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department of Ballistics of the U. S. Artillery School. 
 
 EXTERIOR BALLISTICS 
 
 IN THE 
 
 PLANE OF FIRE 
 
 BY 
 
 JAIVIKS ISA, INOAIvIvS, 
 
 Cai'tain P'ikst Aktilleky, U. S. Army, 
 Instructor, 
 
 NEW YORK: 
 D. VAN NOSTRAND, PUBLISHER, 
 
 23 MURRAY AND 27 WARREN STREETS, 
 1886, 
 
■I^*'" 
 ^V' 
 
 HEADQUARTERS UNITED STATES ARTILLERY SCHOOL. 
 
 Fort Monroe, Va., February, 1885. 
 Approved and Authorized as a Text- Book. 
 
 Pat. 26, Regulations U. S. Artillery School, appioved 1882, viz.: 
 
 " To the end that the school shall keep pace with professional progress, it 
 is made the duty of Instructors and Assistant-Instructors to prepare and 
 arrange, in accordance with the Programme of Instruction, the subject-matter 
 of the courses of study committed to their charge The same shall be sub- 
 mitted to the Staff, and, after approval by that body, the matter shall become 
 the authorized text-books of the school, be printed at the school, issued, and 
 adhered to as such." _ -, ^y 
 
 By order of Lieutenant-Colonel Tidball. 
 
 Tasker H. Bliss, 
 First Lieutenant ist Artillery, Adjutant. 
 
 Copyright, 1886, 
 By D. van NOSTRAND. 
 
PREFACE. 
 
 This work is intended, primarily, as a text-book for 
 the use of the officers under instruction at the U. S. 
 Artiller}^ School, and the arrangement of the matter has 
 been made with reference to the wants of the class-room. 
 The aim has been to present in one volume the various 
 methods for calculating range-tables and solving impor- 
 tant problems relating to trajectories, which are in vogue 
 at the present day, developed from the same point of 
 view and with a uniform notation. The convenience of 
 this is manifest. 
 
 It is hoped, also, that the practical artillerist will find 
 here all that he may require either for computing range- 
 tables for the guns already in use, or for determining 
 in advance the ballistic efficiency of those which may 
 be proposed in the future. 
 
ERRATA 
 
 Page 54, line 27 : 
 
 For - read -. 
 
 u V 
 
 Page 64, line 4 : 
 
 For (i) and {(f) read {i\ and (^X 
 
 Page 72, line 18: 
 
 4 i 
 
 For sec ^ read sec 5 f. / 
 
 Page 73, line 22 : 
 
 ' -^4- ^^^^ V* 
 
 Page 93, line 11 : 
 
 For g read j. 
 
 Page 116, equation {78): 
 
 For r— read 
 
 cos'' (p 2 cos ip 
 
CONTKNTS 
 
 INTRODUCTION. 
 
 Object and Definitions, 
 
 •AGE 
 
 5 
 
 CHAPTER I. 
 
 RESISTANCE OF THE AIR. 
 
 Normal Resistance to the Motion of a Plane, 
 
 Oblique Motion, ....... 
 
 Pressure on a Surface of Revolution, .... 
 
 Applications, ....... 
 
 Resistance of the Air to the Motion of Ogival-headed Projectiles, 
 
 CHAPTER II. 
 
 EXPERIMENTAL RESISTANCE. 
 
 Notable Experiments, .... 
 
 Methods of Determining Resistances, 
 
 Russian Experiments with Spherical Projectiles, 
 
 Mayevski's Deductions from the Krupp Experiments, 
 
 Ilojel's Deductions from the Krupp Experiments, 
 
 Bashforth's Coefficients, 
 
 Law of Resistance deduced from Bashforth's K, . 
 
 Comparison of Resistances, 
 
 Example, ..... 
 
 7 
 
 9 
 
 9 
 
 10-13 
 
 13-16 
 
 17 
 
 19 
 23 
 28 
 
 29 
 31 
 
 35 
 37 
 39 
 
 CHAPTER III. 
 
 DIFFERENTIAL EQUATIONS OF TRANSLATION — GENERAL PROPERTIES OF 
 TRAJECTORIES. 
 
 Preliminary Considerations, 
 
 Notation, ...... 
 
 DifFerential Equations of Translation, 
 
 Minimum Velocity, ..... 
 
 Limiting Velocity, ..... 
 
 Limit of the Inclination in the Descending Branch, 
 
 Asymptote to the Descending Branch, 
 
 Radius of Curvature, .... 
 
 4.1 
 41 
 42 
 46 
 
 47 
 
 48 
 
 49 
 50 
 
CONTENTS. 
 
 CHAPTER IV. 
 
 RECTILINEAR MOTION. 
 
 Relation between Time, Space, and Velocity, 
 Projectiles differing from the Standard, 
 Formulas for Calculating the T- and ^'-Functions, 
 Ballistic Tables, .... 
 Extended Ranges, .... 
 Comparison of Calculated with Observed Velocities, 
 
 PAGE 
 
 52 
 53 
 54 
 57 
 59 
 60 
 
 CHAPTER V. 
 
 RELATION BETWEEN VELOCITY AND INCLINATION. 
 
 General Expressions for the Inclination in Terms of the Velocity 
 
 Bashforth's Method, . 
 High-Angle and Curved Fire, 
 
 Siacci's Method, 
 
 Niven's Method, 
 
 Modification of Niven's Method, 
 
 CHAPTER VI. 
 
 HIGH-ANGLE FIRE. 
 
 Trajectory in Vacuo, 
 Constant Resistance, 
 Resistance Proportional to the First 
 
 Euler's Method, 
 
 Bashforth's Method, . 
 
 Modification of Bashforth's Method, 
 
 Power of the Velocity, 
 
 64 
 
 65 
 66 
 68 
 73 
 75 
 
 77 
 80 
 81 
 91 
 95 
 97 
 
 
 CHAPTER VII. 
 
 
 
 DIRECT FIRE. 
 
 
 Niven's Method, 
 
 . 
 
 102 
 
 Sladen's Method, 
 
 
 . 106 
 
 Siacci's Method, 
 
 
 . 108 
 
 Practical Applications, 
 
 
 .118 
 
 Correction for Altitude, 
 
 
 . 127 
 
EXTERIOR BALLISTICS 
 
 IN THE PLANE OF FIRE. 
 
 INTRODUCTION. 
 
 Definition and Object. — Ballistics, from the Greek 
 l^aUw, I throw, is, in its most general signification, the 
 science which treats of the motion of heavy bodies pro- 
 jected into space in any direction ; but its meaning is usu- 
 ally restricted to the motion of projectiles of regular form 
 fired from cannon or small arms. 
 
 The motion of a projectile may be studied under three 
 different aspects, giving rise to as many different branches 
 of the subject, called respectively Interior Ballistics, Ex- 
 terior Ballistics, and Ballistics of Penetration, 
 
 1. Interior Ballistics.— Interior Ballistics treats of 
 the motion of a projectile within the bore of the gun while 
 it is acted upon by the highly elastic gases into which the 
 powder is converted by combustion. Its object is to deter- 
 mine by calculation the velocity of translation and rotation 
 which the combustion of a given charge of powder of 
 known constituents and quality is capable of imparting to 
 a projectile, and the effect upon the gun. 
 
 2. Exterior Ballistics. — Exterior Ballistics considers 
 the circumstances of motion of a projectile from the time 
 it emerges from the gun until it strikes the object aimed 
 at. Its data are the shape, caliber, and weight of the pro- 
 jectile, its initial velocity both of translation and of rotation. 
 
6 EXTERIOR BALLISTICS. 
 
 the resistance it meets from the air, and the action of grav- 
 ity. 
 
 3. Ballistics of Penetration. — This branch of the 
 subject has reference to the effect of the projectile upon 
 an object; the data being the energy and incHnation with 
 which the projectile strikes the object, the nature of the re- 
 sistance it encounters, etc. 
 
 The above is not the order in which the three divisions 
 of the subject are usually presented to the practical artil- 
 lerist, but the reverse. He desires to penetrate or destroy 
 a given object — say the side of an armored ship. Ballistics 
 of penetration enables him to determine the minimum en- 
 ergy which his projectiles must have on impact, and the 
 proper striking angle, to accomplish the desired result. 
 Exterior Ballistics would then carry the data from the ob- 
 ject to be struck to the gun, and determine the necessary 
 initial velocity and angle of elevation. Lastly, Interior 
 Ballistics would ascertain the proper charge and kind of 
 powder to be used to give the projectile the initial velocity 
 demanded. 
 
 The following pages treat only of Exterior Ballistics; 
 and this subject will be limited, at present, to motion in the 
 vertical plane passing through the axis of the piece. 
 
CHAPTER I. 
 
 RESISTANCE OF THE AIR. 
 
 Preliminary Considerations. — The molecular the- 
 ory of gases is not yet sufficiently developed to be made 
 the basis for calculating the resistance which a projectile 
 experiences in passing through the air. We know, how- 
 ever, that if a body moves in a resisting medium, fluid or 
 gaseous, the particles of the fluid must be displaced to allow 
 the body to pass through ; and hence momentum will be 
 communicated to them, which must be abstracted from the 
 moving body. From the assumed equality of momenta 
 lost and gained Newton deduced the law of the square of 
 the velocity to express the resistance of the air to the mo- 
 tion of a body moving in it. 
 
 The following, which is the ordinary demonstration, 
 supposes the particles of air against which the body im- 
 pinges to be at rest, and takes no account of the reaction of 
 the molecules upon each other, nor of their friction against 
 the surface of the body. The result will therefore be but an 
 approximation, which must be estimated at its true value by 
 means of well-devised and accurately-executed experiments. 
 
 Normal Resistance to the Motion of a Body 
 presenting a Plane Surface to the Medium.— Let 
 a moving body present to the particles of a fluid against 
 which it impinges, and which are supposed to be at rest, a 
 plane surface whose area is 5, and which is normal to the 
 direction of motion. Let w be the weight of the moving 
 body, V its velocity at any time t, d the weight of an unit- 
 volume of the fluid, and ^ the acceleration of gravity. The 
 plane 5 will describe in an element of time dt a path v d t, 
 and displace a volume of fluid Svdt ; therefore the mass 
 
 of fluid put in motion during the element of time is- Svdt. 
 
8 EXTERIOR BALLISTICS. 
 
 And as this moves with the velocity v, its momentum is 
 
 — Sv'dt; and this has been abstracted from the moving 
 
 body, whose velocity has thereby been decreased by dv. 
 Therefore 
 
 dvzm-Sv'dt 
 
 g g 
 
 or IV dv b ^ ^ 
 
 ~ - -y- = - 5 z/" 
 g dt g 
 
 The first member of this last equation is the momentum- 
 decrement of the body, due to the pressure of the fluid 
 upon the plane face 5, and is therefore a measure of this 
 pressure. Calling this latter P, we have 
 
 _, w dv <5 - , 
 
 g dt g 
 
 or, per unit of mass, 
 
 w dt w 
 
 As before stated, several circumstances have been omit- 
 ted in this investigation ^vhich, if taken into account, would 
 probably increase the pressure somewhat, at least for high 
 velocities. We will therefore introduce into the second 
 member of the above equation an undetermined multiplier 
 k {k y i), and we have 
 
 P = k-Sv' .. 
 
 g (0 
 
 The pressure is, therefore, proportional to the area of 
 the plane surface, to the density of the medium, and to the 
 square of the velocity. 
 
 If in equation (i) we make 5=1, the second member 
 will then express the normal pressure upon an unit-surface 
 moving with the velocit}^ v; calling this /o,' we have 
 
 and 
 
 P^AS 
 
EXTERIOR BALLISTICS. 
 
 Oblique Motion. — If the surface 5 is oblique to the 
 direction of motion, let f be the angle which the normal to 
 the plane makes with that direction ; and resolve the velo- 
 city 7.' into its components v cos f, perpendicular, and v sin f, 
 parallel, to vS. This last, neglecting friction, having no re- 
 tarding effect, we have for the normal pressure upon 5 the 
 expression 
 
 P=/^-'z^''5cos' 6=/o 5cos'f / 
 
 Poncelet {Mecanique Industrielle, 403) cites the following 
 empirical formula for calculating the normal pressure, viz. : 
 
 i"fsec' e ^ ' 
 
 derived by Colonel Duchemin from the experiments of 
 Vince, Hutton, and Thibault. As this expression satisfied 
 the whole series of experiments upon which it was based 
 better than any other that was proposed, we will adopt it in 
 what follows. 
 
 Pressvire on a Surface of 
 Revolution. — Let A D B, Fig. 
 I, be the generating curve of a 
 surface of revolution, which we 
 will suppose moves in a resisting 
 medium in the direction of its 
 axis,^_(9 A. \{ m in' in" = <^5 be 
 an element of the surface, inclined ^ 
 to the direction of motion by the 
 angle Ninv=^e, it will suffer a 
 pressure in the direction of the 
 normal N in, equal, by (2), to 
 2p,dS 
 I + sec' e 
 
 Resolving this pressure into two components. 
 
 2 p^d S cos> 8 
 
 2p^d Ssin s 
 
 i°+sec'. ' P^""^'^"'' ^"^ i+^c^' Pe'-Pe"dic"la'-. 
 
lO EXTERIOR BALLISTICS. 
 
 to OA, it is plain that this last will be destroyed by an 
 equal and contrary pressure upon the elementary surface 
 n n' n" situated in the same meridional section as ;;/ in' m" , and 
 making the same angle with the direction of motion. It is 
 only necessary, therefore, to consider the first component, 
 
 2p^d S cos £ 
 I + sec' e 
 
 It is evident that expressions identical with this last are 
 applicable to every element of the zone ;// m' n n' described 
 by the revolution of m in' ; and we may, therefore, extend 
 this so as to include the entire zone by substituting its area 
 for dS. If we take O A for the axis of A'', this area will be 
 expressed by 2 it yds, in which ds is an element of the gene- 
 rating curve ; therefore, the pressure upon any elementary 
 zone will be 
 
 , y ds cos f 
 
 dx' 
 Substituting — dy for ds cos f , and 2 -|- -r-, for i -\- sec* e, and 
 
 integrating between the limits 4- = /, and x^o, we have 
 
 /' y<iy 
 
 As. all service projectiles are solids of revolution, this 
 last equation may be used to calculate the relative pressures 
 sustained by projectiles having differently shaped heads, sup- 
 posing their axes to coincide with the direction of motion at 
 each instant. In appl3nng the formula, y will be eliminated 
 by means of the equation of the generating curve. The 
 superior limit of integration (/) will be the length of the 
 head. R will denote the radius of the projectile. 
 
 Application to Conical Heads. — Let /^ i? be the length 
 of the conical head, the angle at the point being 
 
 2 tan 
 
 ■(0 
 
EXTERIOR BALLISTICS. 
 
 The equation of the generating line is 
 
 II 
 
 y=--^R 
 
 whence 
 
 y dy 
 
 i+i 
 
 and, therefore, 
 
 d^ n\2-^fe) 
 
 ~df 
 
 {n R — x) dx 
 
 47tp, 
 
 = 7tR'p, 
 
 
 R 
 
 x)dx 
 
 When n=:o, the head becomes flat, and the above equa- 
 tion reduces to 
 
 P^nR'p, 
 as it should. 
 
 Application to a Prolate Hemi-Spheroidal Head, 
 with Axes in the Ratio of one to two. — The equation 
 of the generating ellipse is 
 
 4/ + ;l;' = 47?^ 
 whence 
 
 y dy 
 
 x^ dx 
 
 
 4(8i^^ 
 
 and, therefore, since / = 2 7?, 
 
 p— 111 I ^'^-^ 
 
 :=7tR^P,{2\0g2-l) 
 
 Application to Ogival Heads. J^i 
 
 —Let A B D (Fig. 2) be a section of ^ 
 an ogival head made by a plane pass- 
 ing through the axis of the projectile. 
 Let A O = Rbe the radius of the pro- 
 jectile, and A £ = 7t R be the radius 
 
 .\UJ 
 
12 EXTERIOR BALLISTICS. 
 
 of the generating circle, whose equation is, if we make O the 
 origin and O B the axis of X, 
 
 y^ire R^-x'Y-in- \)R 
 Making j^^o, we find 
 
 O B = l=:R V2n ^i 
 Let the angle A E B=iy ; therefore 
 
 V2n— I 
 
 tan y = 
 
 n— I 
 
 which serves to determine the length of the arc of the 
 ogive, A B. 
 
 The differential of the equation of the generating circle 
 is 
 
 , X dx 
 
 ^^~~ {it'R'-xY 
 whence 
 
 , J , (n — i) Rx dx 
 
 and 
 
 , , dx"" n^ R'-X-x' 
 
 dy" 2 x" 
 
 therefore 
 
 ^RV^;r:r, I 2{n— i)Rx' 2 x' ) 
 
 ^=-2^A/^ I {n'R'+x'){n'R'-xy ~ n'R'+x j 
 
 „, ( , n(n—i) . ^ + V2+ I 
 ( 1/2 «— V2+^ 
 
 -«Mog ^'+^:-' } 
 
 = 7rR^AF{n),{say) (3) 
 
 If « is the angle at the point of the projectile, the expres- 
 sion for dj/ gives 
 
 
 2 n — i\ 
 n — I J 
 
 a 
 
EXTERIOR BALLISTICS. 
 
 13 
 
 When n= i, A D B becomes a semi-circle and the head a 
 hemisphere. 
 
 The following- table gives the values oi F (n)^ the lengths 
 of head in calibers, and the angles at the point, for integral 
 values of n from i to 6 : 
 
 n 
 
 Fin) 
 
 LENGTH OF HEAD 
 (0 
 
 ANGLE AT POINT 
 
 I 
 
 0.6137 
 
 0.5000 
 
 180° 00' 00'' 
 
 2 
 
 0.4187 
 
 0.8660 
 
 120° 00' 00'' 
 
 3 
 
 0.3176 
 
 I.II8O 
 
 96° 22' 46'' 
 
 4 
 
 0.2560 
 
 1.3229 
 
 82° 49' 09'' 
 
 5 
 
 0.2146 
 
 1.5000 
 
 73° 44' 23'' 
 
 6 
 
 0.1848 
 
 1.6583 
 
 6f & ^2" 
 
 Resistance of the Air to the Motion of Ogival- 
 heacled Projectiles. — The expression 
 
 P=7zR'p,F(n) 
 which, by substituting for/^ its value, becomes 
 
 g 
 serves to determine the pressure, as deduced by the above 
 theory, upon an ogival head ; and requires that this pressure 
 should be proportional to the density of the air, to the area 
 of the cross-section of the body of the projectile, and to the 
 square of the velocity. The truth of the first two of these 
 deductions may be considered as fully established by expe- 
 riment, and is admitted by all investigators. The relation 
 between the front pressure and the velocity has not been 
 satisfactorily determined by experiment, and we are there- 
 fore unable to verify directly the law of the square deduced 
 above. It seems probable, however, from experiments made 
 to determine the resistance of the air to the motion of pro- 
 
14 EXTERIOR BALLISTICS. 
 
 jectiles, as well as from theory, that this law is approxi- 
 mately true for all velocities. 
 
 If we represent the pressure of the air upon the rear 
 part of the projectile by P' , and the resistance by />, we shall 
 
 evidently have ~ 
 
 p^P-P' 
 
 It is evident that P' will be zero whenever the velocity 
 of the projectile is greater than that of air flowing into a 
 vacuum. In this case, and also when P' is so small rela- 
 tively to P that it may be neglected, we have approxi- 
 
 mately 
 
 p^P 
 
 Application to Ogival Heads struck witli Radii 
 of one and a half Calibers. — Experiments have proven 
 that for practicable velocities exceeding about 1300 f. s. the 
 resistance of the air is sensibly proportional to the square of 
 the velocity ; and a discussion of the published results of 
 Professor Bashforth's experiments has shown that, within 
 the above limits, the resistance to elongated projectiles 
 having ogival heads struck with radii of one and a half cali- 
 bers may be approximately expressed by the equation, 
 
 pz=z- d'v' 
 
 S 
 in which d is the diameter of the projectile in inches, ^ the 
 acceleration of gravity (32.19 ft.), and log A = 6,1525284 — 
 10. Whence 
 
 p — o.o'44i37^'z;' 
 
 Making b = 534.22 grains, which is the weight of a cubic 
 foot of air adopted by Professor Bashforth, and F{n)=:F{^) 
 = 0.3176, we find for the corresponding expression for P 
 
 P = o.o%io6g k d' v' 
 
 A comparison of the second members of these two equa- 
 tions seems to warrant the conclusion that for velocities 
 greater than about 1300 f. s., the rear pressure is either zero 
 or so small relatively to the front pressure that it may be 
 
EXTERIOR BALLISTICS. 1 5 
 
 neglected without sensible error. Equating the two mem- 
 bers, we find for velocities greater than 1300 f. s. 
 
 k— 1.0747 
 
 In the following table the first and second columns give 
 the velocities and corresponding resistances, in pounds, to 
 an elongated projectile one inch in diameter and having an 
 ogival head of one and a half calibers. They were deduced 
 from Bashforth's experiments by Professor A. G. Greenhill, 
 and are taken from his paper published in the Proceedings 
 of the Royal Artillery Institution, No. 2, Vol. XIII. The 
 third column contains the corresponding pressures upon the 
 head of the projectile computed by the formula 
 
 576^ 
 in which the constants have the values already given. The 
 fourth and fifth columns are sufficiently indicated by their 
 titles. 
 
 These results are reproduced graphically in Plate I. 
 A is the curve of resistance (^), drawn by taking the velo- 
 cities for abscissas and the corresponding resistances, in 
 pounds, for ordinates. This curve is similar to that given 
 by Professor Greenhill in his paper above cited. B is the 
 curve of front pressures (P), and is a parabola whose equa- 
 tion is given above. It will be seen that while the velocity 
 decreases from 2800 f. s. to 1300 f s., the two curves closely 
 approximate to each other; the differences (P— />) for the 
 same abscissas being relatively small and alternately plus 
 and minus. As the velocity still further decreases, the curve 
 of resistance falls rapidly below the parabola B, showing 
 that the resistance now decreases in a higher ratio than the 
 square of the velocity. This continues down to about 800 
 f. s., when the parabolic form of the curve is again resumed, 
 but still below B. The differences P— p from z/= 1300 f. s. 
 to 2/= 100 f s. are shown graphically by the curve (7, which 
 may represent, approximately, the rear pressures iox decreas- 
 ing velocities, and possibly account, in a measure, for the 
 
i6 
 
 EXTERIOR BALLISTICS. 
 
 sudden diminution of resistance in the neighborhood of the 
 velocity of sound. 
 
 V 
 
 p 
 
 P 
 
 P-P 
 
 P-P 
 
 V 
 
 p 
 
 P 
 
 P-P 
 
 P-P 
 
 P 
 
 P 
 
 2800 
 2750 
 
 2700 
 
 35.453 
 33.586 
 31.846 
 
 34.603 
 33.378 
 32.176 
 
 -0.850 
 -0.208 
 + 0.330 
 
 
 1080 
 1070 
 1060 
 
 3-999 
 3.756 
 
 3.478 
 
 5.148 
 5.053 
 4.959 
 
 + 1.149 
 1.297 
 1. 481 
 
 0.223 
 0.256 
 0.298 
 
 2650 
 2600 
 2550 
 
 30.241 
 28.613 
 27.243 
 
 30.995 
 29.836 
 28.700 
 
 + 0.754 
 + 1.223 
 
 + 1.457 
 
 
 1050 
 1040 
 1030 
 
 3.139 
 2.823 
 2.604 
 
 4.866 
 4.774 
 4.684 
 
 1.727 
 1. 951 
 2.080 
 
 0.355 
 0.409 
 0.444 
 
 2500 
 
 2450 
 2400 
 
 26.406 
 
 25.898 
 
 25.588 
 
 27.585 
 26.493 
 25.422 
 
 + 1.379 
 +-0.595 
 -0.166 
 
 
 1020 
 
 lOIO 
 
 1000 
 
 2.482 
 2.404 
 2.330 
 
 4.592 
 4.502 
 4.414 
 
 2. 114 
 2.098 
 2.084 
 
 0.459 
 0.466 
 0.472 
 
 2350 
 
 2300 
 2250 
 
 25.242 
 24.760 
 
 23.566 
 
 24.374 
 23.347 
 22.344 
 
 -0.868 
 -1. 413 
 — 1.222 
 
 
 990 
 980 
 970 
 
 2.261 
 
 2.193 
 2.127 
 
 4.326 
 4.239 
 4.153 
 
 2.065 
 2.046 
 2.026 
 
 0.477 
 0.483 
 0.488 
 
 2200 
 2150 
 2100 
 
 22.158 
 20.811 
 19.504 
 
 21.362 
 20.402 
 19.464 
 
 -0.796 
 -0.409 
 —0.040 
 
 
 960 
 
 950 
 940 
 
 2.061 
 1.998 
 1.935 
 
 4.068 
 3.983 
 3.900 
 
 2.007 
 
 1.985 
 1.965 
 
 0.493 
 0.498 
 0.504 
 
 2050 
 2900 
 1950 
 
 18.229 
 17.096 
 16.127 
 
 18.548 
 17.654 
 16.783 
 
 + 0.319 
 
 + 0.558 
 + 0.656 
 
 
 930 
 
 920 
 910 
 
 1.874 
 1. 814 
 1.756 
 
 3.817 
 3.736 
 3.655 
 
 1.943 
 1.922 
 1.899 
 
 0.509 
 
 0.515 
 0.520 
 
 1900 
 1850 
 1800 
 
 15.364 
 14.696 
 
 14.002 
 
 15.934 
 15.106 
 14.300 
 
 + 0.570 
 + 0.410 
 +0.298 
 
 
 900 
 850 
 800 
 
 1.699 
 
 1. 431 
 1. 212 
 
 3.575 
 3.189 
 2.825 
 
 1.876 
 1.758 
 1. 613 
 
 0.525 
 0.551 
 0.580 
 
 1750 
 
 1700 
 1650 
 
 13.318 
 
 12.666 
 12.030 
 
 13.517 
 12.766 
 12.016 
 
 + 0.199 
 + 0.100 
 —0.014 
 
 
 750 
 700 
 650 
 
 1.043 
 0.905 
 0.784 
 
 2.483 
 2. 163 
 1.865 
 
 1.440 
 1.258 
 1. 081 
 
 0.580 
 0.581 
 0.580 
 
 1600 
 1550 
 1500 
 
 II. 416 
 10.829 
 10.263 
 
 11.298 
 
 10.604 
 
 9.930 
 
 —0.018 
 -0.225 
 -0.333 
 
 -0.342 
 -0.273 
 — 0.141 
 
 
 600 
 550 
 500 
 
 450 
 400 
 
 350 
 
 0.674 
 0.572 
 0.473 
 
 0.381 
 0.294 
 0.221 
 
 1.589 
 
 1.335 
 1. 103 
 
 0.894 
 0.706 
 541 
 
 0.915 
 0.763 
 0.630 
 
 0.513 
 0.412 
 0.320 
 
 0.576 
 0.572 
 0.571 
 
 0.574 
 0.583 
 0.592 
 
 1450 
 1400 
 1350 
 
 9.622 
 8.924 
 8.185 
 
 9.280 
 8.651 
 8.044 
 
 1300 
 1250 
 1200 
 
 7.413 
 6.637 
 
 5.884 
 
 7.459 
 6.896 
 
 6.356 
 
 + 0.046 
 
 0.259 
 0.472 
 
 0.006 
 0.038 
 0.070 
 
 300 
 250 
 
 200 
 
 0.162 
 0.112 
 0.072 
 
 0.397 
 0.276 
 0.177 
 
 0.235 
 0,164 
 0.105 
 
 0.592 
 0.595 
 0.591 
 
 II50 
 
 IIOO 
 
 1090 
 
 5.179 
 4.420 
 4.221 
 
 5.837 
 5.340 
 5.244 
 
 0.658 
 
 0.920 
 
 + 1.023 
 
 0.113 
 0.172 
 0.195 
 
 150 
 100 
 
 0.040 
 0.018 
 
 0.099 
 0.044 
 
 0.059 
 + 0.026 
 
 0.594 
 0.591 
 
CHAPTER 11. 
 
 EXPERIMENTAL RESISTANCE. 
 
 Notable Experiments. — Benjamin Robins was the 
 first to execute a systematic and intelligent series of experi- 
 ments to determine the velocity of projectiles and the effect 
 of the resistance of the air, not only in retarding but in de- 
 flecting them from the plane of fire. He was the inventor 
 of the ballistic pendulum, an instrument for measuring the 
 momenta of projectiles and thence their velocities. He also 
 invented the Whirling Machine for determining the resistance 
 of air to bodies of different forms moving with low velo- 
 cities. His *' New Principles of Gunnery," containing the 
 results of his labors, was published in 1742, and immediately 
 attracted the attention of the great Euler, who translated it 
 into French. 
 
 The next series of experiments of any value were made 
 toward the close of the last century by Dr. Hutton, of the 
 Royal Military Academy, Woolwich. He improved the 
 apparatus invented by Robins, and used heavier projectiles 
 with higher velocities. His experiments showed that the 
 resistance is approximately proportional to the square of 
 the diameter of the projectile, and that it increases more 
 rapidly than the square of the velocity up to about 1440 f. s., 
 and nearly as the square of the velocity from 1440 f. s. to 
 1968 f. s. 
 
 In 1839 ^"<^ 1840 experiments were conducted at Metz, 
 on a hitherto unprecedented scale, by a commission ap- 
 pointed by the French Minister of War, consisting of MM. 
 Piobert, Morin, and Didion. They fired spherical projec- 
 tiles weighing from 11 to 50 pounds, with diameters varying 
 from 4 to 8.7 inches, into a ballistic pendulum, at distances 
 of 15,40,65,90, and 115 metres; by this means velocities 
 
I8 EXTERIOR BALLISTICS. 
 
 were determined at points 25, 50, 75, and 100 metres apart, 
 the velocities varying from 200 to 600 metres per second. 
 
 From these experiments General Didion deduced a law 
 of resistance expressed by a binomial, one term of which is 
 proportional to the square, and the other to the cube, of the 
 velocity. This gave good results for short ranges ; but with 
 heavy charges and high angles of projection the calculated 
 ranges were much greater than the observed. 
 
 Another series of experiments was made at Metz, in the 
 years 1856, 1857, and 1858, by means of the electro-ballistic 
 pendulum invented by Captain Navez, of the Belgian Artil- 
 lery. This, unlike the ballistic pendulum, affords the means 
 of measuring the velocity of the same projectile at two 
 points of its trajectory. The results of these elaborate ex- 
 periments may be briefly stated as follows: The resistance 
 for a velocity of 320 m. s. does not differ sensibly from that 
 deduced from the previous experiments at Metz; but the 
 resistances decrease with the velocity below 320 m. s., and 
 increase with the velocity above 320 m. s., more rapidly than 
 resulted from the former experiments. The commission 
 having charge of these experiments, whose president was 
 Colonel Virlet, expressed the resistance of the air by a 
 single term proportional to the cube of the velocity for all 
 velocities. 
 
 In 1865 the Rev. Francis Bashforth, M.A., who had then 
 been recently appointed Professor of Applied Mathematics 
 to the advanced class of artillery officers at Woolwich, 
 began a series of experiments for determining the resistance 
 of the air to the motion of both spherical and oblong projec- 
 tiles, which he continued from time to time until 1880. As 
 the instruments then in use for measuring velocities were 
 incapable of giving the times occupied by a shot in passing 
 over a series of successive equal spaces, he began his labors 
 by inventing and constructing a chronograph to accomplish 
 this object, which was tried late in 1865 in Woolwich 
 Marshes, with ten screens, and with perfect success. It was 
 afterwards removed to Shoeburyness, where most of his 
 
EXTERIOR BALLISTICS. I9 
 
 subsequent experiments were made. He employed rifled 
 guns of 3, 5, 7, and 9-inch calibers, and elongated shot hav- 
 ing ogival heads struck with radii of i^ calibers; also 
 smooth-bore guns of similar calibers for firing spherical 
 shot. From the data derived from these experiments he 
 constructed and published, from time to time, extensive 
 tables connecting space and velocity, and time and velocity, 
 which for accuracy and general usefulness have never been 
 excelled. The first of these tables was published in 1870, 
 and his Final Report, containing coefficients of resistance 
 for ogival-headed shot, for velocities extending from 2800 
 f. s. to JOG f. s., was published in 1880. These experiments 
 will be noticed more in detail further on. 
 
 General Mayevski conducted some experiments at St. 
 Petersburg, in 1868, with spherical projectiles, and in the 
 following year with ogival-headed projectiles, supplement- 
 ing these latter with the experiments made by Bashforth in 
 1867 with 9-inch shot. An account of these experiments, 
 with the results deduced therefrom, is given in his " Traite 
 Balistique Exterieure," Paris, 1872. 
 
 General Mayevski has recently (1882) published the re- 
 sults of a discussion of the extensive experiments made at 
 Meppen in 1881 with the Krupp guns and projectiles. 
 These latter, though varying greatly in caliber, were all 
 sensibl}^ of the same type, being mostly 3 calibers in length, 
 with an ogive of 2 calibers radius. General Mayevski's 
 results, together with Colonel HojeFs still more recent dis- 
 cussion of the same data, will be noticed again. 
 -7? Methods of Determining Resistances. — If a prO'-* 
 jectile be fired horizontally, the path described in the first 
 one or two tenths of a second may, without sensible error, 
 be considered a horizontal right line ; and, therefore, what- 
 ever loss of velocity it may sustain in this short time will be 
 due to the resistance of the air, since the only other force 
 acting upon the projectile, gravity^ may be disregarded, as 
 it acts at right angles to the projectile's motion. For ex- 
 ample, an 8-inch oblong shell, having an initial velocity of 
 
20 EXTERIOR BALLISTICS. 
 
 1400 f. s., will describe a horizontal path, in the first two- 
 tenths of a second after leaving the gun, of 278 ft., while its 
 vertical descent due to gravity will be less than 8 inches. 
 Moreover, if its velocity should be measured at the distance 
 of 278 ft. from the muzzle of the gun, it would be found to 
 be but 1380 f. s., showing a loss of velocity of 20 f. s., due to 
 the resistance of the air. 
 
 The relation between the horizontal space passed over 
 by a projectile and its loss of velocity may be determined 
 as follows : 
 
 Let w be the weight of the projectile in pounds, V and 
 V its velocities, respectively, at the distances^ and a' from 
 the muzzle of the gun, in feet per second, and g the accele- 
 ration of gravity. The vis viva of the projectile at the dis- 
 
 . wV" zv V" 
 
 tance a from the gun is , and at the distance a\ : 
 
 ^ g 
 
 consequently the loss of vis viva in describing the path 
 
 vu 
 a' —a^ is -( F^— V ^) ; and this, by the principle of vis viva, is 
 
 equal to twice the work due to the resistance of the air. If 
 the distance a'— a is not too great, say from 100 to 300 ft., 
 according to the velocity of the projectile, it may be as- 
 sumed that for this distance the resistance will not vary 
 perceptibly ; and if p is the mean resistance for this short 
 portion of the trajectory, we shall have 
 
 '^{V'-V'^) = 2{a'-a)p 
 whence 
 
 P- 2g{a'-a) 
 
 As, the resistance of the air is proportional to its density, 
 which is continually varying, it is necessary, in order to 
 compare a series of observations made at different times, to 
 reduce them all to some mean density taken as a standard. 
 If b is the density of the air at the time the observations are 
 made, and b^ the adopted standard density to which the ob- 
 
/' = 
 
 EXTERIOR BALLISTICS. 21 
 
 servations are to be reduced, the second member of the 
 preceding equation shoidd be multipHed by ~^ which gives 
 
 ' 2g{a' — a) d 
 
 We may take for the value of (\ the weight of a cubic 
 foot of air at a certain temperature and pressure; o will then 
 be the weight of an equal volume of air at the time of mak- 
 ing the experiments, as determined by observations of the 
 thermometer, barometer, and hygrometer. 
 
 As ft is the mean resistance for the distance a^ — a, it may 
 
 VA-V 
 be considered proportional to the mean velocity, v^ — ; 
 
 and substituting this in the above expression, it becomes 
 
 wv{V- V') d, , 
 
 By varying the charge so as to obtain different values 
 for Fand V, the resistance corresponding to different ve- 
 locities may be determined, and thence the /aw of resistance 
 deduced. 
 
 In order to compare the results obtained with projec- 
 tiles of different calibers, the resistance per unit of surface 
 (square foot) is taken ; and, to make the results less sensible 
 to variations of velocity, Didion proposed to divide the 
 values of o by -J^ and compare the quotients (p') instead of 
 
 />. Therefore, making ^t — — ^2-^, equation (4) becomes 
 
 ^ gTzF^via' -a) 3 ^^^ 
 
 It will be observed that since p is divided by ^'', the 
 values of f/ will be constant when the resistance varies as 
 the square of the velocity ; when this is not the case // will 
 evidentl}^ be a function of the velocity; or f/ = A' f{v) 
 (suppose), where the constant A', and the form of the fune- 
 tion,/(2/), are both to be determined. 
 3 
 
/ 
 
 22 EXTERIOR BALLISTICS. 
 
 Two assumptions have been made in deducing the ex- 
 pression for (), neither of which is exactly correct: ist, that 
 the resistance can be considered constant while the pro- 
 jectile is describing the short path a' — a ; and, 2d, that this 
 assumed constant resistance is that due to the mean velo- 
 city, V. The nature of the error thus committed may be 
 exhibited as follows: 
 
 The exact expression for p is 
 
 w dv wv dv 
 
 ^'~~~g~dt~~gds 
 
 Comparing this with (4), it will be seen that we have made 
 
 \V- V _ _dv 
 a' — a ds 
 
 which is true only when the path described by the projec- 
 tile is infinitesimal. 
 
