ment on the Handling and Service of Light Infantry. By J. 
 MONROE, Colonel 22d Regiment, N. G., N. Y. S. M., former- 
 ly Captain U. S. Infantry, l vol., 321110. 60 cents. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 M 
 
 ANUAL OF INSTRUCTIONS FOR MILITARY 
 SURGEONS, 
 
 In the Examination of Recruits and Discharge of Soldiers. With an 
 Appendix containing the Official Regulations of the Provost Mar- 
 shal General's Bureau, and those for the formation of the Invalid 
 Corps, &c., &c. Prepared at the request of the United States 
 Sanitary Commission. By JOHN ORDRONAUX, M. D., Professor 
 of Medical Jurisprudence in Columbia ' College, New York. 
 izmo. Half morocco. $1.50. 
 
 "The author has drawn his materials from the best accredited sources of information 
 and the highest authorities in both hemispheres. lie selects France and Prussia, as the 
 representative military nations of Europe, and he has adopted as closely as possible their 
 order of instruction on the subjects of the enlistments and discharges ot soldiers; and, in 
 the form of an Appendix, he has embodied the Code of Instructions relating to the U. S. 
 Army, adopted by the Board of Medical Officers, convened at Washington for that purjwse, 
 on the 15th of April, 1SG3, to which are also added the Regulations governing the forma- 
 tion of our Invalid Corps. Nothing ol importance to army surgeons has been omitted." 
 Army and yavy Gazette, 
 
 " In a condensed form it is an admirable treatise on the important subjects of which it 
 treats. The author has aimed to be brief without being obscure, to omit nothing of real 
 importance, and to draw his materials from the best sources. He treats of the physical dis- 
 abilities which have relation to the military service, and of these alone." Medical Exami- 
 ners are instructed in their duties, and the method of discovering feigned, artificially pro- 
 duced, and concealed diseases is pointed out The book will prove valuable to all who are 
 concerned in the manipulation of recruits or conscripts. An Appendix contains official 
 regulations and instructions relative to the Provost-Marshal's office, the Invalid Corps, 
 <fcc." Commercial Advertiser. 
 
 H 
 
 INTS ON THE PRESERVATION OF HEALTH 
 
 IN ARMIRS. 
 
 For the use of Volunteer Officers and Soldiers. By JOHN ORDRONAUX, 
 M. D. New edition, i8mo, cloth. 50 cents. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 ARTILLERY TACTICS. 1863. 
 
 Instruction for Heavy Artillery ; prepared by a Board of Officers, for 
 the use of the Army of the United States. With service of a 
 gun mounted on an iron carriage. In one volume, 1 2mo, with 
 numerous illustrations. Price $2. 
 
 "WAR DEPARTMENT, ) 
 
 " WASHINGTON, I). C, Oct. 20, 1SC2. f 
 
 M This system of Heavy Artillery Tactics, prepared under direction of the War Depart- 
 ment, having been approved by the President, is adopted for the instruction of troops 
 when acting as heavy artillery." 
 
 EDWIN M. STANTON, 
 
 Secretary of War. 
 
 " We presume that this is the most complete treatise on Heavy Artillery that has ever been 
 published in this or any other country. It seems to take in every tiling bearing on the 
 subject, and its instructions are ample and exceedingly clear. Some forty illustrative 
 plates are given, and the text is clearly and legibly printed." JT. Y. Commercial Adver- 
 tiser. 
 
 " This volume, prepared under the direction of the War Department and officially adopt- 
 ed as the code of artillery instruction for the public service, like all Van Nostrand's mil- 
 itary publications, is got up in the most substantial and elegant style both of printing and 
 binding. Its contents are evidently the work of thorough practical and scientific military 
 engineers, and embrace all the important as well as miuuto details of heavy artillery prac- 
 tice. 
 
 "The First Part consists of sixteen lessons relating to the service of the single piece, in 
 eluding the gun, howitzer, mortar, and columbiad ; also the formation of batteries, the art 
 of aiming pieces and firing hot-shot. Part Second relates entirely to mechanical manoeu- 
 vres and appliances, for handling, mounting, dismounting, and transporting heavy pieces. 
 Part Third is of a miscellaneous character, containing directions for embarking and disem- 
 barking artillery and ordnance stores; also, tables of dimensions and weights of trims, car- 
 iages, shot, shell, machines, and implements, with charges for and ranges of heavy artil- 
 ! ry- These in.-tnicti<>ns are not only copious in detail, but aptly illustrated with thirty- 
 nine elegant steel-plate engravings." Bulletin* 
 
 u 
 
 S. TACTICS FOR COLORED TROOPS. 
 
 U. S. Infantry Tactics, for the Instruction, Exercise, and Manoeuvres 
 of the Soldier, a Company, Line of Skirmishers, and Battalion, 
 for the use of the COLORED TROOPS of the United States Infantry. 
 Prepared under the direction of the War Department, i volume, 
 plates, 81.50. 
 
 "WAR DEPARTMENT, WASHINGTON, March 9, l^CO. 
 
 "This system of United States Infantry Tactics, prepared under the direction of the War 
 Department, for the use of the Colored Troops of the United states Infantry, having been 
 approved by the President, is adopted for the instnicli<wi <f MH-'H troop*." 
 
 EDWIN M. STANTON, Secretary of War. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 WORD-PLAY. 
 
 The Militiaman's Manual and Sword-Play without a Master. Rapier 
 and Broad-Sword Exercises copiously Explained and Illustrated ; 
 Small-Arm Light Infantry Drill of the United States Army ; 
 Infantry Manual of Percussion Muskets ; Company Drill of the 
 United States Cavalry. By Major M. W. BERRIMAN, engaged 
 ' for the last thirty years in the practical instruction of Military 
 Students. Second edition. 1 vol., i zmo, red cloth. $1. 
 
 " Captain Berrirnan has had thirty years' experience in teaching military students, and 
 his work is written in a simple, clear, and soldierly style. It is illustrated with twelve 
 plates, and is one of the cheapest and most complete works of the kind published in this 
 country." New York World. 
 
 " This work will be found very valuable to all persons seeking military instruction ; but 
 it recommends itself most especially to officers, and those who have to use the sword or 
 sabre. We believe it is the only work on the use of the sword published in this country." 
 New York Tablet. 
 
 "It is a work of obvious merit and value." Boston Traveller. 
 
 A 
 
 SYSTEM OF TARGET PRACTICE. 
 
 For the use of Troops when armed with the Musket, Rifle-Musket, 
 Rifle, or Carbine. Prepared, principally from the French, by 
 Captain HENRY HETH, loth Infantry, U. S. A. l8mo, cloth. 
 50 cents. 
 