 To determine the amount of error committed, we can re- 
 calculate the values of// by means of the law of resistance 
 deduced from the experiments; and it will be found that in 
 the most unfavorable cases the two sets of values of />' will 
 not differ from each other by any appreciable amount. For 
 example, suppose the law of resistance deduced by this 
 method is that of the square of the velocity ; what is the 
 exact expression for // in terms of F~ V and a — a? We 
 have 
 
 , p _ w dv 
 
 ^' ~^:^"J~ '^g^^' vds 
 and therefore 
 
 , , w dv 
 p' dsz=L — — 
 
 whence, integrating between the limits Fand V , to which 
 correspond a and a' , we have, since p' is constant in this 
 case, 
 
 ^' "^ gTzR^oT^) ^^^ Y' 
 To test the two expressions for //, take the follow 
 
EXTERIOR BALLISTICS. 23 
 
 ing data from Bashforth's ''Final Report," page 19, round 
 486: 
 
 F=2826 f. s. ; F' = 2777 f. s. ; 7e' — Solbs. ; 7? = 4 in. = ^ft.; 
 F — F' = 49 ; ^^= 32.191 ; a' — a=^ i$o ft., and z^ = 
 
 V+ V 
 
 2 
 
 = 2801.5. 
 
 We find ■ — ^-i^^-y—, v=: 0.047463; and this is a factor in 
 
 ^-rrR'ia -a) 
 
 both expressions for />'. Therefore, by the approximate 
 
 method, 
 
 f/ = 0.047463 28^-T = 0.00083 
 
 and by the exact method, 
 
 ^ 1 2826 
 f)' = 0.047463 log = 0.00084. 
 
 For a second example, suppose the law of resistance to 
 be that of the cube of the velocity. In this case f/ varies as 
 the first power of the velocity, or f/ =^ A^ v. Therefore 
 
 A, 1 2v dv 
 
 ^^ TT R V 
 
 whence 
 
 II 
 
 ^,^ ee. F^~"F 
 
 gTzK' a' - a 
 and 
 
 .'-A'^^-- "^ v{V-V'y 
 
 ' — "~ gT.k'ia' -a) W 
 
 Comparing this with (5), it will be seen that (omitting the 
 
 factor ^0 the two equations are identical, if we assume 
 
 z;^ = VV ; and this is very nearly correct when, as in the 
 present case, V — V is very small compared with either 
 For v. 
 
 As an example of this method of reducing observations, 
 the experiments made at St. Petersburg in 1868 by General 
 
24 
 
 EXTERIOR BALLISTICS. 
 
 Mayevski, with spherical projectiles, have been selected. 
 In these experiments the velocities were determined by 
 two Boiilenge chronographs, and the times measured were 
 in every case within the limits of o.''io and o.'' 15. 
 
 X 
 
 
 
 
 
 * 
 
 
 
 
 
 < 
 
 •f 
 
 * 
 
 
 
 
 
 it 
 
 ♦ 
 
 
 
 
 \ 
 
 dq\. 
 
 ' 
 
 
 
 \ 
 
 \> 
 
 
 
 
 
 § w 
 
 The experiments were made with 6 and 24-pdr. guns 
 and 120-pdr. mortars, and the velocities ranged from 745 
 f. s. to 1729 f. s. At least eight shots were fired with the 
 
EXTERIOR BALLISTICS. 
 
 25 
 
 same charge; the value of// was calculated for each shot, 
 and the mean of all the values of />' so calculated was taken 
 as corresponding to the mean velocity of all the shots fired 
 with the same charge. The values o^ a' — a varied from 
 164 ft. to 492 ft., the least values being taken for the 
 heaviest charges, and the greatest values for the smallest 
 charges. The greatest loss of velocity {V — V) was 131 
 ft., and the least 33 ft. 
 
 The values of {/ deduced from these experiments are 
 given in the following table. For convenience English 
 units of weight and length are employed ; that is, the 
 weights of the projectiles are given in pounds, the veloci- 
 ties in feet per second, and the radii of the projectiles and 
 the values of <^' — ^ in feet. 
 
 Values of p for Si'Herical Projectiles, deduced from the Experi- 
 ments MADE AT St. Petersburg in 1868. 
 
 
 Mean 
 
 
 
 Mean 
 
 
 Kind of Gun. 
 
 Velocity 
 
 Values of 
 P' 
 
 Kind of Gun. 
 
 Velocity 
 
 Values of 
 
 6-pdr. gun 
 
 745 f. s. 
 
 0.000561 
 
 24-pdr. gun 
 
 1247 f. s. 
 
 0.001054 
 
 24-pdr. gun 
 
 768 " 
 
 508 
 
 0-pdr. gun 
 
 1260 " 
 
 "45 
 
 120-pdr. mort. 
 
 860 " 
 
 687 
 
 120-pdr. mort. 
 
 1339 " 
 
 1117 
 
 6-pdr. gun 
 
 912 " 
 
 807 
 
 6-pdr. gun 
 
 1362 " 
 
 1189 
 
 24-pdr. gun 
 
 942 " 
 
 782 
 
 24-pdr. gun 
 
 1499 " 
 
 1138 
 
 120-pdr. mort. 
 
 1083 " 
 
 934 
 
 120-pdr. mort. 
 
 I5I9 " 
 
 1 163 
 
 24-pdr. gun 
 
 TII9 " 
 
 987 
 
 6-pdr. gun 
 
 1558 " 
 
 1189 
 
 6-pdr. gun 
 
 II22 " 
 
 0.001107 
 
 24-pdr. gun 
 
 1729 " 
 
 0.001178 
 
 These results are reproduced graphically in Fig. 3, the 
 velocities being taken for abscissas, and the corresponding 
 values of// for ordinates. It will be seen that the trend ot 
 the last seven points is nearly parallel to the axis of ab- 
 scissas, and may, therefore, be represented approximately 
 by the right line A, whose equation is 
 
 />'z= 0.00116 
 
 in which the second member is the arithmetical mean of the 
 last seven tabulated values of />'. 
 
26 EXTERIOR BALLISTICS. 
 
 It was found that the remaining points could be best 
 
 represented by a curve B, of the second degree, of the 
 
 form (/ =: p-\-q 7>^, containing two constants p and q whose 
 
 values were determined by the method of least squares, 
 
 each tabular value of // and the corresponding value of 
 
 V furnishing one " observation equation." it was found 
 
 that the most probable values of/ and q were^/ = 0.012 
 
 and ^ = 0.00000034686 ; or, reducing to English units of 
 
 k k 
 
 weight and length by multiplying / by - ^, and q by «, 
 
 where k is the number of pounds in one kilogramme, and m 
 the number of feet in one metre, we have 
 
 ^>' = 0.00022832 -[-0.00000000061309 v" 
 
 or, in a more convenient form, 
 
 ^/ = 0.00022832 )i+(g-^ J [ 
 
 To find the point of intersection of the right line A with 
 the curve B, equate the values of />' given by their respective 
 equations, and solve with reference to v. It will be found 
 that v^ 1233 f. s., at which velocity we assume that the law 
 of resistance changes. 
 
 In strictness there is probably but one laiv of resistance^ 
 and this might be, perhaps, expressed by a very complicated 
 function of the velocity, having variable exponents and co- 
 efficients, depending, upon the ever- varying density of the 
 air, the cohesion of its particles, etc. ; but, however compli- 
 cated it may be, we can hardly conceive of its being other 
 than a continuous function. But, owing to the difficulties 
 with which the subject is surrounded, both experimental 
 and analytical, it is usual to express the resistance by in- 
 , tegral powers of the velocity and constant coefficients, so 
 chosen, as in the above example, as to represent the mean 
 resistance over a certain range of velocity determined by 
 experiment. 
 
 * Mayevski, " Traite de Balistique Exterieure," page 41. 
 
EXTERIOR BALLISTICS. 
 
 Expression for />. — The expression for /> in terms of 
 
 which, since [/ is generally a function of 7', may be written 
 
 The resistance per unit of mass, or the retarding force, will 
 therefore be 
 
 or, taking the diameter of the projectile in inches, 
 
 The first member of this equation expresses the retarding 
 force when the air is at the adopted standard density and 
 the projectile under consideration is similar in every respect 
 to those used in making the experiments which determined 
 //. To generalize the equation for all densities of the at- 
 mosphere we must introduce into the second member the 
 
 factor IT ; and we will also assume, at present, that the equa- 
 tion will hold good for different types of projectiles if d'^ be 
 multiplied by a suitable factor {c), depending upon the kind 
 of projectile used. For the standard projectile and for 
 spherical projectiles, 6=1; for one offering a greater re- 
 sistance than the standard, 6'>i; and if the' resistance 
 offered is less, r < i. Making, then, 
 
 576 
 and 
 
 ^~ d cd' 
 we have for all kinds of projectiles 
 
 p- dv A ^ , . ,^. 
 
 C is called the ballistic coefficient, and c the coefficient of 
 reduction. 
 
i. 
 
 28 EXTERIOR BALLISTICS. 
 
 For the Russian experiments with spherical projectiles 
 the standard density of air to which the experiments were 
 reduced was that of air half saturated with vapor, at a tem- 
 perature of 1 5° C, and barometer at o"'. 75. In this condition 
 of air the weight of a cubic metre is 1^.206; and, therefore, 
 the weight of a cubic foot ( = o) is 0.075283 lbs. = 526.98 grs. 
 The value of ^ taken was 9"\8i = 32.1856 feet. Applying 
 the proper numbers, we have the following working expres- 
 sions for the retarding force for spherical projectiles. 
 
 Velocities greater than 1233 f. s. : 
 
 ^ /? = — 7/%- log A = 6.3088473 - 10 
 Velocities less than 1233 f. s. : 
 
 f- r = c ''' V "^ ?' / ' ^^^ ^ ^ 5.6029333 - 10 
 
 r = 612.25 ^^• 
 
 Oblong Projectiles: Oeneral Mayevski's For- 
 mulas. — General Mayevski, by a method similar in its gen- 
 eral outline to that given above, the details and refinements 
 of which we omit for want of space, has deduced the fol- 
 lowing expressions for the resistance when the Krupp pro- 
 jectile is employed, viz. : '^' 
 
 700™ >V> 419™, /> = 0.0394 TT R^ -^ v^ 
 
 419'" >v> 375"\ ^o = 0.0^94 r R' -yv' 
 
 375"" > -^ > 295"^, p — o.o'67 7: R" -^v" 
 295^^ > z; > 240^ /> = 0.0^583 ;r /?^ y 7^^ 
 240™ > v> o™, /> = 0.014 7: T?'^ -^ v" 
 Changing these expressions to the form here adopted 
 
 * Revue d^Artilleriey April, 1883. 
 
EXTERIOR BALLISTICS. 29 
 
 [equation (6)], and reducing to English units of weight and 
 length, they become 
 
 2300 ft. > z/> 1370 ft. : 
 
 ir- 
 
 = ^T/%- log yi =6.1192437 - 
 1370 ft. >^'> 1230 ft.: 
 
 - ID 
 
 i'- 
 
 --^ 7>\- log ^ = 2.9808825 - 
 
 1230 ft. > •z/>97o ft.: 
 
 ID 
 
 ir- 
 
 - J, v" ; log A = 6.8018436 - 
 970 ft. > z/> 790 ft.: 
 
 •20 
 
 i"- 
 
 ^ 3 , 
 
 790 ft. > 7' > ft. : 
 
 • ID 
 
 i" 
 
 = ^7^- log ^=5.6698755 - 
 
 ID 
 
 Colonel Hojel's Deductions from the Krupp Ex- 
 periments.— Colonel Hojel, of the Dutch Artillery, has 
 also made a study of the Krupp experiments discussed by 
 General Mayevski : and, as it is interesting and instructive 
 to compare the resistance formulas deduced by each of these 
 two experts, both using the same data, we give a brief syn- 
 opsis of Colonel Hojel's method and results. 
 
 He expresses the resistance by the following formula, 
 easily deduced from equation (6): 
 
 in which, from (4), 
 
 It is assumed that the loss of velocit}^ V — V\ is some func- 
 tion of the mean velocity v, which can be expressed approx- 
 imately, for a limited range of velocity, by a monomial of the 
 form 
 
 4 
 
30 EXTERIOR BALLISTICS. 
 
 in which A and n are constants to be determined. The 
 method of procedure is analogous to that followed m deter- 
 mining fj', and need not be repeated. Colonel Hojel has 
 considered it necessary to employ fractional exponents, 
 thereby sacrificing simplicity without apparently gaining 
 in accuracy. The results he arrived at are as follows: " 
 700^ >v> soo'", /{v) = 2A 868 v'-'' 
 500™ > -6^ > 400™, / (tj) = 0.29932 z/'" 
 400™ >v> 350'", / (v) = o.o'205 524 7/'-'' 
 350°^ > ^ > 300"\ / (v) = o.o'2 1692 V* 
 300™ >v> I40"\ /{z') = 0.033814 v'-' 
 Substituting these values oi /{v) in the equation 
 
 w^ zv -^ ■' 4w -^ ^ ^ 
 and reducing the results to English units, that is, taking w 
 in pounds, v in feet, and d in inches, we have as the equiva- 
 lents of Hojel's expressions, all reductions being made, the 
 
 following : 
 
 2300 ft. > 7^ > 1640 ft. : 
 
 a- A 
 ±- p z=z ~ v'''\- log y4 =6.4211771 — ID 
 
 1640 ft. > 7^> 1310 ft. : 
 
 -|.«-^^^-"; iog^ = 5.3923859- 10 
 
 1 3 10 ft. > 7/ > II 50 ft. : 
 
 0- A 
 
 -|-^ = — 7/^«%- log ^ = 0.4035263 - 10 
 
 1150 ft. >7'>98o ft.: 
 
 a- A 
 ^p = —v\- log ^ = 6.8232495 - 20 
 
 980 ft. > 7.' > 460 ft. : 
 
 <r A 
 
 ^ f)= — v"-" ; log A — 4.3060287 — 10 
 
 Comparison of Resistances dedviced from tlie 
 above Formnlas. — Making ^= i and f^, = o, in the above 
 
 * Revue iV Artilleries June, 1884. 
 
EXTERIOR BALLISTICS. 
 
 31 
 
 formulas, gives the resistance in pounds per circular inch at 
 the standard density of the air. Calling this ^o^, we have 
 
 A ^ 
 
 The following table gives the values of p^ for different 
 velocities according to Mayevski's and Hojel's formulas re- 
 spectively ; and also the same derived from " Table de 
 Krupp," Essen, 1881: 
 
 Velocity 
 in feet 
 per sec. 
 
 According 
 
 to 
 Mayevski. 
 
 P/ 
 
 According 
 
 to 
 
 Hojel. 
 
 p' 
 
 According 
 . to 
 Krupp. 
 
 Velocity 
 in feet 
 per sec. 
 
 P/ . 
 According 
 
 to 
 Mayevski. 
 
 According 
 
 to 
 
 Hojel. 
 
 p' 
 
 According 
 
 to 
 
 Krupp. 
 
 2300 
 2250 
 2200 
 
 21.629 
 20.699 
 19.789 
 
 21.598 
 20.710 
 19.840 
 
 21.637 
 20.643 
 19.738 
 
 1250 
 1200 
 II50 
 
 5.807 
 
 4.899 
 3.960 
 
 5.715 
 4.888 
 4.160 
 
 5-753 
 4.904 
 
 3-943 
 
 2150 
 2100 
 2050 
 
 18,900 
 18.031 
 17.183 
 
 18.987 
 18.153 
 17.337 
 
 18.900 
 17.962 
 17.091 
 
 1 100 
 1050 
 1000 
 
 3-171 
 2-513 
 1.969 
 
 3.331 
 2.640 
 2.068 
 
 3-105 
 2.480 
 2.044 
 
 2000 
 1950 
 1900 
 
 16.355 
 15.547 
 14.760 
 
 16.538 
 15-757 
 14-995 
 
 16.287 
 
 15-359 
 14. 611 
 
 950 
 900 
 850 
 
 I. 581 
 1.344 
 1. 132 
 
 1-749 
 1.527 
 1.324 
 
 1.720 
 1.486 
 1. 318 
 
 1850 
 1800 
 1750 
 
 13-993 
 13.247 
 12.521 
 
 14-250 
 
 13-523 
 12.815 
 
 13.929 
 I3-I81 
 12.500 
 
 800 
 750 
 700 
 
 0.944 
 0.817 
 0.712 
 
 1. 138 
 0.969 
 0.815 
 
 1. 162 
 0.983 
 0.804 
 
 1700 
 1650 
 1600 
 
 II. 816 
 II. 131 
 10.467 
 
 12.125 
 11.453 
 10.713 
 
 II. 818 
 11.059 
 10.400 
 
 650 
 600 
 
 550 
 
 0.614 
 0.523 
 0.439 
 
 0.677 
 0.554 
 0.446 
 
 0.648 
 
 0.514 
 0.413 
 
 1550 
 1500 
 1450 
 
 9.823 
 9.199 
 8.596 
 
 9.981 
 9.277 
 8.601 
 
 9-752 
 9.126 
 8.490 
 
 500 
 450 
 400 
 
 0.364 
 0.294 
 0.232 
 
 0.351 
 0.270 
 0.201 
 
 0.313 
 
 1400 
 1350 
 1300 
 
 8.014 
 7.315 
 6.535 
 
 7.954 
 7-334 
 6.6^1 
 
 7.920 
 
 7.238 
 6.445 
 
 i 
 
 
 
 
 Bashforth's Coefficients. — Professor Bashforth adopt- 
 ed an entirely different method from that just developed to 
 determine the coefficients of resistance, of which we will 
 give an outline, referring for further particulars to his 
 work,* which is well known in this country. 
 
 * " Motion of Projectiles," London, 1875 ^n^ 1881, 
 
32 EXTERIOR BALLISTICS. 
 
 ds 
 We have v =: — , whence, differentiating and making s 
 
 the equicrescent variable, 
 
 dv ds d^i 
 
 '~dt~ 'df~ 
 
 dv 
 and this value of -r substituted in (6) gives 
 
 g_ _ ds d't _ /dsV d'^t __ ^ d't 
 w^'~ df ~~\dt) ds''~^'' ds' 
 
 From this it follows that if the resistance varied as the cube 
 
 of the velocity, — would be constant; and we should have 
 ds"^ 
 
 --,=2^, (say); 
 
 whence, integrating twice, 
 
 t -=1 bs" -\- a s -\- c 
 
 which is the relation between the time and space upon this 
 hypothesis. When the resistance is not proportional to the 
 
 cube of the velocity, - in the equation 
 
 ^ ds' ^ 
 
 — /> = — -- ir — 2b V 
 w * ds 
 
 will be variable, and its value must be so determined by ex- 
 periment as to satisfy this equation for each value of v, 
 Bashforth's method of deducing these values is briefly as 
 follows : 
 
 Ten screens are placed at equal distances (150 feet) apart 
 in the plane of fire, and the exact time of the passage 
 of a projectile through each screen is measured by the 
 Bashforth chronograph. The first, second, third, etc., dif- 
 ferences of these observed times are taken, which call 
 d,, d,,d,, etc. 
 
 Let s be the distance the projectile has moved from 
 some assumed point to any one of the screens, say the first ; 
 
EXTERIOR BALLISTICS. 33 
 
 /the constant distance between the screens; and /,^ /,+/^ /,+2/, 
 etc., the observed times of the projectile's passing succes- 
 sive screens. Then from a well-known equation of finite 
 differences we have 
 
 , , n(n— 1) . , n(n— i)in — 2) , . , 
 
 ts.ni=^t,-\- ltd, + ^——-^ d, H ^^ ~\\ ^- d, + etc. 
 
 1.2 I • - • 3 
 
 in which ;/ is an arbitrary variable. Arranging the second 
 member according to the powers of//, we have 
 
 ts.ni^t,-\-n \d, — \d^-\-\d^ — -d,\ etc. ) 
 \ 2 3 4 / 
 
 -f etc., etc., 
 
 terms multiplied by the cube and higher powers of ^/. 
 
 Since / is a function of s, we have t^—f{s) and t,^„i:= 
 f{s + 111). Expanding this last by Taylor's formula, we have 
 
 , dt, nl , dU, n'l' ^ 
 
 whence, equating the coefficients of the first and second 
 powers of 71 in the two expansions of /^ + „/, we have 
 
 /^^ = ^-i^,+ i-^3_i^^ + etc. 
 ds ' 2 ' ' 3 4 
 
 and 
 
 ,„ ^V, , , , II - 10 7 1 X 
 
 :r-^^=:^,-^3 + — <- — < + etC. 
 
 The first of these equations gives 
 ds I 
 
 dt, ^-d,-\d,-^^\d,-\d, 
 and the second 
 
 7; 
 
 ds-" ' 
 
 where i\ is the velocity and - /> the resistance per unit of 
 
 mass at the distance s from the gun. 
 
 .J,,_-q^^_^^ + iL^._I|^. + etc.) 
 
34 
 
 EXTERIOR BALLISTICS. 
 
 As an example take the following experiment made with 
 a 6.92-inch spherical shot, weighing- 44.094 lbs., fired from a 
 7-inch gun."^ The times of passing the successive screens 
 were as follows : 
 
 Screens. 
 
 Passed at, 
 Seconds. 
 
 d. 
 
 d^ 
 
 ^3 
 
 I 
 
 2 . 90068 
 
 8431 
 
 306 
 
 10 
 
 2 
 
 2.98499 
 
 8737 
 
 316 
 
 TO 
 
 •3 
 
 3.07236 
 
 9053 
 
 326 
 
 10 
 
 4 
 
 3. 16289 
 
 9379 
 
 336 
 
 10 
 
 5 
 
 3.25668 
 
 9715 
 
 346 
 
 10 
 
 6 
 
 3.35383 
 
 10061 
 
 356 
 
 I I 
 
 7 
 
 3-45444 
 
 10417 
 
 367 
 
 II 
 
 8 
 
 3.55861 
 
 10784 
 
 378 
 
 
 9 
 
 3.66645 
 
 11162 
 
 
 
 10 
 
 3.77807 
 
 
 
 
 To find, for example, the velocity at the first screen, we 
 have 
 
 150 
 
 1 1.4 t. s., 
 
 = 1465.3 f"- s. 
 
 ' 0.08431—^0.00306-1-^0.00010 
 and at the seventh screen 
 
 150 
 ' 0.10417 — ^0.003674-^0.00011 
 
 The retarding forces at the same screens are as follows: 
 
 or V^ 
 
 ^ f)^=z - — ^- (o . 00306 — o . oooio) = o . ooooooi 3 1 56 Z^,' = 2<^, V,^ 
 
 and 
 
 - Pt= 7 — '-^(0.00367 — 0.00011) = 0. ooooooi 5822 z'/ = 2^, z;/. 
 
 As these small numbers are inconvenient in practice, 
 
 * Bashforth, page 43. 
 
EXTERIOR BALLISTICS. 35 
 
 Bashforth substituted for them a coefficient K, defined by 
 the equation 
 
 A-=24J(.ooo)'. 
 
 In the experiment selected above the weight of a cubic 
 foot of air was 553.9 grains = (?, while the standard weight 
 adopted was 530.6 grains = d^. Therefore we have 
 
 (150) (6.92) 553.9 
 
 and 
 
 j^ 0.00356 ^^ ^„ 
 
 A; = ^\K,— 139.6* 
 
 0.00296 ' ^^ 
 
 That is to say, when the velocity of a spherical projectile 
 is 1811.4 f. s., A"=ii6.i; and when its velocity is 1465.3 
 f. s., A'= 139.6. By interpolation the values of K, after 
 having been determined for a sufficient number of velo- 
 cities, are arranged in tabular form with the velocity as 
 argument. 
 
 Bashforth determined the values of K by this original 
 and beautiful method for both spherical and ogival-headed 
 projectiles ; and for the latter for velocities extending from 
 2900 f. s. down to 100 f. s. The experiments upon which 
 they were based were made under his own direction at 
 various times between 1865 and 1879, ^'ith his chronograph, 
 probably the most complete and accurate instrument for 
 measuring small intervals of time yet invented. 
 
 Law of Resistance deduced from Bashforth's 
 K. — It will be seen, by examining Bashforth's table of A" for 
 ogival-headed projectiles, that as the velocity decreases 
 from 2800 f. s. down to about 1300 f. s., the values of K 
 gradually increase, then become nearly constant down to 
 about ii3of. s., then rapidly decrease down to about 1030 
 f. s., become nearly constant again down to about 800 f. s., 
 and then gradually increase as the velocity decreases, to the 
 
 ♦ Bashforth's " Mathematical Treatise," page 97. 
 
36 EXTERIOR BALLISTICS. 
 
 limit of the table. These variations show that the law of 
 resistance is not the same for all velocities, but that it 
 changes several times between practical limits. We may 
 use Bashforth's K for determining these different laws of 
 resistance as follows : 
 
 We have for the standard density of the air, 
 
 ^ p = 2bv' 3= _ _— — (7) 
 
 w ^ zv (looo) 
 
 and 
 
 from which we get 
 
 ,_ S76Kv 
 ^^ ;r^(ioooy 
 
 The values of />' have been computed by means of this 
 formula, for ogival-headed projectiles, from if — 2900 f. s. to 
 V = 100 f. s., and their discussion has yielded the following 
 results : 
 
 Velocities greater than 1330 f. s. : 
 o A 
 
 ^p — —,7>\- log ^ =: 6.1525284— 10 
 
 1330 f. s. > 't^> II20 f. s. : 
 ^/> = -^7^'; log ^=: 3.0364351 - 10 
 
 1 1 20 f . s. > 2/ > 990 f . s. : 
 ^/> = -^-^"/ log yi = 3.8865079 -20 
 
 990 f. s. > 7^ > 790 f. s. : 
 fv^^'c'^'' log ^=2.8754872 -10 
 
 790 f. s. > 7/ > 100 f. s. : 
 
 p- A 
 ^pz=.-v\- log 7^ = 5.7703827- 10 
 
 These expressions, derived as they are from Bashforth's 
 
EXTERIOR 15ATXISTICS. 37 
 
 coefficients, give substantially the same resistances for like 
 velocities as those computed directly by means of equation 
 (7). The agreement between the two for high velocities is 
 shown graphically by Plate I., in which A is Bashforth's 
 curve of resistance, while that part of the parabola, B, com- 
 prised between the limits ^^2800 f. s. and 7'= 1330 f. s., is 
 the curve of resistance deduced from the first of the above 
 expressions. If, hovvever, we compare these expressions 
 with those deduced by Mayevski or Hojel from the Krupp 
 experiments, it will be found that these latter give a less 
 resistance than the former for all velocities. 
 
 This is undoubtedly due to the superior centring of the 
 projectiles in the Krupp guns over the English, and to the 
 different shapes of the projectiles used in the two series of 
 experiments, particularly to the difference in the shapes of 
 the heads. The English projectiles, as we have seen, had 
 ogival heads struck with radii of i| calibers, while those 
 fired at Meppen had similar heads of 2 calibres, and, 
 therefore, suffered less resistance than the former indepen- 
 dently of their greater steadiness. 
 
 Comparison of Resistances. — Let f) and {>^ be the re- 
 sistances of the air to the motion of two different projectiles 
 of similar forms ; w and zv^ their weights ; 5 and S^ the areas 
 of their greatest transverse sections; d and d^ their dia- 
 meters ; and D and D^ their densities. Then, if we suppose, 
 in the case of oblong projectiles, that their axes coincide 
 with the direction of motion, we shall have from (6) for the 
 same velocity, since 5 and S^ are proportional to the squares 
 of their diameters. 
 
 i" 
 
 s 
 
 w 
 
 A V ^ 
 
 ; and ^ = — 
 
 i''~ 
 
 
 that is, for the same velocity the resistances are proportional 
 to the areas of the greatest transverse sections, while the 
 retardations are directly proportional to the areas and in- 
 5 
 
38 EXTERIOR BALLISTICS. 
 
 versely proportional 
 tiles we have 
 
 to 
 
 the ) 
 
 A^eights. 
 
 For 
 
 spher 
 
 ical 
 
 projec- 
 
 .5=i;^^^ S,. 
 
 = i^ 
 
 ^A 
 
 , 7i>- 
 
 = i;r^^A 
 
 an 
 
 d w^ = 
 
 :t-;r 
 
 ^;^.; 
 
 therefore 
 
 
 
 
 _d^D, 
 ~ dD 
 
 
 
 
 
 that is, for spherical projectiles the retardations are in- 
 versely proportional to the products of the diameters and 
 densities. This shows that for equal velocities the loss of 
 velocity in a unit of time will be less, and, therefore, the 
 range greater, cceteris paribus, the greater the diameter and 
 density of the projectile. 
 
 As the weight of an oblong projectile is considerably 
 greater than that of a spherical projectile of the same caliber 
 and material, it follows that the retardation of the former 
 for equal velocities is much less than the latter, indepen- 
 dently of the ogival form of the head of an oblong projectile 
 which diminishes the resistance still more. Indeed, the re 
 tarding effect of the air to the motion of a standard oblong 
 projectile, for velocities exceeding 1330 f. s., is less than for a 
 spherical projectile of the same diameter and weight, and 
 moving with the same velocity, in the ratio of 14208 to 
 20358. As an example, if d and w are the diameter and 
 weight of a solid spherical cast-iron shot which shall suffer 
 the same retardation as an 8-inch oblong projectile weighing 
 180 lbs. and moving with the same velocity, we shall have, 
 since we know that a solid shot 14.87 inches in diameter 
 weighs 450 lbs., 
 
 ,_ (14.87)' X 180X20358 
 
 and 
 
 ^ „ — 29.65 inches 
 
 450X64X 14208 ^ •" 
 
 450 X (20.65)' . ,, 
 
 w— ^^ . W, ^^ —3567 lbs. 
 (14.87 ' ^^ ^ 
 
 The retarding effect of the air to the motion of projectiles 
 
EXTERIOR BALLISTICS. 
 
 39 
 
 of different calibers but having the same initial velocity and 
 angle of projection, is shown graphically in Fig. 4, which was 
 carefully drawn to scale. A is the curve which a projectile 
 would describe in vacuo, B that actually described b}^ a 
 spherical projectile 14.87 in diameter weighing 450 lbs., and 
 C that described by a spherical shot 5.9 inches in diameter 
 
 weighing 26.92 lbs. The initial velocity of each is 1712.6 
 f. s., and angle of projection 30°. 
 
 Example. — Calculate the resistance of the air and the re- 
 tardation for a 15-inch spherical solid shot moving with a 
 velocity of 1400 f. s. Here ^= 14.87 in., 7(^ = 450 lbs., and 
 A ~ 20358X iQ-l 
 
 Substituting these values in equation (6), we have 
 
 and 
 
 dv 
 dt 
 
 (14.87)' 20358 , 
 ^-^-^ X -^ X (1400)^ 
 32.16 10 ^ -1- / 
 
 (i4.87r 
 
 450 
 
 X '-'^^ X (.400)' 
 
 2743 lbs.. 
 
 196.07 f. s. ; 
 
 that is, at the instant the projectile was moving with a 
 velocity of 1400 f. s. it suffered a resistance of 2743 lbs. ; 
 and if this resistance were to remain constant for one second 
 the velocity of the projectile would be diminished by 196.07 
 ft. As, however, the resistance is not constant, but varies as 
 the square of the velocity, it will require an integration to 
 determine the actual loss of velocity in one second. 
 We have from (6) 
 
 dt IV 
 
40 EXTERIOR BALLISTICS. 
 
 or 
 
 dv iV . , 
 
 -^,=- Adt 
 whence, integraling between the limits F, 7>, we have 
 
 Now, making V= 1400 and t=zi, we find v — 1228 f. s. ; 
 and the loss of velocit}^ in one second is 1400 — 1228 = 172 ft, 
 
CHAPTER III. 
 
 DIFFERENTIAL EQUATIONS OF TRANSLATION — GENERAL 
 PROPERTIES OF TRAJECTORIES. 
 
 Preliiiiiiiary Considerations.— A projectile fired from 
 a gun with a certain initial velocity is acted upon during its 
 flight only by gravity and the resistance of the air; the 
 former in a vertical direction, and the latter along the tan- 
 gent to the curve described by the projectile's centre of 
 gravity. It will be assumed, as a first approximation, that 
 the projectile, if spherical, has no motion of rotation ; and, 
 in the case of oblong projectiles, that the axis of the pro- 
 jectile lies constantly in the tangent to the trajectory ; also 
 that the air through which it moves is quiescent and of uni- 
 form densit}'. xA.s none of these conditions are ever fulfilled 
 in practice, the equations deduced will only give what may 
 be called the normal trajectory^ or the trajectory in the plane 
 of fire, and from which the actual trajectory will deviate 
 more or less It is evident, however, that this deviation 
 from the plane of fire is relatively small ; that is, small in 
 comparison with the whole extent of the trajectory, owing 
 to the very great density of the projectile as compared with 
 that of the air. 
 
 Notation.— In Figure 5, let (9, the point of projection, 
 be taken for the origin of rectangular co-ordinates, of which 
 let the axis of X be horizontal and that of F vertical. Let 
 O A be the line of projection, and O B E the trajectory de- 
 scribed. The following notation will be adopted: 
 
 o denotes the acceleration of gravity, which will be taken 
 at 32.16 f. s. ; 
 
 IV the weight of the projectile in pounds; 
 
 d its diameter in inches; 
 
 (p the angle of projection, A O E ; 
 
42 EXTERIOR BALLISTICS. 
 
 V the velocity of projection, or muzzle velocity ; 
 [/ the horizontal velocity of projection = Fcos (f ; 
 
 V the velocity of the projectile at any point M of the 
 trajectory ; 
 
 3 the angle included between the tangent to the curve 
 at any point Jf and the axis of X, = T M H ; 
 CO the angle of fall, CEO; 
 Y 
 
 D 
 
 u the horizontal velocity = ^' cos ^; 
 
 / the time of describing any portion of the trajectory 
 from the origin ; 
 
 s the length of any portion of the arc, as O in ; 
 
 X the horizontal range, O E ; 
 
 T the time of flight ; 
 
 ft the resistance of the air, or the resistance a projectile 
 encounters in the direction of its motion, in pounds. 
 
 Dift'erential Equations of Translation. — The ac- 
 celeration'^" in the direction of motion due to the resistance 
 
 of the air is — //; and the correspondins^ acceleration due to 
 
 gravity is ^ sin /> ; therefore the /<?/<:?/ acceleration in the 
 direction of motion is expressed by the equation, 
 
 f =-^-,-,-sin,> (8) 
 
 The velocities parallel to X and Y are, respectively, 
 
 * The term "acceleration" is here used for retardation. To avoid multiplying terms re- 
 tardation will be regarded as negative acceleration. 
 
EXTERIOR BALLISTICS. 43 
 
 V COS <>and v sin /> ; and the accelerations parallel to the same 
 
 o g 
 
 axes are -- /> cos /> and j^ + -- p sin />. 
 Therefore 
 
 ^ (^ cos '>) ^ g , , 
 
 ^ ,, = - — /' COS /!/ (9) 
 
 at zu ' ^^^ 
 
 and 
 
 d {v sin /5^) ^. 
 
 dt "- - ' 
 
 -^ ^ f> sin ^y 
 
 7£/ 
 
 Performing- the differentiations indicated in the above 
 equations, multiplying the first by sin & and the second by 
 cos />, and taking their difference, gives 
 
 — ^ = -^^cos/V (10) 
 
 Introducing the horizontal velocity u = 7' cos /> in (9) and 
 (10), and substituting for •_'^ ft its value from (6), they become, 
 
 making/ (7/) = 7^", 
 
 du A u"" • , 
 
 rf7 "" "~ 6'^ cos""-^^^ ^^^^ 
 
 and 
 
 -^^ = — a- cos' fi (12) 
 
 whence, eliminating <3^/, 
 
 <^ /> g C du 
 
 (13) 
 
 cos"^'<> ^ ?/**^' 
 
 Symbolizing the integral of the first member of (13) by 
 (/>)„, that is, making 
 
 ^^^" J "cos^'^"^ 
 
 71 k^ C 
 
 and writing for the sake of symmetry, for -^, we shall 
 
 have 
 
 rdu k^ 
 
 id-\ = n k' I = h C 
 
44 
 
 EXTERIOR BALLISTICS. 
 
 If (z) is the value of (f"^) when // is infinite, we have 
 C=(0; and therefore 
 
 whence 
 
 and 
 
 ={t\-{»). 
 
 k 
 
 k sec (5* 
 
 From (ii) we have 
 
 C ^ , Kidn 
 
 (it ■-— cos"-' f>—- 
 
 A ?/" 
 
 and this substituted in the equations 
 
 c/x = ?/ d/, dy = // tan ^ dt, ds = // sec li dt, 
 
 gives 
 
 ^,= __^cos«-,>_ 
 
 ./j/= --^sln/^cos'-^/^f-, 
 
 ^^ = 
 
 From (12) w^e have 
 
 C 
 
 cos" 
 
 ,>i^ 
 
 dt= - 
 
 It d /> 
 
 ^^ cos'' ^> 
 
 d tan ^y 
 
 whence, as before, 
 
 dx=^ d tan & 
 
 g 
 
 dy 
 ds 
 
 tan b- d tan /V 
 
 — sec ^ ^ tan ^^ 
 
 (14) 
 (•5) 
 
 (>-) 
 
 (18) 
 
 (19) 
 (20) 
 
 (21) 
 
 (22) 
 (23) 
 (24) 
 
EXTERIOR BALLISTICS. 
 