 "WAR DEPARTMENT. ) 
 
 " WASHINGTON, March let, 185& } 
 
 "The System of Target Practice, prepared under direction of the War Department by 
 Captain Henry Heth, 10th Infantry, having been approved, is adopted for the instruction 
 of troops when armed with the musket, rifle-musket, rifle, or carbine." 
 
 JOHN B. FLOYD, Secretary of War. 
 
 C!CHOOL OF THE GUIDES. 
 
 Designed for the use of the Militia of the United States. Flexible 
 cloth. 50 cents. 
 
 "This excellent compilation condenses into a compass of less than sixty pages all the 
 instruction necessary for the guides, and the information being disconnected with other 
 matters, is more readily referred to and more easily acquired." Louisville Journal 
 
 " It has received high praise, and will prove of great service in perfecting the drill of ou 
 Militia." 2V. American and U. S. Gazette, Phil. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 N 
 
 CLAN'S SYSTEM FOR TRAINING / CAVALRY 
 HORSES. 
 
 By KENNER GAJIRARD, Captain Fifth Cavalry, U. S. A. 1 vol., i zmo, 
 cloth. 24 Lithographed plates. $1.50. 
 
 * * * ^e are glad when competent men bring forward works that are intended to 
 facilitate the formation of an effective cavalry force. Of this class is Nolan's Syst&m for 
 Training Cavalry Iforses, prepared for use in this country, by Captain Kenner Garrard, 
 U. 8. A. Captain Nolan was distinguished in the British service for his knowledge of tho 
 cavalry arm, and for his general talents. As the work had become out of print, Captain 
 Garrard has done well in reproducing it: he has added to it a chapter on Karey's Method 
 of Training Horses, and another on Horse Shoeing. The volume is well illustrated. It 
 cannot be too warmly ttimniendod to general use." Boston Daily Evening Traveller, 
 
 A USTRIAN INFANTRY TACTICS. 
 
 Evolutions of the Line as practised by the Auftrian Infantry, and 
 pted in 1853. Translated by Capt. C. M. WILCOX, Seventh 
 Regiment, U. S. Infantry. 1 vol., izmo. Three large plates, 
 cloth. $1. 
 
 "The movements of armios engaged in battle have often been compared to those of 
 the chess-board, and we cannot doubt that there are certain principles of tactics in actual 
 war as in that game, which may determine the result independently, in a great measure, 
 of the personal strength and courage of the men engaged. Tho difference between these 
 principles as applied in the American Army and in the Austrian, is so wide as to have 
 suggested the translation of the work before us, which contains the whole result of the 
 famous Field-Marshal UADETZKY'S experience for twonty-flve years, while in supremo 
 command in Italy." New York Century. 
 
 R 
 
 HYMED TACTICS, BY " Gov. 
 
 l vol., i8mo, paper. With portraits. 25 cents. 
 
 "It will strike tho military man, familiar with the tedious routine of drill, by theory, 
 practice, and memory, as a most unique and valuable method of strengthening the latter, 
 with the least mental exertion. The author is a thorough soldier, and his ability aa a 
 rhymester will be conceded by any intelligent reader." New York Leader. 
 
 "Our author deserves great credit for the ingenuity he has displayed in putting into 
 verse a Manual which would at first glance seem to defy the most persistent efforts of tho 
 rhymer. The book contains a number of illustrations representing some of the more 
 rtimrult positions, in the figures of which portraits of several prominent officer* of th 
 Ni-w York Voluntr may be recognized." Nw York 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 T 
 
 REATISE ON GRAND MILITARY OPERATIONS. 
 
 Illustrated by a Critical and Military History of the Wars of Frederick 
 the Great. With a summary of the most important principles 
 of the Art of War. By BARON DE JOMINI. Illustrated by Mapa 
 and Plans. Translated from the French, by Col. S, B. HOLA- 
 BIRD, A. D. C., U. S. Army. In two vols., octavo. In press 
 
 H 
 
 ISTORY OF WEST POINT. 
 
 And its Military Importance during the American R^olution ; and the 
 Origin and Progress of the United States Military Academy. By 
 Captain EDWARD C. BOYNTON, A. M., Adjutant of the Military 
 Academy. With numerous Maps and Engravings, i vol., octavo. 
 Blue cloth, $5.00. 
 
 M 
 
 ILITARY BRIDGES, 
 
 For the Passage of Infantry, Artillery, and Baggage-Trains ; with sug- 
 gestions of many new expedients and constructions for crossing 
 streams and chasms ; designed to utilize the resources ordinarily 
 at command and reduce the amount and cost of army transporta- 
 tion. Including also designs for Trestle and Truss Bridges for 
 Military Railroads, adapted especially to the wants of the Ser- 
 vice of the United States. By HERMAN HAUPT, Brig.-Gen. in 
 charge of the construction and operation of the U. S. Military 
 Railways, Author of " General Theory of Bridge Construction, 
 &c." With 300 Plates and Illustrations. Octavo. 
 
 R 
 
 EPORT OF THE ENGINEER AND ARTILLERY 
 OPERATIONS OF THE ARMY OF THE PO- 
 TOMAC, 
 
 From its Organization to the close of the Peninsular Campaign. By 
 Brig.-Gen. J. G. BARNARD, and other Engineer Officers, and 
 Brig.-Gen. W. F. BARRY, Chief of Artillery. Illustrated by 
 numerous Maps, Plans, &c. Octavo. $3.50. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 OlEGE OF. BOMARSUND (1854). 
 
 Journals of Operations of the Artillery and Engineers. Published 
 by permission of the Minister of War. Illustrated by Maps 
 and plans. Translated from the French by an Army Officer. 
 l vol., izmo, cloth. 75 cents. 
 
 " To military men this little volume is of special interest. It contains a translation by 
 an officer of the United States Army, of the Journal of operations by the artillery and en- 
 gineers at the siege of Bomarsund in 1S54, published by permission of the Freiu-h Minister 
 of War in the Journal des Arrne.es speeialea et de VEtat Major. The account of the 
 same successful attack, given by Sir Howard Douglas in the new edition of his work on 
 Gunnery, is appended; and the narrative is illustrated by elaborate maps aud plans. 1 ' 
 New York Paper. 
 
 M 
 
 AXIMS AND INSTRUCTIONS ON THE ART 
 OF WAR. 
 