 45 
 
 Eliminating- u from these last four equations by means 
 of (15), they take the following eleg-ant forms : 
 
 it= ~ ~ 
 
 k_ d tan d^ (25) 
 
 , ^ ^t an d^ (26) 
 
 , k- tan ^y^/ tan /V (27) 
 
 _ _ /P sec d d tan /> (28) 
 
 7?^' w<7r/'j-.— Subject to the conditions specified in the pre- 
 liminary considerations, equations (16) to (20) or (25) to (28) 
 contain the whole theory of the motion of translation of a 
 projectile in a medium whose resistance can be expressed by 
 an integral power of the velocity. Equation (16) gives the 
 velocity in terms of the inclination; (18) and (19) or (26) and 
 (27), could they be integrated generally, would give the co- 
 ordinates of any point of the trajectory, while the time would 
 depend upon the integration of (17) or (25). But, unfortu- 
 nately, the ''laws of resistance" which obtain in our atmo- 
 sphere do not admit of the integration of these equations ; 
 we are, therefore, obliged to resort to indirect solutions 
 giving approximations more or less exact. Of these many 
 have been proposed by different investigators; but, with 
 few exceptions, they are either too operose for practical use 
 or not sufficiently approximate. 
 
 General Didion, in the fifth section of his '* Traite de 
 Balistique," gives a full and interesting ri^sumi^ o{ \\\q labors 
 of mathematicians upon this difficult problem up to his 
 time (1847), ^"<^ ^" the same work gives an original solution 
 of his own of great value. Within the last quarter of a cen- 
 tury much has been accomplished to improve and simplify 
 6 
 
46 EXTERIOR BALLISTICS. 
 
 the methods for calculating tables of fire and for the solution 
 of the various problems relating to trajectories ; and we will 
 endeavor in the following pages to present such of these 
 methods as are of recognized value, developed after a uni- 
 form plan and based upon the preceding differential equa- 
 tions. 
 
 Oeiieral Properties of Trajectories. — Though it 
 is impossible with our present knowledge to deduce the 
 equation of the trajectory described by a projectile, there 
 are certain general properties of such trajectories which 
 may be determined without knowing the law of resistance, 
 if we admit that the resistance increases as some power of 
 the velocity greater than the first, from zero to infinity; 
 
 whence, making — = /(^)> we shall have f {v) > o, and 
 
 /(x)= X. 
 
 Variation of tlie Velocity — Miniiniim Velocity. 
 
 — The acceleration in the dircctio7i of motion is [equation (8)] 
 
 f =-."T/(^') + sin*] 
 
 in which — ^sin d is the component of gravity in the direc- 
 tion of motion; and, therefore, whether the velocity is in- 
 creasing or decreasing with the time at any point of the tra- 
 jectory, depends upon the algebraic sign of the second mem- 
 ber; and this, since f {v) \ = — ) is considered positive, 
 
 depends upon the sign of sin d^. In the ascending branch 
 sin & is positive, and, therefore, from the point of projection 
 to the summit the velocity is decreasing. At the summit 
 sin ?^ = o, and at this point gravity, which has hitherto con- 
 spired with the resistance to diminish the velocity, ceases 
 to act for an instant in the direction of motion, and then, as 
 sin d- changes sign in the descending branch, begins to act 
 in opposition to the resistance ; that is, its action tends to 
 increase the velocity. The component of gravity acting 
 perpendicular to the projectile's motion (^ cos d), and which 
 
EXTERIOR BALLISTICS. 47 
 
 is a maximum at the summit, tends to increase the in- 
 clination in the descending branch, and thus to increase 
 (numerically) — sin &, until at a certain point of the de- 
 scending branch where the inclination is (say) — &' the 
 acceleration of gravity in the direction of motion has in- 
 creased until it just equals the retardation due to the re- 
 sistance of the air, which latter has continually decreased 
 with the velocity. Beyond this point, as the component of 
 gravity in the direction of motion still increases with the 
 inclination while the resistance remains constant for an in- 
 stant, the velocity also increases; and, therefore, at the 
 point where 
 
 w 
 the velocity is a minimum, and — = o. 
 
 Passing the point of minimum velocity, the acceleration 
 of gravity and the retardation due to the resistance of the 
 air both increase; but that there is no maximum velocity, 
 properly speaking, may be shown as follows : 
 
 Differentiating the above expression for the acceleration, 
 we have 
 
 d'^v ' dv ^ d& 
 
 and putting in place of ^ its value from (10), we shall have 
 
 d'v ^,. ^dv , .^-^cos^/> 
 
 df '*'' ' V/ ' V 
 
 dv 
 and this is necessarily positive whenever — == o. The velo- 
 city, therefore, can only be a minimum ; but it tends towards 
 
 1- • • 1 • ^ P 10 '^ 
 
 a hmitmp: value, viz., when — - =: i, and //=^ . 
 
 Liinitiiig" Velocity. — As the limiting velocities of all 
 service spherical projectiles are less than 1233 f. s., we can 
 
48 
 
 EXTERIOR liALLlSTlCS. 
 
 determine these velocities by means of the expression for 
 the resistance given in Chapter II., from which we get 
 
 A (P 
 
 o zv 
 
 (.+o>) 
 
 := I 
 
 where ^4 = 0.000040048 and r = 610.25. Solving with re- 
 ference to 7' we ore t 
 
 Z'+^^f--' 
 
 which gives tlie limiting velocity. 
 
 The following table contains the limiting velocities of 
 spherical projectiles in our service calculated by the above 
 formula : 
 
 Solid Shot. 
 
 Inches. 
 
 Lbs. 
 
 Final 
 Velocity. ' 
 Feet. i 
 
 Shells 
 Unfilled. 
 
 Inches. 
 
 7(' 
 
 Lbs. 
 
 Final 
 
 Velocity. 
 
 iFeet. 
 
 20-inch 
 
 19.87 
 
 1080 
 
 859 : 
 
 15-inch 
 
 14.87 
 
 330 
 
 1 
 726 1 
 
 15-inch 
 
 14.87 
 
 450 
 
 783 
 
 13-inch 
 
 12,87 
 
 216 
 
 682 
 
 13-inch 
 
 12.87 
 
 283 
 
 743 
 
 lo-inch 
 
 9.87 
 
 101.75 
 
 635 
 
 lo-inch 
 
 9.87 
 
 128 
 
 684 
 
 8-inch 
 
 7.88 
 
 45 
 
 561 
 
 i2-pdr. 
 
 4.52 
 
 12.3 
 
 526 
 
 i2-pdr. 
 
 4.52 
 
 8.34 
 
 458 
 
 Limit of the Iiieliiiatioii of the Trajectory in the 
 Desceiidinj>- Braiicli. — We have assumed above that tlie 
 descending branch of tlie trajectory ultimately becomes 
 vertical. To prove this, take equation (10), viz. : 
 
 and integrating from a point of the trajectory where ^y = if 
 and ^ = o, we have 
 
 As the velocity v, between the limits / = o and / = x , is 
 
XY ) 
 
 EXTERIOR BALLISTICS. 49 
 
 finite and continuous, and cannot become zero, we have, 
 since v is a function of />, 
 
 where A^ is some value of v greater than its least, and less 
 than its greatest value between the limits of integration. 
 As (^ is negative in the descending branch, the above 
 
 equation shows that, when / is infinite, /V is equal to — '-. 
 
 2 
 
 From (24) we have 
 
 tan('' + ^' 
 
 z^^/i \4 2 
 
 A log 
 
 
 
 
 ot/s 
 
 = —v\ . 
 
 COS /> 
 
 and, 
 
 therefore 
 
 I, when 
 
 t is 
 
 infinite. 
 
 c — 
 
 2 
 
 C0 
 
 cos/y- 
 
 : K' 
 
 
 <b-^ — 
 
 tan 
 
 \4 4. 
 
 tan o 
 
 where K' is some value of -ir greater than its least, and 
 less than its "freatest value between the limits of inte- 
 
 ?5 
 
 »(i+-9.,. 
 
 tan 
 
 gration ; and, as log ^ — ^ ^ is infinite, so is the arc 
 
 tan o 
 
 which conesponds to / = x . 
 
 Asymptote to the Descending- Branch.— As the 
 
 tangent to the descending branch at infinity is vertical, if it 
 can be shown that it cuts the axis of X at a finite distance, 
 it is an asymptote. To determine this, take equation (22) 
 which ofives 
 
 .'•-=/_'. -'^'' = ^"'('f 
 
 where K" is a finite quantity, since v^ is finite between the 
 limits of integration. Therefore the descending branch has 
 
 a vertical asymptote. 
 
50 EXTERIOR BALLISTICS. 
 
 Radius of Curvature. — Designate the radius of curva- 
 
 ture by y. We have by the differential calculus v = -^ 
 
 (since the trajectory is concave toward the axis ofX); we 
 also have ds^=zvdt ; consequently y z=z —- — —, and therefore 
 from (12) 
 
 y zzz — sec (J \ 
 
 g 
 
 The radius of curvature is therefore independent of the 
 resistance of the air, and at any point of the trajectory de- 
 pends only upon the velocity and the inclination, and, there- 
 fore, has the same value for the corresponding points of a 
 parabola described by a projectile in vacuo. The above ex- 
 pression shows that the radius of curvature decreases from 
 the point of projection to the summit of the trajectory, 
 since v and sec d- both decrease between those limits. Be- 
 yond the summit v still decreases, but as sec d- increases we 
 cannot determine by simple inspection where y ceases to 
 decrease and becomes a minimum. Differentiatinof the ex- 
 pression for y, we have 
 
 dy 2v sec d^ dv , 7/ ,, ., 
 
 -TTT = — — 777 + — tan tJ sec o- 
 
 d(> g dty g 
 
 From (13) and (6) we have 
 
 d{v cos d) ft 
 
 ■fe 
 
 V 
 
 dd- w 
 
 whence, differentiating and reducing, 
 
 + sin & 
 
 dv '' f (^ 
 
 d& cos d- \ zv 
 
 Substituting this in the expression for -^ gives 
 
 dy zr 
 —^ = — sec 
 ^'^ g 
 
 ^.>g + 3sin,y) 
 
 This equation shows that beyond the summit --~r is posi- 
 
EXTERIOR BALLISTICS. 5 I 
 
 tive up to the point where — + 3 sin d =r o, and then 
 
 changes its sign. At this point, therefore, the radius of 
 
 curvature becomes a minimum and afterwards increases to 
 
 infinit}^ 
 
 At the point of maximum curvature we have, in conse- 
 
 20 
 quence of the condition ^^ + 3 sin & zzz o, 
 
 -777 = V tan If 
 
 dt^ 2 
 
 and therefore, since 0- is negative in the descending branch, 
 
 -777- is positive at that point, and v is decreasing with d-] 
 au 
 
 in other words, the velocity has not yet become a mini- 
 mum. Therefore the point of maximum curvature is near- 
 er the summit of the trajectory than the point of minimum 
 velocity. 
 
CHAPTER IV. 
 
 RECTILINEAR MOTION. 
 
 Relation between Time, Space, and Velocity. — 
 
 For many practical purposes, and especially with the heavy, 
 elongated projectiles fired from modern guns, useful results 
 may be obtained by considering the path of the projectile 
 a horizontal right line, and therefore unaffected by gravity. 
 Upon this supposition f'i- becomes zero, and equations (17), 
 (18), and (20) become 
 
 C dv 
 
 and 
 
 n dx ^=- (is ^=^ — — — 
 
 A v^-^ 
 
 whence integrating, and making / and ^ zero when 7^= F, 
 we have 
 
 t-c\ ^ L__l 
 
 ((;/- \)Av^-' {n- \)A F^'M 
 and 
 
 ,^r S I L_ ^ 
 
 \{n — 2)Av^-^ {71— 2) A F«-^f 
 
 Writing, for convenience, 
 
 T {%>) for ; r ^ ^ -, and 5 {v) for ; , . „_„ 
 
 these equations become 
 
 t^C\T{v)-T{.^\ 7\ (29) 
 
 and rji ' ' 
 
 s=C\S{v)-S{zt)\ ' (30) 
 
 When n = 2, the above expression for s becomes inde- 
 terminate. In this case we have 
 
EXTERIOR BALLISTICS. 53 
 
 , C dv 
 
 whence 
 
 s = —\\og V-\ogv I 
 and therefore, when n = 2, 
 
 Equations (29) and (30) (or their equivalents) were first 
 given by Bashforth in his *' Mathematical Treatise," Lon- 
 don, 1 873. He also gave in the same work tables of 5 (v) and 
 T{7>) for both spherical and elongated shot; the former ex- 
 tending from V =: 1900 f. s. to v = 500 f. s., and the latter 
 from V = 1700 f. s. to v =: 540 f. s. In a " Supplement " to his 
 work above cited, published in 1881, he extended the tables 
 for elongated projectiles to include velocities from 2900 f. s. 
 to 100 f. s. 
 
 Projectiles differing from tlie Standard. — It will 
 be seen that the value of the functions T{v)a.nd S (v) depend 
 upon those of v and A, the former of which is independent 
 of the nature of the shot, while the latter depends partly 
 upon the form of the standard projectile, which in this 
 country and England has an ogival head struck with a 
 radius of ij calibers, and a body 2^ calibers long. The fac- 
 tor 6^ ( or -^ ~~) depends upon the weight and diameter of 
 \ o ca / • 
 
 the projectile, the density of the air, and the coefficient c ; 
 which latter varies with the type of projectile used. The 
 factor^ varies, therefore, with c ; but by the manner in which 
 A and c enter the expressions for / and s, it will be seen 
 that the results will be the same if we make A constant, 
 and give to ^ a suitable value determined by experiment for 
 each kind of projectile. By this means the tables of the 
 functions T{v) and 5(z/), computed upon the supposition 
 that ^ = I, can be used for all types* of projectiles. We 
 will now show how these tables may be computed for ob- 
 long projectiles, making use of the expressions for the re- 
 7 
 
54 EXTERIOR BALLISTICS. 
 
 sistance derived from Bashforth's experiments given in 
 Chapter I. 
 
 Oblong Projectiles, Velocities greater than 1330 
 
 f. s. — For velocities greater than 1330 f. s. we have ^^ = 2 
 and log ^ =6.1525284 — 10; therefore 
 
 r(.) = -iandr(F)=-i, 
 
 or, since the value of t depends upon the difference of T{y) 
 and T{V), we may, if convenient, introduce an arbitrary 
 constant into the expression for T{v). Therefore we may 
 take 
 
 and, similarly, 
 
 •S (^) = ^ (- log r + log 0',) = ^ log ^ 
 
 To avoid large numbers and to give uniformity to the 
 tables we will determine the constants Q, and Q\ so that 
 the functions shall both reduce to zero for the same value 
 of v; and it will be convenient to begin the table with the 
 highest value of v likely to occur in practice, which we will 
 assume (following Bashforth) to be 2800 f. s. 
 
 We therefore have 
 
 A \2800 ' ---V 
 
 2800 
 
 I 1... Q\ 
 
 loR -S^ =0 G'l = 2800 
 ^ 2800 ' 
 
 Substituting the above values of A, Q^, and Q\ in the 
 expressions for T{v) and S (v), and reducing, we have for 
 velocities between 2800 f. s. and 1330 f. s. 
 
 T{v) = [3.8474716] -^- - 2.5137 
 
 and 
 
 S{v) =155866.12 — [4.2096873] log V. 
 
 The numbers in brackets are the logarithms of the nu- 
 merical coefficients of the quantities to which they^^are 
 
EXTERIOR BALLISTICS. 55 
 
 prefixed ; and the factor lo^ v is the common logarithm of 
 z', the modulus being included in the coefficient. 
 
 Velocities between 1330 f. s. and 1130 f. s.— For 
 
 velocities between 1330 f. s. and 11 20 f. s. we have n — i 
 and log A = 3.0364351 — 10; therefore, as before, 
 
 
 Arbitrary Constants. — To deduce suitable values for 
 the arbitrary constants Q^ and ^'2, we must recollect that 
 the function representing the resistance of the air changes 
 its form abruptly when the velocity is 1330 f. s. ; and to 
 prevent a correspondingly abrupt change in our table at 
 the same point — that is, to make the numbers in the table a 
 continuous series — we must give to g^ and Q^ such values 
 as shall make the second set of functions equal in value to 
 the first when z;=i330. They will, therefore, be deter- 
 mined by the following relations: 
 
 _L/ L_ - ^) = lf_J L_^ 
 
 2 A V(i33o)' ^ ^7 A V1330 2800/ 
 and 
 
 I / I I ^/ \ I 1 2800 
 
 in which the A in the first member must not be confounded 
 with that in the second. Making the necessary reductions, 
 we have 
 
 and 
 
 Tizi) = [6.6625349] A-+ 0.1791 
 
 V 
 
 5(z/)= [6.9635649]-^ - 1674.: 
 
 Velocities between 1130 f. s. and 990 f. s.— For 
 
 velocities between 1120 f. s. and 990 f. s. we have ;/ = 6 
 and log A — 3.8865079 — 20 ; therefore 
 
 ^(-^ = 5i-(^+^") 
 
56 EXTERIOR BALLISTICS. 
 
 and . V 
 
 The constants must be determined as before, by equating 
 the above expressions to the corresponding ones in the case 
 immediately preceding, making ^= 1120. The results are, 
 all reductions being made, 
 
 r(T^) = [15.4145221] ■;:^ + 2.3705 
 
 and 
 
 5(2;)=[i5.5ii432i] I- + 4472.7 
 
 Velocities between 990 f. s. and 790 f. s.— For 
 
 velocities between 990 f. s. and 790 f. s. we have // = 3 and 
 log A = 2.8754872 — 10; whence 
 
 and 
 
 Proceeding as before, we have 
 
 r(2;) = [6.8234828] i,- 1.6937 
 
 and 
 
 *^(^) = [7-i245i28] i- 5602.3 
 
 Velocities less than 790 f. s. — For velocities less 
 than 790 f. s. we have « 1= 2 and log ^4 = 5.7703827 — 10 ; 
 therefore 
 
 ^(-)=z(^ + a) 
 
 and 
 
 whence, as before, 
 
 T{v) = [4.2296173] -^ - 12.4999 
 
 S{v) — 124466.4— [4-59' 8330] log 2/. 
 
EXTERIOR BALLISTICS. 57 
 
 Ballistic Tables. — Table I. gives the values of the time 
 and space functions for oblong projectiles, computed by the 
 above formulas, and extends from v zizz 2800 f. s. to v = 400 
 f s. The first differences are given in adjacent columns; 
 and as the second differences rarely exceed eight units of 
 the last order, it will hardh^ ever be necessary to consider 
 them in using this table. 
 
 Table II. gives the values of these functions for spherical 
 projectiles, and is based upon the Russian experiments dis- 
 cussed in Chapter II. 
 
 EXAMPLES OF THE USE OF TABLES I. AJ^D II. 
 
 Example i. — The velocity of an 8-inch service projectile 
 weighing 180 lbs. was found by the Boulenge chronograph 
 to be 1398 f. s. at 300 ft. from the' gun. What was the 
 muzzle velocity ? 
 
 Here C == ^, v = 1398, and s = 300, to find V. From 
 64 
 
 (30) we have 
 
 and from Table 1. yXW"* 
 
 5(1398) =4903.8 - ^^^^^'^ =4888.7 
 
 also 
 
 s 64 ^ 
 
 C = 300 X-^= 106.7 
 
 whence 
 
 5(F) = 4782.0 
 
 . •. F= 141 5 + ^1^ = 14^9-4 f- s. 
 
 Example 2. — Determine the remaining velocity and the 
 time of flight of the 12-inch service projectile, weighing 800 
 lbs., at 1000 yds. from the gun, the muzzle velocity being 
 1886 f. s. 
 
58 EXTERIOR BALLISTICS. 
 
 1. Fand s are given, to find v; where </= 12, 2£/ = 800 
 
 800 
 
 F= 1886, J =: 3000, and C ^^ 
 
 144 
 
 We have 
 
 5(.) = 5(,886) + 32^^4 
 
 From Table I., 
 
 5 (1886) = 2803.7 - 0.6 X 37.4 = 2781.3 
 3000-X 144^ 
 800 ^^ 
 
 , 10 X 27.0 ^ ^ 
 
 . •. z/= 1740 H — = 1746.7 f. s. 
 
 ^ 40.3 
 
 2. Fand z/ are given, to find // from Table I., 
 
 T{v)= 1.5 16 
 r(F)=i.2i7 
 
 r(z;)- r(F) = 0.299 
 
 .-./ = 0.299 X ^=1^66 
 144 
 
 " Example 3. — Suppose we wish to determine the value 
 
 of the coefficient of reduction, c, for a particular projectile 
 
 whose form differs from the standard projectile. From (30) 
 
 we have 
 
 ^ w s 
 
 u Td}'' S(v)-S(V) 
 
 whence ^ ^ ^ ^ 
 
 jv S{v)-S {V) 
 d-" s 
 
 It is, therefore, only necessary to measure the velocity 
 of the projectile at two points of its trajectory as nearly in 
 the same horizontal line as practicable, and at a known dis- 
 tance apart, and substitute the values thus obtained in the 
 above formula. For example, the 40-centimetre (71 -ton) 
 Krupp gun fires a projectile weighing 17 15 lbs. with a 
 muzzle velocity of 1703 f. s. By experiment it is found 
 that the velocity at 1800 ft. from the gun is 1646 f s. What 
 is the value of c for this projectile ? 
 
EXTERIOR BALLISTICS. 
 
 59 
 
 Here 
 
 F= 1703, V == I 
 
 646, ^ == 1 80 
 
 15.748. 
 
 
 
 From Table I., 
 
 
 
 ^(^) = 3742.2 
 
 
 
 5(F) 3= 3499-7 
 
 
 
 log 242.5 
 
 = 2.3846580 
 
 
 - w 
 
 = 0.8397959 
 
 
 clogs 
 
 == 6.7447275 
 
 2t/= 1715, and d 
 
 log ^ = 9.9691814 ^ = 0.9315 
 .-. log (7= 0.87061451 
 
 Extended Ranges. — For the heaviest elongated pro- 
 jectiles, fired with high initial velocities, the remaining 
 velocities and times of flight may be determined by this 
 method with sufficient accuracy for quite extended ranges; 
 that is to say, for ranges due to an angle of projection of 
 10° or 12°, or, in other words, when the least value of cos ^ 
 for the entire trajectory does not depart very much from 
 unity, its assumed value. 
 
 Example 4. — Compute the remaining velocities, with the 
 data of the last example, at 1800 ft., 3600 ft., 5400 ft, ... up 
 to 18000 ft. from the gun. 
 
 The work may be arranged as follows: 
 
 S{v) = 3499-7» log 6^= 0.8706145. 
 
 J 
 
 c 
 
 Siv) 
 
 V 
 
 Computed by 
 Krupp's Formula. 
 
 1800 ft. 
 3600 - 
 5400 '' 
 
 7200 " 
 
 242.47 
 484.9 
 727-4 
 969-9 
 
 3742.2 
 3984.6 
 4227.1 
 4469.6 
 
 1645 f. s. 
 1589 '' 
 1536 - 
 1484 " 
 
 1646 f. 
 1590 ' 
 1536 * 
 1484 ' 
 
 S. 
 
 9000 " 
 10800 '' 
 12600 '' 
 
 I2I2.3 
 
 1454.8 
 1697.3 
 
 4712.0 
 
 4954-5 
 5197.0 
 
 1434 " 
 1385 '' 
 1338 " 
 
 1434 ' 
 1385 ' 
 1338 ' 
 
 
 14400 '' 
 16200 " 
 
 1939.8 
 2182.2 
 
 5439-5 
 5681.9 
 
 1293 " 
 1250 " 
 
 1293 * 
 I25I ' 
 
 
 18000 " 
 
 2424.7 
 
 5924.4 
 
 1211 *' 
 
 I2II " 
 
60 EXTERIOR BALLISTICS. 
 
 The numbers in the second column are simple multiples 
 of the first number in that column; those in the third column 
 are found by adding S {V) = 3499.7 to the numbers on the 
 same lines in the second column, and the velocities in the 
 fourth column are taken from Table I. with the argument 
 S{v). 
 
 The velocities in the last column were computed by 
 Krupp's formula. They are copied, as also the data of the 
 problem, from " Professional Papers No. 25, Corps of En- 
 gineers, U. S. A.," page 41. 
 
 In this example the angles of projection and fall for a 
 range of 18000 feet are, respectively, 7° 18' and 9° 20'; while 
 an 8-inch shell weighing 180 lbs. would require for the same 
 range, with the same initial velocity, an angle of projection 
 of 11° 5^ and the angle of fall would be 19° 40'. 
 
 In this latter case the velocity computed by the above 
 method would not be a very close approximation. 
 
 Comparison of Calculated with Observed Velo- 
 cities, — The following table, taken, with the exception of 
 the last two columns, from "Annexe a la Table de Krupp," 
 etc., Essen, 1881, shows the agreement between the observed 
 and calculated velocities for projectiles having ogives of 2 
 calibers. The sixth column gives the distances, in metres, 
 between the points at which the velocities were measured 
 {X^ and X^). The seventh and eighth columns give the 
 observed velocities at the distances from the gun X, and X^ 
 respectively. The ninth column gives the velocities at the 
 distances X^ from the gun computed by Krupp's table and 
 formula. The tenth column gives the velocities at the dis- 
 tances X^ computed by equation (30), using Table I. of this 
 work. The coefficient of reduction (c) was taken at 0.907, 
 which is its mean value for velocities between 2300 f. s. and 
 1200 f. s., as determined by a comparison of Bashforth's and 
 Krupp's tables of resistances given in Chapters I. and II. 
 The only discrepancies of any account between the calcu- 
 lated velocities in this column and the observed velocities 
 occur when the curvature of the trajectory is considerable, 
 
EXTERIOR BALLISTICS. 
 
 6i 
 
 
 
 JU 
 
 
 -H.S 
 
 
 c« 
 
 rt 
 
 
 . 
 
 i 
 
 
 
 
 
 
 •§^ 
 
 tn 
 
 >, 
 
 >, 
 
 & 
 
 V 
 
 u 
 >» / 
 
 13 
 
 C 
 
 s 
 
 6 
 
 s 
 s 
 
 B 
 
 1 
 
 
 
 
 
 ^ c< 
 
 53 
 
 
 Is 
 
 r 
 
 ■0 c 
 
 2 
 
 } 
 
 1 '^ 
 
 a 
 
 
 S 
 
 
 I 
 
 240 
 
 2.8 
 
 125 
 
 1-245 
 
 1450 
 
 467 
 
 380 
 
 379.9 
 
 380.7 
 
 380.6 
 
 2 
 
 240 
 
 2.8 
 
 161 
 
 1.245 1450 1 
 
 454.5 
 
 390 
 
 388.3 
 
 •387.7 
 
 387.5 
 
 3 
 
 172.6 
 
 2.8 
 
 61.5 
 
 1.226 
 
 1389 
 
 477 
 
 388 
 
 388.7 
 
 389.3 
 
 388.7 
 
 4 
 
 172.6 
 
 2 8 
 
 61.5 
 
 1.226 
 
 1429 
 
 514.7 
 
 416.6 
 
 417.^ 
 
 417.6 
 
 415.7 
 
 5 
 
 149. 1 
 
 2.8 
 
 39-3 
 
 1.260 1429 1 
 
 518 
 
 401.6 
 
 402.1 
 
 403.0 
 
 401.2 
 
 6 
 
 149. 1 
 
 2.5 
 
 33.5 
 
 1.240 
 
 1429 
 
 507.7 
 
 380 
 
 380.7 
 
 379.9 
 
 379.1 
 
 7 
 
 149. 1 
 
 2.8 
 
 31-3 
 
 1.265 
 
 924 
 
 475.8 
 
 387.8 
 
 388.2 
 
 387.7 
 
 387.3 
 
 8 
 
 355 
 
 2.8 
 
 525 
 
 1.200 
 
 1884 
 
 495-9 
 
 432.7 
 
 433-1 
 
 433.8 
 
 432.6 
 
 9 
 
 355 
 
 2.8 
 
 525 
 
 1.200 
 
 2384 
 
 490 
 
 415 
 
 411. 8 
 
 414.4 
 
 412.3 
 
 lO 
 
 355 
 
 2.8 
 
 525 
 
 1.200 
 
 2389 
 
 488.5 
 
 409.6 
 
 410.4 
 
 412.3 
 
 410.9 
 
 II 
 
 149. 1 
 
 2.8 
 
 31.3 
 
 1.265 
 
 1950 
 
 609- 
 
 394 
 
 393-9 
 
 395.4 
 
 392.7 
 
 12 
 
 149. 1 
 
 4 
 
 51 
 
 1.206 
 
 1929 
 
 505-2 
 
 394.6 
 
 393.3 
 
 393.4 
 
 392.3 
 
 13 
 
 152.4 
 
 4 
 
 51.5 
 
 1.205 
 
 1450 
 
 472.4 
 
 391.3 
 
 389-3 
 
 389.1 
 
 388.6 
 
 14 
 
 152.4 
 
 2.8 
 
 32.5 
 
 1.205 
 
 1450 
 
 577 
 
 422 
 
 422.0 
 
 424.2 
 
 421.5 
 
 15 
 
 149-1 
 
 2.8 
 
 31.3 
 
 1.230 
 
 1450 
 
 632.4 
 
 460.9 
 
 460.3 
 
 462.8 
 
 459.8 
 
 i6 
 
 240 
 
 3.8 
 
 215 
 
 1.208 
 
 1904 
 
 480.4 
 
 412.8 
 
 412.0 
 
 412.4 
 
 411. 1 
 
 17 
 
 400 
 
 2.8 
 
 777 
 
 1. 180 
 
 2384 
 
 499.4 
 
 433.7 
 
 432.1 
 
 433 -o 
 
 431.7 
 
 i8 
 
 400 
 
 2.8 
 
 643 
 
 1. 190 
 
 2384 
 
 533.4 
 
 443-8 
 
 447.0 
 
 448.2 
 
 446.6 
 
 19 
 
 400 
 
 2.8 
 
 643 
 
 I.I90 
 
 2384 
 
 531.5 
 
 444-5 
 
 445-4 
 
 446.6 
 
 445.0 
 
 20 
 
 84 
 
 2.8 
 
 6.55 
 
 1. 197 
 
 2447 
 
 446.9 
 
 266 
 
 267.2 
 
 259-7 
 
 267.4 
 
 21 
 
 120 
 
 2.8 
 
 16.4 
 
 1. 211 
 
 2447 
 
 463.3 
 
 284.1 
 
 289.2 
 
 281.6 
 
 289.3 
 
 22 
 
 149. 1 
 
 2.8 
 
 31-3 
 
 1.285 
 
 3448 
 
 536.6 
 
 294.8 
 
 290.6 
 
 283.7 
 
 290.5 
 
 23 
 
 105 
 
 3.5 
 
 16 
 
 1.300 
 
 3436 
 
 481.5 
 
 282 
 
 278-4 
 
 271.2 
 
 279.6 
 
 24 
 
 96 
 
 3.5 
 
 12 
 
 1.340 
 
 3439 
 
 425.8 
 
 256.2 
 
 .250.5 
 
 244.1 
 
 254.4 
 
 25 
 
 107 
 
 2.7 
 
 12.5 
 
 I. 218 
 
 777.5 
 
 205.1 
 
 188.2 
 
 189.8 
 
 187.7 
 
 189.8 
 
 20 
 
 152.4 
 
 2.8 
 
 31.5 
 
 1.206 
 
 966.5 
 
 203 
 
 188 
 
 187.4 
 
 185.9 
 
 188.0 
 
 27 
 
 105 
 
 3.5 
 
 16 
 
 1.222 
 
 950 
 
 514.2 
 
 426.9 
 
 421. 1 
 
 422.2 
 
 420.4 
 
 28 
 
 149. 1 
 
 2.8 
 
 39 
 
 I. 218 
 
 1429 
 
 470 
 
 369-5 
 
 370.4 
 
 369.1 
 
 369.3 
 
 29 
 
 283 
 
 2.5 
 
 234-7 
 
 1.206 
 
 4450 
 
 464.7 
 
 321.2 
 
 31S.9 
 
 311-3 
 
 317.6 
 
 30 
 
 283 
 
 2.5 
 
 234-7 
 
 1.205 
 
 |i879 
 
 465-3 
 
 403.9 
 
 403.3 
 
 404.6 
 
 403.7 
 
 31 
 
 283 
 
 2.5 
 
 234.7 
 
 1.200 
 
 11919 
 
 465.9 
 
 385.4 
 
 384.7 
 
 384-0 
 
 383.8 
 
 32 
 
 283 
 
 2.5 
 
 234.7 
 
 1.200 
 
 12425.5 
 
 466.5 
 
 370.6 
 
 368.0 
 
 366.6 
 
 367.0 
 
 33 
 
 283 
 
 2.5 
 
 234-7 
 
 1.220 
 
 2921.5 
 
 464.8 
 
 347-8 
 
 350.9 
 
 347-7 
 
 349.7 
 
 34 
 
 283 
 
 2.5 
 
 234-7 
 
 1.227 
 
 3426.0 
 
 463-7 
 
 336.0 
 
 337.6 
 
 331-4 
 
 336.6 
 
 35 
 
 283 
 
 2.5 
 
 234.7 
 
 1.220 
 
 I4446.5 
 
 460.0 
 
 316.6 
 
 316.6 
 
 308.6 
 
 315.0 
 
 36 
 
 283 
 
 2.5 
 
 234.7 
 
 1. 192 
 
 ,5945.0 
 
 1 
 
 455.8 
 
 295.0 
 
 293.9 
 
 285.6 
 
 293-0 
 
 37 
 
 283 
 
 2.5 
 
 234.7 
 
 1.206 
 
 5945.0 
 
 453.1 
 
 294.7 
 
 291.5 
 
 283.2 
 
 291.4 
 
62 EXTERIOR BALLISTICS. 
 
 as in'the last four rounds, and one or two others. Equation 
 (30) is based upon the supposition that the path of the pro- 
 jectile is a horizontal right line, and, of course, gives only 
 approximate results when this path has any appreciable 
 curvature. It will be shown subsequently that, to obtain 
 the real velocity, the " v " computed by (30) should be mul- 
 tiplied by the ratio of the cosines of the angles of projec- 
 tion and fall. In No. 37, for example, it will be found that 
 to attain a range of 5945 metres (3! miles) the angle of pro- 
 jection would have to be 12° 37', and the angle of fall would 
 be 17° 40'. Making the necessary correction, we should 
 find the velocity to be 290.7 m. 
 
 The last column gives the remaining velocities computed 
 by Mayevski's formulas. They follow very closely those 
 computed by Krupp. 
 
 In the absence of tables we ma}^ determine remaining 
 
 velocities which exceed 1300 f. s. as follows: We have 
 
 found, when n = 2, 
 
 C , V 
 •^ = -X log — 
 
 V ^ , As ^ UAs^ , ^ 
 
 V 
 
 . As . i/AsV . 
 
 As 
 As -yr is usually a small quantity, all its powers higher 
 
 than the first may be neglected, and we may put 
 
 V 6 
 
 V As 
 
 V 
 
 1+4 
 
 For oblong projectiles having ogival heads of i J- calibers 
 A ^0.000142. If the ogive is of 2 calibers, A =0.0001316. 
 This method gives correct results for distances of a mile, or 
 even more, especially for the heavy projectiles used with 
 modern seacoast guns. If the data are given in French units 
 — that is zv, d, and d^ in kilogrammes, din centimetres, and s 
 and V in metres — the value of A will be 0.000030357. 
 
EXTERIOR BALLISTICS. 63 
 
 Example. Let dz=.io.^ cm., 2e/ = 455 kg., <5 = 1.274 kg., 
 <5^ = 1.206 kg., F= 520.8 m., and .^=1900 m. [Krupp's 
 Bulletin, No. 31.] 
 
 We have 
 
 ^ 455 X 1.206 , 
 
 C = , \^ =■ 0.46301 
 
 (30.5r X 1.274 
 
 and 
 
 520.8 520.8 . 
 
 0.000030357 X 1900 1. 12457 
 ^ ~^ 0.46301 
 
 The measured velocity in this example was 465.5 m., 
 while the velocity computed by Krupp was 460.1 m. 
 
CHAPTER V. 
 
 RELATION BETWEEN VELOCITY AND INCLINATION. 
 
 Expressions for the Velocity. — Equation (15), which, 
 
 since {i) = --— -|- (^), may be written 
 
 (f)»-(#)» = ^-{jr--^4 (31) 
 
 gives the relation between the horizontal velocities ^and 11 
 and the corresponding inclinations ^ and d^\ and of these 
 four quantities any three being given, the fourth can be ac- 
 curately computed, provided, of course, that the value of k 
 has been accurately determined by experiment. The func- 
 tions (^)„ and (?^)„ are the integrals of ;^^-^-, and the fol- 
 
 COS t/" 
 
 lowing are the forms they take for the values of n here 
 adopted : 
 
 ('>), = i { tan » sec » + log tan (^ + y) } 
 
 {»), = tan » + i tan' » 
 
 + A|og.„g+|) 
 
 It is evident that all these expressions become o when 
 /> — o, negative when f'^ is negative, and infinite when 
 
 ?^ =: ' ; or, in symbols, (o) = o,(— ^) = — (/5^), and r' j = x 
 
 If there were buto^ie " law of resistance" — in other words, 
 \^ n had but one value for all velocities — it would be easy to 
 calculate the velocity for any given value of /> by means of 
 
EXTERIOR BALLISTICS. 
 
 65 
 
 (31). It would only be necessary to tabulate the values of (/>)„ 
 for all practical values of d- as the argument, and to pro- 
 vide a similar table of (-j with ?/ as the argument. But, as 
 
 we have seen, ;i may change its value two or three times in 
 the same trajectory ; and though it would be possible to 
 ascertain by trial the exact point of the trajectory where 
 this change occurred, yet the labor involved would be very 
 great. 
 