 Maxims, Advice, and Instruction on the Art of War ; or, A Prac- 
 tical Military Guide for the use of Soldiers of all Arms and of 
 all Countries. Translated from the French by Captain LENDY, 
 Director of the Practical Military College, late of the French 
 Staff, etc., etc. l vol., i8mo, cloth. 75 cents. 
 
 "We do not pretend to much military science, but we have found this small volume easy 
 to understand and interesting to read. It is compiled from old works, but is adapted to 
 new notions and improvements, and it gives in a nut-shell a general idea of the whole busi- 
 ness of war. Some men who have always maintained 'Quaker 1 principles, and \vho luivo 
 never studied the trade and mystery of fighting, find it difficult to comprehend the various 
 strategic movements that are chronicled from day to day in the newspapers. These men 
 should look into the subject of war, and we advise them, as & beginning, to read this book. 
 It will probably help their cloudy perceptions, and enable them to see clearly the mean- 
 ing of military operations, which now they cannot understand. 11 Providcnca Journal. 
 
 N 
 
 OTES ON SEA-COAST DEFENCE: 
 
 Consisting of Sea-Coast Fortification ; the Fifteen-Inch Gun ; and 
 Casemate Embrasure. By Gen. J. G. BARNARD, Corps of En- 
 gineers, U. S. A. l vol., 8vo, cloth, plates. <$i 50. 
 
 "This small volume by one of the most accomplished officers in the United States 
 service is especially valuable at this time. Concisely and thoroughly Major Barnard dis- 
 msse.n the subjects included in this volume, and gives information that will bo read with 
 pn-sit profit by military men, and by all interested in the art of war as a defensive force.' 1 
 yew York Coimnerciul. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 M 
 
 ANUAL FOR QUARTERMASTERS AND CoM- 
 MISS ARIES, 
 
 Containing Instructions in the Preparation of Vouchers, Abstracts, 
 Returns, &c., embracing all the recent changes in the Armjf 
 Regulations, together with instructions respecting Taxation of 
 Salaries, etc. By Captain R. F. HUNTER, late of the U. S. 
 Army. I2mo, cloth. 1. 
 
 "This is a compendious volume of 110 pages, containing a large amount of useful infor- 
 mation in a small compass. The directions for making up the abstracts and returns of the 
 Quartermaster's and Commissary's departments will afford great facilities to persons chur;:- 
 ed with those duties ; and as this is the only work in existence which is devoted to these 
 particular objects, and ns the accounts of Quartermasters and Commissaries are 
 to the most rigid scrutiny, this Manual supplies a want which has long been 
 and sensibly felt by those for whose use and particular bone fit the book is intended. The 
 arrangement of the matter is extremely perspicuous, and the explanations are complete and 
 easily understood." Army and Navy Gazette. 
 
 "This is the only work of the kind extant. It is based on the latest regulations of tho 
 War Department, and will be regarded as authority by those officers for whose uso it is 
 4esigned." Saturday Evening Gaaette, 
 
 A RMY PAY DIGEST, AND READY CALCULA- 
 TOR; OR, REGIMENTAL PAY TABLE. 
 
 Compiled by Major EZRA WEBB. Octavo, cloth. $2. 
 
 " A complete condensation of the military laws and general army orders, as relates to pay 
 emoluments, &c., in the United States Army, from the commencement of the Eebellion to 
 the present time an invaluable companion to paymasters as well as to all officers and sol- 
 diers in our armies. It is desirable to every one interested in the pay of the army or seek- 
 ing information on the subject (including pensions, claims against the United States and 
 mode of procedure), saving, as it will, a great amount of research, putting very desirable- 
 information within the reach of every one. All may see at a glance the pay of officers (in- 
 cluding subsistence, forage, servants and their clothing, transportation, fuel, and quarters-) 
 and men of all arms and grades per day or days, month or months ; the organization of tlu> 
 army, from ,'the company' to the ' corps d' arme>.' Indeed, it is emphatically the hook 
 for the times; and a copy should be in the hands of every man in the army, as also bank- 
 ers, contractors, claim agents, &c." JV r eio York Herald. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 R 
 
 IFLES AND RIFLE PRACTICE. 
 
 An Elementary Treatise on the Theory of Rifle Firing ; explaining 
 the causes of Inaccuracy of Fire and the manner of correcting it; 
 with descriptions of the Infantry Rifles of Europe and the Uni- 
 ted States, their Balls and Cartridges. By Capt. C. M. WIL- 
 cox, U. S. A. New edition, with engravings and cuts. Green 
 cloth. $1.75. 
 
 " Although eminently a scientific work, special care seems to have been taken to avoid 
 the use of technical terms, and to make the whole subject readily coinprchensililo to the 
 practical enquirer. It was designed ch icily for the use of Volunteers and the Militia : but 
 tlu- War Department has evinced its approval of its merits by ordering from the pub- 
 lisher one thousand copies for the use of the United States Army." Louixville Journal. 
 
 ' The book will be found intensely interesting to all who are watching the changes in the 
 art of war arising from the introduction of tho new ri tied arms. We recommend to our 
 readers to buy the book." Jf Hilary Gazette. 
 
 " A most valuable treatise." Xew York Herald. 
 
 u This book is quite original in its character. That character is completeness. It ren- 
 ders a study of most of the works on the rifle that have been published (juitc unnecessary, 
 AVi- eordially recommend the book.'' United Service Gazette, London. 
 
 "The work being in all its parts derived from tho best sources, is of the highest author- 
 ity, and will be accepted as the standard on the subject of which it treats." New Yorker. 
 
 N 
 
 TEW BAYONET EXERCISE. 
 
 A New Manual of the Bayonet, for the Army and Militia of the 
 United States. By Colonel J. C. KELTON, U. S. A. With 
 thirty beautifully-engraved plates. Red cloth. $1.75. 
 
 This Manual was prepared for the use of the Corps of Cadets, and has been introduced 
 at thi! Military Academy with satisfactory results. It is simply the theory of the attack 
 and defence of the sword applied to the bayonet, on tho authority of men skilled in tho 
 use of arms. 
 
 The Manual contains practical lessons in Fencing, and prescribes the defence against 
 Cavalry, and the manner of conducting a contest with a Swordsman. 
 
 ' This work merits a favorable reception at the hands of all military men. It contains 
 all the instruction necessary to enable an officer to drill his men in the use of this weapon. 
 The introduction of the Sabre Bayonet in our anny renders a knowledge of the exercisu 
 more imperative." 1 New York Times. 
 
 MANUAL OF SWORD. AND SABRE Ex 
 
 ERCISE. 
 By Colonel J. C. KELTON, U. S. A. Thirty plates. In press. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 E WAR IN THE UNITED STATES. 
 