 Basliforth's Method. — Professor Bash forth overcomes 
 this difficulty by giving to 71 the constant value 3, and 
 making /r' to vary in such a manner as to satisfy (31) for all 
 velocities. His method of procedure is as follows: making 
 « = 3 and /> = o, (31) becomes 
 
 C/' 
 
 i^tan ^ + i tan>^ 
 
 in which 6^ and (f are the horizontal velocity and inclination, 
 respectively, at the beginning of an}^ arc of the trajectory 
 we may be considering; and v^ the velocity at the summit. 
 In Bash forth 's notation 
 
 3^ ^' 
 
 ^(loooy w' 
 
 substituting this in the above equation and multiplying by 
 (1000)^ to avoid the inconvenience of very small numbers, 
 we have 
 
 /iooo\^ /iooo\' K d' i ^ , . 3 ) 
 
 by means of which either z^^, [/, or (p can be determined 
 when the other two are known. When the resistance can 
 be taken proportional to the cube of the velocity, K is con- 
 stant; but for all other velocities it is a variable, and we 
 must take a certain mean of its values for the arc under con- 
 sideration. Prof. Bashforth takes the arithmetical mean, 
 which will generally give very accurate results for arcs of 
 
66 EXTERIOR BALLISTICS. 
 
 lo or 15 degrees in extent. In his work he gives the ne- 
 
 cessar}^ tables for suitably determining — for all velocities 
 
 from 100 f. s. to 2900 f. s., and also tables giving values of 
 3 tan ip -\- tan^ ip for all practical values of ^ . 
 
 Other approximate methods involving less labor will be 
 given further on. 
 
 High Aiig:le and Curved Fire. — When the initial 
 velocity does not exceed 800 f s., which includes nearly all 
 mortar and howitzer practice, the law of resistance for 
 oblong projectiles is that of the square of the velocity; 
 whence, making n ^ 2, and dropping the subscript, (31) be- 
 comes 
 
 or, writing / (u) for 
 
 (^)-(^)=^{/W-/(C/)) (32) 
 
 The value of /(?/) for any given value of ti can be taken 
 directly from Tables T. and II., the method of construction 
 of which will be given further on. Table III. gives (^) and 
 extends from ^ = o to (^ = 60°. 
 
 To use (32) for computing low velocities (and also for 
 high velocities, exceeding 1330 f. s.), we have 
 
 /«=f I (?)-('?)} + /(f^) (33) 
 
 2 
 in which u and B are the only variables; -^, (^), and I{U)j 
 
 having been determined, do not change their values for the 
 same trajectory. 
 
 To illustrate the ease with which velocities may be cal- 
 culated by (33), take the following data from Bashforth's 
 "Treatise," page 115: 
 

 EXTERIOR BALLISTICS. 
 
 67 
 
 V^ 751 f. s. ; ^ == 30°; w = 70 lbs., and (i' = 6.27 inches. 
 Here C/== 751 cos 30° ^ 650.385 f. s. ; and from Table 
 
 I., /(r7) = a93354; -g. = -^ = 1. 12323. 
 We will, following Bashforth, compute the velocities for 
 
 ^ = 28°, 24°, 20^ 
 
 40°. The work may be conve- 
 
 niently arranged as follows: 
 
 {f) z= 0.60799 I{U) = 0.93354. 
 
 e 
 
 (») 
 
 (<<,) - (0) 
 
 ~({6) - (0)) 
 
 /(«) 
 
 (Table I.) 
 u 
 
 « sec 6 = V 
 
 Bash- 
 forth's 
 
 Differ- 
 ence. 
 
 30° 
 
 0.60799 
 
 . 00000 
 
 0.00000 
 
 0.93354 
 
 650.38 
 
 751-0 
 
 75I.O 
 
 0.0 
 
 28" 
 
 .55580 
 
 .05219 
 
 .05862 
 
 0.99216 
 
 636.09 
 
 720.4 
 
 720.4 
 
 0.0 
 
 24° 
 
 .45953 
 
 .14846 
 
 .16675 
 
 I . 10029 
 
 612.03 
 
 669.5 
 
 670.2 
 
 - -7 
 
 20° 
 
 .37185 
 
 .23614 
 
 .26524 
 
 I. 19878 
 
 592.33 
 
 630.3 
 
 630.5 
 
 .2 
 
 16° 
 
 .29063 
 
 .31736 
 
 .35647 
 
 I . 29001 
 
 575.69 
 
 598.9 
 
 598.9 
 
 0.0 
 
 12° 
 
 .21415 
 
 .39384 
 
 •44237 
 
 1.37591 
 
 561.23 
 
 573.8 
 
 573.5 
 
 + .3 
 
 8° 
 
 . 14100 
 
 .46699 
 
 .52454 
 
 1.45808 
 
 548.38 
 
 553.8 
 
 553.1 
 
 •7 
 
 4° 
 
 . 06998 
 
 .53801 
 
 .60431 
 
 i^537S5 
 
 536.71 
 
 538.0 
 
 537.0 
 
 i.o 
 
 o"^ 
 
 .00000 
 
 .60799 
 
 .68291 
 
 I. 61645 
 
 525-91 
 
 525.9 
 
 524.6 
 
 1.3 
 
 -4" 
 
 — .06998 
 
 .67797 
 
 .76151 
 
 1.69505 
 
 515.74 
 
 517.0 
 
 515.5 
 
 1.5 
 
 8° 
 
 .14100 
 
 • 74899 
 
 .84129 
 
 1.77483 
 
 505.99 
 
 511.0 
 
 509.3 
 
 1.7 
 
 12° 
 
 .21415 
 
 .82214 
 
 •92345 
 
 1.85699 
 
 496.52 
 
 507.6 
 
 505.7 
 
 1.9 
 
 16° 
 
 . 29063 
 
 .89862 
 
 1.00935 
 
 1.94289 
 
 487.15 
 
 506.8 
 
 504.7 
 
 2.1 
 
 20° 
 
 .37185 
 
 .97984 
 
 . I. 10056 
 
 2.03410 
 
 477.77 
 
 508.4 
 
 506.2 
 
 2.2 
 
 24" 
 
 •45953 
 
 1.06752 
 
 I . 19906 
 
 2. 13260 
 
 468.22 
 
 *5i2.5 
 
 510.2 
 
 2.3 
 
 28° 
 
 •55580 
 
 I. 16379 
 
 1.30720 
 
 2 . 24074 
 
 458.38 
 
 5i9^i 
 
 516.8 
 
 2.3 
 
 32° 
 
 .66343 
 
 I. 27142 
 
 1.42809 
 
 2.36163 
 
 448.06 
 
 528.3 
 
 525.9 
 
 2.4 
 
 36° 
 
 .78617 
 
 I. 39416 
 
 1.56596 
 
 2.49950 
 
 437.11 
 
 540.3 
 
 537.9 
 
 2.4 
 
 40° 
 
 .92914 
 
 1.53713 
 
 1.72654 
 
 2.66008 
 
 425.32 
 
 555.2 
 
 552.8 
 
 2.4 
 
 The numbers in the second column are taken directly 
 from Table III. for the values of f^ given in column i. Sub- 
 tracting the numbers in column 2 from {(p) (=0.60799) gives 
 
 2 
 those in column 3; and these multiplied by -^ {= 1. 12323) 
 
 are written in column 4. Adding I (U) (=0.93354) to 
 these last gives the values of / (ti) in column 5. 
 
 The values of u are then taken from Table I., and these 
 multiplied by sec '^ give the velocities sought. For com- 
 parison the velocities computed by Bashforth, by his method 
 already explained, are also given ; and it will be seen that 
 
68 EXTERIOR BALLISTICS. 
 
 the differences between his velocities and those computed 
 by (33) are practically nil. 
 
 This method of determining velocities may be used 
 without material error when the initial velocity is as great 
 as 1000 f. s. 
 
 Example. — The 8-inch howitzer is fired with a quadrant 
 elevation of 23°; muzzle velocity, 920 f. s. ; weight of shell, 
 180 lbs.; diameter, 8 inches. What will be the velocity in 
 the descending branch when /> = — 27° 54' ? (See Mac- 
 kinlay's '' Text-Book," page 109.) 
 
 Here 
 
 F=920, Z7= 920 cos 23°= 846.86 
 
 /(/7) =0.40884; log ^ = 9.85 194 
 
 The computation is as follows: 
 
 (23°) = 0.43690 
 (-27° 540=— 0.55327 
 
 log 0.99017 = 9.99571 
 
 C 
 log - = 9.85194 
 
 log 0.70412 = 9.84765 
 I{U)= 0.40884 
 
 I {11) := I.I 1296 . • . ^27. 5^. = 609.4 f. S. 
 
 Mackinlay gets by Niven's method, dividing the tra- 
 jectory into two parts, 6^270 54' = 610.6 f. s. It will be seen 
 that by the method developed above for calculating veloci- 
 ties, the length of the arc taken makes no difference in the 
 accuracy of the results. 
 
 Siacci's Method. — Equation (13) may be written 
 
 /^ dd- _gC r ^ sec' & d u 
 
 Since ^ is a function of u, there must be some constant 
 mean value of sec d- which will satisfy the above definite 
 
EXTERIOR BALLISTICS. 69 
 
 integral. Representing this mean value of sec d- by a, and 
 writing U' and u' for af/and au respectively, we have 
 
 n d& _agC_ f^ _duf__ 
 
 Making 
 
 ^(«') = ^7^ + e 
 
 (34) becomes 
 
 tan ^ - tan ,!' = ^{ /(«')- 7(^7)} (35) 
 
 The values of I {ii') are given in Table 1. for oblong pro- 
 jectiles, and in Table II. for spherical projectiles. The 
 method of computing the /-function is entirely similar to 
 that already described for the 5 and /-functions, and need 
 not be repeated. For oblong projectiles the formulae areas 
 follows, in which, for uniformity, / (z^) is employed as the 
 general functional symbol: 
 
 2800 f. s. > 7^ > 1330 f. s. : 
 
 / W = [5.3547876] ^ — 0.028872 
 
 1 330 f. s. > 7/ > II 20 f. s. : 
 /(t/) =[8.2947896] ^ + 0.015293 
 
 1120 f. s. > T^ > 990 f. s.: 
 7(7') = [17.1436868] -^ +0.085087 
 
 990 f. s. > z/ > 790 f. s. : 
 7(2;) = [8.4557375] -L — 0.061373 
 
 790 f. s. > z^ > o : 
 I{v)^ [5.7369333] -^ — 0.356474 
 
70 
 
 EXTERIOR BALLISTICS. 
 
 If we compare (34) with (31) it will be seen that 
 
 „_ i (f).-w« I ^ 
 
 ( tan (p — tan § ) 
 and this value of a renders (34) and (35) exact equations; in 
 fact, reduces them to (31). It would seem at first as if 
 nothing had been gained by introducing a into (35), since 
 its value depends upon that of ^2, and must, therefore, change 
 when n changes. The following table gives the values of a 
 for the arcs contained in the first column, when ;/ = 2, w = 3, 
 and n=z6, computed by the above formula : 
 
 Arc 
 Mo* 
 
 30° to 20° 
 
 30^ 
 
 10^ 
 
 ic- 
 
 30° '' —20^ 
 
 30^ 
 
 30^ 
 
 I . 1066 
 
 1-0741 
 I. 0531 
 I. 0419 
 
 I .0409 
 
 I. 0531 
 
 I . 1069 
 
 1.0749 
 I. 0541 
 
 I .0429 
 I .0418 
 
 I. 0541 
 
 1079 
 
 0772 
 
 0573 
 
 0460 
 
 0443 
 0573 
 
 It is evident from this table that when the angle of pro- 
 jection is as great as 30°, the velocity at any point of the tra- 
 jectory may be computed with sufficient accuracy by using 
 either set of values «; since the greatest difference between 
 those in the second and fourth columns on the same line is 
 but 0.0042, and this would make but a slight difference in 
 the values of U' or u'. MoreoVer,"since U' — a Fcos ^, and 
 u' =^ av cos ^?, it is apparent that U' and u' differ less from V 
 and V respectively than do U and u; and this is important 
 when, as is usually the case, the law of resistance is different 
 for the initial and terminal velocities. 
 
 If in the above expression for a we make n = 2, we have 
 Didion's expression for «, viz. : 
 
 ^^ (y)-W 
 
 tan (p — tan ^ 
 
EXTERIOR BALLISTICS. 7 1 
 
 in which 
 
 (i?) — i I tan ^ sec & + log tan ^- + — ) I 
 
 Example. — 'A 12-inch service projectile, weighing 800 lbs., 
 is fired at an angle of projection of 30° and a muzzle velocity 
 of 1886 f. s. Required its velocity when (a) the inclination 
 of the trajectory is 15°, and (b) when the inclination is — 15°. 
 
 Here^=i: 12, w — 800, V = 1886, and ip = 30°. From (35) 
 we get 
 
 / {u') =: /(^') -f -^ I tan ^ - tan ?? i 
 (a) ^ = 15°. From our data we have 
 
 „^ (30°)-(.5°) ^^gd3g821^,.o888 
 tan 30° — tan 15° 0.30940 
 
 U' = a Fcos30° = 1778.34 .'./{[/') = 0.04270 
 
 ^ _ w 800 
 
 d^ 144 
 and 
 
 tan 30° — tan 15° =0.30940 
 
 Tt>\ X 288 X 0.30940 
 
 .-./(.)= 0.04270 + 3^ ^ ^3^3^ - 0.14500 
 
 .-. «'= 1149.77. 
 
 1149.77 . 
 
 . • . z/,.o == — ^^-^ = 1093.3 I- s. 
 " a cos 15° ^^ ^ 
 
 (b) x^= — 15°. We have 
 
 ^^ (30°) + (15°) ^ 0.87911 ^ J ^.^ 
 tan 30° + tan 15° 0.84530 "^ 
 
 C/' — « Fcos 30°= 1698.65 .-. 7(^0 = 0.04958 
 tan 30° + tan 1 5" == 0.84530 
 .-. I {u') =0.04958 + 0.29260 = 0.34218 
 .-. ?/' = 891.14 
 .-. z;,,,. =887.1 f. s. 
 
 The values of v^^^ and z/_,^, computed by (31) are 1097.6 
 and 892.9 respectively. 
 
72 EXTERIOR BALLISTICS. 
 
 Siacci's Modification of (35) for Direct Fire.— 
 
 Since in direct fire the angle of projection does not exceed 
 15°, and is generally much less, the values o^ a for this kind 
 of fire will not differ much from unity. For example, with 
 10° elevation, and an angle of fall of — 12°, we shall have 
 for a 
 
 ,,_ (10°) + (12°) _ Q.39i39 _^^^., 
 ■" tan 10° + tan 12° ~ 0.38889 "~ "^ 
 
 It is manifest, therefore, that for sucli small angles no 
 material error would result in making «= i ; the following, 
 however, is a closer approximation. If we consider that 
 part of the trajectory lying above the horizontal plane 
 passing through the muzzle of the gun, it will be seen that * 
 a should be greater than unity and less than sec co. Siacci 
 makes 
 
 W-2 
 
 a = (sec^)«-i 
 
 therefore, when « = 2, a =1 ; when « = 3, a = V sec ^, and 
 
 when n =^ 6^ a =z sec f ; and the average value of a for the 
 whole trajectory generally fulfils the above condition. 
 
 This value of a substituted in (34) gives, by an easy 
 reduction, 
 
 •tan c^ - tan ^ =: /^ , \ . L-— - -L \ 
 
 - — ^ n A cos (p { {u sec cpf F" ) 
 
 or, writing u' for u sec ^, and proceeding as already ex- 
 plained, 
 
 ' Example. — Take the follow^ing data: 
 
 800 
 ^= 12 ; 7£/ = 800; 6'= ; F= 1886 ; ^ =1 10°. Compute 
 
 144 
 the remaining velocity in the descending branch when 
 t?=^ 13°. We have 
 
 / {u') = -^ cos" (f (tan ^ - tan ^) + / (F) 
 
EXTERIOR BALLISTICS. 
 
 and the computation will be as follows: 
 
 log (tan 10° + tan 13°) = 9.60980 
 
 log- -^ = 9.55630 
 
 2 log- cos 10° = 9.98670 
 
 log 0.142 1 7 = 9.15280 
 7(1886)1=0.03477 
 
 / (//') z= 0. 1 7694 // = 1 07 1 . 76 
 
 IO7T.76 COS lo"^ 
 
 n 
 
 COS 13° 
 
 = 1083.2 f. s. 
 
 The velocity at the same point computed by (31), divid- 
 ing- the trajectory into three arcs, with the points of division 
 corresponding- to velocities of 1330 f. s. and 1120 f. s. respec- 
 tively, is 7' =: 1081.55 f. s. This agreement is very close; 
 but if we make if = 30° and ^ == 15°, as in the preceding ex- 
 ample, we should find by tiiis method ?''i5« = 1113.1; and if 
 d- =z — 15°, we should find 7^_i^« = 859.3, which differ consid- 
 erably from their true values. 
 
 Mven's Method.— W. D. Niven, Esq., M.A., F.R.S., 
 has given the following method for determining velocities 
 in terms of the inclination : 
 
 Equation (13) may be written 
 
 J , ^ Aj , («sec.?r" "-A J „. «'"*■ 
 
 in which, as before, a is some mean value of sec d^ between 
 the limits sec <p and sec ??, and 1/ =z av cos d^ and U' ^=.a Fcos (p. 
 Integrating, we have 
 
 ' an A \ //« 'U'-S ~ a InA u'^ nA U'^S ^^^^ 
 
 iplying botl" 
 degreed, and making 
 
 Multiplying both members by - — to reduce ^ — ?^ to 
 
 i^(,-^) = Z) 
 
74 EXTERIOR BALLISTICS, 
 
 and 
 
 n TT A n"" ^ ^ 
 the above equation becomes 
 
 n = ^\D{,/)-j?{u')\* (38) 
 
 which is the equivalent of Niven's expression for the velo- 
 city and inclination. Mr. Niven has published a table of the 
 />>• function for velocities extending- from 400 f. s. to 2500 f. s. 
 (See Table VI. ii Mackinlay's "Text-Book.") It will be 
 seen by comparing the expressions for D {v) and I [v) that 
 we have the relation 
 
 and, therefore, in terms of the /-function, (38) becomes 
 
 .^ = t|'{^M-/(^0} (39) 
 
 log ^==1.4570926 
 
 Comparing (37) with (31), it is apparent that to make (37) 
 or (38) exact equations we must have 
 
 -\^^r 
 
 For direct fire Didion's value of a may be used ; but for 
 high-angle firing- the following gives more accurate results, 
 obtained from the above equation by making a/ = 2 : 
 
 a = 
 
 i'^f[ 
 
 Example. — Take the following data: 
 df=l2; w=r8oo; F=: 1886; ^ — 30° and <> = — 30° ; 
 
 /? = 30° + 30° = 60° ; to find v,^.. 
 
 % 
 
 * If we use Niven's tables, in which the functions decrease with the velocity. (38) should be 
 written 
 
 i>«£j/?(i/0-^(«')[ 
 
EXTERIOR BALLISTICS. 
 
 75 
 
 We have from (38) 
 
 D{u') = D{U') + ^D 
 
 The computation may be conveniently arranged as fol- 
 lows : 
 
 log (ip) = 978390 
 
 constant = 1.758 12 
 
 c log 30 = 8.52288 
 
 log 
 
 3) 0.06490 
 
 log a = 0.02163 
 
 log D^ 177815 
 
 r log (7= 9.25527 
 
 11.3516= 1.05505 
 
 log F= 3.27554 
 
 log a = 0.02163 
 
 log cos ip = 9.93753 
 
 log U' = 3.23470 
 6^'= 1716.74 
 
 (Niven's Table) D {U') = 84.6090 
 
 C 
 
 D{u') 
 
 Dzzz II. 3516 
 
 73-2574 
 
 .*.«' = 827.12 =:« Z/ cos ?? 
 
 . • . v.j^^. = 908.7 f. S. 
 
 Siacci's method, using Table I. of this work, gives 
 
 ^_3oo = 907.5 f. s. ; while equation (31) gives v_^^ = 913.2 f. s. 
 
 Modificatioii of (38) for Direct Fire. — If we make 
 
 a = (sec (fY^ 
 
 we shall have, by a process similar to that already employed 
 in Siacci's method, the following modified form of (38), 
 which can be used in all problems of direct fire, viz.: 
 
 C 
 
 j9 = 
 
 cos (f 
 
 in which u' ^=^u sec ip. 
 Example, — Let <a^ = 1 2 ; 
 
 \^D iu') - D {y)\^ 
 
 w 
 
 800; V: 
 
 (40) 
 
 \ 
 
 886; ^ = 10°; 
 
 = — 13®. The computation is as follows : 
 
y6 EXTERIOR BALLISTICS. 
 
 log Z^= 1. 36173 
 
 log cos (f =z 9.99335 
 
 c\oo; C= 9-25527 
 log 4.0771 = 0.6T035 
 i; (1886) = 84.9966 ^^^^ 
 
 D («0 = 80.9195 .-.//= 1068. 14 = z'-^;^^ 
 .' . V = 1079.6 f. s. 
 
 which is within 2 feet of the value of z/ computed by the exact 
 formula (31). This modified form of Niven's method, for sim- 
 plicity and accuracy, seems to leave nothing to be desired. 
 
 For small angles of projection, say not exceeding 5°, we 
 may put ?/ = v, and cos'^ = i ; and (40) becomes 
 
 % Example, — In the preceding example suppose ^ = 3°. 
 What will be the value of d- when the velocity is reduced 
 to 1500 f. s.? 
 
 (a) By Niven's Table : 
 
 Z> (1886) = 84.9966 
 Z> (1500)== 83^9359, 
 
 log 1.0607 =: 0.02560 
 
 log 6^ = 0.74473 
 
 log D = 0.77033 
 
 />=5°.89 = 3°-'> 
 .-. ??= - 2°.89 
 
 (b) By Table 1. : 
 
 7(1500)= 0.07173 
 /(i886) = 0.03477 
 
 log 0.03696 = 8.56773 
 
 log?= 145709 
 log (7 = 0.74473 
 
 log 7^ = 0.76955 
 D = 5°.88 
 .-. ^= -2°.88 
 
CHAPTER VI. 
 
 TRAJECTORIES— HIGH-ANGLE FIRE. 
 
 As we have seen, the differential equations for x,y^ t, and 
 s do not generally admit of integration in finite terms for 
 any law of resistance pertaining to our atmosphere ; that 
 is, for any recognized value of ?i. It is true that Professor 
 Greenhill has recently* succeeded, by a profound analysis, 
 in deducing exact finite expressions for x and y by means of 
 elliptic functions, when ?^ = 3 ; but these results, though of 
 great interest to the mathematician, are far too complicated 
 for the practical use of the artillerist. When /^ = 2 the ex- 
 pression for ds can be integrated and useful results deduced 
 therefrom, as will be seen further on. 
 
 For low velocities, such as are generally employed in 
 high-angle and curved fire, the effect of the resistance of 
 the air upon heavy projectiles is comparatively slight; and 
 for a first (though rough) approximation we may, in such 
 cases, omit the resistance altogether, or, better still, we may 
 suppose the projectile subject to a mean constarit resistance. 
 A still closer approximation may be obtained by taking a 
 resistance proportional to the first power of the velocity. 
 As the differential equations for the co-ordinates and time 
 are susceptible of exact integration upon each one of these 
 hypotheses, we will consider them in turn. 
 
 TRAJECTORY IN VACUO. 
 Making p = o, (9) becomes 
 
 duzuzo 
 and therefore, in vacuo, the horizontal velocity is constant, or 
 
 /^= U 
 Integrating (21), (22), (23), and (24) between the limits 
 (p and d- gives, \i ti ^ U, 
 
 * " Proceedings of the Roj^al Artillery Institution," Vol. XI. 
 10 
 
78 EXTERIOR BALLISTICS. 
 
 and 
 
 / = —(tan f — tan d) (4O 
 
 ;ir = — (tan ip — tan d) (42) 
 
 772 
 
 7 = — '(tan' ip ~ tan' />) (43) 
 
 
 ((^) - ('>)) (44) 
 
 Equation of Trajectory in Vacuo. — Eliminating 
 tan d- from (42) and (43) gives 
 
 y ^=L X tan (p 
 
 2W 
 
 which is the equation of a parabola whose axis is vertical 
 A parabola, therefore, is the curve a projectile would de- 
 scribe in vacuo. 
 
 Since a parabola is symmetrical with respect to its axis, 
 the ascending branch is similar in every respect to the de- 
 scending branch, the angle of fall being equal to the angle 
 of projection ; and generally, for the same value of j, tan d^ 
 has numerically the same value, but with contrary signs, in 
 both branches; being positive in the ascending branch, 
 negative in the descending branch, and zero at the vertex. 
 
 If we make ?^ = — ^ in (42) it becomes 
 
 ^- 2 C/' V sin 2ip 
 
 X = tan <p = i 
 
 g g 
 
 and this, for a given velocity, is evidently a maximum when 
 
 f = 45°. 
 
 Subtracting (42) from the above equation, and reducing, 
 gives 
 
 X — X— — (tan <p + tan ^) 
 
 2 tan ^ ^ ^ ' ^ 
 
 also, dividing (43) by (42) gives 
 
 f = ^(tan^ + tane?) 
 
 whence 
 
 :^ = ^(-^-^)tan^ (45) 
 
EXTERIOR BALLISTICS. 79 
 
 Making ?? = — ^ in (41), we have 
 
 ^ 2U ^ 2V . 
 
 Y rzz tan w = — sin <p 
 
 g g 
 
 Subtracting (41) from this last equation gives 
 
 T — t=— (tan (p + tan d) 
 also, (43) divided by (41) gives 
 
 -7 = 7 (tan ^ + tan??) 
 
 ^{T-t) f46) 
 
 whence 
 
 2 
 Dividing (44) by (42) gives 
 
 s^ (y)-(^) ^^ 
 
 X tan (f — tan d^ 
 
 Didion's «, then, is the ratio of a parabolic arc whose 
 extremities have the same inclination as the arc of the tra- 
 jectory under consideration, to its horizontal projection. 
 
 Expression for the Velocity. — From (43) we have, 
 since V cos (p zz^v cos d- = U, 
 
 v" sin'' d-z^zV sm^ (p — 2gy. 
 
 Adding v" cos'' d^ to the first member, and its equal, 
 V cos"* (f, to the second member, and reducing, we have 
 
 v'' = V - 2gy 
 
 If h is the vertical height through which the projectile 
 must fall to acquire the velocity of projection (F), we shall 
 have Tza 7 
 
 V^ zzz2 gk 
 
 and this substituted in the above formula gives 
 
 v'' = 2g{h-y) 
 that is, the velocity of the projectile at any point of the 
 trajectory is that which it would acquire by falling through 
 a vertical distance equal to ^ — j^. 
 
 All the properties of the trajectory in vacuo may be 
 easily and elegantly determined by means of the funda- 
 mental equations (41) to (44) inclusive. 
 
80 EXTERIOR BALLISTICS. 
 
 CONSTANT RESISTANCE. 
 
 P _ 
 
 Suppose the resistance constant, and put ~ ^ m ; then 
 
 zv 
 
 the elimination of dt from (9) and (12) gives 
 
 du d& 
 
 in 
 
 u cos ?> 
 
 whence ^ 
 
 log u = m log tan 1 - -] I -f- ^. 
 
 Let v^ be the velocity when ?> = o, that is, at the summit 
 of the trajectory ; then C — log v^, and we have 
 
 (f+4) <«) 
 
 r= 2/„ tan 
 
 4 
 
 Substituting this value oi u in equations (21) to (24), and 
 
 integrating so that /, x, y, and s shall all be zero at the 
 
 origin, that is, when -& =npy we have, making the necessary 
 
 reductions, 
 
 TT sm w — m sin i^ — m 
 
 j^2 COS (p (sin ^ — 2m) ^ cos ?^ (sin d — 2m) 
 
 ~ g{i — 4^') "" ^ <^ (i - 4^^') 
 
 j^2 I + sin ^ (sin (p — 2m) ^9 1 + sin d- (sin ?^ — 2/;?) 
 
 ^ ~ 4^(1 -Iff) "" 4^(1 -f^) 
 
 ,j, cos^ (f -{-2m (sin ip — in) ^ ^ cos'' d- ~\-2m (sin z? — ??/) 
 
 4w^(i — ^^z'') 4^«^(i — ^^^) 
 
 When 2?;^ = i, the differential expression for x becomes 
 logarithmic, as do those for /, y, and s when in — \. The 
 integrations are easily obtained for these values of m^ but 
 are omitted on account of their length, and as being of no 
 great practical importance. In the application of these for- 
 mulae it will be necessary, since the resistance of the air is 
 not constant, but varies with the velocity, to determine a 
 proper mean value for m between the limits of integration ; 
 and this we may do as follows : After having computed the 
 horizontal velocities u^ and u^ by means of (33), corre- 
 sponding to the inclinations a and /9, the value of in may be 
 determined by the following equation deduced from the 
 above expression for 71 : 
 
EXTERIOR BALLISTICS. 8 1 
 
 ^jj^ ^ log u^ - log U^ 
 
 logta„(^ + f)-logta„(^+4) 
 
 Example. — Compute the values of t, .r, y, and s, from 
 (p = 30° to ?? = o, with the data given on pag-e 6y. We have 
 
 ,,, _ log 75 1 + log cos 30" - log 525.9 1 _^^.^_ 
 '"^ - log tan 60° - ^-^^^^^ 
 
 Substituting in the above formulae, we find 
 
 ^ = 3-I073 + 7.4295 = 10^537 
 X = 16908 — 10557 = 6351 ft. 
 y = 4446 — 2526 = 1920 ft. 
 
 ^=: III55 — 4578 = 6577 ft. 
 
 Bashforth gets, by dividing the arc into 8 parts, 
 t = io''.4i3, X = 6074 ft., and 7 = 1882 ft. 
 
 It is easy to see how by suitable tables, the construction 
 of which offers no difficulty, the time and co-ordinates ma}^ 
 by this method be readily, and for arcs of limited extent 
 accurately, computed. For example, we have 
 
 x = A V~A' v' 
 A being a function of m and ^, and A^ the same function of 
 m and d^. 
 
 RESISTANCE PROPORTIONAL TO THE FIRST POWER OF THE 
 
 VELOCITY. 
 
 Differential Equations. — When ;/ = i, the differential 
 equations (13), (17), (18), and (19) become respectively, since 
 
 tiA 
 
 CO^ ^^ 
 
 
 
 dt=- 
 
 k du 
 g u 
 
 dx = 
 
 k 
 
 du 
 
 dy = - 
 
 k 
 
 tan -& du 
 
82 EXTERIOR BALLISTICS. 
 
 Time and Co-ordinates. — The integration of the first 
 three of these equations between the limits {cp, d) and {[/, 7i) 
 gives (supposing k constant) 
 
 tan <p — tzin^ = k(~ — ^') {48) 
 
 or, using common logarithms, 
 
 f=M-\og- (49) 
 
 in which M = 2.30259; and 
 
 :^=:^{U-u) (50) 
 
 Substituting for tan ?^ in the expression for dj/ its value 
 from (48), it becomes 
 
 dy= (7-, -^ tsiu <p) du -\ 
 
 or 
 
 dj/= IjY -{- tan ^ j<^4r — /&^^ 
 
 whence, supposing y to vanish with x and if, 
 
 7 = (-^ + tan <pj x — kt (51) 
 
 Determination of h. — In the above integrations we 
 have assumed k to be constant, whereas it varies with the 
 velocity ; but our results will be correct if we give to ^ a 
 proper mean of all its values between the limits of integra- 
 tion ; and as k varies slowly and with considerable regularity 
 for all velocities for which this method will be used, we will 
 take for k the value corresponding to the arithmetical mean 
 of the two velocities at the extremities of the arc under 
 consideration. It is evident that the smaller the arc of the 
 trajectory over which we integrate, the less will be the 
 error committed in taking this value for k. But it will be 
 
EXTERIOR BALLISTICS. 
 
 83 
 
 shown by examples that no material error will result for 
 velocities less than about 1000 f. s., when the whole tra- 
 jectory is divided into two arcs with the point of division at 
 the summit. 
 
 When ;/ = I, we^have 
 
 
 w 
 
 whence from (6) and (7) 
 
 C 
 
 (loooy 
 
 C m (say) 
 
 The following table gives the values of tn for velocities 
 extending from 900 f. s. to 500 f. s., with first differences : 
 
 TABLE OF 7n. 
 
 V 
 
 m 
 
 d, 
 
 V 
 
 tn 
 
 d, 
 
 500 
 
 32.814 
 
 66^ 
 
 710 
 
 23.700 
 
 346 
 
 510 
 
 32.146 
 
 618 
 
 720 
 
 23.354 
 
 357 
 
 520 
 
 31.528 
 
 572 
 
 730 
 
 22.997 
 
 340 
 
 530 
 
 30.956 
 
 554 
 
 740 
 
 22.657 
 
 323 
 
 540 
 
 30.402 
 
 539 
 
 750 
 
 22.334 
 
 335 
 
 550 
 
 29.863 
 
 527 
 
 760 
 
 21.999 
 
 376 
 
 560 
 
 29.336 
 
 490 
 
 770 
 
 21.623 
 
 388 
 
 570 
 
 28 . 846 
 
 427 
 
 780 
 
 21.235 
 
 372 
 
 580 
 
 28.419 
 
 392 
 
 790 
 
 20.863 
 
 358 
 
 590 
 
 28.027 
 
 387 
 
 800 
 
 20.505 
 
 344 
 
 600 
 
 27.640 
 
 384 
 
 810 
 
 20.161 
 
 384 
 
 610 
 
 27.256 
 
 381 
 
 820 
 
 19.777 
 
 448 
 
 620 
 
 26.875 
 
 382 
 
 830 
 
 19.329 
 
 433 
 
 630 
 
 26.493 
 
 382 
 
 840 
 
 18.896 
 
 442 
 
 640 
 
 26. I II 
 
 356 
 
 850 
 
 18.454 
 
 426 
 
 650 
 
 25-755 
 
 388 
 
 860 
 
 18.028 
 
 412 
 
 660 
 
 25.367 
 
 365 
 
 870 
 
 17.616 
 
 398 
 
 670 
 
 25.002 
 
 343 
 
 880 
 
 17.218 
 
 385 
 
 680 
 
 24.659 
 
 321 
 
 890 
 
 16.833 
 
 372 
 
 690 
 
 24.338 
 
 300 
 
 900 
 
 16.461 
 
 359 
 
 700 
 
 24.038 
 
 338 
 
 
 
 
84 
 
 EXTERIOR BALLISTICS. 
 
 The value of k in the ascending- branch will be assumed 
 to be that due to the velocity | {y-\-v^\ and in the descend- 
 ing branch, to \ (^o + ^e)* ^e being the velocity at the point of 
 fall. The first step, then, is to compute v^ and Vq ; and this 
 can readily be done by means of (33), as already explained. 
 
 Expressions for the Ascending and Descending- 
 Branches. — It will be seen that x, y, and t are functions of 
 6^ and u; and these latter depend upon (p and ?^, as shown in 
 equation (48). 
 
 From this equation we have 
 
 ■^ + tan ^ 
 
 - +tan?^ = - 
 
 in which u^ is the value of 21 at the summit; whence 
 
 k 
 
 U 
 
 -f- tan <p 
 
 and, since d- is negative in the descending branch, 
 
 k 
 
 ^fl = 
 
 + tan d- 
 
 (52) 
 
 (53) 
 
 The following expressions for t, x, and y for the ascend- 
 ing and descending branches are easily deduced from (49), 
 (50), and (51), in connection with (52) and (53): 
 
 ASCENDING BRANCH. 
 
 '0 = ^— log — 
 
 =}{--) 
 
 DESCENDING BRANCH. 
 
 k 
 JJ^o = ■— ^0 
 
 kL 
 
 ye 
 
 (^o— ^e) 
 
 kto 
 
 In using these formulae, u^ and Uq are to be computed by 
 means of (52) and (53). 
 
 The zero subscript is to be interpreted " from the origin 
 to the summit"; and the theta subscript "from the summit 
 
EXTERIOR BALLISTICS. 85 
 
 to a point in the descending branch where the inclination 
 is^^/' 
 
 The method of computing a trajectory by these simple 
 formulas will be best exhibited by examples, which we will 
 select from those that have been worked out by other 
 methods of recognized accuracy, or which have been tested 
 by firing. 
 
 Example i. — -Calculate the trajectory with the data on 
 page 6^^ viz. : 
 
 F=75if. s. ; ^ = 30° (whence C/'= Fcos^ = 650.385); d:=. 
 
 2 2(1'' 
 
 6.27 inches; w=.jo lbs. (whence -^ = = 1.12323). 
 
 Assuming — 37° to be the angle of fall, we will divide 
 the trajectory into two arcs, the first extending from 30° to 
 0°, and the second from 0° to —37°. The velocities v,, and 
 z/_370 are computed as follows : 
 
 From Table III. we take out (30°) = 0.60799, and (37°) = 
 0.81977; and from Table I., /(^) = / (650.385) = 0.93354. 
 Then 
 
 2 
 — (30°) = 1. 1 2323 X 0.60799 = 0.68291 
 
 /(^):zz 0.93354 
 
 I{v^= 1.61645 
 (Table I.) v^ = 525.91 
 2 
 -^(37°) = 1-12323 X 0.81977 = 0.92079 
 
 I (y^ = 1.61645 
 
 /(^^_3,o) = 2.53724 
 
 z/_3,« = 434.25 sec 37° == 543.74 f. s. 
 
 The mean velocity from which to determine k in the 
 ascending branch is i (751 + 525.91) = 638 f. s. ; whence 
 m = 26.187. The remaining calculations may be conve- 
 niently arranged as follows: 
 II 
 
86 EXTERIOR BALLISTICS. 
 
 log m = 1.4180857 
 
 log (:: = 0.2505630 
 
 log ^= 1.507 7210 U= 32.19) 
 
 log k = 3-1763697 
 log C/= 2.8131705 
 
 log 2.3078 = 0.3631992 = log jj 
 
 [Equation (52)] tan <p = 0.5774 
 
 log 2.8852 = 0.4601759 (sub. from log X^ 
 
 log ?^o = 2.7161938 
 u^ = 520.228 
 
 ^=r 650.385 
 
 log 130.157 = 2.1144675 
 log - = 1.6686487 
 
 s • 
 
 log;ro = 3.783 1162 
 x^ = 6069 ft. 
 Bashforth gets by 8 steps, 6074 
 
 Difference, 5 ft. 
 
 log 17= 2.8 1 3 1705 
 log «;== 2.7161938 
 
 log 0.0969767 = 8.9866674 
 
 log J/=: 0.3622157 (add log-— j 
 
 . . log /o =1.0175318 
 
 Bashforth'gets 10^413 
 
 Difference, o''.ooi 
 
 log — ^ = 1.0669224 (add log k) 
 
 4.2432921 = log 175 10 
 log kt\ — 4.1939015 — log 15628 
 
 y,^ 1882 
 
 Bashforth gets 1882 
 
 Difference, o 
 
EXTERIOR BALLISTICS. 87 
 
 These results, being practically identical with those de- 
 duced with vastly greater labor by Prof. Bashforth, pnn^e 
 that when the law of resistance is that of the square of the 
 velocity, as in this example, we may get quite as close an 
 approximation to the true trajectory by assuming that the 
 resistance is proportional to the first power of the velocity 
 as we can upon the hypothesis of the law of the cube, and 
 with a great gain in simplicity and labor. 
 
 We have next to compute the descending branch from 
 f^ =0° to 3 = — 37°. The mean velocity from which to 
 determine k in this branch is 
 
 i (525.91 + 543.74) = 534.8 f. s. 
 whence m = 30.690. 
 
 log m = 1.4869969 
 log 6' = 0.2505630 
 log £ = 1. 5077210 
 
 log k = 3.2452809 
 log z^o = 2.7209 114 
 
 k 
 [Equation (53)] log 3.34480 = 0.5243695 = log — 
 
 tan 37° = 0.75355 
 
 log 4.09835 = 0.6126090 
 
 log 2^.3,0 = 2.6326719 
 
 f^_3,o = 429.21 
 ^0=525.91 
 
 log 96.70 = 1.9854265 
 
 log 7= 1-7375599 
 
 log ^-„« = 3.7229864 
 
 ^_3,0= 5284 ft. 
 
88 EXTERIOR BALLISTICS. 
 
 log 2^0 = 2. 7209 114 
 log ?/_3,o = 2.6326719 
 
 log 0.0882395 = 8.945663 1 
 log ^]/ = 0.3622157 
 
 log/-3,o= 1.0454387 
 
 /_3,o3:zIlM03 
 k 
 
 log— ^.3,0 = 4.2473 5 59 = log 17675 
 log k t.,,. = 4.2907196 = log 1953 1 
 
 J/_3,,= - 1856 ft. > 
 
 The projectile is still 1882 — 1856 — 26 ft. above the level 
 of the gun = Ay. If Ax and At are the corresponding addi- 
 tions to the range and time of flight, we shall have approxi- 
 mately 
 
 Ax 
 Ax = 26 cot 37° =r 35 ft. ; and At = = o''.o8o. 
 
 We therefore have 
 
 ^=6069 + 5284 -f- 35 = 11388 ft. 
 r=i 10.412 -[- II. 103 + 0.080 = 2i'^595 
 
 These values agree almost exactly with those deduced 
 by interpolation from the table on page 117 of Bashforth's 
 work. 
 
 Example 2. — The 8-inch howitzer is fired with a quad- 
 rant elevation of 23°. Muzzle velocity, 920 f. s. ; weight of 
 shell, 180 lbs. ; diameter, 8 inches. Find the range and 
 time of flight. (Mackinlay's "Text-Book of Gunnery," 
 page 107.) 
 
 Assuming the angle of fall to be — 27° 54', we find by the 
 above method 
 
 X=z 7886 + 7108— 13 = 14981 ft. 
 
 T = 10.183 + 10.801 — 0.022 = 20^^.962 
 
 Mackinlay gets, using Niven's method, 
 
 X— 14787 ft, and r=2o".8i3 
 He states that "the published range-table gives 15000ft. 
 as the range, and 2i'^5 for the time of flight." 
 
EXTERIOR BALLISTICS. 89 
 
 Example 3. — Let V =. 2g% m. = 977.71 ft., d ^= \^ cm., 
 w = io k.g-., f = 35° 21', o — 1.270 k.g-., and 0,= 1.206 kg. 
 Find Xand T. (Krupp's Bulletin, No. 55, December, 1884.) 
 For the Krupp projectiles and low velocities we will 
 take for c the ratio of the coefficients of resistance deduced 
 from the Krupp and Bashforth experiments respectively, 
 and which are given in Chapter II. Let these coefficients 
 be represented by A and A' . Then for velocities less than 
 790 f s. we have 
 
 10^^ = 5.6698755- 10 
 log ^'=5.7703827 — 10 
 log c = 9.8994928 
 .•.^=0.7934 
 To find cT, expressed in English units, when w and d are 
 given in kilogrammes and centimetres respectively, we have 
 
 ^ _ loooo k w 
 ~ \^m^ c d' 
 in which k is the number of pounds in one kilogramme, and 
 in the number of feet in one metre. Reducing, we have 
 
 C-= [1.2534887] J 
 
 As the initial velocity in this example is considerable, 
 we will take into account the density of the air at the time 
 the shots were fired, and also the diminution of density due 
 to the altitude attained by the projectile; and for this pur- 
 pose we will assume the mean value of y for the whole tra- 
 jectory to be 2000 ft. 
 
 The complete expression for (7 is (Chapter VII.), 
 
 from which we determine log 6" as follows: 
 
 log w =: 1.4771213 
 
 ^ log ^^ = 7.6478175 
 
 constant log = 1.2534887 
 
 log 0, = 0.0813473 
 
 ^ log ^ = 9.8961963 
 
 z 
 log eh =1:0.0312468 
 
 log (7=0.3872179 
 
90 EXTEklOR BALLISTICS. 
 
 Assuming the angle of fall to be — 44° 40', and proceed- 
 ing as in the first example, we find 
 
 X= 10408 + 8736 + 104 = 19248 ft. 
 7^r=: 15.088 + 16.324 + 0.221 == 3i''.633 
 Krupp gives the ranges of three shots fired with the 
 initial velocity and angle of departure of this example, and 
 the ranges reduced to the level of the mortar, as follows: 
 
 NO. OF SHOT. 
 
 RANGE IN FEET. 
 
 18 
 
 19039 
 
 19 
 
 19265 
 
 20 
 
 19364 
 
 Mean of the three shots = 19223 ft. 
 Computed — mean = 25 ft. 
 
 Example 4. — Given F= 206.6 m. — 677.834 ft., d = 21 
 cm., w = gi k.g., and (f = 60°, to find Jfand T. (Krupp's 
 Bulletin, No. 31, Dec. 30, 1881.) 
 
 It will be found that (assuming the angle of fall to be 
 — 63° 30', and taking no account of atmospheric conditions) 
 
 ^ = 5390 + 4945 + 67 = 10402 ft. 
 T= 17.016+17.543+0.250 = 34''.8o9 
 Krupp gives the observed ranges of five shots, with the 
 above data, as follows : 
 
 NO. OF SHOT. OBSERVED RANGE. 
 
 22 10332 ft. 
 
 23 10305 " 
 
 24 10384 " 
 
 25 10463 " 
 
 26 10440 ** 
 
 Mean of the five shots = 10385 ft. 
 Computed — mean = 17 ft. 
 
 Example 5. — Given F=: 204.1 m. = 669.63 ft., </ = 21 cm., 
 z£/ = 91 k.g., and (p — 45°, to find X and T. (Krupp's Bul- 
 letin, No. 31, January 19, 1882.) 
 
 Assuming the angle of fall to be — 49°, we find as fol- 
 lows: 
 
 ^=6152 + 5678 + 56 = 1 1886 ft. 
 
 r= 13.817 + 14.238 + 0.147 = 28^202 
 
EXTERIOR BALLISTICS. 9 1 
 
 The following ranges were measured at Meppen : 
 
 NO. OF SHOT. OBSERVED RANGE. 
 
 71 11923 ft. 
 
 72 I 1920 " 
 
 73 11841 " 
 
 74 1 1 808 '' 
 
 75 11749 *' 
 
 Mean of the five shots = 11 848 ft. 
 Computed— mean = 38 ft. 
 
 Example 6. — Compute JTand 2" with the data of the pre- 
 ceding example, except that ^ — 30°. 
 
 Assuming the angle of fall to be — 33°, we find as follows : 
 
 X= 5478 + 5 143 + 26 = 10647 ft. 
 
 r= 9.908 -)- 10.183 -f 0.054 = 20". 145 
 
 Krupp gives as the mean of five measured ranges, 
 Jf = 10779 ft. 
 
 Computed — mean = — 132 ft. 
 
 euler's method. 
 
 Expression for s. — If we make nz=z2, that is, suppose 
 the resistance of the air proportional to the square of the 
 velocity, we shall have from (20) 
 
 C du 
 
 ^ — ~ 'aH. 
 whence, integrating and supposing j = o when u =z U, we 
 have 
 
 therefore (page 52) 
 
 s = CiS{u)-S{U)^ (54) 
 
 which gives the length of any arc of a trajectory when the 
 resistance is proportional to the sqiiare of the velocity, by 
 means of the table of space functions. 
 
 We may also obtain another expression for s, better 
 suited to our purpose, as follows: 
 
92 EXTERIOR BALLISTICS. 
 
 Since 
 
 ' J c 
 
 COS' 
 
 we have, when n=^2, 
 
 d(d) = -^^ = sec ?^ ^ tan & 
 
 ^ ^ cos ?7 
 
 and this substituted in (28) gives 
 
 in which 
 
 (?^) = i I tan?? sec ^? + log tan ^- + ^^ I 
 
 whence, integrating between the limits ip and ??, we have 
 
 or, if we use common logarithms, 
 
 in which J/= 2.30259. 
 
 Expressions for a? and t/.— Equation (55) gives the 
 value of s from the origin. If / is the length of an arc of 
 the trajectory from the origin to where the inclination is d-\ 
 and s" the length to some other point further on where the 
 inclination is d-" (??'> W), we shall have from (55) 
 
 /=i:^— log ^ ^ - 
 
 and 
 
 whence 
 
 s" — s' — As—'M — los- 
 
 If??'' differs but little from ??' (say one degree), the cor- 
 responding values of Ax and Ay can be calculated with sufli- 
 
 «■ 
 
 -(f) 
 
 «- 
 
 -(*") 
 
 w- 
 
 -(f) 
 
 (0- 
 
 - (^") 
 
EXTERIOR BALLISTICS. 93 
 
 cient accuracy by multiplying Js by cos ^ {d-' -\- d-") for the 
 former, and sin ^ {&' -\~ &") for the latter; or, 
 
 Ax^M— log ^f^.^ ~ ^/2 cos I (ir + ^^'0 = M—J^ (sav) 
 
 Jj/ = M J log ll^^j sin i {^r + &") = M^A: (say) 
 
 For the entire range we evidently have 
 
 X= y Jx =r M~ I A^=M-^ 
 K g 
 
 the summation extending from ^ = ^ to ^ = w, w being the 
 angle of fall. 
 
 To determine the value of co we have, since the sum of 
 the positive increments of ^'^ in the ascending branch is equal 
 (numerically) to the sum of the negative increments in the 
 descending: branch, 
 
 Expression for the Time.— For the time of flight we 
 have, when dx is small, 
 
 u 
 in which u is the mean horizontal velocity corresponding 
 to Ax ; but, from (15), when n = 2, 
 __ k 
 
 whence 
 
 \{i)-{^)\ 
 
 I Ax ^ ( '^^ — ^^^'^ ^ ^ 
 At = 
 
 k 
 or, substituting for Ax its value given above, 
 
 M = ^AZS,.. ,.A\ 
 
 If we put 
 
 je=Jf{(0-w[* 
 
 12 
 
94 EXTERIOR BALLISTICS. 
 
 we may have 
 
 log J0=log J^ + i log [(0 - i^)] 
 
 The two values of log [{i) — (^)] corresponding to the 
 extremities of the arc Js, are 
 
 log [ (0 -(<?')]. and log [(0 -(#")] 
 the first of which is too small and the second too great; 
 whence, taking their arithmetical mean, 
 
 log Je=\og J?+ilog[{i)-{d')] + i\og[{i)-{9")l 
 by means of which may be computed, and we then have 
 
 Tables. — General Otto, of the Prussian Artillery, has 
 published extensive tables* of the values of {&), q, C, and 6 ■— 
 the last three double entry tables with i and (p for the argu- 
 ments — by means of which it is easy to solve many of the 
 problems of high-angle fire. 
 
 Determination of k^, — General Otto, in the work 
 above cited, gives the following method for determining k"" : 
 We have 
 
 and 
 whence 
 
 an equation independent o{ P. 
 
 independent of X and T, being functions of the angle i and 
 
 the angle of projection cp ; and their ratio -^ may be tabu- 
 lated with these angles for arguments. General Otto has 
 inserted such a table in his work calculated for angles of 
 
 * " Tafeln fiir den Bombenwurf." Translated into French by Rieffel with the title " Tables 
 Balistiqucs Generales pourie tir eleve." Paris, 1844. 
 
 X^ 
 
 g 
 
 
 / 
 
 
 
 T'z=. 
 
 
 
 
 
 
 MX 
 
 e 
 
 
 
 
 
 gT^" 
 
 6' 
 
 
 
 
 
 dent oiU 
 
 \ Moreover 
 
 e 
 
 and 6" 
 
 are 
 
 both 
 
EXTERIOR BALLISTICS. 95 
 
 projection beginning at 30° and proceeding by intervals of 
 5° up to 75°. 
 
 Now, suppose a certain projectile is fired with a known 
 angle of projection (p, and its horizontal range X, and time 
 of flight 7", are carefully measured. With this data we 
 
 compute-^ by means of the above equation; and entering 
 
 Otto's Table III. with the argument ^5 find in the proper 
 
 column the computed value of -^, and take out the corre- 
 
 sponding value oil. Next, with (p and ? as arguments, take 
 from Table IF. the value of ?^, from which k^ can be computed 
 by the following formula, derived from the expression for X 
 given above : 
 
 ^ ~ M e 
 
 bashforth's method. 
 
 For all values of n greater than unity the differential 
 equations of motion take their simplest form when ?/ = 3. 
 For this reason Professor Bash forth assumes the cubic law 
 of resistance throughout the whole extent of the trajectory, 
 and employs variable coefficients to make the results con- 
 form to the actual resistance. 
 
 Making ;/ == 3, equation (25) becomes 
 
 - k d tan d- 
 
 at =^ 
 
 g 
 
 { « - W j * 
 in which 
 
 {&) = tan &-\-^ tan^ ^ 
 
 From (14) we have, when ;2 = 3 and ?? = o, 
 
 ... k' 
 
 W = -3 
 
 and this substituted in the above expression for dt gives, by 
 a slight reduction, 
 
96 EXTERIOR BALLISTICS. 
 
 ^^ _ _ 3 d tan d^ 
 
 ^ {1-^^(3 tan .^ + tan^^)p 
 
 Introducint^ Bashfortli's coefficient K, making 
 
 g %v Viooo/ 
 to correspond with his notation, and integrating between 
 the limits (^, d) and (o, /), we have 
 
 <^/ I i_;k(3 tan/^ + tan^^)i * ^ " 
 Operating in the same way upon (26) and {2^)^ we obtain 
 
 1~7 ^^ 
 
 z;,' /^-^ d tan /> 
 
 S j I I _ -^ (3 tan /> + tan^ if) \ 
 
 v'' r^ tan d- d tan d- 
 
 y-irf T^ — — T;T* = T^n 
 
 and ^.. ^ tan d- d tan ^ _ t^^ 
 
 -y{2> tan ,> + tan^ (>) U' ^ 
 
 Professor Bashforth has published extensive tables of the 
 definite integrals ''*7^,*X:J,and '^F^^ for values of ^ extending 
 from +60° to — 60°, and of y from o to 100, calculated by 
 quadratures; by means of which the principal elements of a 
 trajectory may be accurately determined as follows: 
 
 As the coefficient of resistance K generally varies with 
 the velocity, the trajectory must be divided into arcs of such 
 limited extent that the value of K for each arc may be con- 
 sidered constant ; and it should be so taken as to give, as 
 nearly as possible, its mean value for the arc under con- 
 sideration. 
 
 In the equation given on page 65, viz.: 
 
 /loooX-' /iooo\' . K d" { ^ , ♦ . I 
 
 suppose U and ^ to be the initial horizontal velocity and 
 angle of projection respectively, and both known ; and let 
 &, also known, be the inclination of the forward extremity 
 
\a^. 
 
 — *• » TJ J. X 
 
 EXTERIOR BALLISTICS. 97 
 
 of the first arc into which the trajectory is divided. Now, 
 assuming a mean velocity for this arc, take out the corre- 
 sponding value of K from the proper table and compute 
 
 (I ooo\ ^ 
 - — 1 ; then, in the same equation, changing (p to />, 17 be- 
 
 comes tlie horizontal velocit}^ at the forward extremity ot 
 the arc, which can also be computed. 
 
 Next compute y by means of the equation given above, 
 with which and the known values of ^ and ^ enter the 
 tables and take out '^T^ , ^X^ , and ^Y^-^ lastly, multiplying 
 
 2 
 
 the first by — ^, and each of the others by -— , we have the 
 
 ^ g ^ g 
 
 time of describing the first arc of the trajectory and the co- 
 ordinates of its for vvard extremity. By repeating the process 
 with the second and following arcs into which the trajectory 
 may be divided, the whole trajectory becomes known. 
 
 Professor Bashforth gives various other tables in his 
 work, besides those we have mentioned, for facilitating the 
 calculation of trajectories by his method, with examples of 
 their application and full directions for their use. 
 
 Modiflcatioii of Bashfortli's Method for low Velo- 
 cities. — When the initial velocity. does not exceed 790 f. s. 
 the law of resistance is that of the square of the velocity for 
 the entire trajectory; and even when the initial velocity is 
 as great as 1000 f. s. examples show that no material error 
 results if we still retain the law of the square in our calcu- 
 lations ; and this furnishes a very easy method for calcu- 
 lating trajectories for high angles of projection and for the 
 initial velocities usually employed in high-angle fire, and 
 which, it is believed, gives as accurate results as by any 
 other method, and with less labor. 
 
 Making ;/ =2, equation (25) becomes 
 
 k d tan & 
 
 dt 
 in which 
 
 6 {(,-)_(^)|4 
 ((?) = !{ tan d sec & + log tan g + |^) | 
 
98 EXTERIOR BALLISTICS. 
 
 We also have from (15), when « = 2, and ^ = 0, 
 
 k^ I 
 
 ( = — = — (say) 
 
 and this substituted in the above expression for ^/ gives 
 Vc. d tan /> 
 
 dt— — 
 
 ? ji_^(#)|i 
 
 whence 
 
 tan ^ V, 
 
 In the same wa}^ we obtain from (26) and (27) the follow- 
 
 ing expressions for x and y : 
 
 d tan d- v^ 
 
 < Pi 
 
 r(^>) 
 
 "^x,' 
 
 ^"^ - . ^</> tan ^ ^ tan & 
 
 
 
 It will be seen that this method depends upon tables of 
 definite integrals which must be calculated by quadratures 
 as in Bashforth's method, and with the same number of 
 arguments; but the great advantage of these formulas over 
 Bashforth's is in the fact that y is constant for a given tra- 
 jectory, and, therefore, the labor of calculation is the same 
 for all angles of projection. 
 
 To determine the value of k^ for oblong projectiles of 
 the standard type we have 
 
 2A 
 
 Taking the value of A derived from the Bashforth experi- 
 ments for velocities less than 790 f. s., and making ^^=1 32.16, 
 
 -« fi"d k' ^ [5.4359033] c 
 
 For the Krupp projectiles we should have, taking May- 
 evski's value of A, 
 
 '^' = [5-5367564] c 
 
 The numbers between brackets are the logarithms of the 
 factors by which C is to be multiplied. 
 
EXTERIOR BALLISTICS. 99 
 
 For computing- v^ we have from (32), when ^ = 0, 
 
 /(t/„)=-J(^)+/(f/) (56) 
 
 in which ^ may be the inclination at any point in either 
 
 branch, and U the corresponding horizontal velocity. The 
 
 values of (^) are given in Table III. 
 
 To show the practical working of this method, we will 
 
 take the example from Bashforth already given (see 
 
 page 6j). The data are: V:^j^\ f. s. ; ^ = 30°; ^ = 6.27 
 
 inches, and w:=z'/o lbs.; whence ^=650.385 f. s., and 
 
 70 
 C^^-rp — - == 1.78059. Determine the range, time of flight, 
 
 angle of fall, and terminal velocity. 
 
 First compute v^. We have from Table III. 
 
 (30°) = 0.60799 
 whence, from (56), 
 
 ^^^S~ "^ ""(^50.385) = 0.68291 + 0.93354 = I.61645 
 
 therefore, from Table I., ' 
 
 ^0 = 525.91 f. s. 
 
 Computation of y : 
 
 log (7=0.2505630 
 constant log = 5 -435903 3 
 
 log /^'' = 5.6864663 
 log z/q' = 5.4418228 
 
 log r = 97553565 
 
 r = 0.56932 
 
 As general tables of the definite integrals '^7'^, '^X^ , and 
 ** V^ have not yet been prepared, the following table has 
 been calculated for this particular example, merely to illus- 
 trate the method : 
 
lOO 
 
 EXTERIOR BALLISTICS. 
 
 
 r = 
 
 = 0.56932 
 
 
 
 
 T 
 
 X 
 
 V 
 
 30° 
 
 0.63676 
 
 . 70486 
 
 0.21775 
 
 24 
 
 .47838 
 
 .51493 
 
 .12039 
 
 18 
 
 .34169 
 
 .35965 
 
 .06045 
 
 12 
 
 .21944 
 
 .22662 
 
 . 02460 
 
 + 6 
 
 + .10673 
 
 + .10838 
 
 + .00575 
 
 
 
 .00000 
 
 . 00000 
 
 . 00000 
 
 - 6 
 
 - .10358 
 
 — . 10208 
 
 + .00531 
 
 12 
 
 .20647 
 
 .20061 
 
 .02091 
 
 18 
 
 .31104 
 
 .29793 
 
 .04701 
 
 24 
 
 .41977 
 
 . 39620 
 
 .08479 
 
 30 
 
 •53551 
 
 .49759 
 
 .13656 
 
 36 
 
 .66179 
 
 .60449 
 
 .20615 
 
 37 
 
 .68417 
 
 .62303 
 
 .21987 
 
 The value of ^°°V° by the above table is 0.21775, and as 
 this must be equal to °F" we see at a glance that co lies 
 between — 36° and — 37° ; and by interpolation we get 
 w=r— 36°5i'; and therefore °X'J = 0.62025 and ^T'J 0.68081. 
 Adding to these the numbers corresponding to the argument 
 30°, we get "PX- = 1.32511, and *^7:y^ = I.3I757- Lastly, 
 
 multiplying the first of these by -^,and the second by — , we 
 
 obtain 
 
 X= 11396 ft. 
 and 
 
 r= 21^546 
 
 which agree with Bashforth's calculations. 
 
 The terminal velocity is found from (32), viz.: 
 
 and 
 
 V... = «,.. sec CO 
 
 We find 
 
 and 
 
 ^o. = 434.7 f. s. 
 ^«o = 543-2 f. s. 
 It will be seen that the inverse problem, namely, Given 
 
EXTERIOR BALLISTICS. lOI 
 
 the terminal velocity and angle of fall, to determine the 
 initial velocity, angle of projection, range, and time, can be 
 solved by this method with the same ease and accuracy as 
 the direct problem. We should first compute the summit 
 velocity by the equation 
 
 /W = /(0-|=H (57) 
 
 and then all the other elements would be determined, as 
 already explained. 
 
 In calculating trajectories by this method with the help 
 of tables of the definite integrals '^T^ , etc., it will generally 
 be necessary, as in Bashforth's method, to interpolate with 
 reference to y as well as d-, and for this purpose the integrals 
 must be tabulated for different values of y proceeding by 
 constant diff'erences, and including the highest and lowest 
 values of y likely to be needed in practice, which are, ap- 
 proximately, I and O.2. 
 
 13 
 
CHAPTER VII. 
 
 TRAJECTORIES CONTINUED — DIRECT FIRE. 
 
 Niven's Method. — If a is some mean value of sec d 
 between the limits of integration ; that is, if we make 
 
 a = sec ^? (say) 
 
 then equations (17) to (20) may be written as follows: 
 
 _ 6; d {a li) 
 
 ^ A (a uf 
 
 C -T-d (a m) 
 
 ^^=-^cos^-^^^^^ (58) 
 
 C . -. d{au) 
 
 dy— — -7- smd . .„_\ 
 
 A {a lif ' 
 
 C d (a u) 
 
 A (auf-' 
 
 Making a u=iu\ and integrating so that t, x, y, and s 
 
 shall each be zero when u' = U\ we have 
 
 t = —£_\_l L_l 
 
 C 
 
 cos i)^ 
 
 y = 
 
 {n-2)A "-''^^ ( u'^-' — U'""-- 
 
 c 
 
 11 — 2) A \ u"-' U'"^ ) 
 
 
 
 Comparing these equations with those deduced in Chap- 
 ter IV. for rectilinear motion, it will be evident that we 
 have as follows: 
 
 t = ciT{u^)- r{U')-] (59) 
 
 x=Cco?>^[S {u') - S ( U')~j (60) 
 
 y=C sin J [S (?/) - S{U'\^x tan 5 (61) 
 
 s=ClS{u')-S{U')'] (62) 
 
EXTERIOR BALLISTICS. IO3 
 
 The first three of these equations (or their equivalents) 
 were first published by Mr. Niven in 1877, and in connection 
 with equation (38), viz.: 
 
 D=Ccos.J[D {u') - D ( U')] (63) 
 
 constitute what is known as "Niven's Method." 
 
 If we use the /-function instead of the Z>-function, equa- 
 tion (63) becomes 
 
 /} = 25_^ cos &U W) - I ( U')-\ (64) 
 
 or, better still, for direct fire (see Chapter V.), 
 
 D = 25_^ sec (f [/ (u sec f) - I { F)] (65) 
 
 in which 
 
 log ^=:l. 45 70926* 
 
 The values of ^ adopted by Mr. Niven are as follows: 
 For the /^-integral 
 
 -— tan <p 4- tan ^ 
 tan *. = —^ 
 
 For the X-, V-, and T-integrals 
 - - U 
 
 for the ascending branch, and 
 
 U + ic 3 
 for the descending branch of the trajectory. For the 
 method of deducing these expressions for ^, see a paper by 
 Professor J. M. Rice, U. S. Navy, in the eighth volume of 
 " Proceedings Naval Institute," page 191. 
 
 We will now apply these formulae to the solution of a 
 problem of direct fire; and, as we wish to compare the re- 
 sults obtained with those to be deduced from other methods 
 we will use Table I. of this work instead of Niven's tables, 
 and we will also perform the calculations with more accu- 
 racy than is generally necessary in practice. 
 
104 EXTERIOR BALLISTICS. 
 
 Example of Niven s Method. — A 1 2-inch service projectile 
 is fired at an angle of departure of io°, and an initial velocity 
 of 1886 f. s. Find v, x, y, and / (a) when & = o, and (b) 
 when & = — 1;^°. 
 
 Here d= 12 in., z£'= 800 lbs., C — ,<c^ 10°, V^ 1886 
 
 144 
 
 f. s., U— 1886 cos 10° = 1857.33. 
 
 (a) ?? = o .-, n= 10°. We have first 
 
 tan ?^, = i tan 10° = 0.0831635 
 .-. 5, = 5° 2' i8'^ and U' = Usgc'J,=^ 1864.56 
 Next compute u' by means of the equation 
 
 nu') = ^^sec&, + I{U') 
 
 or 
 
 / (u^) = 0.06308 + 0.03624 = 0.09932 
 
 .-. u' = 1328.96 = ?^ sec d-^ 
 .-. ti^= 132372 
 
 Next compute the value of ^ to be used with the X-, 
 F-, and ^-integrals. We have 
 
 ^ = 5° 2' 18'' + ^^57-33 - 132372 X 1? .. 5° 35' 51'' 
 ^1857.33+132372 3 
 
 The new values of U^ and 1/ are, therefore, 
 
 U' = 1866.25, and u' = 1330.06 
 
 From Table I. we find 
 
 5(^/0-2855.3 5 (?0 = 5239-2 
 
 ' T{U')= 1.258 T{u')= 2.778 
 
 .•.4 = ^{2.778- 1.258} ::=8^444 
 
 ■^o = Y^cos5| 5239-2 - 2855.3 | — 13180.7 ft. 
 
 yo = ^ tan d^ = 1291.8 ft. 
 
 (b) ^= — 13°. It will be necessary in this case to take 
 a new origin at the summit of the trajectory, as thei'e is no 
 
EXTERIOR BALLISTICS. I05 
 
 provision made in this method for calculating an arc of a 
 trajectory lying- partly in the ascending and partly in the 
 descending branches. Indeed, since the differential ex- 
 pression for J/ contains sin ^ as a factor, which becomes zero 
 at the summit and changes its sign in the descending branch, 
 equation (61) does not hold true, unless the limits of integra- 
 tion {if and d^) are both positive or both negative. 
 
 We have, then, for this arc of the trajectory the follow- 
 ing data : 
 
 F= U^ 1323.72, ip =0°, ^= - 13°, and D= 13° 
 
 tan ^j = — i tan 13°= — o.ii5434i_ .' .^,=z — 6° 35' s" 
 
 [/'= 1332. SI 7(^0 = 0.09860 
 
 7 {u') = 0.08222 + 0.09860 = 0.18082 
 
 .' . u' — 1064.39 = Vq cos d^ sec d^^ 
 
 . • . vq^ 1085.18, and Uq = 1057.37 
 
 ^ :^ - 6° 35' ^" - ^32372-1052:37 jz_I3 _ _60 6'o'' 
 1323.72 + 1057.37 3 
 
 The new values of U^ and u^ are, therefore, 
 
 f/^= 1331.26, and u' z= 1063.39. 
 
 From Table I. we get 
 
 5 {[/') = 5232.9 5 («0 = 701 1.7 
 
 tIu') = 2.773 ^M = 4-282 
 
 .•.^ = ^{4.282-2.7731 = 8^383 
 
 X = — cos ?? j 7011.7 — 5232.9 [ = 9826.3 ft. 
 
 144 
 
 y =z X tan ?? 1= — 1050. 1 
 The co-ordinates of the point of the trajectory whose in- 
 clination is— 13°, taking the origin at the point of projec- 
 tion, are therefore 
 
 X= 1 3 180.7 + 9826.3 = 23007.0 ft. 
 F== 1291.8 — 1050.1 = 241.7 ft. 
 And the time, 
 
 7^=8.444 + 8.383 = 16^827 
 For comparison we have computed the same elements 
 
I06 EXTERIOR BALLISTICS. 
 
 directly from equations (i6), (25), (26), and (27), dividing the 
 whole arc into three parts, with the points of division corre- 
 sponding to velocities of 1330 f. s. and 1120 f. s. respectively. 
 The integrals for each arc were computed by quadratures, 
 and the following are the final results: 
 
 ^^=1081.55 f. s.; Xi= 23025.7 ft.; F=: 243.14 ft., and 
 
 r= 16^843. 
 
 The agreement between these two sets of values is re- 
 markably close, and shows that for the purpose of com- 
 puting co-ordinates of different points of a trajectory, 
 Niven's method is all that could be desired so far as ac- 
 curacy is concerned. For high angles of projection the 
 trajectory should be divided into arcs not exceeding 10° or 
 15° each, and always with one point of division at the sum- 
 mit. 
 
 Example 2. — Given d ^ 12 in., 'w=^ 800 lbs., F= 1886 f. s., 
 and ip = 30°. Compute the time and co-ordinates when 
 d- = 24°. 
 
 Answer : 
 
 BY niven's method. BY QUADRATURES. 
 
 ^, = 27° 4' 29'' 
 
 "5 = 2f 19' 4" 
 
 Xq = 8482.0 ft. 8481.4 ft. 
 
 _;/, = 4381.2 ft. 4381.9 ft. 
 
 /^ = 5''.889 5^888 
 
 Vff = 1400.58 f. s. 1400.4 f. s. 
 
 In the same manner, by successive steps, can the whole 
 trajectory be computed. In practice it is never necessary 
 to divide a trajectory into arcs of less than 10°. 
 
 Sladen's Method for Low-Aiigle Firing/'^ — When 
 the angle of projection is small, say not exceeding 3°, the 
 time corresponding to a given range can be computed with 
 great accuracy by means of (29) and (30). We should first 
 find V by means of the equation 
 
 * "Principles of Gunnery," by Major J, Sladen, R.A., London, 1879, Chapter VI. 
 
EXTERIOR BALLISTICS. 
 
 107 
 
 and then with th.is value of v compute T by means of (29). 
 In the same manner we could find the value of / for a given 
 value of Xy less than X ; and these values of T and t substi- 
 tuted in (46), viz., 
 
 would give the value of jj^ corresponding to x ; since, under 
 the conditions supposed, the vertical component of the velo- 
 city would be so small as to produce no appreciable resist- 
 ance to the projectile in that direction. 
 
 Example i — Required the following co ordinates of the 
 trajectory described by a 500-grain bullet fired from a 
 Springfield rifle, for a range of 600 ft., viz. : when ;ir= 150 ft., 
 300 ft., and 450 ft. respectively ; r^ = 524.29, ^^ = 534.22. 
 
 Here ^== 0.45 in., zv = 500 grains = J^ lb., F= 1280 f. s., 
 and X= 600 ft. We first find 5 (K) = 5509.70; r(F) = 2.985; 
 and 
 
 i\ X 534.22 
 
 C 
 
 0.35942 
 
 (0.45) X 524-29 
 
 The principal steps of the remaining calculations are 
 given in the following table : 
 
 (ft.) 
 
 X 
 C 
 
 S{v) 
 
 (f. s.) 
 
 / 
 
 (inches.) 
 
 (inches.) 
 
 (inches.) 
 
 150 
 
 417-34 
 
 5727.04 
 
 1209.72 
 
 0". 12055 
 
 9-365 
 
 9.406 
 
 7-950 
 
 300 
 
 834.69 
 
 6344-39 
 
 1146.76 
 
 0". 24814 
 
 13-167 
 
 12.987 
 
 10.600 
 
 450 
 
 1252.03 
 
 6761.73 
 
 I09I .31 
 
 0". 38235 
 
 10.386 
 
 9-956 
 
 7-950 
 
 Coo 
 
 1669.38 
 
 7179-08 
 
 1046.55 
 
 0". 52313 
 
 {T) 
 
 0.000 
 
 0.000 
 
 0.000 
 
 The sixth column gives the computed values oiy, and the 
 seventh the mean of five trajectories measured with great 
 care at Creedmoor by Mr. H. G. Sinclair, in charge of the 
 " Forest and Stream Trajectory Test." The last column 
 gives the corresponding values of j in vacuo, computed by 
 (45)- 
 
t08 EXTERIOR BALLISTICS. 
 
 SIACCl'S METHOD FOR DIRECT FIRE. 
 
 dy 
 Expression for y. — We have from (35), since tan ^ = -7^ 
 
 dy ^^ a C 
 
 dx 
 or 
 
 2 j dy 
 
 tan^-^{/(«')-/(^')[ 
 
 ^{-^-ta„,}-/(i/')=-/(«') 
 We also have from (58) 
 
 a . du' 
 
 ax =: 
 
 C A u'^-' 
 
 whence multiplying the last two equations together, mem- 
 ber by member, 
 2 
 
 C 
 
 Integrating and making x and j both zero at the origin, 
 where //' = U\ we have 
 
 {</^-u„,^.(-|./(^V- = ^|3^ 
 
 2 j ^ \ a ^,^„^ I fl{u')du' 
 
 Making for convenience 
 
 -.K)=i/^^' 
 
 (in which the ^'s must not be confounded) the above equa- 
 tion becomes 
 
 ^,{>/-^tan^} -^I{U')x=- \a{u')-A{U')\ 
 
 From (60) we have 
 
 ^x = S{u')-S{U') 
 
 whence, by division, 
 
 ^ \y nn<.l nu'\- A{u')-A{U') 
 _|__tan^}-/(f/)_- ^-(„,)_5(f;,) 
 
 aC iA(u')-A(C/') ,,rml iA^\ 
 
 or 
 
 z 
 
 X 
 
EXTERIOR BALLISTICS. IO9 
 
 Calculation of the ^-Function.— We have (Chap- 
 ter V.) 
 
 and therefore 
 
 _ g Q , 
 
 ^ l2\n- I) A' u"^'^ + {n-2)Au'^-' + ^' 
 which becomes, when ;/ = 2, 
 
 The constants Q, corresponding to the five different ex- 
 pressions for the resistance, are given in Chapter V., and 
 the values of Q' are to be determined as explained in Chapter 
 IV. Making the necessary substitutions, and using A {v) as 
 the general functional symbol, we have for standard oblong 
 projectiles the following expressions for calculating the A- 
 functions : 
 
 2800 f. s. > -t^ > 1330 f. s. : 
 
 A {v) = [8 9012292] -^, + [2.6701589] log v - 1714-55 
 
 1330 f. s. > z' > II 20 f. s. : 
 
 A (7;) = [14.6562945] ^ + [5.1480576] i - 53.13 
 
 1 1 20 f. s. > z' > 990 f . s. : 
 A (v) = [32.2571789] ^„ + [14.4412953] ^ + 126.68 
 
 990 f. s. > z^ > 790 f . s. : 
 A (v) = [14.9781903] — , — [5.9124902] ^ + 449.89 
 
 790 f. s. > -z/ > 100 f. s. : 
 A {v) = [9.6655206] ^ + [4.1438598] log V - 45916.40 
 
 The values of A {v) calculated by the above formulae are 
 given in Table I. 
 14 
 
no EXTERIOR BALLISTICS. 
 