 A Report to the Swiss Military Department. Preceded by a Dis' 
 course to the Federal Military Society assembled at Berne, Aug. 
 18, 1862. By FERDINAND LECOMTE, Lieut.-Col. Swiss Confed- 
 eration . Author of " Relation Historique et Critique de la Cam- 
 pagne d'ltalie en 1859," "L'ltalie en 1860," and "Le Ge- 
 neral Jomini, sa Via, et ses Ecrits," etc., etc. Translated from 
 the French by a Staff Officer, i vol., I2mo. $1. 
 
 " Returning to Switzerland from a campaign authorized by the Swiss Military Depart- 
 ment, Col. Lecomlo addressed a discourse to the Federal Military Society, at Berne, in 
 which he stated very clearly and concisely the circumstances leading to the present war, 
 the situation of the country at the time of the commencement of the troubles, and the 
 progress of events up very nearly to the present time. 
 
 "In his quality of a Swiss federal officer, Col. Lecomte, bearing the recommendations of 
 the Federal Military Department of Switzerland, of Mr. Fo^ir. Ambassador of the V. EL :;t 
 Berne, and of others, was well received by Mr. Soward, Secretary of State, and by Geni-ral 
 McClellan, and by the Swiss Consul at New York. General McClellan, at Washington 
 attached him to his staff as a voluntary aide-de-camp, he retaining his Swiss rank of Major, 
 and with the condition of being able at any time to return to his country, should he bo 
 called thither by his government. He met on that staff with other European office; 
 cupyingthat position on the same terms with himself. So that he had good opportunities 
 of being informed on the merits of the war, and the manner of its conduct, and being an 
 intelligent man, as this report demonstrates, he made the most of that opportunity. 
 
 "He very lucidly describes the theatre of the war, statistically and geographically, the 
 parties in the strife and their relations to each other ; the causes of the war ; the earliest 
 hostilities; the relative strength of tho armies; the principal military acts, from Big Bethel 
 onwards; the armament, equipment, clothing, materials, subsistence, &c., of the service; 
 armored vessels and their transactions ; his own personal impressions in regard to the de- 
 fects of the American Army, &c. Then there is a supplementary report of great interest, 
 describing the later events of the author's observation and experience : the -whole making 
 one of the most valuable contributions to the literary history of the war we have had." 
 Express, 
 
 LAW OF FREEDOM AND BONDAGE IN 
 THE UNITED STATES.' 
 
 By JOHN CODMAN HURD, Counsellor at Law. 2 vols., octavo. Price, 
 bound in cloth, 87. Law sheep, $8. 
 
 "Mr. Kurd has completed a work which must take its place as the standard authority in 
 the branch of Law to which it relates. It is strictly a legal work, committed to no theory, 
 designed to sustain no individual phase of opinion, but comprising an outline of the entire 
 legislation, constitutional and statutory of the general government and the individual 
 <>:>. the. subject of slavery, with an analysis of all the legal decisions and judicial <1<'<-t,i 
 i :: out of sucli legislation." Forth American Review. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 E "C. S. A.," AND THE BATTLE OF 
 
 BULL RUN. 
 
 (A Letter to an English friend), by J. G. BARNARD, Lt.-Col. of Engi- 
 neers, U. S. A., Brigadier-General and Chief Engineer, Army 
 of the Potomac. With five maps. 1 vol., 8vo, cloth. $1 50. 
 
 "This hook was begun by the author as a letter to a friend in England, but ns he pro- 
 .i:i<l his MSS. increased in magnitude, he changed his original plan, and the book 
 result. General Barnard 1 gives by far the. best, most comprehensible, and complete 
 :ii-count of the Rattle of Bull Uuii wo have seen. It is illustrated by some beautifully drawn 
 maps, prepared for the War Department by the topographical engineers. lie demonstrates 
 to. -i .-. rtaiiity that but for the causeless panic the day might not have been lost The 
 author writes with viiror and earnestness, and has contributed one of the most valuable re- 
 cords yet published of the history of the war." Boston Commercial Bulletin, 
 
 "The work is clearly written, and can but leave the impression upon every reader's 
 mind that it is truth. "We commend it to the perusal of every one who wants an intelli- 
 gent, truthful, and graphic description of the ' C. S. A.,' and the Battle of Bull Eun." New 
 York Observer. 
 
 ^HE POLITICAL AND MILITARY HISTORY 
 OF THE CAMPAIGN OF WATERLOO. 
 
 I 1 
 
 Translated from the French of General BARON DE JOMINI. By 
 Capt. S. V. BENET, U. S. Ordnance. l vol., I2mo, cloth. 
 Third edition. $1.25. 
 
 "Baron Joinini has the reputation of being one of the greatest military historians and 
 critics of the century. His merits have been recognized by the highest military authori- 
 ties in Iv.irop.-. and \vore rewarded in a conspicuous manner by the greatest military power 
 in Christendom. Ho learned the art of war in the school of experience, the best and only 
 fi.'iisliing school of the soldier. lie served with distinction in nearly all the campaigns of 
 Napoleon, and it was mainly from the gigantic military operations of this matchless mas- 
 ter of the art that he was enabled to discover its true principles, and to ascertain the best 
 means of their application to the infinity of combinations which actual war presents. 
 Joinini criticises the details of Waterloo with great science, and yet in a manner that 
 s the general reader as well as the professional." New York World. 
 
 'Tiiis book by Joinini, though forming the twenty^feecond chapter of his 'Life of Na- 
 poleon,' is really a unit in itself, and forms a complete summary of the campaign. It is 
 an interesting volume, and deserves a y\ano in the affections of all who would be accom- 
 : military men.' 1 New York Times. 
 
 'The present volume is the concluding portion of his great work, 'Vie Politiquo ct 
 
 Militaire de Napoleon,' published in 1826. Capt. Benet's translation of it has been for 
 
 IBM IK fore the public, and has now reached a second edition; it is very ably cxe- 
 
 c:i:.ed, an 1 forms a work which will always be interesting, especially so at a time when 
 
 military affairs are uppermost iu the public mind.Fhlladelj)7ii<i North American. 
 
A 
 
 TREATISE ON THE CAMP AND MARCH. 
 
 With which is connected the Construction of Field Works and Mili- 
 tary Bridges ; with an Appendix of Artillery Ranges, &c. For 
 the use of Volunteers and Militia in the United States. By 
 Captain HENRY D. GRAFTON, U. S. A. l vol., izmo, cloth. 
 75 cents. 
 
 /^UNNERY IN 1858. 
 