 Equation {66), together with (35), (59), and (60), are the 
 fundamental equations of *' Siacci's method." This method, 
 by Major F. Siacci, of the Italian Artillery, was published 
 in the Revue d' Artillerie for October, 1880. A translation 
 of this paper by Lieutenant O. B. Mitcham, Ordnance De- 
 partment, U. S. A., was printed in the report of the Chief 
 of Ordnance for 1881. Lieutenant Mitcham added to his 
 translation a ballistic table adapted to English units, and 
 based upon the coefficients of resistance deduced by Gene- 
 ral Mayevski from the Russian and English experiments 
 noticed in Chapter IL In this table he gives for the first 
 time the values of T{v). 
 
 We will, for convenience, collect thesd equations to- 
 gether and renumber them : 
 
 They are : 
 
 tan ^ - tan ?? = ^ I / (;/) — I{U') | {^7) 
 
 x^^-\s{u')-S{U')\ (68) 
 
 : — : I >i 1 1 in — ^ 
 
 S{u') — i,{U') 
 
 t =ClT{u')-T{U')^ (70) 
 
 u' — av cos d^ (71) 
 
 As the origin of co-ordinates is at the point of departure, 
 y is zero at the origin and also at the point in the descend- 
 ing branch where the trajectory pierces the horizontal plane 
 passing through the muzzle of the gun. Calling the velo- 
 city at this point v^, we shall have, making — d^ z:z w, 
 
 u'o> = « ^ ^ cos CO (72) 
 
 From (69) we have 
 
 aC \A (u'^)-A (U') .. ^„^ ) ._s 
 
 ^ 2 [ S {u'^) — S {[/') ^ ) 
 
 and from {6y) 
 
 a C 
 
 ~ ^ 2 \s{u') — :^{U') ^'^^M ^ ^^ 
 
 tan 
 
 ^ =^ "^ I / {ti'^) - 7(^0 I - tan CO (74) 
 
EXTERIOR BALLISTICS. Ill 
 
 Eliminating^ tan ^ from these last two equations gives 
 
 tan ^^ = — I ^ (^^ ^) - ■5l/?.)-5(^0 ^ 
 From (68) and (70) we have 
 
 X=z— \s{2/^)-S{U')\ (76) 
 
 and a I ^ ^ ' ) 
 
 T= C[T(u'^)^T{U')] {77) 
 
 By means of equations {67) to {77) all problems of ex- 
 terior ballistics in the plane of fire may be solved. If we 
 wish to compute the co-ordinates of the extremities of any 
 arc of a trajectory having the inclinations (f and d^, we should 
 make use of equations {67) to (71). If the object is to deter- 
 mine the elements of a complete trajectory lying above the 
 horizontal plane passing through the muzzle of the gun, at 
 one operation, we should employ equations (72) to {77). We 
 will give an example of each, using Didion's value of a. 
 
 Example i. — Given F= 1886 f. s. ; <^= 12 in.; 2£; = 800 
 lbs., ^ = 10°, and ?? = — 13°; to find z/^, ;ir0, je, and /e. (See 
 example i, Niven's method.) 
 We have first 
 
 (10°) + (13°) 
 
 a = — ^ i \ I o = 1.00723 1 
 
 Next ^^" 10° + tan 13° ^ ^ 
 
 U' = 1886 « cos 10° = 1870.78 
 
 From Table I., 
 
 5(^0=-2838.3;zJ (^0=44.06; /(^0=O-O358i; r<^U')^i.2t,o 
 
 From {67^ we have 
 
 /(^/.) =^ 1 ^"'^^ '""^ + ^""^ '^° 1 +^(^') 
 
 = 0.14554 + 0.03581 =0.18135 
 
 .-. 2^'=: 1063.42; 5(/0==7Oii<4; -^K)=440.44; 7 V) =4-282. 
 
 These values substituted in (68), (69), and (70) give 
 
 xq^=. 23017 ft. 
 
 yQ = 248.06 ft. 
 
 tQ z= i6''.844 
 
112 EXTERIOR BALLISTICS. 
 
 From (71) we have 
 
 Ve = K = 1083.6 f. s. 
 
 a cos a 
 
 These results are quite as accurate as those deduced by 
 Niven's method by two steps. 
 
 Example 2. — Required the horizontal range, time ot 
 flight, and striking velocity, with the data ot Example i. 
 
 In computing « we will assume an angle of fall of — 14° 30', 
 which gives 
 
 «== 1.008645 
 
 .-. ^'=1873.40 
 5(^0=2828.5; A{U')=Al-7^\ 7(^/0=0.03563; n^0=i-243- 
 From (73) we have 
 
 ^^^^g|i=^^tan, + /(t/') = o.09856 
 
 from which to calculate ic'^. As the relation between the 
 S-function and y^-function does not admit of a direct solu- 
 tion of this equation, it will be necessary to determine the 
 value of z/o, by successive approximations; and for this pur- 
 pose the rule of ** Double Position" is well adapted. This 
 rule is deduced as follows : Let u^ and u^ be two near values 
 of?/ (or the quantity to be determined), one greater and the 
 other less ; and e^ and e^ the errors respectively, when n^ and 
 u^ are substituted for u in the equation to be solved. Tiien, 
 upon the hypothesis that the errors in the results are pro- 
 portional to the errors in the assumed data, we have 
 
 e^\ e^W u — //j : u — u^ 
 
 whence, by division, 
 
 e^— e^\ e^W u^ — u^'. u — u^ 
 or 
 
 e^ — e^\ e^\ : u^ — u^\ ii — ti^ 
 
 from which is derived the following rule: As the difference 
 of the errors is to the difference of the assumed numbers, so 
 is the lesser of the two errors (numerically) to the correc- 
 tion to be applied to the corresponding assumed number. 
 
EXTERIOR BALLISTICS. II 3 
 
 If 11^ and u^ are selected with judgment, the resulting 
 value of II will generally be sufficiently correct by a single 
 application of the rule, or, at most, by two trials. 
 
 In our example assume it^ =z 1050, for a first trial ; whence 
 5 (1050) = 7143.7, and A (1050) =464.94 ; and these in the 
 above equation give 
 
 464.94 — 43.71 ^ 
 
 ^ ^ ^ -to / _ 0.09762 
 7143.7-2828.5 
 
 If we had taken for 71^ the correct value of u^^, the second 
 member would have been 0.09856, and hence ^, = — 0.00094. 
 Whenever ^, is negative the assumed value of u' ^ is too 
 great; we will, therefore, next suppose 2/2= 1040, and pro- 
 ceeding in the same way we find ^^ = +0-00128. The cor- 
 rect value of u^^ is, then, between 1050 ft. and 1040 ft. Ap- 
 plying the rule, we have the following proportion : 
 
 222 : 10 :: 94 : 4.23 
 
 consequently u'^ = 1050 — 4.23= 1045.77 f- s. : and this satis- 
 fies the above equation. 
 We next find 
 
 5(?/^) = 7i87.i; ^ (//^)=473.2o; 7(2^'^) =0.1 9 154; T{u'^)=4.44S 
 We now have from (75) 
 
 tan io = j o. 191 54 — 0.09856 i = 0.2605 1 
 
 .-..(>= 14" 36^ (By Table III.) 
 From {26) and (yy) 
 
 I 7187.1 — 2828.5 I =24007 ft. 
 
 r= c:[ 4.448 - 1.243] = i7".8o6 
 From (72) 
 
 ^« = ^=i07i.4f. s. 
 
 a cos 
 
 Various other problems may be solved by a suitable com- 
 bination of equations {6y) to (71). Indeed, if a velocity, 
 
 a 
 
114 EXTERIOR BALLISTICS. 
 
 either initial or terminal, and one other element be given, 
 all the other elements may be computed, though in certain 
 cases this can only be accomplished by successive approxi- 
 mations. Most of these problems, for direct fire, will be 
 solved further on. 
 
 Api>licatioii of Siacci's Equations to Mortar- 
 Firing. — For low velocities, such as are used in mortar- 
 firing, we may take for a in all cases the following value : 
 
 tan ^ 
 
 This simplifies the calculations, and gives results sufficiently 
 accurate for most practical purposes, as the fbllowing ex- 
 amples will show : 
 
 Example i.— Given F=75i f. s. ; ^ = 30°; and log C zizz 
 0.25056. Required X, T, w, and v^. (See Example i, Chap- 
 ter VI.) 
 
 We have, Table III., {(f) = 0.60799. 
 
 log {(f) = 9.78390 
 log tan <p = 9.76144 
 
 log a == 0.02246 
 
 log V=: 2.87564 
 
 log cos ^ = 9.93753' 
 
 log U' = 2.83563 U' = 684.90 
 
 5(£/0=i368i.i; ^(^0-= 344443;/ (^0=0-80679; T{U')=^ 
 12.274. 
 
 log 2 = 0.30103 [Equation (73)] 
 
 c. log a — 9.97754 
 ' c. log 6'= 9.74944 (^dd log t^" f) 
 
 log 0.61 581 =9.78945 
 7 (£/') = 0.80679 
 
 1.42260 
 
 • ^ (»'.)- 3444-43 ^,fo 
 5(«'„)— 13681.1 * 
 
EXTERIOR BALLISTICS. II5 
 
 By double position we find from this equation 
 7/^ = 45978 
 .-. 5 (?/<,) = 20443.1 ; /(?/'^) = 2.22481 : T {2/^) =24,4.04 
 
 X=— I 20443.1 - 13681.1 I =11434 ft. 
 
 Tzzz (7 [24.404 — 12.274] = 2 I ''.60 
 
 tan (o = j 2.22481 — 1.42260 [ [Eq. (75)] 
 
 .•... = 36° 57' 
 
 ?/ 
 
 ^co = ~ — = 546.3 f. s. [Eq. (72)] 
 
 a cos CO -^^ ^ L n \/ /J 
 
 Example 2. — Given f^== 977.71 f. s., ip — 35° 21', and 
 log C'^: 0.38722. Required X, 7", w, and t/^^. (See Example 
 3, Chapter VL) 
 Answer: 
 
 ^=19328 ft. 
 ^-31^63 
 ?/'„ =517.63 
 CO = 44° 44' 
 v^ =1675.65 f. s. ^ ^ 
 
 Example 3. — Given F:^ 609.63 f. s. ; ^ = 45°, and log 6^ = 
 0.56809; required X, T, oj, and ?^^. (See Example 5, Chap- 
 ter VI.) 
 Answer: 
 
 X= 11984 ft. 
 r= 28^30 
 ?/a. = 436.52 
 CO = 49° 10' 
 7;^ = 581.64 
 
 Siacci's Equations for Direct Fire.— As already 
 stated, a is some mean value of the secants of the inclina- 
 tions of the extremities of the arc of the trajectory over 
 which we integrate ; and consequently if we take the whole 
 
 r 
 
Il6 EXTERIOR BALLISTICS. 
 
 trajectory lying above the level of the gun, a will be greater 
 than I and less than sec co. To illustrate, suppose we have for 
 our data a given projectile fired with a certain known initial 
 velocity and angle of projection, and we wish to calculate 
 the angle of fall, terminal velocity, range, and time of flight. 
 If we calculate these elements by means of (75), {ji), (76), 
 and {j']^^ making a = i, they will be too great ; while if a is 
 made equal to sec co, or even sec ^, they will be too small ; 
 and the correct value of each element would be found by 
 giving to a some value intermediate to the two. Moreover, 
 the value of a which would give the exact range would not 
 give the exact time of flight or terminal velocity. These 
 principles are further illustrated by the follow^ing numerical 
 results, calculated from the data, F= 1404 f. s. ; ^=10°; 
 w z=z 183 lbs., and <^= 8 in. : 
 
 a = 1 a = sec <p 
 
 X= 13752 ft. X— 13622 ft. 
 
 v^ = 892.2 f. s. v^ =881.4 f. s. 
 
 co=-ifif fti = -i3°23' 
 
 T=if.04 T=12\SS 
 
 As the true values of these elements lie between those 
 we have computed, it will be seen that either set of values 
 is correct enough for most purposes. It is, therefore, ap- 
 parent that in direct fire we may give to a that value which 
 shall reduce the above equations to their simplest forms, pro- 
 vided it lies between the limits a= i and a = sec (p. 
 
 As we have already seen (Chapter V.\ Major Siacci 
 gives to a the value 
 
 n-2 
 
 a = (sec (f) «^i 
 by means of which equation (37) was obtained, viz.: 
 
 tan^ = tany-— J- j /(«')- /(F)} (78) 
 
 in which 
 
 , cos ^ 
 
 cos (p 
 
EXTERIOR BALLISTICS. II7 
 
 Making the same substitution in (68), (69), and (70), they 
 become respectively 
 
 x- = C[S{u')-S{V)-] (79) 
 
 ;i' ^2 cos' (f { S (?/) — 5 ( F) ^ M ' ^ 
 
 When ^ and d- are so small that the ratio of their cosines 
 does not differ much from unity, we may put 
 
 and the above equations become 
 
 tan & = tan <p ^ ^ ^ (^) - /(H [ (82) 
 
 ^ 2 cos <p { ^ ^ M 
 
 ;r=6^[5(7;)-.V(F)] (83) 
 
 -^'-tanc 6- • i ^e.)- ^(F) [ ,3. 
 
 --tan <p - ^ ^^^^, ^ j ^^^^-^_- - /(^^) j l«4j 
 
 /-=— ^] r(^)-r(F)i (85) 
 
 cos ^ ( ^ ^ ^ M 
 
 We shall retain this form of the ballistic equations in 
 what follows, though when very accurate results are de- 
 sired we must use ?/ instead of z^ 
 
 When J/ = 0, we have from (84) 
 
 Substituting for tan (p in (84) its value from (82), and re- 
 ducing, we have, when j' = o, 
 
 2 cos= <p tan « = C I / (V) - ^ ^^.^ _ ^ ^y^ \ 
 For small angles of projection we may put 
 
 2 cos''' (f 
 and, therefore. 
 
 cos <p 
 
 2 cos (p tan o) = 2 sui co cos co ~ = sui 2ft> 
 
 ^ cos ^6» 
 
 1 A{v)-A(V)l , . 
 
 sin 2<. = C- I / (.•) - s{v)-S{V) \ ^^7) 
 
 For the larger angles of projection employed in direct 
 
 ^5 
 
Il8 EXTERIOR BALLISTICS. 
 
 fire, if accurate results are desired, we must determine (o by 
 the equation 
 
 tan CO = tan w ^ \ I {v) - I (V) \ 
 
 ^ 2 COS if \ ^ ■' ^ ^ \ 
 
 using ?/ instead oi v, as already explained. 
 
 Practical Applications. — We will now apply Siacci's 
 equations to the solution of some of the most important 
 problems of direct fire. 
 
 Problem i. — Given the initial velocity and angle of pro- 
 jection, to determine the range, time of flight, angle of fall, and 
 terminal velocity. 
 
 We have [equation (86)] 
 
 A{:v)-A {y) _ sin 2^ 
 S{v)--S{l^) C "T" ^^^ 
 
 from which to calculate v by '' Double Position," as already 
 explained. Having found v^ the remaining elements are 
 computed by the equations 
 
 x=c[se.o-5(F)] 
 
 r=— ^ I T{v)-T{V)\ 
 COS ^ \ ' ' ) 
 
 For curved fire we may proceed as follows: We have, 
 from the origin to the summit, 
 
 Now, if we assume tiiat the time from the point of pro- 
 jection to the summit is one-half the time of flight, we shall 
 have, from the above expressions for 7' and 4, 
 
 r(7;) = 2 T{v^-T{y) 
 which gives z^ by means of the 7^-functions, v^ being computed 
 bv the equation 
 
 derived from (82). 
 
 Example i. — The 8-inch rifle (converted) fires an ogival- 
 
EXTERIOR BALLISTICS. II9 
 
 headed shot weig-hing 183 lbs. If the angle of projection 
 is 10°, and the initial velocity 1404 f. s., find the range, time 
 of flight, angle of fall, and terminal velocity. 
 
 We have F^ 1404 f. s. ; ^=zio°; ze; = 183 lbs.; d=Z 
 inches, whence log C — 0.45627 : to find X, T, od, and v. 
 From Table I. we find 
 
 5(F) = 4878.6 -0.8 X 25.1 =4858.5 
 A {V) = 163.96 — 0.8 X 2.16 = 162.23 
 / (F) = 0.08661 — 0.8 X 0.00082 = 0.08599 
 T{V) = 2.514—0.8 X 0.018=2.500. 
 Next compute v: 
 
 log sin 2^ = 9.53405 
 log (7=0.45627 
 
 log o. II 96 1 = 9.07778 
 /(F) = 0.08599 
 
 0.20560 
 
 The value of v satisfying this equation is found to be 
 V = 873.8 ft., whence 
 
 5 {v) = 9641.8 A (z/^) = 1 145.65 
 
 / (v) = 0.36668 T {v'^) = 7.030 
 X, T, (0, and z' are now computed as follows : 
 
 log C = 0.45627 
 log[S(2.)- 5(F)] = 3^7973 
 
 log X= 4.13600' 
 
 X= 13677 ft. ==4559 yc^s. 
 
 \og[T{vy- r(F)] = 0.65610 
 
 log sec <p = 0.00665 
 
 log r= I.I 1902 
 
 ^''- I ^^''^ -s{z;)-SjV)\ = 9-^0704 
 log sin 2co =z 9.66331 
 
 2C0 = 27° 25' 30'' 
 
 CO 
 
 = 13° 42' 45' 
 
I20 EXTERIOR BALLISTICS. 
 
 The value of o; computed by the more exact foi inula 
 
 tan CO — — - — ^— \ I {v) -^-^ —~j^ \ 
 
 ig 2 cos' (f I ^ ^ ^ (v) — ^ {V) ) 
 
 ..==13° 21^ 30'' 
 
 differing by 21' from the less approximate value. 
 We have found above 
 
 z;= 873.8 f. s. 
 but this is only an approximation. To determine its true 
 value, that is, i^s true value so far as the formulce are eonee?ned, 
 we should have 
 
 cos 10° „^ r 
 
 V — 873.8 5 — -, — 7, = 884.45 f . s. 
 
 '^ cos 13° 21' 30' 
 
 differing from the approximate value by about 10 feet. 
 
 Example 2. — "A 6-inch projectile leaves the gun at an 
 angle of departure of 4°, with an initial velocity of 2100 f. s. ; 
 7e^= 64 lbs., </= 6 inches. Find the range in horizontal plane 
 through the muzzle of the gun, and time of flight." ('' Ex- 
 terior Ballistics," by Lieutenants Meigs and Ingersoll, 
 U.S.N.) 
 
 We have (Table I.) 
 5(F) = 2024.8;^(F) = 20.57; /(F) = o.02246; r(F) = o.838 
 
 Takin^: <:=i i, we have 
 
 Next we have 3^ 
 
 AM^.20-57 ^ 36 ,i„ go + / (F) ^ 0..0074 
 5 {v) — 2024.8 64 \ \ J 
 
 from which equation we readily find 
 
 V = 993.77 f- s. 
 .' . S {v) = 7801.8, and T {v)=z 5.051 
 X— C [7801.8 — 2024.8] = 10270 ft. 
 
 Problem 2. — Given the angle of fall a7id terminal velocity, to 
 determine the initial velocity, angle of projection, range, and time 
 of flight. 
 
'i 
 
 EXTERIOR BALLISTICS. 12 
 
 We have [equation (87)] 
 
 A(v)~A{V) _ . / X sin 2co 
 S {v) - S{V) - ^""^ C~~ 
 
 from which to calculate Fby double position. 
 
 We may also determine V by the equation (see Prob- 
 lem i) 
 
 r(F) = 2 r(zO- T{z') 
 
 v^ being found by the equation 
 
 / (vo) = / {v) ^— 
 
 derived from (82). 
 
 Having found F by either method, <p, X, and Tare com- 
 puted by the equations 
 
 ^\A(v) — A{V) ,,,^J 
 
 X^C\S{v)-S{V)-] 
 
 r=-^i T{v) — T{V)\ 
 COS (p { ) 
 
 Example i.^Given </=4.5 inches; 7e'= 35 lbs. ; w=: 15°, 
 and z/= 772.74 f. s. ; to determine ^, X, and T. 
 
 It will be found that we have the following equation from 
 which to find V : 
 
 2058.17 — ^(F) 
 
 > -r -F777V = 0.26807 
 
 11633.6 — ^ (F) ^ 
 
 For the first trial assume V ^z 1500, and, substituting in 
 the first member of the above equation, it reduces it to 
 0.26691, which is too small by 0.00116 = ^j. Next make 
 F= 1480, and we shall find that the first member now be- 
 comes too great by 0.00140 =: e^; then 
 256 : 20 : : 116 : 9.1 
 The correct value of Fis therefore 1500 — 9,1 =: 1490.9 f. s., 
 from which are easily found 
 
 ^ = 9° 51^ X= 12440 ft. ; T=i2".72. 
 
 Example 2. — " In attacking a place with curved fire it 
 was required to drop shell into the place with an angle of 
 
122 EXTERIOR BALLISTICS. 
 
 descent of 12°, and terminal velocity of 600 f. s., using the 
 8-inch howitzer and a projectile of 180 lbs.; find the requi- 
 site position of the battery, and the requisite elevation and 
 charg-e of powder."'^ 
 
 Here <3f=8 inches; zv =: iSo lbs.; 7^=600 f. s., and 
 co^ 12°; to find X, V, and (p. We have 
 
 log sin 2C0 = 9.60931 
 log (7 = 0.44909 
 
 log 0.14462 = 9.16022 
 / (7;) = 1. 15929 
 
 I{v^ = 1. 01467 v^ = 630.85 f. s. 
 
 whence we find 
 
 T{V) = 2X 14-396— 15779 = 13-012 
 
 F:= 665.1 f. S. 
 
 5 (v) = 15926.6 
 5(F) 3^ 141 78.9 
 
 log 1747.7 = 3-24247 
 
 log A"=: 3.69156 
 
 X=49i5 ft. = 1638 yds. 
 
 I{z'o)= 1. 01 467 
 
 /(F) = 0.87708 
 
 log 0.13759 = 9.13859 
 log sin 2(p = 9.58768 
 
 2<p = 22° 46' ^ = 11° 23' 
 
 Problem 3. — Given the range and initial velocity, to deter- 
 mine the other elements of the trajectory. 
 
 This is by far the most important of the ballistic prob- 
 lems, and it happens, fortunately, to be one of those most 
 easily solved by Siacci's formulae. 
 
 For the terminal velocity we have 
 
 * Prof. A. G. Greenhill in " Proceedings Royal Artillery Institution," No. 2, vol. xiii. page 79. 
 
EXTERIOR BALLISTICS. 
 
 123 
 
 and then, with Fand v known, all the other elements can be 
 computed by formulcE already considered. 
 
 Example i.— Find the elevation required for a range of 
 2000 yards with the i6-pdr. M. L. R. i^im, the muzzle velo- 
 city being 1355 f. s. ; find also the time of flight and angle 
 of descent. 
 
 Here <^r=: 3.6; 7(y = 16; log (7 = 0.09152 ; F= 1355, and 
 X = 6000. 
 
 Answer : 
 
 4° 41 
 
 T = 5^91 
 0^ =6° 13^ 
 Example 2. — Compnte a range table for the Z-inch rifle {con- 
 verted), up to 15000 ft. 
 
 We have for chilled shot, 7£^ = 183 lbs.; <^=: 8 in. (whence 
 log (7 = 0.45627), and V— 1404 f. s. First take from Table 
 I. the following numbers, which are to be used in all the 
 calculations : 
 
 5 (r) = 4858.5, y^(F)r= 162.23, /(F) = 0.08595, r(F)=: 2.500 
 
 The remainder of the work niay be concisely tabulated 
 as follows : 
 
 X 
 
 ft. 
 
 X 
 
 c 
 
 S{v) 
 
 v 
 
 A{v) 
 
 /(v) 
 
 T(v) 
 
 1500 
 
 524-59 
 
 5383-1 
 
 1303.0 
 
 212.04 
 
 0. 10442 
 
 2.884 
 
 3000 
 
 1049 
 
 2 
 
 5907.7 
 
 I2I2.8 
 
 272.28 
 
 .12579 
 
 3 
 
 305 
 
 4500 
 
 1573 
 
 8 
 
 6432.3 
 
 II34-3 
 
 344 -^o 
 
 .15038 
 
 3 
 
 753 
 
 6000 
 
 2098 
 
 4 
 
 6956.9 
 
 I 69.2 
 
 430.79 
 
 .17826 
 
 4 
 
 230 
 
 7500 
 
 2622 
 
 9 
 
 7481.4 
 
 1019.2 
 
 532.14 
 
 . 20929 
 
 4 
 
 732 
 
 9000 
 
 3147 
 
 5 
 
 8006.0 
 
 978.8 
 
 650.68 
 
 .24314 
 
 5 
 
 257 
 
 10500 
 
 3672 
 
 I 
 
 8530.6 
 
 942.5 
 
 787.72 
 
 -27973 
 
 5 
 
 804 
 
 12000 
 
 4196 
 
 7 
 
 9055.2 
 
 908.8 
 
 944.68 
 
 •31914 
 
 6 
 
 371 
 
 13500 
 
 4721 
 
 3 
 
 9579.8 
 
 877-4 
 
 1123.07 
 
 .36148 
 
 6 
 
 959 
 
 15000 
 
 5245-9 
 
 10104.4 
 
 848.1 
 
 1324.47 
 
 . 40684 
 
 7.567 
 
 The numbers in the first column are the ranges for which 
 the elements of the trajectory are to be computed. The 
 numbers in the second column are simple multiples of the 
 first number in the column. Adding S {V) to the numbers 
 
124 
 
 EXTERIOR BALLISTICS. 
 
 in the second column ^ives those in the third column, and 
 with these we take from Table 1. the values of v, and at the 
 same time those of A {^v), I {v), and T {v). 
 
 The time of fliglit, angle of departure, and angle of fall 
 are then computed by the following formulas: 
 
 'T= — ^ \ T{v)- T{V)\ 
 
 cos (p 
 
 and 
 
 sm 2lp: 
 
 tan Col = 
 
 ciiM^Am-ii^V) 
 
 S{v)-S{V) 
 C ( , , , A (v] 
 
 -,{n^) 
 
 A{V)) 
 
 2 cos' (p { ^ ' S (v) — S {V) ) 
 Lastly, the values of v, tabulated above, a?-e to be multi- 
 plied by cos (f sec &-> to obtain the correct striking velocities. 
 In our example the results are as follows: 
 
 yds 
 
 <!> 
 
 a, 
 
 
 T 
 
 500 
 
 o°44' 
 
 o°47' 
 
 1303 
 
 I^IO 
 
 1000 
 
 i°33' 
 
 i°43' 
 
 I2I3 
 
 2^30 
 
 1500 
 
 2° 2/ 
 
 2° 50^ 
 
 II35 
 
 3''-59 
 
 2000 
 
 3° 2/ 
 
 4° 08' 
 
 1070 
 
 4^96 
 
 2500 
 
 4° 32' 
 
 5° 38' 
 
 I02I 
 
 6^40 
 
 3000 
 
 5° 43' 
 
 7° 14' 
 
 982 
 
 7^92 
 
 3500 
 
 6° 59' 
 
 9° 01^ 
 
 947 
 
 9^52 
 
 4000 
 
 8° 21^ 
 
 10° 58^ 
 
 916 
 
 11^19 
 
 4500 
 
 9° 49' 
 
 13° 06' 
 
 888 
 
 12^94 
 
 5000 
 
 11° 24' 
 
 15° 25' 
 
 862 
 
 14^78 
 
 By interpolation, using first and second differences, the 
 interval between successive values of the argument {X) may 
 be reduced from 500 yards to 100 yards. 
 
 Example 3. — Given d — 20 93 cm. ; if> = 140 kg. ; V = 521 
 m. s. ; d^ = 1.206; d= 1.233 ; X=4097 m.; angle o( jump = 8'; 
 required the angle of elevation == ^ — 8', the angle of fall, 
 the striking velocity, and the time of flight.^ 
 
 Making the ballistic coefficient {c) =0.907, we have for 
 
 * '■ Ballistische Formeln-von Mayevski nach Siacci. Fur Elevationen unter 15 Grad," Essen, 
 Fried. Krupp'sche Buchdruckerei, 1883, page 22. Also quoted by Siacci in " Rivista di Artiglieria 
 e Genio," vol. ii. page 414, who solves the example, using Mayevski's table. 
 
EXTERIOR BALLISTrcS. 
 
 125 
 
 computing C in English units, when <^ is expressed in centi- 
 metres and w in kil(3grarames, the following expression : 
 
 C-[i..953743]f ^ 
 
 The following are the results obtained by experiment, 
 by Mayevski's calculations, by Siacci's calculations, and by 
 Table I. of this work : 
 
 
 T 
 
 Angle of 
 Elevation. 
 
 Angle of 
 Fall. 
 
 Striking Velocity, 
 f. s. 
 
 By experiment 
 Mayevski... 
 
 Siacci 
 
 Table I 
 
 9"-7 
 9".6 
 
 9".675 
 
 9".66 
 
 5° 30' 
 5° 32' 
 
 5° 31' 
 5° 29' 30" 
 
 7° 16' 
 
 I 176 
 I 169 
 
 Example 4. — Given ^=24 cm.; 7e/ = 2i5 kg.; F= 529 
 m. s. = 1735.6 f. s. ; required the angle of departure for each 
 of the horizontal ranges contained in the first column of the 
 followintr table : 
 
 Horizontal 
 
 Range. 
 
 in 
 
 5/ 
 J 
 
 Computed by 
 Table I. 
 
 Observed 
 value of 
 
 Values of <f> computed by 
 
 Mayevski's 
 Table. 
 
 Hojel's 
 Table. 
 
 2026 
 
 0.9569 
 
 2°.;' 
 
 2° .9' 
 
 2° 18' 
 
 2° 14' 
 
 3000 
 
 0.9407 
 
 3° 36' 
 
 3° 41' 
 
 3° 37^ 
 
 3° 35' 
 
 4000 
 
 0.9756 
 
 5° 5' 
 
 5° 10' 
 
 5° 6' 
 
 5° 5' 
 
 5964 
 
 0.9560 
 
 8" 41' 
 
 8° 35' 
 
 8° 44^ 
 
 8° 44' 
 
 7600 
 
 0.9461 
 
 12° 31' 
 
 12° 5' 
 
 12° 31' 
 
 12° 32' 
 
 The data in the first, second, and fourth columns are 
 taken from Krupp's Bulletin, No. 56 (February, 1885), page 
 4. The values of <p in the third column were computed by 
 Siacci's method, using Table I. of this work. In the last 
 two columns are given the values of ^ computed by Siacci's 
 method with Mayevski's and Hojel's tables respectively. 
 
 Problem 4. — With a given initial velocity^ required the angle 
 16 
 
126 EXTERIOR BALLISTICS. 
 
 of projection necessary to cause a projectile to pass through a 
 given point. 
 
 Let X and y be the co-ordinates of the given point. Then 
 from (83) and (84) we have 
 
 and ^ 
 
 Example. — An 8-inch service projectile is fired with an 
 initial velocity of 1404 f. s. from a point 33 feet above the 
 water; find the necessary angle of projection to attain a 
 range on the water of 3000 yards. 
 Here <^=: 8, ze/ = 180, F= 1404, x = 9000 ft., and j/= — 33 ft- 
 
 We have ^ 
 
 ^ (^^) = I^ ^ 9000 + 4858.5 = 8058.5 
 
 ••• ^ = 975-07 
 In calculating tan ^ we will, at first, omit the factor cos" (p 
 in the second member. 
 
 33 , 180(663.56—162.23 „ I 
 
 = — 0.00367 -|- 0.09945 = 0.09578 
 
 Therefore the approximate value of ^ is 5° 28'. Complet- 
 ing the calculation by introducing cos"" ip we have 
 
 ? = 5°3i' 
 which needs no further correction. 
 
 Problem 5. — Given the initial and terminal velocities, to 
 calculate the trajectory. 
 
 For the solution of this problem we have the following 
 equations: ^ A {v) - A {V) ,,„,! 
 
 ^ \ ^'> s{v)-s(y)S 
 
 sm 2(« 
 
 X=C[5(^)-5(F)] 
 
 7-=-^ I T{v)- T{V)\ 
 cos <f \ ' S 
 
EXTERIOR BALLISTICS. I27 
 
 Example. — In experimenting- with the 15-inch S. B. gun, 
 it is desired to place a target at such a distance from the 
 gun that the projectile (solid shot weighing 450 lbs.) shall 
 have a velocity of 1000 f. s. when it reaches the target, and 
 this without diminishing the muzzle velocity, which is 1534 
 f. s. What is the required distance and the angle of pro- 
 jection ? 
 
 We readily find, using Table II., 
 
 and ^ = 2° 33' 
 
 X=4678 ft. 
 
 CORRECTION FOR VARIATION IN THE DENSITY OF THE AIR. 
 
 The ballistic coefficient (Q is determined by the equation 
 
 r- ^ h. 
 
 cd' d 
 in which d^ is the adopted standard density of the air, and d 
 the density at the time of firing. 
 
 In computing Tables I. and II. the value of d^ was taken 
 as the weight, in grains, of a cubic foot of air at a tempera- 
 ture of 62° F. and a pressure of 30 inches of mercury. Ac- 
 cording to Bashforth we have 
 
 '^z = 534-22 grs. 
 
 For any other temperature (/), and barometric pressure 
 {b)j we may determine the value of d near enough for most 
 practical purposes by the following simple equation: 
 ^_ 20.212 b 
 ~ I -f .002178 t 
 
 Correction for Altitude. — When a projectile is fired 
 at such an angle of projection as to reach a great altitude in 
 its flight, the value of o, determined as above, will be too 
 great. We may calculate approximately, in this case, as 
 follows : 
 
 If o' is the density of the air at the height y above the 
 surface of the earth, we shall have 
 
 d'^de-'x 
 
128 
 
 EXTERIOR BALLISTICS. 
 
 where ?. is the height of a homogeneous atmosphere of the 
 
 density <5, which would exert a pressure equal to that of the 
 
 actual atmosphere.'^' 
 
 d o ^ 
 
 The factor -— becomes, therefore, ~ e^; and (7 must be 
 o o 
 
 multiplied b}^ this if we wish to take into account the dimi- 
 nution of density due to the height of the projectile, taking 
 for J a mean value for the arc of the trajectory which we are 
 computing. 
 
 y 
 
 The following table gives the values of ^-a. for every lOO 
 feet from j = o to /= 10,000 feet. In the computation ?. 
 was assumed to be 27800 feet, which is its approximate 
 value for a temperature of 15° C. and barometer at o"'.75. 
 The table is substantially the same as that given by Bash- 
 forth {" Motion of Projectiles," page 103), but in a moie con- 
 venient form. 
 
 y 
 
 
 
 100 
 
 200 
 
 300 
 
 400 
 
 500 
 
 6qo 
 
 700 
 
 800 
 
 900 
 
 
 
 I. 0000 
 
 0036 
 
 0072 
 
 0108 
 
 0145 
 
 0181 
 
 0218 
 
 0255 
 
 0292 
 
 0329 
 
 1000 
 
 1,0366 
 
 0403 
 
 0441 
 
 0479 
 
 0516 
 
 0554 
 
 0592 
 
 0631 
 
 0669 
 
 '0707 
 
 2000 
 
 1.0746 
 
 0785 
 
 0824 
 
 0863 
 
 0902 
 
 0941 
 
 0981 
 
 1020 
 
 1060 
 
 1 100 
 
 3000 
 
 I. I 140 
 
 1180 
 
 1220 
 
 1260 
 
 1 301 
 
 1 34 1 
 
 1382 
 
 1423 
 
 1464 
 
 1506 
 
 4000 
 
 I -1547 
 
 1589 
 
 1630 
 
 1672 
 
 1714 
 
 1756 
 
 1799 
 
 1841 
 
 1884 
 
 1927 
 
 5000 
 
 I. 1970 
 
 2013 
 
 2057 
 
 2100 
 
 2144 
 
 2187 
 
 2231 
 
 2276 
 
 2320 
 
 2364 
 
 6000 
 
 1.2409 
 
 2-154 
 
 2499 
 
 2544 
 
 2589 
 
 2634 
 
 2679 
 
 2725 
 
 2771 
 
 2817 
 
 7000 
 
 1.2863 
 
 2909 
 
 2956 
 
 3003 
 
 3049 
 
 3096 
 
 3H4 
 
 3191 
 
 3239 
 
 3286 
 
 8000 
 
 I 3334 
 
 3382 
 
 3431 
 
 3479 
 
 3528 
 
 3576 
 
 3625 
 
 3675 
 
 3724 
 
 3773 
 
 9000 
 
 1.3823 
 
 3873 
 
 3923 
 
 3973 
 
 4023 
 
 4074 
 
 4125 
 
 4176 
 
 4227 
 
 4278 
 
 * Chauvenet's " Practical Astronomy," vol. i. page 138. 
 
BALLISTIC TABLES. 
 
 The term ''Ballistic Table" was applied by Siacci to 
 tlie tabulated values of the funclions S{v), A {v), I{v), and 
 7\v). Table L g-ives the values of these functions for ob- 
 long projectiles having ogival heads struck with radii of i| 
 calibers. It is based upon the experiments of Bashforth, 
 and was calculated by the formulas developed in the preced- 
 ing pages. 
 
 The table extends from z/=28oo to ^ = 400, which limits 
 are extensive enough for the solution of nearly all practical 
 problems of exterior ballistics. It may occasionally happen 
 in mortar practice that the horizontal velocity {v cos <f) may 
 be less than 400 (as in problem 4, Chapter V.) In such 
 cases we may employ the formulas by which this part of the 
 table was computed, viz.: 
 
 5 (v) = 124466.4 - [4.59i833(>] log ^ 
 
 A (v) = [9.6655206] -^ -f [4.1438598] log V - 45916.40 
 
 /(^) = [5.7369333] ^ - 0.356474 
 T{v) = [4.2296173] ^ - 12.4999 
 
 Example i.— Let (^=8 in., w = 180 lbs., F= 700 f. s., and 
 ^ = 60°. Find V when ^ = — 60°. 
 We have from (33) 
 
 and U ^=. joo cos 60° = 350, which is below the limit of 
 
2 BALLISTIC TABLES. 
 
 the table. The operation may be concisely arranged as 
 follows : 
 
 const. log=:: 57369333 
 2 log f/= 5.0881360 
 
 0.6487973 = log 445448 
 (60) = 2.39053 
 
 log 4 (60°) = 0.9805542 
 log C= 0.4490925 
 
 0.5314617 = log 3.39987 
 
 0.895 1103 = log 7-85435 
 
 2)4.8418230 
 
 2 42091 15 =: log 263.6 
 . • . 7/ =: 263.6 X 2 = 527.2 f. S. 
 
 Example 2. — Given 5 {v) = 25496.8, to find v. 
 We proceed as follows: 
 
 1 24466.4 
 25496.8 
 
 log 98969.6 = 4.9954886 
 const, log = 4.5918330 
 
 log (log z/) = 0.4036556 
 .-. log 7;=2.533i2 
 £^=341.3 
 
 Table II. is the ballistic table for spherical projectiles, 
 and extends from z^= 2000 to ^^ = 450. It is based upon the 
 Russian experiments discussed in Chapter II., and is be- 
 lieved to be the only ballistic table for spherical projectiles 
 yet published. 
 
 Table III. is abridged from Didion's " Traite de Bal- 
 istique." 
 
 Forniulse for Interpolation. — To find the value of 
 f{z^ when V lies between v^ and v^, two consecutive values 
 of V, in Tables I. and II. Let v^ — v^r=^ h. Then, if d^ and d^ 
 
BALLISTIC TABLES. 
 
 are the first and second diflferences of the function, we shall 
 have, since y(?7) increases while v decreases, 
 
 
 2 
 
 by means of which f{v) can be computed. Conversely, if 
 f{7>) is given, and our object is to find v, we have 
 
 
 7\ — v\ d^ 
 2 
 
 In using this last formula, first compute —^ — by omit- 
 
 Ti 
 
 ting the second term of the second member (which is usually 
 very small), and then supply this term, using the approxi- 
 mate value of-^-^^ — already found. 
 Ii ^ 
 
 If the second differences are too small to be taken into 
 account, the above formulae become 
 
 /(z,)=/(t;,) + ^S-^rf, 
 
 and 
 
 which expresses the ordinary rules of proportional parts. 
 
 Example i. — Find from Table I. S{v) when z/= 1432.6. 
 We have v, = 1435, f{v^ = 4704.8, h — 5, and d, = 24.6. 
 
 .•.S{v) = 4704.8 + 1 435 - 1432.6 ^ ^^^^ ^ ^^j^^^ 
 
 Example 2. — Given A (7/) = 229.89, to find v. Here 7/^ = 
 1274, /(7/,) = 229.29, </,= 1.25, and /^= 2. 
 
 2 
 
 . • . 7; = 1 274 (229.89 — 229.29) = 1 273.04 
 
 1.25 
 
 Example 3. — Find from Table II. A {v) when 77 = 517.8. 
 
4 BALLISTIC TABLES. 
 
 We have e^, = 520, ^(^0 = 3755-9. >^^ = 5» ^, = 158.2, and 
 ^,= 7.8. 
 
 2.2 2.2 / 2.2X7.8 
 
 .-. ^ (^) = 3755.9+ -X 158.2 ---(i--)^ 
 = 3755-9 + 69-60 — 0.96 = 3824.5 
 Example 4.— Find from Table HI. the value of (^) when 
 ^ = 54° 32'. Here ?^, == 54° 2o\ (^,) = 17619 1» h=z2o',d,z^ 
 .02971, d^ = .00074. 
 
 .-. (^)z= 1.76191 +0.6X 0.02971 —0.6 X 0.4 X 0.00037 
 = 1.76191 +0.01783 —0.00009= 1.77965 
 
TABLE I. 
 
 Ballistic Tabic for Ogival-Hcaded Projectiles. 
 
 V 
 
 6- (7') 
 
 Diflf. 
 
 A iv) 
 
 Diff. 
 
 1 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 2800 
 
 2750 
 
 2700 
 
 j 000.0 
 
 126.8 
 
 [ 256.0 
 
 1268 
 1292 
 1315 
 
 0.00 
 
 0.07 
 0.28 
 
 7 
 21 
 
 36 
 
 0.00000 
 0.00106 
 0.00218 
 
 106 
 112 
 
 118 
 
 0.000 
 0.046 
 0.093 
 
 46 
 
 47 
 49 
 
 2650 
 2600 
 
 2550 
 
 387.5 
 
 521.6 
 
 658.3 
 
 1341 
 1367 
 
 1393 
 
 0.64 
 1. 18 
 1.89 
 
 54 
 71 
 93 
 
 0.00336 
 0.00461 
 0.00594 
 
 125 
 
 140 
 
 0.142 
 0.193 
 0.246 
 
 51 
 53 
 56 
 
 2500 
 
 2450 
 2400 
 
 797.6 
 939.8 
 
 1085.0 
 
 1422 
 
 1452 
 1481 
 
 2.82 
 3.97 
 5.37 
 
 115 
 140 
 166 
 
 0.00734 
 0.00883 
 0.01043 
 
 149 
 160 
 169 
 
 0.302 
 
 0.359 
 0.419 
 
 57 
 60 
 62 
 
 2350 
 
 2300 
 2250 
 
 I233.I 
 
 IJ84.5 
 
 1539.2 
 
 '514 
 1547 
 1582 
 
 7.03 
 
 9.00 
 
 11.31 
 
 197 
 231 
 266 
 
 O.OI2I2 
 0.01392 
 0.01584 
 
 180 
 192 
 205 
 
 0.481 
 0.546 
 0.614 
 
 65 
 . 68 
 
 72 
 
 2200 
 2190 
 2180 
 
 1697.4 
 
 1729.5 
 I76I.7 
 
 321 
 322 
 323 
 
 13.97 
 14.55 
 15.15 
 
 58 
 60 
 62 
 
 0.01789 
 0.01832 
 0.01876 
 
 43 
 44 
 44 
 
 0.686 
 0.700 
 0.715 
 
 14 
 ^5 
 15 
 
 2170 
 
 2160 
 
 2150 
 
 1794.0 
 1826.5 
 1859.2 
 
 325 
 327 
 328 
 
 15.77 
 16.40 
 
 17.05 
 
 65 
 67 
 
 0.01920 
 0.01964 
 0.02010 
 
 44 
 46 
 46 
 
 0.730 
 
 0.745 
 0.760 
 
 15 
 15 
 
 15 
 
 2140 
 
 2130 
 
 2120 
 
 1892.0 
 1924.9 
 
 1958.0 
 
 329 
 331 
 
 17.72 
 18.40 
 19.10 
 
 70 
 73 
 
 0.02056 
 0.02102 
 0.02149 
 
 46 
 
 47 
 48 
 
 0.775 
 0.791 
 0.806 
 
 16 
 
 15 
 16 
 
 2IIO 
 2100 
 2090 
 
 I99I.3 
 
 2024.8 
 2058.4 
 
 335 
 336 
 337 
 
 19.83 
 
 20.57 
 21.33 
 
 74 
 76 
 
 79 
 
 0.02197 
 0.02246 
 0.02295 
 
 49 
 49 
 
 50 
 
 0.822 
 0.838 
 0.854 
 
 16 
 16 
 16 
 
 2080 
 2070 
 2060 
 
 2092.1 
 2126.0 
 2I60.I 
 
 339 
 341 
 343 > 
 
 22.12 
 22.92 
 23.74 
 
 80 
 82 
 85 
 
 0.02345 
 0.02396 
 0.02447 
 
 51 
 51 
 
 52 
 
 0.870 
 0.886 
 0.903 
 
 16 
 17 
 17 
 
 2050 
 2040 
 2030 
 
 2194.4 
 2228.8 
 2263.4 
 
 344 
 346 
 348 
 
 24.59 
 25.46 
 
 26.35 
 
 [ 
 
 87 
 89 
 91 
 
 0.02499 
 0.02552 
 0.02606 
 
 53 
 54 
 54 
 
 0.920 
 0.937 
 0.954 
 
 17 
 17 
 17 
 
 2020 
 2010 
 2000 
 
 2298.2 
 
 2333.1 
 2368.2 
 
 349 
 351 
 353 
 
 27.26 
 28.20 
 29.16 
 
 94 
 96 
 98 
 
 0.02660 
 0.02715 
 0.02772 
 
 55 
 57 
 57 1 
 
 0.971 
 0.988 
 1.005 
 
 17 
 17 
 18 
 
TABLE L— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A {V) 
 
 Diff. 
 
 7(7') 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 1990 
 
 1980 
 
 1970 
 
 2403-5 
 2439.0 
 2474.6 
 
 355 
 
 ^ 356 
 
 358 
 
 30.14 
 31-15 
 32.19 
 
 lOI 
 
 104 
 107 
 
 0.02829 
 0.02886 
 0.02945 
 
 57 
 59 
 60 
 
 1.023 
 1. 041 
 1-059 
 
 18 
 18 
 18 
 
 i960 
 
 1950 
 1940 
 
 2510.4 
 2546.4 
 2582.6 
 
 360 
 362 
 
 363 
 
 33-26 
 
 34-35 
 35-48 
 
 109 
 113 
 115 
 
 0.03005 
 0.03066 
 0.03127 
 
 61 
 61 
 62 
 
 1.077 
 1.096 
 1. 114 
 
 19 
 
 18 
 
 19 
 
 1930 
 
 1920 
 I9I0 
 
 2618.9 
 2655.5 
 2692.2 
 
 306 
 
 367 
 
 370 
 
 36.63 
 37-81 
 39.02 
 
 118 
 121 
 124 
 
 0.03189 
 0.03253 
 0.03318 
 
 64 
 65 
 65 
 
 I-I33 
 1. 152 
 1. 171 
 
 19 
 19 
 
 20 
 
 1900 
 1890 
 1880 
 
 2729.2 
 2766.3 
 2803.7 
 
 371 
 374 
 375 
 
 40.26 
 
 41-53 
 42.83 
 
 127 
 130 
 
 0.03383 
 0.03450 
 0.03517 
 
 67 
 69 
 
 1. 191 
 1. 210 
 1.230 
 
 19 
 20 
 20 
 
 1870 
 i860 
 1850 
 
 2841.2 
 2878.9 
 2916.9 
 
 377 
 380 
 382 
 
 44.16 
 
 1 45-53 
 46.93 
 
 137 
 140 
 
 143 
 
 0.03586 
 0.03656 
 
 ; 0.03727 
 
 70 
 
 71 
 
 72 
 
 1.250 
 1.270 
 1. 291 
 
 20 
 21 
 20 
 
 1840 
 
 1830 
 
 1820 
 
 2955-1 
 2993-4 
 3032.0 
 
 386 
 388 
 
 48.36 
 49-83 
 51-34 
 
 147 
 151 
 
 155 
 
 0.03799 
 0.03872 
 0.03946 
 
 73 1 
 
 74 
 
 76 
 
 1. 311 
 1-332 
 1-353 
 
 21 
 21 
 
 22 
 
 I8I0 
 
 1800 
 1790 
 
 3070.8 
 3109.8 
 3149.0 
 
 390 
 392 
 394 
 
 52.89 
 
 54-47 
 56.09 
 
 158 
 162 
 167 
 
 ' 0.04022 
 
 0.04099 
 
 10.04177 
 
 77 
 78 
 80 
 
 1-375 
 1.396 
 1.418 
 
 21 
 
 22 
 22 
 
 1780 
 1770 
 1760 
 
 3188.4 
 3228.0 
 3267.9 
 
 396 
 
 399 
 401 
 
 1 57-76 
 
 1 59-47 
 61.21 
 
 171 
 
 174 
 179 
 
 i 
 0.04257 
 
 0.04338 
 0.044.20 
 
 81 1 
 821 
 84! 
 
 1.440 
 1.463 
 1-485 
 
 23 
 22 
 
 23 
 
 1750 
 1740 
 1730 
 
 3308.0 
 3348.3 
 3388.9 
 
 403 
 406 
 409 
 
 63.00 
 
 64-83 
 66.71 
 
 183 
 188 
 
 193 
 
 0.04504 
 0.04589 
 0.04676 
 
 85 1 
 
 87 
 
 88! 
 
 1.508 
 1-531 
 
 1-555 
 
 23 
 24 
 23 
 
 1720 
 I7I0 
 1700 
 
 3429.8 
 3470-8 
 3512. 1 
 
 410 
 413 
 
 415 
 
 ! 68.64 
 
 : 70.61 
 72.63 
 
 1 
 
 197 
 
 202 
 207 
 
 0.04764 
 0.04854 
 0.04945 
 
 90 
 
 9r\ 
 
 1-578 
 1.602 
 1.626 
 
 24 
 24 
 
 25 
 
 1690 
 
 1680 
 
 1670 
 
 3553-6 
 3595-4 
 36374 
 
 418 
 420 
 423 
 
 1 
 74-70 
 76.83 
 79.01 
 
 213 
 218 
 223 
 
 0.05038 
 0.05133 
 0.05229 
 
 95 
 96 1 
 98 1 
 
 1. 651 
 1.676 
 1. 701 
 
 25 
 25 
 25 
 
 1660 
 1650 
 1640 
 
 3679-7 
 3722.2 
 
 3765-0 
 
 425 
 428 
 
 430 
 
 81.24 
 83-52 
 85.86 
 
 228 
 
 234 
 241 
 
 6 
 
 0.05327 
 
 0.05427 
 
 ,0.05529 
 
 100 
 102 
 
 103 1 
 
 1.726 
 
 1-752 
 1.778 
 
 26 
 26 
 26 
 
TABLE I.— Continued. 
 
 3808.0 
 
 3851-3 
 3894.9 
 
 3938.7 
 3960.7 
 3982.8 
 
 4005.0 
 4027.3 
 4049.6 
 
 4072.0 
 4094.4 
 4116.9 
 
 4139-5 
 4162.2 
 4185.0 
 
 4207.8 
 4230.7 
 4253-6 
 
 4276.7 
 4299.8 
 4323-0 
 
 4346.2 
 4369.6 
 4393-0 
 
 4416.5 
 4440.1 
 4463-8 
 
 4487-5 
 4511-3 
 
 I 4535-2 
 
 4559-2 
 4583.2 
 4607.4 
 
 4631.6 
 
 4655-9 
 4680.3 
 
 Diff. I 
 
 I 
 
 433 I 
 436 I 
 4381 
 
 220 1 
 
 221 j 
 
 222 I 
 
 223 
 223 
 224 
 
 224 
 
 225 
 226 
 
 227 
 228 
 228 
 
 229 
 229 
 231 
 
 231 
 232 
 232 
 
 234 
 234 
 
 235 
 
 236 
 237 
 237 
 
 238 
 
 239 
 
 240 
 
 240 
 242 
 
 242 
 
 243 
 244 
 245 
 
 A {7') 
 
 88.27 
 90-73 
 93-25 
 
 95-84 
 97.16 
 98.49 
 
 99.84 
 
 IOI.2I 
 
 102.60 
 104.00 
 
 105.42 
 106.86 
 
 108.32 
 
 109.79 
 
 111.29 
 
 112.80 
 
 114-33 
 
 115.88 
 
 117-45 
 
 119.04 
 120.65 
 
 123-93 
 
 125.60 
 
 127.29 
 
 129.01 
 
 130.75 
 
 132.50 
 134.28 
 
 136.09 
 
 137.92 
 
 139-77 
 141.65 
 
 T43-54 
 T45-47 
 147.42 
 
 Diff. 
 
 246 
 
 252 
 259 
 
 132 
 133 
 
 135 I 
 
 137 
 139 
 140 
 
 142 
 144 
 146 
 
 147 
 150 
 151 
 
 153 
 
 155 
 157 
 
 159 
 i6i 
 163 
 
 165 
 167 
 169 
 
 172 
 174 
 
 175 
 
 178 
 181 
 183 
 
 185 
 188 
 
 193 
 195 
 197 
 
 7 
 
 /{v) 
 
 0.05632 
 0.05738 
 0.05845 
 
 0.05955 
 
 0.06010 
 0.06066 
 
 0.06123 
 0.06180 
 0.06238 
 
 0.06296 
 
 0.06355 
 
 0.06414 
 0.06474 
 
 0.06534 
 0.06595 
 
 0.06657 
 0.06719 
 0,06782 
 
 0.06846 
 0.06910 
 
 0.06975 
 
 0.07040 
 0.07106 
 
 0.07173 
 
 0.07241 
 
 0.07309 
 0.07378 
 
 0.07447 
 0.07517 
 0.07588 
 
 0.07660 
 
 0.07732 
 0.07805 
 
 0.07879 
 
 0.07954 
 
 0.08029 
 
 Diff. 
 
 106 
 107 
 
 55 
 56 
 
 57 
 
 57 
 58 
 58 
 
 59 
 59 
 60 
 
 60 
 61 
 62 
 
 62 
 
 63 
 64 
 
 64 
 65 
 65 
 
 66 
 
 67 
 68 
 
 68 
 69 
 69 
 
 70 
 71 
 
 72 
 
 72 
 73 
 74 
 
 75 
 75 
 76 
 
 T{v)' 
 
 Diff. 
 
 1.804 
 
 1-831 
 1.858 
 
 27 
 27 
 27 
 
 1.885 
 1.899 
 
 14 
 14 
 
 1.913 
 
 14 
 
 1.927 
 
 14 
 
 1. 941 
 
 14 
 
 1-955 
 
 14 
 
 1.969 
 1.983 
 1.998 
 
 14 
 15 
 14 
 
 2.012 
 
 15 
 
 2.027 
 
 15 
 
 2.042 
 
 15 
 
 2.057 
 
 15 
 
 2.072 
 2.086 
 
 14 
 15 
 
 2.101 
 
 16 
 
 2. 117 
 
 15 
 
 2.132 
 
 15 
 
 2.147 
 2.162 
 
 15 
 16 
 
 2.J78 
 
 16 
 
 2.194 
 
 16 
 
 2.210 
 
 16 
 
 2.226 
 
 16 
 
 2.242 
 
 16 
 
 2.258 
 
 16 
 
 2.274 
 
 16 
 
 2.290 
 
 17 
 
 2.307 
 
 16 
 
 2.323 
 
 17 
 
 2-340 
 
 17 
 
 2-357 
 
 17 
 
 2.374 
 
 17 
 
TABLE I. -Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A {j^ 
 
 Diff. 
 
 7(7.) 
 
 Diff. 
 
 r{v) 
 
 Diff. 
 
 1435 
 1430 
 1425 
 
 4704.8 
 1 4729-4 
 
 i 4754-1 
 
 246 
 
 247 
 247 
 
 149-39 
 151-39 
 
 153-42 
 
 200 
 
 203 
 
 205 
 
 0.08105 
 0.08182 
 0.08260 
 
 77 
 78 
 78 
 
 2.391 
 2.408 
 2.425 
 
 18 
 
 1420 
 
 I4I5 
 
 I4I0 
 
 1 4778.8 
 1 4803.6 
 , 4828.5 
 
 248 
 249 
 
 250 
 
 155-47 
 T57-55 
 159.66 
 
 208 
 211 
 214 
 
 0.08338 
 0.08418 
 0.08498 
 
 80 
 81 
 81 
 
 2.443 
 2.460 
 
 2.478 
 
 1 
 
 17 
 
 18 
 18 
 
 1405 
 
 1400 
 
 1395. 
 
 ! 
 
 J 4853-5 
 i 4878.6 
 
 49P3-8 
 
 251 
 
 252 
 
 253 
 
 1 161.80 
 1 163.96 
 j 166.15 
 
 216 
 219 
 222 
 
 0.08579 
 0.08661 
 0.08744 
 
 82 
 
 83 
 84 
 
 2.496 
 2.514 
 2^-532 
 
 18 
 18 
 18 
 
 1390 
 
 1385 
 
 1380 
 
 4929-1 
 
 4954-5 
 
 j 4979-9 
 
 254 
 254 
 256 
 
 168.37 
 170.62 
 172.90 
 
 225 
 228 
 231 
 
 0.08828 
 0.08913 
 0.08999 
 
 85 
 86 
 
 87 
 
 2.550 
 2.568 
 
 2-587 
 
 18 
 
 19 
 18 
 
 1375 
 1370 
 
 '365 
 
 5005.5 
 
 ■ 5031-1 
 5056.8 
 
 256 
 
 257 
 258 
 
 175.21 
 
 177-55 
 179.92 
 
 234 
 237 
 241 
 
 0.09086 
 0.09173 
 0.09262 
 
 87 
 89 
 89 
 
 2.605 
 2.624 
 2.643 
 
 19 
 19 
 19 
 
 1360 
 
 1355 
 1350 
 
 5082.6 
 
 ! 5108.6 
 5134.6 
 
 260 
 260 
 261 
 
 182.33 
 184.76 
 187.23 
 
 243 
 247 
 250 
 
 0.09351 
 c. 09442 
 0-09533 
 
 91 
 91 
 
 93 
 
 2.662 
 2.681 
 
 2.700 
 
 19 
 
 19 
 
 .19 
 
 1345 
 1340 
 
 1335 
 
 5160.7 
 5186.9 
 5213-2 
 
 262 i 
 263' 
 
 263 , 
 
 1 
 
 189.73 
 192.27 
 194.84 
 
 254 
 
 257 
 260 
 
 0.09626 
 0.09719 
 0.09813 
 
 94 
 94 
 95 
 
 2.719 
 
 2-739 
 
 2-758 
 
 20 
 
 •9 
 
 20 
 
 1330 
 1325 
 
 1320 
 
 5239-5 
 5265.8 
 5292.0 
 
 263! 
 
 262 j 
 106 , 
 
 197.44 
 200.06 
 202.69 
 
 262 
 263 
 107 
 
 0.09908 
 0.10004 
 o.idioi 
 
 96 1 
 
 97 
 
 39 
 
 2-778 
 2.798 
 2.818 
 
 20 
 
 20 
 
 8 
 
 I3I8 
 I3I6 
 I3I4 
 
 5302.6 
 
 53^3-2 
 5323-8 
 
 106 : 
 
 106 
 
 107 
 
 203.76 
 204.84 
 205.92 
 
 108 
 108 
 109 
 
 0.10140 
 0.10179 
 0.10219 
 
 39 1 
 
 40 1 
 
 40' 
 
 2.826 
 
 2.834 
 2.842 
 
 8 
 8 
 8 
 
 I3I2 
 I3I0 
 
 .1308 
 
 5334-5 
 5345-2 
 5355-9 
 
 107 
 
 107 
 108 
 
 207.01 
 208.11 
 209.22 
 
 I 10 
 I r I 
 
 III! 
 
 1 
 
 0.10259 
 0.10299 
 0.10339 
 
 40 
 40 
 41 
 
 2.850 
 2.858 
 2.866 
 
 8 
 8 
 9 
 
 1306 
 
 1304 
 1302 
 
 5366.7 
 
 5377-5 
 
 108 
 108 
 109 
 
 210.33 
 
 211.45 
 
 •212.58 
 
 1 
 112 
 
 113 
 114 
 
 0.10380 
 0.10421 
 0.10462 
 
 41 
 41 
 41 
 
 2.875 
 2.883 
 2.892 
 
 8 
 
 9 
 8 
 
 1300 
 1298 
 1296 
 
 5399-2 
 5410.1 
 
 5421.0 
 
 109 
 109 
 
 no 
 
 213.72 
 214.87 
 216.02 1 
 
 115 
 115 
 
 117 
 
 0.10503 
 0.10544 
 0.10586 
 
 41 
 42 
 42 
 
 2.900 
 2.908 
 2.917 
 
 8 
 
 9 
 
 8 
 
TABLE I.— Continued. 
 
 V 
 
 Six,) 
 
 1 
 
 Diff. 
 
 1 
 
 A{v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 I 
 
 : T{v) 
 
 Diff. 
 
 1294 
 
 I 292 
 1290 
 
 5432.0 
 
 5443-0 
 5454.0 
 
 no 
 no 
 III 
 
 1 
 
 1 217.19 
 
 1 218.36 
 
 ! 219.54 
 
 1 
 
 117 
 118 
 119 
 
 0.10628 
 0.10670 
 
 0.10713 
 
 42 
 43 
 43 
 
 1 2.925 
 
 2.934 
 
 1 2.942 
 
 9 
 
 8 
 8 
 
 1288 
 1286 
 
 T284 
 
 5465.1 
 5476.2 
 
 5487.3 
 
 III 
 III 
 112 
 
 220.73 
 221.93 
 223.13 
 
 120 
 120 
 122 
 
 0.10756 
 0.10799 
 0.10842 
 
 43 
 43 
 44 
 
 ! 2.950 
 
 1 2.959 
 
 2.968 
 
 9 
 9 
 9 
 
 1282 
 1280 
 1278 
 
 549«-5 
 5509-7 
 5521.0 
 
 112 
 113 
 113; 
 
 224.35 
 225.57 
 226.80 
 
 122 
 123 
 124 
 
 0.10886 
 0.10930 
 
 0.10974 
 
 44 
 44 
 45 
 
 2.977 
 2.985 
 2.994 
 
 8 
 
 9 
 9 
 
 1276 
 
 1274 
 1272 
 
 5532.3 
 5543-6 
 5554-9 
 
 113 i 
 113! 
 
 114 
 
 228.04 
 229.29 
 230.54 
 
 125; 
 
 125 
 
 127 ! 
 
 0.I10I9 
 0.11064 
 0.11109 
 
 45 
 45 
 45 
 
 3.003 
 3.012 
 3.021 
 
 9 
 9 
 9 
 
 1270 
 
 1268 
 1266 
 
 i 5566.3 
 
 5589-1 
 
 114 
 114 
 115 
 
 231.81 
 234.37 
 
 127 
 129 
 J29 
 
 0.11154 
 0.11200 
 0.11246 
 
 46 
 46 
 46 
 
 3-030 
 
 3-039 
 3.048 
 
 9 
 9 
 9 
 
 1264 
 J262 
 1260 
 
 5600.6 
 5612.1 
 5623.7 
 
 115 
 116 
 
 116! 
 
 1 
 
 235-66 
 236.97 
 238.28 
 
 13.1 1 
 
 131 1 
 
 132 1 
 
 0.11292 
 0.11338 
 O.I 1385 
 
 46 
 47 
 
 47 
 
 3-057 
 3.066 
 
 3-075 
 
 9 
 9 
 9 
 
 1258 
 
 1256 
 
 •1254 
 
 5635-3 
 5647.0 
 5658.6 
 
 117 
 116 
 117 
 
 239.60 
 240.94 
 
 242.28 
 
 134: 
 134 i 
 136! 
 
 0.11432 
 O.II479 
 0.11527 
 
 47 
 48 
 48 
 
 3.084 
 3-094 
 3-103 
 
 10 
 
 9 
 10 
 
 1252 
 1250 
 1248 
 
 5670.3 
 5682.1 
 
 5693-9 
 
 118 
 118 
 118 
 
 1 
 
 243-64 
 245.00 
 246.37 
 
 136 1 
 
 1371 
 139' 
 
 O.II575 
 O.I1623 
 0.11671 
 
 48 
 48 
 49 
 
 3-1^3 
 3.122 
 
 9 
 
 9 
 
 10 
 
 1246 
 
 1244 
 1242 
 
 5705-7 
 5717-6 
 5729-5 
 
 119 
 119 
 119 
 
 247.76 
 249-15 
 
 250-55 
 
 139; 
 140 i 
 142 
 
 O.II72O 
 O.II769 
 0.11819 
 
 49 
 
 50 
 
 50 
 
 3-141 
 3-150 
 3.160 
 
 9 
 10 
 
 9 
 
 1240 
 
 1238 
 
 1236 
 
 5741.4 
 5753-4 
 5765.4 
 
 120 
 120 
 121 
 
 251.97 
 
 253-39 
 
 254.83 
 
 142 
 
 144 j 
 
 144 
 
 0.11869 
 O.II919 
 0.11969 
 
 50 
 50 
 5^ 
 
 3.169 
 
 3-179 
 3-189 
 
 10 
 
 10 
 
 9 
 
 1234 
 1232 ; 
 1230 
 
 5777-5 
 5789.6 
 5801.7 
 
 121 
 121 
 122 
 
 256.27 
 
 257.73 
 259.20 
 
 146! 
 
 147 1 
 
 148 ■ 
 
 0.12020 
 O.T2071 
 0.12123 
 
 51 
 
 52 
 52 
 
 3-198 
 3.208 
 3.218 
 
 10 
 10 
 10 
 
TABLE L— Continued. 
 
 V 
 
 S{v) 
 
 Diff. j 
 
 1228 
 1226 
 
 1224 
 
 5813.9 
 5826.1 
 
 5838.4 
 
 i 
 122 
 
 123 
 123! 
 
 1222 
 1220 
 I218 
 
 5850.7 
 5863.0 
 
 5875-4 
 
 123 
 124 
 124 
 
 I216 
 I 2 14 
 I2I2 
 
 5887.8 
 
 5900.3 
 
 1 5912.8 
 
 125 i 
 
 125 1 
 125 
 
 I2IO 
 1208 
 1206 
 
 5925.3 
 5937-9 
 
 1 5950.5 
 
 126 
 126 
 127 
 
 I 204 
 1202 
 1200 
 
 5963.2 
 
 5975-9 
 5988.6 
 
 127I 
 
 127 
 
 128 
 
 1 
 
 II98 
 II96 
 II94 
 
 6001.4 
 6014.2 
 6027.1 
 
 128 
 129 
 129 
 
 1 
 
 II92 
 I 1 90 
 
 I188 
 
 6040.0 
 6053.0 
 6066.0 
 
 130 
 130 
 131 
 
 I 186 
 I 184 
 I182 
 
 6079.1 
 6092.2 
 6105.3 
 
 131 
 131 
 
 132 ! 
 
 1 
 
 I180 
 II78 
 II76 
 
 6118.5 
 
 6131-7 
 6145.0 
 
 132 
 
 II74 
 II72 
 II70 
 
 6158.3 
 6171.7 
 6185. I 
 
 134 
 134! 
 
 135 ! 
 
 I168 
 I166 
 1 164 
 
 6198.6 
 6212. 1 
 6225.6 
 
 135 
 135 
 136' 
 
 A{v) 
 
 260.68 
 262.17 
 263.67 
 
 265.18 
 266.71 
 268.24 
 
 269.79 
 
 271-35 
 272.92 
 
 274.51 
 276.11 
 
 277.72 
 
 279.34 
 280.97 
 282.62 
 
 284.28 
 
 285.95 
 287.63 
 
 289.33 
 291.04 
 292.76 
 
 294.50 
 296.25 
 298.02 
 
 299.80 
 
 301.59 
 303-40 
 
 305.22 
 307.06 
 308.91 
 
 310.77 
 312.65 
 
 314-55 
 
 Diff. 
 
 i 
 
 149 
 
 150 
 151 
 
 I{v) 
 
 Diff. 
 
 r(z/) 
 
 O.I2I75 
 
 0.12227 
 0.12280 
 
 52 
 53 
 53 
 
 ! 
 
 3.228 
 3-238 
 3-M8 
 
 '53 
 153 
 
 155 
 
 0.12333 
 0.12386 
 0.12439 
 
 53 
 53 
 54 
 
 3-258 
 3.268 
 3-278 
 
 156 
 
 \ 157 
 
 159 
 
 0.12493 
 
 0.12547 
 
 O.T2602 
 
 54 
 55 
 
 55 
 
 3.288 
 
 1 3-299 
 
 3-309 
 
 1 160 
 i 161 
 1 162 
 
 0.12657 
 
 O.I 27 I 2 
 0.12768 
 
 55 
 56 
 56 
 
 1 3-319 
 
 i 3-329 
 
 3-340 
 
 163 
 
 165 
 166 
 
 0.12824 
 0.12881 
 0.12938 
 
 57 
 57 
 57 
 
 3-350 
 3-361 
 3-371 
 
 167 
 168 
 170 
 
 0.12995 
 
 O.T3053 
 O.I3III 
 
 58 
 58 
 58 
 
 3-382 
 3-393 
 3.404 
 
 171 
 
 172 
 1.74 
 
 O.I3169 
 0.13228 
 0.13287 
 
 59 
 59 
 60 
 
 3.415 
 3.426 
 
 3.437 
 
 175 
 177 
 178 
 
 0.13347 
 0.13407 
 
 0.13467 
 
 60 
 60 
 61 
 
 3.448 
 3.459 
 3.470 
 
 179 
 181 
 182 
 
 0.13528 
 
 0.13589 
 0.13651 
 
 61 
 62 
 62 
 
 3.481 
 3.492 
 
 3.504 
 
 i 
 
 184 
 
 185 
 186 
 
 O.I3713 
 0.13776 
 
 0.13839 
 
 63 
 63 
 63 
 
 3.515 
 3-527 
 
 3-538 ! 
 
 188 
 190 
 191 
 
 0.13902 
 0.13966 
 
 O.T403O 
 
 64 
 64 
 
 65 
 
 3-550 
 3-561 
 
 3-573' 
 
 Diff. 
 
TABLE 1.— Continued. 
 
 S{v) 
 
 Diff. 
 
 162 
 160 
 159 
 
 158 
 157 
 156 
 
 1531 
 
 152 
 151 
 150 
 
 149 
 
 148 
 
 147 
 
 146 
 
 145 
 144 
 
 143 
 142 
 141 
 
 140 
 
 139 
 138 
 
 137 
 136 
 135 
 
 134 
 133 
 132 
 
 131 
 130 
 129 
 
 6239.2 
 6252.8 
 6259.7 
 
 6266.6 
 
 6273.4 
 6280.3 
 
 6287.2 
 6294.1 
 6301.0 
 
 6307.9 
 6314.8 
 6321.8 
 
 6328.8 
 
 6335-7 
 6342.7 
 
 63497 
 6356.7 
 63637 
 
 6370.7 
 6377.8 
 6384.8 
 
 6391.9 
 6399.0 
 
 6406. T 
 
 6413.2 
 6420.3 
 6427.4 
 
 6434.6 
 6441.7 
 6448.9 
 
 6456.1 
 
 6463.3 
 6470.4 
 
 136 
 69 
 69 
 
 68 
 69 
 69 
 
 69 
 69 
 69 
 
 69 
 
 70 
 70 
 
 69 
 
 70 
 70 
 
 70 
 70 
 70 
 
 71 
 
 70 
 
 71 
 
 71 
 7T 
 71 
 
 72 
 
 71 
 
 72 
 72 
 
 72 
 
 71 
 
 72 
 
 A {7') 
 
 316.46 
 
 318.39 
 31936 
 
 320.34 
 321.32 
 322.30 
 
 323.28 
 324.27 
 325.26 
 
 326.26 
 
 327.26 
 
 328.27 
 
 329.28 
 330.29 
 331-31 
 
 33^-33 
 333-3^ 
 334-39 
 
 335-43 
 336.47 
 337-51 
 
 338.56 
 339-61 
 340.67 
 
 341.73 
 342.79 
 343-^6 
 
 344-94 
 346.02 
 
 347.10 
 
 348.19 
 349.28 
 
 350.38 
 
 )iff. 
 
 1(7') 
 
 1 
 
 Diff. 
 
 193 
 
 97 
 98 
 
 i 
 I 
 0.14095 
 
 O.I4160 
 
 O.I4I92 
 
 65 
 33 
 
 98 
 98 
 98 
 
 0.14225 
 0.14258 
 O.I429I 
 
 33 
 33 
 
 33 
 
 99 
 99 
 
 1 0.14324 
 1 0.14358 
 
 34 
 33 ! 
 
 T(v) 
 
 Diff. 
 
 100 
 
 lOI 
 lOI 
 
 lOI 
 
 102 
 102 
 
 103 
 
 103 
 104 
 
 104 
 104 
 
 105 
 105 
 
 106 
 106 
 
 106 
 
 107 
 
 108 
 
 108 
 108 
 
 109 
 
 109 
 1 10 
 
 109 
 
 II 
 
 -.--too-! 
 10.14391 
 
 0.14425 
 
 0.14458 
 
 \ 0.14492 
 
 i 0.14526 
 1 0.14560 
 1 0.14594 
 
 i O.T4628 
 
 ; 0.14662 
 0.14697 
 
 0.14731 
 0.14766 
 0.1 480 1 
 
 0.14836 
 
 0.14871 
 i 0.14906 
 
 0.14942 
 0.14977 
 0.15013 
 
 0.15049 
 0.15085 
 0.15121 
 
 ^0.15157 
 io.15193 
 ' 0.15229 
 
 34 
 
 33 
 34 
 34 
 
 34 
 34 
 34 
 
 34 
 
 35 
 34 
 
 35 
 35 
 35 
 
 35 
 35 
 36 
 
 35 
 36 
 36 
 
 36 
 36 
 36 
 
 36 
 36 
 
 3-584 
 3-596 
 3.602 
 
 3.608 
 3.614 
 3.62c 
 
 3.626 
 3-632 
 3-^3^ 
 
 3-644 
 3-650 
 3656 
 
 3.662 
 3.668 
 3-674 
 
 3-680 
 3.686 
 3-693 
 
 3-699 
 3-705 
 3. 711 
 
 3-717 
 3-723 
 3-730 
 
 3-736 
 
 3-742 
 3-748 
 
 3-755 
 3-761 
 3-767 
 
 3-774 
 3-780 
 3.786 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 Ah) 
 
 Diff. 
 