 A Treatise on Rifles, Cannon, and Sporting Arms. By WM. GREENER, 
 C. E. l vol., 8vo, cloth. $3. Full calf, $4 50. 
 
 M 
 
 ANUAL OF HEAVY ARTILLERY. 
 
 For the use of Volunteers, l vol., izmo, red cloth. 7 5 cents. 
 
 "Should be in the hands of every Artillerist'" X. Y. lUuxtrutl Xeica. 
 
 "This is a concise and well-prepared Manual, adapted to the wants of Volunteers. The 
 instruction, which is of an important nature, is presented in a simple and clear style, such 
 as will be easily understood. The volume is also illustrated with explanatory cuts and 
 drawings. It is a work of practical value, and one needed at the present time in the ser- 
 vice." Boston Commercial Bulletin. 
 
 H 
 
 INTS TO COMPANY OFFICERS ON THEIR 
 MILITARY DUTIES. 
 
 By Capt. C. C. ANDREWS, 3d Regt. Minnesota Vols. i vol., i8mo, 
 cloth. 50 cents. 
 
 " This is a hand-book of good practical advice, which officers of all ranks may study with 
 advantage." Philadelphia Press. 
 
 " This little volume contains many valuable suggestions, and conveys not a little im- 
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 bered by every young officer." Cincinnati Daily Gazette. 
 
 "We wish it could be read and studied by all having men under their command."-^ 
 N. Y. Commercial Advertiser. 
 
OIEGE AND REDUCTION OF FORT PULASKI, 
 GEORGIA. 
 
 Papers on Practical Engineering. No. 8. Official Report to the 
 U. S. Engineer Department of the Siege and Reduction of Fort 
 Pulaski, Ga., February, March, and April, 1862. By Brig.- 
 General Q. A. GILLMORE, U. S. A. Illustrated by Maps and 
 Views. 1 vol., 8vo, cloth. $2 50. 
 
 " This is an official history of the siege of Fort Pulaski, from the commencement, with all 
 the details in full, made up from a daily record, forming a most valuable paper for future 
 reference. The situation and construction of the Fort, the position of the guns both of tho 
 rebels and the Federals, and their operation, are made plain by maps and engraved views 
 ol' dirteront sections. Additional reports from other officers are furnished in the appendix, 
 and every thing has been done to render the work full and reliable." Boston Journal, 
 
 DICTIONARY OF ALL OFFICERS IN THE UNITED 
 
 STATES ARMY, 
 
 From 1789 to January 1st, 1853, and of the Navy and Marine Corps. 
 Second edition, with a Supplement, bringing it down to January 
 1, 1860. By Col. CHAS. K. GARDNER. 1 vol., I2mo, cloth. 
 $3. 
 
 U 
 
 NION FOUNDATIONS. 
 
 A Study of American Nationality, as a Fact of Science. By Capt. 
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 cents. 
 
 pEXAS, AND ITS LATE MILITARY OCCUPA- 
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 fly Capt. EDWIN D. PHILLIPS, 1st Infantry, U. S. A. 8vo, pipej 
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 A/foRDECAi's REPORT. 
 
 Military Commission to Europe in 1855 and 1856. Report of Major 
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 With Views and Maps. $1 50. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
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 TREATISE ON ORDNANCE AND NAVAL 
 
 GUNNERY. 
 
 Compiled and arranged as a Text-Book for the U. S. Naval Acade- 
 my, by Lieutenant EDWARD SIMPSON, U. S. N. Third edi- 
 tion, revised and enlarged. 1 vol., 8vo, plates and cuts, half 
 morocco. $5.00. 
 
 " As the compiler has charge of the instruction in Naval Gunnery at the Naval Acad- 
 emy, his work, in the compilation of which he has consulted a large number of eminent 
 authorities, is probably well suited for the purpose designed by it namely, the circulation 
 of information which many officers, owing to constant service afloat, may not have been 
 able to collect In simple and plain language it gives instruction as to cannon, gun-car- 
 riages, gunpowder, projectiles, fuzes, locks, and primers ; the theory of pointing guns, rifles, 
 the practice of gunnery, and a great variety of other similar matters, interesting to fight- 
 ing men ou sea and land." 'Washington Daily Globe. 
 
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 tions are excellent, and many of them unique, being colored or bronzed so as to represent 
 various military arms, Ac., with more than photographic literalness," Washington Star. 
 
 " It is scarcely necessary for us to say, that a work prepared by a writer BO practically 
 conversant with all the subjects of which he treats, and who has such a reputation for 
 scientific ability, cannot fail to take at once a high place among the text-books of our naval 
 service. It has been approved by the Secretary of the Navy, and will henceforth be one of 
 the standard authorities on all matters connected with Naval Gunnery." yew York 
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 UCE'S SEAMANSHIP : 
 
 Compiled from various authorities, and Illustrated with numerous 
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 In two parts. Second Edition. One royal octavo volume, 
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A 
 
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 IEBER ON GUERILLA PARTIES. 
 
 Guerilla Parties considered with reference to the Laws and Usages of 
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 NSTRUCTIONS FOR THE GOVERNMENT OF 
 
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 Prepared by FRANCIS LIEBER, LL. D., and revised by a Board of 
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 ALPHABETICAL ARMY REGISTER, 1863. 
 
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 ter for 1863. Octavo. 50 cents. 
 
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 ALLECK'S INTERNATIONAL LAW. 
 
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 ing the Army, i vol., 8vo, law sheep. $6. 
 
 " In preparing this work on the laws of war, Gen. Halleck appears to have made ft very 
 extended research among the authorities. His citations range through most of the writers 
 niul decisions touching upon such subjects, including the leading European publicists. for 
 centuries back. His use of authorities is valuable, also, as being not only legal, but histor- 
 ical. Upon points of military usage he cites examples from history freely and with effect 
 referring not only to the modern military historians, but even going back to the military 
 days of Eome and Greece. 
 
 "General Ilalleck appears to have thoroughly digested the whole range of topics which 
 he has to consider, and forms his opinions with judgment, and expresses them clearly and 
 briefly." Boston Journal. , 
 
 "Gen. Halleck has been engaged many years on the compilation of this work ; in fact 
 he began collecting the materials for it during the Mexican War, and has since been 
 diligently adding to them, and the result of his labors is embodied in the volume before 
 \is. The attentive perusal of a work of this description would demand far more time than 
 we could give it; dnd, after all, the true value of it can only be ascertained with certainty 
 by the test of constant consultation, as cases of international law arise. "We do not, on a 
 hasty glance, perceive that General Ilalleck advances any new opinions of his own on any 
 of the many vexed questions in this most difficult department of jurisprudence, but we 
 notice evidence of indefatigable labor and of pains-taking reference to the best authorities, 
 which must give his work, at all events, the value of a faithful compendium. He gives a 
 host of authorities for every doctrine that is laid down, and cites not merely from the 
 most eminent jurists, such as Wheaton, Kent, Story, Stowell, Bynkerschoeck, Vutt.-il. (\\-- 
 tius, Puffendorlf, Laurent, Ompteda, Kamptz, Phillimore, Pando, lleffter, Martens, Wild- 
 man, and others, but from the best authorities on military and naval warfare, such as 
 Joniini, Schwartz, Merlin, Dolloz, Lampredi, Hautefeuille, De Cussy, Kiquelane, Ortolan, 
 Pistoye, Duverdy, &c., tc. ; on Commercial law, as Chitty, Duer, Manning, Kutherforth, 
 Masse, Leiber, Ac., &c. ; on diplomacy and history, as Home, Marcy, Gardner, Mackin- 
 tosh, Hal lam, Alison, Burlamaqui, &c., &c. The work is very systematically and clearly laid 
 out. and embraces every department of international law. Such a book of reference as thisi 
 ought to be in the hands of every commanding officer by land and by sea, and it is not too 
 large and unwieldy to be easy of carriage. This edition is well printed and strongly bound." 
 iit Inquirer. 
 
 "The work will bo found to be of great iise to army and navy officers, to professional 
 lawyers, and to all interested in the topics of which it treats topics to which present 
 events give a greatly enhanced importance such as "Declaration of War and its KtTects;" 
 4i Sieges and Blockades;" " Visitation and Search;" "Right of Search;" "Prize- Courts;" 
 " Military Occupation ;" "Treaties of Peace;* 1 "Sovereignty of States," &c., and valuable 
 information for consuls and ambassadors." X. Y. Evening Pout. 
 
E 
 
 D. VAN NOSTRAND'S PUBLICATIONS. 
 
 LEMENTARY INSTRUCTION IN NAVAL 
 .NANCE AND GUNNERY. 
 
 By JAMES H. WARD, Commander U. S. Navy, Author of " Naval 
 Tactics," and "Steam for the Million." New Edition, revised 
 and enlarged. 8vo, cloth. $2. 
 
 " It conveys an amount of information in the same space to be found nowhere else, and 
 given with a clearness which renders it useful as well to the general as the professional 
 inquirer." JV: Y. Evening Post. 
 
 N 
 
 AUTICAL ROUTINE AND STOWAGE. 
 
 With Short Rules in Navigation. By JOHN McLzoo MURPHY and 
 WM. N. JEFFERS, Jr., U. S. N. i vol., 8vo, blue cloth. 
 $2 50. 
 
 T 
 
 OTTEN'S NAVAL TEXT-BOOK. 
 
 Naval Text-Book and Dictionary, compiled for the use of the Mid- 
 shipmen of the U. S. Navy. By Commander B. J. TOTTEN, 
 U. S. N. Second and revised edition. 1 vol., I2mo. $2 50. 
 
 " This work is prepared for the Midshipmen of the United States Navy. It is a complete 
 manual of instructions as to the duties which pertain to their office, and appears to have 
 been prepared with great caro, avoiding errors and inaccuracies which had crept into a 
 former edition of the work, and embracing valuable additional matter. It is a book which 
 should be in the hands of every midshipman, and officers of high rank in the navy would 
 often find it a useful companion." Boston Journal. 
 
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 UNNERY INSTRUCTIONS. 
 
 Simplified for the Volunteer Officers of the U. S. Navy, with hints 
 to Executive and other Officers. By Lieut. EDWARD BARRETT, 
 U. S. N., Instructor of Gunnery, Navy Yard, Brooklyn, i 
 vol., i2mo, cloth. $1 25. 
 
 "It is a thorough work, treating plainly on its subject, and contains also some valuable 
 hints to executive officers. No officer in the volunteer navy should be without a copy." 
 f! > </on Evening Traveller. 
 
H 
 
 ISTORY OF THE UNITED STATES NAVAL 
 
 ACADEMY. 
 
 With Biographical Sketches, and the names of all the Superintend- 
 ents, Professors and Graduates ; to which is added a Record of 
 some of the earliest votes by Congress, of Thanks, Medals and 
 Swords to Naval Officers. By EDWARD CHAUNCEY MARSHALL, 
 A. M. i vol., izmo, cloth, plates. $1. 
 
 " Every naval man will find it not only a pleasant companion, but an invaluable book of 
 reference. It is seldom that so much information is made accessible in so agreeable 
 a manner in so small a space." New York Times. 
 
 M 
 
 ANUAL OF INTERNAL RULES AND REG- 
 ULATIONS FOR MEN-OF-WAR. 
 
 By Commodore U. P. LEVY,U. S. N., late Flag Officer commanding 
 U. S. Naval Force in the Mediterranean, &c. Flexible blue 
 cloth. Third edition, revised and enlarged. 50 cents. 
 
 "Among the professional publications for which we are indebted to the war, we willing- 
 ly give a prominent place to this useful little Manual of Ilules and Regulations to be 
 observed^on board of ships of 'war. Its authorship is a sufficient guarantee for its accuracy 
 and practical value; and as a guide to young officers in providing for the disciplinei 
 police, and sanitary government of the vessels under their command, we know of nothing 
 superior."^ Y. Herald. 
 
 N 
 
 AVAL LIGHT ARTILLERY. 
 
 Instructions for Naval Light Artillery, afloat and ashore, prepared 
 and arranged for the U. S. Naval Academy, by Lieutenant W. 
 H. PARKER, U. S. N. Second edition, revised by Lieut. S. B. 
 LUCE, U. S. N., Assistant Inftructor of Gunnery and Tactics at 
 the United States Naval Academy, i vol., 8vo, cloth, with 22 
 plates. $2.00. 
 
 "The service for which this is the text-book of instruction is of special importance in 
 the present war. The use of light boat-pieces is constant and important, and young offi- 
 cers are frequently obliged to leave their boats, tike their pieces ashore, and manoeuvre 
 them as field artillery. Not unfrequently, also, they are incorporated, when ashore, with 
 troops, and must handle their guns like the artillery soldiers of a battery. ' The Exercise 
 of the Howitzer Afloat 1 was prepared and arranged by Captain Dahlgren. whose name 
 gives additional sanction and value to the book. A manual for the Sword and Pistol i* 
 also given. The plates are numerous and exceedingly clear, and the whole typogr* 
 excellent." Philadelphia Inquirer. 
 
H 
 
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 OLLEY'S RAILWAY PRACTICE. 
 
 American and European Railway Practice, in the Economical Gener, 
 ation of Steam, including the materials and construction of CoaU 
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 Circulation, Superheating, Supplying and Heating Feed-w^ter, 
 &c., and the adaptation of Wood and Coke-burning Engines to 
 Coal-burning; and in Permanent Way, including Road-bed, 
 Sleepers, Rails, Joint Fastenings, Street Railways, &c., &c. By 
 ALEXANDER L. HOLLEY, B. P. With 77 lithographed plates. 
 i vol., folio, cloth. $10. 
 
 "This is an elaborate treatise by one of our ablest civil engineers, on the construction 
 and use of locomotives, with a few chapters on the building of Eailroads * * * All the- so 
 subjects are treated by the Author who is a first class railroad engineer, in both an intelli- 
 gent and intelligible manner. The facts and ideas are well arranged, and presented in a 
 clear and simple style, accompanied by beautiful engravings, and we presume the work 
 will be regarded as indispensable by all who arc interested in a knowledge of the construction 
 of railroads, and rolling stock, or the working of locomotives." Scientific American. 
 
 E 
 
 UROPEAN ORDNANCE AND IRON-CLAD DE- 
 
 FENCES, 
 
 With some account of the American Practice, embracing the Fabrica- 
 tion and Test of Heavy Guns; Projectiles and Rifling; the 
 Manufacture and Test of Armor, from official data, with a detail- 
 ed account of English experiment ; the principles, structure, and 
 classification of Iron-Clad Vessels ; Marine Steam Machinery, 
 &c. By ALEX. L. HOLLEY, B. P., Author of " American and 
 European Railway Practice," &c. i vol., 8vo, cloth. With 
 250 illustrations. In press. 
 
 ^ I A HE PRINCIPLES OF STRATEGY AND GRAND 
 TACTICS. 
 
 Translated from the French of General G. H. DUFOUR. By WILLIAM 
 P. CRAIGHILL, Capt. of Engineers U. S. Army, and Assistant 
 Professor of Engineering, U. S. Military Academy, West Point. 
 From the last French Edition. Illustrated. In one volume, 
 izmo. $2.50. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
 L 
 
 ESSONS AND PRACTICAL NOTES ON STEAM, 
 
 The Steam-Engine, Propellers, &c., &c., for Young Marine Engi- 
 neers, Students, and others. By the late W. R. KING, U. S. N. 
 Revised by Chief-Engineer J. W. KING, U. S. Navy. Fourth 
 edition, enlarged. 8vo, cloth. $2 oo. 
 
 "Tliis is the second edition of a valuable work of the late "W. II. KING, U. S. N. It con- 
 tains lessons and practical notes on Steam and the Steam-Engine, Propellers, &<. It is 
 calculated to be of great use to young marine engineers, students, and others. The text is 
 illustrated and explained by numerous diagrams and representations of machinery. This 
 new edition has been revised and enlarged by Chief Engineer J. W. KING. U. S. N., 
 brother to the deceased author of the work." Boxton Daily Advertiser. 
 
 "This is one of the best, because eminently plain and practical, treatises on the Steam- 
 Engine ever published." Philadelphia Press. 
 
 "Its republication at this time, when so many young men are entering the service as 
 naval engineers, is most opportune. Each of them ought to have a copy." Philadelphia 
 Evening Bulletin. 
 
 OTEAM FOR THE MILLION. 
 
 A Popular Treatise on Steam and its Application to the Useful Arts, 
 especially to Navigation. By J. H. WARD, Commander U. S. 
 Navy. New and revised edition, i vol., 8vo, cloth. $1. 
 
 "A most excellent work for the young engineer and general reader. Many facts rela- 
 ting to the management of the boiler and engine are set forth with a simplicity of lan- 
 guage, and perfection of detail, that brings the subject home to the reader. Mr. Ward is 
 also peculiarly happy in his illustrations." American Engineer, 
 
 QCREW PROPULSION. 
 
 Notes on Screw Propulsion, its Rise and History. By Capt. W. H. 
 WALKER, U. S. Navy. 1 vol., 8vo, cloth. 75 cents. 
 
 " Some interesting notes on screw propulsion, its rise and progress, have just been issued 
 by Commander "W. H. WALKER, U. S. N., from which all that is likely to be desired on 
 the subject may be readily acquired. * * * * After thoroughly demonstrating the 
 efficiency of the screw, Mr. Walker proceeds to point out the various other points to be 
 attended to in order to secure an efficient man-of-war, and eulogizes throughout the readi- 
 ness of the British Admiralty to test every novelty calculated to give satisfactory results. 
 * * * * Commander Walker's book contains an immense amount of concise practical 
 data, and every item of information recorded fully proves that the variou* j>o>nts bearing 
 upon it have been well considered previously to expressing an opinion." London Mining 
 Journal. 
 
 u Every engineer should have it in his library." American Engineer, 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 TACTICAL TREATISE ON LIMES, HYDRAU- 
 LIC CEMENTS, AND MORTARS. 
 
 Papers on Practical Engineering, U. S. Engineer Department, No. 
 9, containing Reports of numerous experiments conducted in 
 New York City, during the years 1858 to 1861 inclusive. By 
 
 8. A. GILLMORE, Brig.-General U. S. Volunteers, and Majo* 
 . S. Corps of Engineers. With numerous illustrations. One 
 volume octavo. $3.50. 
 
 ~^HE CONTRACTORS' MANUAL AND BUILD- 
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 By A. B. CLOUGH, Architect, l vol., i8mo. 5? cents. 
 
 PRINCIPLES AND PRACTICE OF EMBANKING 
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 As applied to the Levees of the Mississippi. By WILLIAM HEWSON, 
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 OODBURY ON THE ARCH. 
 
 Treatise on the various Elements of Stability in the well-proportioned 
 Arch. With numerous Tables of the Ultimate and Actual 
 Thrust. By Captain D. P. WOODBURY, U. S. Corps of Engi- 
 neers, l vol., 8vo. Engravings. Cloth, $2.50. 
 
 CjouADRON TACTICS UNDER STEAM. 
 
 Bv FOXHALL A. PARKER, Commander U. S. Navy. Published by 
 authority of the Navy Department, i vol., 8vo., with numer- 
 ous Plates. $5,00. 
 
D. VAN NOSTRAND S PUBLICATIONS. 
 
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 ODELS OF FORTIFICATIONS. 
 
 VAUBAN'S FIRST SYSTEM. One Front and two' Bastion? 
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 THE MODERN SYSTEM. One Front Scale, 20 Yards to an 
 Inch. 
 
 FIELD-WORKS. The Square Redoubt Scale, 5 Yards to an Inch. 
 
 The above models are moulded from those made by Mr. KIMBER, of 
 London, and are intended as illustrations of his works upon For- 
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 colored in oil, and mounted in strong covered cases. They are 
 admirably adapted for teaching the first principles of fortification, 
 and should be in every College, Military, and High* School. 
 
 Mr. KIMBER'S three volumes, viz., Vauban's First System, the Modern 
 System, and Field-Works, will accompany the models. 
 Price for the set of three, with books, $60. 
 
 R 
 
 IFLED ORDNANCE : 
 
 A Practical Treatise on the Application of the Principle of the Rifle 
 to Guns and Mortars of every calibre. To which is added, a 
 new theory of the initial action and force of Fired Gunpowder. 
 By LYNALL THOMAS, F. R. S. L. Fifth edition, revised. One 
 volume, octavo, illustrated. $2.00. 
 
 F 
 
 IELD TACTICS FOR INFANTRY, 
 
 Comprising the Battalion movements, and Brigade evolutions, useful 
 in the Field, on the March, and in the presence of the Enemy. 
 The tabular form is used to distinguish the commands of the 
 General, and the commands of the Colonel. By Brig.-Gen. 
 WM. H. MORRIS, U. S. Vols., late 2 d U. S. Infantry. i8mo, 
 Illustrated. In Press. 
 
M 
 
 D. VAN NOSTRAND'S PUBLICATIONS. 
 
 GORE'S TREASON OF LEE. 
 
 "Mr. Lee's Plan March 29, 1777. The Treason of Charles 
 Lee, Major-General, Second in Command in the American Army 
 of the Revolution. By GEORGE H. MOORE, Librarian of the 
 New York Historical Society, i vol. 8vo, cloth. Two Steel 
 Portraits, and Two Lithograph Fac-similes of Documents. $2. 
 
 ** It is a clear and most interesting development of one of .the strangest events in tho 
 history of the Eevolution. It is as important as it is curious, for the acts and motives of 
 a man who held so high a rank in the army and in the public estimation should be known. 
 They affect the character of others, and throw light on transactions which could not 
 otherwise be explained." 
 
 JARED SPARKS. 
 
 "Your paper was certainly the most instructive one over presented (within my obser- 
 vation) to any one of our Historical Societies. 
 
 "The work does you great credit; it is full of interest, of facts collected from far and 
 near. The story is well told, tho criticism careful and discriminating. I feel certain it 
 will bring you much reputation for its completeness and manner of execution. * * * 
 Go on ; and you will win honor for yourself, while you will assist to make American His- 
 tory what it ought to be." 
 
 GEORGE BANCROFT. 
 
 " I have read it with great interest, It is a curious, valuable, and conclusively argued 
 contribution to our revolutionary history." 
 
 GULIAN C. VEEPLANCK. 
 
 " I am greatly indebted to you for a copy of your beautiful monograph. * * * I re-. 
 Joice that you have found the means (and made such good use of them) of putting his 
 worthlessness beyond all question." 
 
 EDWARD EVERETT. 
 
 "You have done a good service to history. I ran it through with the greatest interest." 
 
 I:OP>EET C. WINTHROP. 
 
 " Many thanks for Lee's Treason. * * * * Moore has made out the case against 
 him," 
 
 AV. F. DE SAUSSURE, (of S. C.) 
 
 "Tho Treason of !><, is pl;wd beyond doubt, and the original documents eslaMisliin- 
 It are published in the 'recent hi^hlv valuable monograph of G. II. Moore, Es>q., on !!i:it 
 ubj^ct EDtretC* Life, of Washington. 
 
D. VAN NOSTRAND'S PUBLICATIONS. 
 
 "We commend Mr. Moore's work aa the most valuable contribution to our Revolution- 
 ary history that has appeared for many a day, and assure our readers that the perusal of 
 its elegant and eloquent pages cannot but repay the few hours that it will require." His- 
 torical Jfagasin*. 
 
 " "We commend this essay to the attention of historical students, admiring the sim- 
 plicity and lucidity of its style." Ettprew. 
 
 * A work which we have read with great pleasure, * * * * well worthy the at- 
 tention of our readers, and we take great pleasure in recommending it to them." Boston 
 
 " This beautifully printed volume is an important contribntion to the history of the war 
 of the Revolution. It establishes beyond a question the treason of one of the most dia- 
 ti m:uished generals of that war, who was second in command to Washington." Provi- 
 dence Journal. 
 
 " The researches of Mr. Moore reflect great credit on his Industry and penetration as a 
 historical student, and we unite with those better capable of judging than ourselves, that 
 he has brought to light important facts, which tend more to clear up obscure points in our 
 revolutionary history than any thing that has appeared since the events alluded to took 
 place." Providence Journal. 
 
 "The volume abounds with curious details, and will be read with great interest by the 
 student of American history." 2f. 1'. Tribune* 
 
 " No student of American history can afford to be without this book." It. I. School- 
 master. 
 
 " We recommend this valuable contribution to the history of the American Revolution 
 to the attention of our readers. * * * * Apart from its value as an authentic and 
 original account of an important episode in the American Revolution, it shows in strong 
 a id instructive contrast the pictures of the infamous traitor and true patriot, * * * 
 Charles Lee, * * * and George Washington. These pictures are good even to study 
 t the present time." Courier and Enquirer. 
 
 "One of the most valuable contributions to our Revolutionary history that has ever been 
 published. * * * Mr. Moore's carefulness and completeness of research ore fine quali- 
 ties of the historian, happily exhibited in this volume." Christian Intelligence)'. 
 
 " Another of those startling and unique works that occasionally blaze out upon the sea 
 of literature, amazing every one with its strange developments. The author fixes black 
 and damning treason upon General Lee, by indubitable testimony, as strongly and clearly 
 as ever it was attached to Benedict Arnold." Chautavqua Democrat. 
 
 " Sound judgment, thorough research, just appreciation of character, an acute perception 
 of the logical connection of events chronologically disjoined, and a ready command of 
 clear, precise, and appropriate language, have enabled Mr. Moore to make a volume, which, 
 taken in all its bearings, may unhesitatingly be pronounced the most important mono- 
 graph ever contributed to the history of the War of Independence." Xew York Times. 
 
 " Crammed with the valuable results of original investigations. Many of the docu- 
 ments never published and throwing a new and unexpected light on a very intercctiQ' 
 episode of the Revolution." Evening Pvs{ .. 
 
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