 I{z) 
 
 Diff. 
 
 T (7') 
 
 Diff. 
 
 II28 
 1.27 
 
 II26 
 
 6477-6 
 6484.8 
 6492.1 
 
 72 
 
 73 
 72 
 
 351 47 
 352-57 
 353-68 
 
 no 
 III 
 111 
 
 0.15265 
 
 0.15302 
 0.15338 
 
 37 
 36 
 37 
 
 3-793 
 
 3-799 
 3.806 
 
 6 
 
 7 
 6 
 
 II25 
 
 II24 
 
 6499.3 
 6506.6 
 
 73 
 73 
 
 354-79 
 355-90 
 
 II I j 
 113 
 
 0.15375 
 O.I54I2 
 
 ^7 
 37 
 
 3.812 
 3-818 
 
 6 
 7 
 
 II23 
 
 65139 
 
 73 
 
 357-03 
 
 113 1 
 
 0.15449 
 
 38 1 
 
 3-825 
 
 6 
 
 II22 i 
 II2I 1 
 II20 
 
 6521.2 
 6528.6 
 6536.0 
 
 74 
 74 
 74 
 
 358.16 
 35930 
 36045 
 
 114 
 115 
 115 
 
 0.15487 
 
 0.15524 
 15562 
 
 37 1 
 38; 
 
 38 1 
 
 3.831 
 3-838 
 3-844 
 
 7 
 6 
 
 7 
 
 III9 
 II18 
 I I 17 
 
 6543-4 
 6550-8 
 6558-3 
 
 74 
 
 75 
 75 
 
 361.60 
 362.76 
 36392 
 
 116 
 116 
 117 
 
 0.15600 
 
 0.15638 
 0.15676 
 
 38 
 38 
 39 
 
 3-851 
 3.858 
 3.864 
 
 7 
 6 
 
 7 
 
 II16 
 11 14 
 
 6565.8 
 
 ^573-3 
 6580.8 
 
 75 
 75 
 76 
 
 365-09 
 366.28 
 
 367-47 
 
 119 
 119 
 
 120 
 
 0.15715 
 0.15754 
 0.15793 
 
 39 
 39 
 39 
 
 1 3.871 
 3.878 
 3-885 
 
 7 
 7 
 7 
 
 III3 
 II12 
 
 6588.4 
 6596.0 
 
 76 
 
 77 
 
 368.67 
 369.88 
 
 121 
 121 
 
 0.15832 
 
 0.15872 
 
 40 
 40 
 
 3.892 
 3.898 
 
 6 
 
 7 
 
 IIII 
 
 6603.7 
 
 77 
 
 37109 
 
 123 
 
 0.15912 
 
 40 
 
 3905 
 
 • 
 
 7 
 
 TIIO 
 
 6611.4 
 
 77 
 
 372.32 
 
 123 
 
 0.15952 
 
 41 
 
 3912 
 
 7 
 
 1 109 
 1108 
 
 6619. 1 
 6626.9 
 
 78 
 78 
 
 373-55 
 374-79 
 
 124 
 125 
 
 O.T5993 
 0.16033 
 
 40 
 41 
 
 3.919 
 3926 
 
 1 
 
 7 
 7 
 
 ITO7 
 I 106 
 1 105 
 
 6634.7 
 6642.5 
 6650.3 
 
 78 
 78 
 79 
 
 376.04 
 
 377-30 
 
 i 37857 
 
 126 
 127 
 128 
 
 0.16074 
 0.16115 
 0.16157 
 
 41 
 
 42 
 
 41 
 
 3-933 
 3940 
 3-947 
 
 7 
 7 
 8 
 
 1 104 
 I 103 
 II02 
 
 6658.2 
 6666.2 
 6674.1 
 
 80 
 
 79 
 
 80 
 
 379-85 
 381.14 
 
 382.44 
 
 129 
 130 
 131 
 
 0.16198 
 0.16240 
 0.16282 
 
 42 
 42 
 43 
 
 3-955 
 3-962 
 
 3-969 
 
 7 
 7 
 7 
 
 IIOI 
 I 100 
 1099 
 
 6682.1 
 6690.2 
 6698.3 
 
 81 
 81 
 81 
 
 j 383-75 
 38506 
 
 T31 
 132 
 
 0.16325 
 0.16367 
 0.16410 
 
 42 
 43 
 43 
 
 3-976 
 3-983 
 3-991 
 
 7 
 8 
 
 7 
 
 1098 
 1097 
 1096 
 
 6706.4 
 
 6714-5 
 6722.7 
 
 81 
 82 
 83 
 
 387-71 
 389.06 
 
 ' 39041 
 
 135 
 135 
 137 
 
 0.16453 
 0.16497 
 0.16541 
 
 44 
 44 
 44 
 
 3-998 
 4.006 
 
 4013 
 
 8 
 
 7 
 8 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A^zi) 
 
 Difif. 
 
 nv) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 1094 1 
 1093 i 
 
 6731.0 
 6739.2 
 6747-5 
 
 82 
 
 83 
 
 84 
 
 391-78 
 393-15 
 394-53 
 
 137 
 138 
 
 140 
 
 0.16585 
 0.16629 
 0.16674 
 
 44 
 45 
 45 
 
 4.021 
 4.029 
 4-036 
 
 8 
 
 7 
 8 
 
 1092 
 I09I 
 
 1090 1 
 
 6755-9 
 6764.3 
 6772.7 
 
 84 
 84 
 85 
 
 395-93 
 397.34 
 398.75 
 
 141 
 141 
 142 
 
 0.16719 
 0.16764 
 0.16810 
 
 45 
 46 
 46 
 
 4-044 
 4.051 
 4.059 
 
 7 
 8 
 8 
 
 1089 
 
 1088 
 1087 
 
 6781.2 
 6789.7 
 6798.2 
 
 85 
 85 
 86 
 
 400.17 
 401.60 
 403-05 
 
 143 
 145 
 145 
 
 0.16856 
 0.16902 
 0.16948 
 
 46. 
 46 
 
 47 
 
 4.067 
 
 4.075 
 4.083 
 
 8 
 8 
 8 
 
 1086 
 1085 j 
 
 1084 
 
 6806.8 
 6815.4 
 6824.1 
 
 86 1 
 
 87 
 
 87 
 
 1 404-50 
 405.97 
 407-45 
 
 147 
 148 
 149 
 
 0.16995 
 
 0.17042 
 0.17089 
 
 47 
 47 
 48 
 
 ' 4.091 
 4.098 
 4.106 
 
 7 
 8 
 8 
 
 1083 
 
 T082 
 I08I 
 
 6832.8 
 
 6841.5 
 6850.3 
 
 87 
 88 
 88 
 
 408.94 
 410.44 
 411.95 
 
 150 
 151 
 152 
 
 0.17137 
 
 0.17185 
 0.17233 
 
 48 
 48 
 
 49 
 
 4.114 
 4.122 
 4.130 
 
 8 
 8 
 8 
 
 1080 
 
 1079 
 1078 
 
 6859.1 
 6867.9 
 6876.8 
 
 88 
 89 
 90 
 
 413-47 
 415.00 
 
 416.54 
 
 153 
 154 
 156 
 
 0.17282 
 
 0.17331 
 0.17380 
 
 49 
 49 
 49 
 
 4.138 
 4.146 
 
 4.155 
 
 8 
 
 9 
 8 
 
 1077 
 
 1076 
 
 1075 
 
 6885.8 
 6894.7 
 6903.7 
 
 89 
 90 
 
 91 
 
 418.10 
 419.66 
 421.24 
 
 156 
 158 
 159 
 
 0.17429 
 
 0.17479 
 0.17529 
 
 50 
 50 
 51 
 
 4.163 
 4.172 
 4.180 
 
 9 
 
 8 
 
 9 
 
 1074 
 
 ro73 
 1072 
 
 6912.8 
 6921.9 
 6931. 1 
 
 91 
 92 
 92 
 
 422.83 
 424.44 
 426.06 
 
 161 
 162 
 163 
 
 0.17580 
 0.17631 
 0.17682 
 
 51 
 51 
 51 
 
 4.189 
 
 4.197 
 4.206 
 
 8 
 
 9 
 
 8 
 
 1071 
 
 1070 
 1069 
 
 6940.3 
 6949.5 
 6958.8 
 
 92 
 93 
 93 
 
 427.69 
 
 429.33 
 430.98 
 
 164 
 
 165 
 166 
 
 0.17733 
 0.17785 
 
 0.17837 
 
 52 
 
 52 
 53 
 
 4.214 
 4.223 
 4.232 
 
 9 
 9 
 9 
 
 1068 
 1067 
 1066 
 
 6968.1 
 
 6977-5 
 6986.9 
 
 94 
 94 
 94 
 
 432.64 
 
 434.32 
 436.01 
 
 168 
 169 
 171 
 
 0.17890 
 
 0.17943 
 0.17996 
 
 53 
 53 
 53 
 
 4.241 
 
 4.250 
 
 i 4.259 
 
 9 
 9 
 9 
 
 1065 
 1064 
 1063 
 
 6996.3 
 
 7005.8 
 7015-4 
 
 95 
 96 
 96 
 
 437.72 
 439-44 
 441.17 
 
 172 
 173 
 175 
 
 0.18049 
 0.18103 
 0.18158 
 
 54 
 
 55 
 55 
 
 4.268 
 
 4.277 
 . 4.286 
 
 9 
 9 
 9 
 
 ^3 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A (v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 1 T{v) 
 
 1 
 
 Diff. 
 
 1062 
 1061 
 1060 
 
 7025.0 
 7034.6 
 7044-3 
 
 96 
 97 
 97 
 
 442.92 
 444-68 
 446.45 
 
 176 
 
 177 
 178 
 
 0.18213 
 0.18268 
 0.18323 
 
 55 
 55 
 56 
 
 1 
 
 1 4-295 
 
 i 4-304 
 
 4-313 
 
 1 
 
 1 
 
 9 
 
 9 
 
 i 9 
 
 1059 
 1058 
 
 1057 
 
 7054.0 
 7063.8 
 7073.6 
 
 98 
 98 
 99 
 
 448.23 
 450-03 
 451.84 
 
 180 
 181 
 182 
 
 0.18379 
 
 0-18435 
 0.1 849 1 
 
 56 
 56 
 57 
 
 '] 4-322 
 4-332 
 4.341 
 
 10 
 9 
 9 
 
 1056 
 
 1055 
 1054 
 
 1 7083.5 
 7093-4 
 7103.4 
 
 99 
 100 
 100 
 
 453.66 
 
 455.50 
 457-36 
 
 184 
 186 
 
 187 
 
 0.18548 
 0.18605 
 0.18663 
 
 57 
 58 
 58 
 
 4-350 
 4-360 
 4-369 
 
 10 
 9 
 9 
 
 1053 
 
 1052 
 105 1 
 
 7113-4 
 7123.4 
 
 7133-5 
 
 100 
 
 lOI 
 I02 
 
 459.23 
 461.12 
 463.02 
 
 189 
 190 
 192 
 
 O.18721 
 0.18779 
 0.18838 
 
 58 
 59 
 59 
 
 4.378 
 4.387 
 4.397 
 
 9 
 10 
 
 9 
 
 1050 
 I049 
 1048 
 
 7143.7 
 
 7153-9 
 7164.1 
 
 102 
 I02 
 103 
 
 464-94 
 466.87 
 468.81 
 
 193 
 194 
 196 
 
 0.18897 
 0.18956 
 O.I 90 1 6 
 
 59 
 60 
 61 
 
 4.406 
 4.416 
 4.426 
 
 10 
 10 
 10 
 
 1047 
 1046 
 1045 
 
 7174-4 
 7184.7 
 
 7195-I 
 
 I03 
 104 
 
 105 
 
 470-77 
 472-74 
 474-73 
 
 197 
 199 
 201 
 
 0.19077 
 0.19138 
 0.19199 
 
 61 
 61 
 61 
 
 4.436 
 4.446 
 
 4-455 
 
 10 
 
 9 
 10 
 
 1044 
 
 1043 
 1042 
 
 7205.6 
 7216.1 
 7226.6 
 
 105 
 
 105 
 
 106 
 
 476.74 
 
 478.77 
 480.81 
 
 203 
 204 
 206 
 
 0.19260 
 0.19322 
 0.19385 
 
 62 
 63 
 
 4-465 
 4-475 
 4-485 
 
 10 
 10 
 10 
 
 1041 
 1040 
 1039 
 
 7237.2 
 7247.9 
 7258.6 
 
 107 
 107 
 107 
 
 482.87 
 
 484.95 
 487.04 
 
 208 
 209 
 211 
 
 0.19448 
 0.19511 
 
 0-19575 
 
 ^3 
 64 
 64 
 
 4-495 
 4-505 
 4-516 
 
 10 
 II 
 10 
 
 1038 
 
 1037 
 1036 
 
 7269.3 
 7280.1 
 7291.0 
 
 108 
 
 109 
 109 
 
 489-15 
 491.28 
 
 493.42 
 
 213 
 214 
 216 
 
 0-19639 
 0.19703 
 0.19768 
 
 64 
 
 65 
 66 
 
 4-526 
 
 4.537 
 4.547 
 
 II 
 
 10 
 II 
 
 1035 
 1034 
 
 7301.9 
 7312.9 
 
 73239 
 
 no 
 no 
 III 
 
 495.58 
 497.76 
 499-95 
 
 218 
 219 
 222 
 
 0.19834 
 0.19900 
 0.19966 
 
 66 
 66 
 67 
 
 4.558 
 4-569 
 4-579 
 
 II 
 10 
 II 
 
 1032 
 1031 
 1030 
 
 7335.0 
 7346.1 
 7357.3 
 
 III 
 112 
 112 
 
 502.17 
 504.40 
 506.65 ' 
 
 223 
 225 
 226 1 
 
 0.20033 
 0.20100 
 0.20168 
 
 67 
 68 
 68 
 
 4-590 
 4.600 
 4.611 
 
 10 
 II 
 II 
 
 14 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T{.v) 
 
 Diff. 
 
 1029 
 
 1028 
 
 1027 
 
 7368.5 
 7379-8 
 739I-I 
 
 113 
 113 
 114 
 
 i 
 
 508.91 
 511.20 
 513-50 
 
 229 
 230 
 
 232 
 
 1 
 
 0.20236 
 0.20305 
 0.20374 
 
 69 
 69 
 69 
 
 4.622 
 4-633 
 4.645 
 
 II 
 12 
 II 
 
 1026 
 1025 
 1024 
 
 7402.5 
 7414.0 
 
 7425-5 
 
 115 
 115 
 116 
 
 515-82 
 518.17 
 
 520.54 
 
 235 
 237 
 238 
 
 0.20443 
 0.20513 
 0.20584 
 
 70 
 71 
 71 
 
 4.656 
 4.667 
 4.678 
 
 II 
 II 
 II 
 
 1023 
 
 1022 
 
 I02I 
 
 7437-1 
 7448.7 
 7460.4 
 
 116 
 117 
 117 
 
 522.92 
 
 525-32 
 527-75 
 
 240, 
 
 243 
 
 245 
 
 0.20655 
 0.20726 
 0.20798 
 
 71 
 
 72 
 
 73 
 
 4.689 
 4.701 
 4.712 
 
 12 
 II 
 II 
 
 1020 
 IOI9 
 IO18 
 
 7472.1 
 7483.9 
 7495.7 
 
 118 
 118 
 ii9| 
 
 530.20 
 532.66 
 535-14 
 
 ! 
 246 
 248 
 251 
 
 0.20871 
 0.20944 
 O.21017 
 
 73 
 73 
 74 
 
 4.723 
 4.735 
 4-747 
 
 12 
 12 
 12 
 
 ICI7 
 IO16 
 IOI5 
 
 7507.6 
 7519-6 
 7531-6 
 
 120 
 120 
 121 
 
 537-65 
 
 540.17 
 542.72 
 
 252 
 255 
 258 
 
 O.21091 
 0.2 1 165 
 0.21240 
 
 1 
 
 74 
 75 
 76 
 
 4.759 
 4.771 
 4-782 
 
 12 
 II 
 12 
 
 IOI4 
 IOI3 
 IOI2 
 
 7543-7 
 7555-8 
 7568.0 
 
 121 
 122 
 123 
 
 545-30 
 547-89 
 
 550.51 
 
 259 
 262 
 
 265 
 
 O.21316 
 0.21392 
 0.21468 
 
 76 
 76 
 77 
 
 4.794 
 4.806 
 4.818 
 
 12 
 12 
 12 
 
 lOII 
 lOIO 
 1009 
 
 7580.3 
 7592.6 
 7605.0 
 
 123 
 124 
 124 
 
 553-i6 
 
 555-82 
 558-51 
 
 266 
 269 
 
 272 
 
 0.21545 
 0.21623 
 O.21701 
 
 78 
 78 
 79 
 
 4.830 
 4.842 
 
 4.855 
 
 12 
 
 13 
 
 12 
 
 1008 
 1007 
 1006 
 
 7617.4 
 7629.9 
 7642.5 
 
 125 
 126 
 
 1.6 
 
 561.23 
 563.96 
 566.71 
 
 273 
 
 275 
 278 
 
 0.21780 
 0.21859 
 0.21939 
 
 79 
 80 
 80 
 
 4.867 
 4.880 
 4.892 
 
 13 
 12 
 
 13 
 
 1005 
 1004 
 1003 
 
 7655-1 
 7667.8 
 7680.6 
 
 127 
 128 
 128 
 
 569-49 
 572.29 
 
 575.11 
 
 280 
 282 
 285 
 
 0.22019 
 0.22100 
 0.22182 
 
 81 
 82 
 82 
 
 4.905 
 4.918 
 
 4-930 
 
 13 
 12 
 
 13 
 
 1002 
 lOOI 
 
 1000 
 
 7693-4 
 7706.3 
 
 7719-3 
 
 129 
 130 
 131 
 
 577-96 
 580.83 
 
 583-72 
 
 287 
 289 
 292 
 
 0.22264 
 0.22347 
 0.22430 
 
 83 
 83 
 84 
 
 4.943 
 4.955 
 4.968 
 
 12 
 13 
 13 
 
 999 
 998 
 
 997 
 
 7732.4 
 7745-6 
 7758.8 
 
 132 
 132 
 133 
 
 586.64 
 
 589-59 
 592.56 
 
 295 
 297 
 300 
 
 0.22514 
 0.22599 
 0.22684 
 
 85 
 85 
 86 
 
 4.981 
 
 4.995 
 5.008 
 
 14 
 13 
 14 
 
 15 
 
TABLE I.— Continued. 
 
 V 
 
 S\v) 
 
 Diff. 
 
 A{t^ 
 
 Diff. 
 
 /(zO 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 996 
 
 995 
 994 
 
 7772.1 
 
 7785.4 
 7798.7 
 
 134 
 
 595.56 
 
 598.59 
 601.65 
 
 303 
 306 
 
 Z^9 
 
 0.22770 
 0.22857 
 0.22944 
 
 87 
 87 
 87 
 
 5.022 
 
 5.035 
 5.048 
 
 T3 
 13 
 14 
 
 993 
 992 
 991 
 
 7812. 1 
 
 7825.5 
 7839.0 
 
 134 
 135 
 135 
 
 604.74 
 607.85 
 610.99 
 
 311 
 314 
 317 
 
 0.23031 
 0.23118 
 0.23206 
 
 87 
 88 
 
 89 
 
 5.062 
 
 5-075 
 5.089 
 
 13 
 14 
 13 
 
 990 
 989 
 988 
 
 7852.5 
 7866.1 
 7879.7 
 
 136 
 136 
 137 
 
 614.16 
 
 617.33 
 620.52 
 
 317 
 
 319 
 321 
 
 0.23295 
 0.23384 
 0.23474 
 
 89 
 90 
 90 
 
 5.102 
 5. 116 
 5-130 
 
 14 
 14 
 14 
 
 987 
 986 
 985 
 
 7893.4 
 7907.1 
 7920.8 
 
 137 
 ^37 
 137 
 
 623.73 
 626.96 
 630.21 
 
 323 
 325 
 327 
 
 0.23564 
 0.23655 
 0.23746 
 
 91 
 91 
 91 
 
 5-144 
 5.158 
 5-171 
 
 14 
 13 
 14 
 
 984 
 
 983 
 982 
 
 7934-5 
 7948.3 
 7962.1 
 
 138 
 138 
 138 
 
 633-48 
 636.77 
 640.08 
 
 329 
 
 0.23837 
 0.23929 
 0.24021 
 
 92 
 92 
 92 
 
 5.185 
 5.199 
 5.213 
 
 14 
 14 
 14 
 
 981 
 980 
 979 
 
 7975-9 
 7989.8 
 8003.7 
 
 139 
 139 
 139 
 
 643-41 
 646.76 
 650.12 
 
 335 
 339 
 
 0.24T13 
 0.24206 
 0.24299 
 
 93 
 93 
 93 
 
 5.227 
 5-241 
 
 5-255 
 
 14 
 14 
 15 
 
 978 
 
 977 
 976 
 
 8017.6 
 8031.5 
 
 8045.5 
 
 139 
 140 
 140 
 
 653-51 
 656.92 
 660.35 
 
 341 
 343 
 
 345 
 
 0.24392 
 0.24486 
 0.24580 
 
 94 
 94 
 95 
 
 5.270 
 5.284 
 5-299 
 
 14 
 15 
 14 
 
 975 
 974 
 973 
 
 8059.5 
 8073-5 
 8087.6 
 
 140 
 141 
 141 
 
 663.80 
 667.26 
 670.75 
 
 346 
 349 
 
 351 
 
 0.24675 
 
 0.24770 
 0.24865 
 
 95 
 95 
 96 
 
 5-3^3 
 
 5-327 
 5.342 
 
 14 
 15 
 14 
 
 972 
 971 
 970 
 
 8101.7 
 8115.8 
 8129.9 
 
 141 
 141 
 142 
 
 674.26 
 677.80 
 681.35 
 
 354 
 
 355 
 
 357 
 
 0.24961 
 
 0.25057 
 0.25154 
 
 96 
 97 
 97 
 
 5.356 
 5.371 
 5-385 
 
 15 
 14 
 15 
 
 969 
 968 
 967 
 
 8144. 1 
 
 8158.3 
 8172.5 
 
 142 
 142 
 143 
 
 684.92 
 688.51 
 692.12 
 
 359 
 361 
 
 363 1 
 
 0.25251 
 0.25348 
 0.25446 
 
 97 
 
 98 
 98 
 
 5.400 
 
 5.415 
 5-429 
 
 15 
 14 
 15 
 
 966 
 
 965 
 964 
 
 8i86.8 
 8201. 1 
 8215.4 
 
 143 
 143 
 144 
 
 695.75 
 699.41 
 
 703-09 
 
 366 
 368 
 
 370 
 
 0.25544 
 0.25643 
 0.25742 
 
 99 
 99 
 99 
 
 5-444 
 5-459 
 5-474 
 
 15 
 
 15 
 , 15 
 
 16 
 
TABLE 1.— Continued. 
 
 V 
 
 i 
 
 Diff. 
 
 A(v) 
 
 Diff. 
 
 /{v) 
 
 Diff. 
 
 T(v) 
 
 Diff. 
 
 963 
 
 962 
 961 
 
 : 8229.8 
 8244.2 
 8258.6 
 
 144 
 144 
 144 
 
 706.79 
 710.51 
 714.26 
 
 372 
 375 
 
 377 
 
 0.25841 
 0.25941 
 
 0.26041 
 
 100 
 100 
 
 lOI 
 
 5-489 
 
 5-503 
 
 j 5-518 
 
 1 
 
 14 
 15 
 
 15 
 
 960 
 
 959 
 
 958 
 
 1 
 
 8273.0 
 
 \ 8287.4 
 i 8301.9 
 
 144 
 145 
 145 
 
 718.03 
 721.81 
 
 1 725.62 
 
 378 
 381 
 384 
 
 0.26142 
 0.26243 
 0.26344 
 
 lOI 
 
 101 
 
 102 
 
 5-533 
 ' 5-548 
 1 5-564 
 
 15 
 16 
 
 15 
 
 957 
 956 
 955 
 
 8316.4 
 
 ! 8331.0 
 
 ! 8345.6 
 
 146 
 146 
 146 
 
 729.46 
 
 1 733.32 
 737.20 
 
 386 
 3SS 
 390 
 
 0.26446 
 0.26549 
 0.26652 
 
 103 
 103 
 103 
 
 5-579 
 5-594 
 5.609 
 
 15 
 15 
 16 
 
 954 
 953 
 952 
 
 i 8360.2 
 
 8374.8 
 
 i 8389.5 
 
 146 
 147 
 J47 
 
 741.10 
 
 745-03 
 748.98 
 
 393 
 395 
 398 
 
 0.26755 
 0.26858 
 
 0.26962 
 
 103 
 
 T04 
 
 105 
 
 5-625 
 5-640 
 5-655 
 
 15 
 15 
 16 
 
 951 
 950 
 949 
 
 8404.2 
 
 i 8419.0 
 
 8433.8 
 
 148 
 T48 
 148 
 
 752.96 
 756.96 
 760.98 
 
 400 
 402 
 404 
 
 0,27067 
 
 0.27172 
 0.27277 
 
 105 
 105 
 
 106 
 
 5-671 
 5.686 
 
 5-702 
 
 T5 
 16 
 
 948 
 
 947 
 946 
 
 8448.6 
 1 8463.4 
 , 8478.3 
 
 148 
 149 
 149 
 
 765.02 
 769.09 
 773.18 
 
 407 
 409 
 412 
 
 0.27383 
 
 0.27489 
 
 0.27596 
 
 106 
 
 107 
 
 107 
 
 5-718 
 
 ■5-733 
 
 5-749 
 
 15 
 16 
 16 
 
 945 
 944 
 943 
 
 8493.2 
 8508.1 
 
 ! 8523.1 
 
 149 
 150 
 
 150 
 
 777-30 
 
 781.45 
 785.62 
 
 415 
 417 
 420 
 
 0.27703 
 
 0.278II 
 
 0.27919 
 
 108 
 108 
 108 
 
 5-765 
 5-781 
 5-797 
 
 16 
 16 
 15 
 
 942 
 941 
 940 
 
 1 8538.1 
 
 \ 8553.1 
 \ 8568.2 
 
 1 
 
 150 
 151 
 151 
 
 789.82 
 794.04 
 798.29 
 
 422 
 
 425 
 427 
 
 0.28027 
 0.28136 
 0.28246 
 
 109 
 no 
 no 
 
 5-812 
 5-828 
 5-844 
 
 16 
 16 
 16 
 
 939 
 
 938 
 937 
 
 8583.3 
 8598.4 
 8613.6 
 
 151 
 
 152 
 152 
 
 802.56 
 806.85 
 811. 17 
 
 429 
 
 432 1 
 435 
 
 0.28356 
 0.28467 
 0.28578 
 
 III 
 III 
 III 
 
 5.860 
 5-877 
 5-893 
 
 17 
 16 
 16 
 
 936 
 935 
 934 
 
 8628.8 
 8644.0 
 8659.2 
 
 152 
 152 
 153 
 
 815-52 
 819.89 
 824.30 
 
 437 
 441 
 
 443 
 
 0.28689 
 0.28801 
 0.28913 
 
 112 
 112 
 113 
 
 5-909 
 5-926 
 5-942 
 
 17 
 16 
 16 
 
 933 
 932 
 931 
 
 8674.5 
 8689.8 
 8705.2 
 
 153 
 
 ^54 
 154 
 
 . 828.73 
 837-67 
 
 445 
 449 
 451 
 
 0.29026 
 0.29140 
 
 0.29254 
 
 114 
 114 
 114 
 
 5-958 
 5-974 
 •5-991 
 
 16 
 
 17 
 16 
 
 T7 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 /(Z') 
 
 Diff. 
 
 Tiv) 
 
 Diff. 
 
 930 
 929 
 928 
 
 8720.6 
 8736.0 
 8751.5 
 
 154 
 155 
 155 
 
 842.18 
 846.71 
 
 851.27 
 
 453 
 456 
 459 
 
 0.29368 
 0.29483 
 
 0.29598 
 
 ^15 
 115 
 116 
 
 6.007 
 6.024 
 6.041 
 
 17 
 17 
 16 
 
 927 
 
 926 
 
 925 
 
 8767.0 
 8782.5 
 8798.0 
 
 155 
 155 
 156 
 
 855.86 
 860.48 
 865.13 
 
 462 1 
 
 465 
 468 
 
 0.29714 
 
 0.29830 
 
 0.29947 
 
 116 
 117 
 
 117 
 
 6.057 
 
 6.074 
 6.091 
 
 17 
 17 
 17 
 
 924 
 923 
 
 922 
 
 8813.6 
 8829.2 
 8844.9 
 
 156 
 157 
 157 
 
 869.81 
 874-51 
 879-25 
 
 470 
 474 
 477 
 
 0.30064 
 0.30T82 
 30300 
 
 118 
 118 
 119 
 
 6.108 
 6.125 
 6. 141 
 
 17 
 16 
 
 17 
 
 921 
 
 920 
 
 919 
 
 8860.6 
 8876.3 
 8892.0 
 
 157 
 157 
 158 
 
 884.02 
 888.81 
 
 479 1 
 4821 
 
 485 j 
 
 0.30419 
 0.30538 
 
 0.30658 
 
 119 
 
 120 
 120 
 
 6.158 
 
 6.175 
 6.192 
 
 17 
 17 
 18 
 
 918 
 917 
 
 916 
 
 8907.8 
 8923.7 
 8939-5 
 
 159 
 158 
 159 
 
 898.48 
 903.36 
 908.27 
 
 488 
 491 
 494 
 
 0.30778 
 0.30899 
 0.31020 
 
 121 
 121 
 122 
 
 6.210 
 6.227 
 6.245 
 
 17 
 18 
 
 17 
 
 915 
 914 
 
 913 
 
 8955-4 
 8971-3 
 8987-3 
 
 159 
 160 
 160 
 
 913.21 
 918.18 
 923.19 
 
 497 
 501 
 
 503 
 
 0.3II42 
 0.31264 
 0.31387 
 
 122 
 123 
 124 
 
 6.262 
 6.279 
 6.297 
 
 17 
 18 
 
 17 
 
 912 
 911 
 
 910 
 
 9003-3 
 9019.3 
 
 9035-4 
 
 160 
 161 
 161 
 
 928.22 
 933-28 
 938.37 
 
 506 
 509 
 513 
 
 0.3I5II 
 0.31635 
 0.31760 
 
 124 
 125 
 125 
 
 6.314 
 6.332 
 6.349 
 
 18 
 
 17 
 18 
 
 909 
 908 
 907 
 
 9051-5 
 9067.6 
 9083.8 
 
 161 
 162 
 162 
 
 943-50 
 948.65 
 
 953-84 
 
 515 
 519 
 
 522 
 
 0.31885 
 0.320II 
 
 0.32137 
 
 126 
 126 
 127 
 
 6.367 
 
 6.385 
 6.403 
 
 18 
 18 
 18 
 
 906 
 
 905 
 904 
 
 9100.0 
 9116.2 
 9132.5 
 
 162 
 
 163 
 163 
 
 959.06 
 964.31 
 969.60 
 
 525 
 529 
 532 
 
 0.32264 
 
 0.32392 
 
 0.32520 
 
 128 
 128 
 129 
 
 6.421 
 
 6.439 
 6.457 
 
 18 
 18 
 18 
 
 903 
 
 902 
 901 
 
 9148.8 
 9165.2 
 9181.6 
 
 .64 
 
 164 
 164 
 
 974-92 
 980.27 
 
 985-65 
 
 535 
 538 
 541 
 
 0.32649 
 0.32778 
 
 0.32908 
 
 129 
 130 
 130 
 
 6.475 
 6.493 
 6. 511 
 
 18 
 18 
 18 
 
 900 
 
 899 
 898 
 
 9198.0 
 
 9214-5 
 9231.0 
 
 165 
 165 
 165 
 
 991.06 
 
 996.51 
 1001.99 
 
 545 
 548 
 
 552 
 
 0.33038 
 0.33169 
 0.33300 
 
 131 
 131 
 132 
 
 6.529 
 6.548 
 6.566 
 
 19 
 
 18 
 
 19 
 
 iS 
 
TABLE I.— Continued. 
 
 S(v) 
 
 9247-5 
 9264.1 
 9280.7 
 
 9297.3 
 9314-0 
 9330-7 
 
 9347.5 
 9364.3 
 9381. 1 
 
 9398.0 
 9414.9 
 9431-9 
 
 9448.9 
 9465.9 
 9483.0 
 
 9500.1 
 9517.2 
 9534.4 
 
 9551.6 
 9568.9 
 9586.2 
 
 9603.5 
 9620.9 
 
 9638.3 
 
 9655.8 
 
 9673.3 
 9690.8 
 
 9708.4 
 9726.0 
 9743.7 
 
 9761.4 
 9779.T 
 9796.9 
 
 Diff. 
 
 166 
 166 
 166 
 
 167 
 167 
 168 
 
 168 
 168 
 169 
 
 169 
 170 
 
 170 
 
 170 
 171 
 171 
 
 171 
 172 
 172 
 
 173 
 173 
 173 
 
 174 
 174 
 
 175 
 
 175 
 175 
 176 
 
 176 
 177 
 177 
 
 177 
 178 
 178 
 
 A{v) 
 
 007.51 
 013.06 
 018.65 
 
 024.27 
 029.92 
 035-61 
 
 041.34 
 047.10 
 052.90 
 
 058.73 
 064.60 
 070.52 
 
 076.47 
 082.45 
 088.47 
 
 094-53 
 100.62 
 106.75 
 
 112.92 
 119.13 
 125-38 
 
 131.67 
 
 138.00 
 144-37 
 
 150.78 
 
 157-23 
 163.72 
 
 170.25 
 176.82 
 183.44 
 
 190.09 
 196.79 
 203.54 
 
 Diff. 
 
 555 
 559 
 562 
 
 565 
 569 
 573 
 
 576 
 580 
 583 
 
 587 
 592 
 595 
 
 598 
 602 
 606 
 
 609 
 613 
 617 
 
 621 
 625 
 629 
 
 ^33 
 637 
 641 
 
 645 
 649 
 653 
 
 657 
 662 
 665 
 
 670 
 
 675 
 678 
 
 I{v) 
 
 0.33432 
 0.33565 
 0.33698 
 
 0.33832 
 0.33966 
 0.34101 
 
 0.34237 
 0.34373 
 0.34510 
 
 0.34647 
 
 0.34785 
 0.34924 
 
 0.35063 
 0.35203 
 0.35344 
 
 0.35485 
 0.35627 
 
 0-35770 
 
 0.35913 
 
 0.36057 
 
 0.36202 
 
 0.36347 
 0.36493 
 0.36639 
 
 0.36786 
 
 0.36934 
 0.37083 
 
 0.37232 
 0.37382 
 
 0.37532 
 
 0.37683 
 
 0.37835 
 0.37988 
 
 Diff. 
 
 133 
 ^33 
 134 
 
 134 
 135 
 136 
 
 136 
 137 
 137 
 
 138 
 139 
 139 
 
 140 
 141 
 141 
 
 142 
 143 
 143 
 
 144 
 145 
 145 
 
 146 
 
 146 
 147 
 
 148 
 149 
 149 
 
 150 
 150 
 151 
 
 152 
 ^53 
 153 
 
 T{v) 
 
 6.585 
 6.603 
 6.622 
 
 6.640 
 6.659 
 6.677 
 
 6.696 
 6.714 
 6.733 
 
 6.753 
 6.772 
 6.791 
 
 6.811 
 6.830 
 6.849 
 
 6.868 
 6.888 
 6.907 
 
 6.927 
 
 6.947 
 6.966 
 
 6.986 
 7.006 
 7.026 
 
 7.046 
 7-065 
 7.085 
 
 7.105 
 7.126 
 7.146 
 
 7.167 
 7.187 
 7.208 
 
 Diff. 
 
 19 
 
TABLE I.— Continued. 
 
 864 
 863 
 862 
 
 861 
 860 
 859 
 
 858 
 
 857 
 856 
 
 855 
 854 
 853 
 
 852 
 
 851 
 850 
 
 849 
 848 
 
 847 
 
 846 
 
 845 
 844 
 
 843 
 842 
 841 
 
 840 
 
 839 
 838 
 
 837 
 836 
 
 835 
 834 
 832 
 
 Siv) 
 
 9814.7 
 9832.6 
 9850-5 
 
 •4 
 9886.4 
 9904.4 
 
 9922.5 
 9940.6 
 9958.7 
 
 9976.9 
 
 9995-2 
 10013.5 
 
 10031.8 
 10050.2 
 10068.6 
 
 10087. 1 
 10105.6 
 10124.1 
 
 10142.7 
 10161.3 
 10180.0 
 
 10198.8 
 10217.5 
 T0236.3 
 
 10255.2 
 10274.1 
 10293.0 
 
 10312.0 
 10331.0 
 10350.1 
 
 10369.2 
 10388.4 
 10407.6 
 
 Diff. 
 
 179 
 179 
 
 1791 
 
 I 
 180 
 180 
 181 
 
 181 
 181 
 182 
 
 183 
 183 
 183 
 
 184 
 184 
 
 185 
 
 185 
 185 
 186 
 
 186 
 187 
 188 
 
 187 
 188 
 189 
 
 189 
 189 
 190 
 
 190 
 
 191 
 191 
 
 192 
 192 
 193 
 
 A{v) 
 
 210.32 
 217.15 
 224.02 
 
 230.93 
 237.89 
 244.89 
 
 251-94 
 259.04 
 266.18 
 
 273.36 
 280.59 
 287.87 
 
 295-19 
 302.56 
 
 309-98 
 
 317-44 
 324.96 
 
 332.52 
 
 340.13 
 347.79 
 
 355-50 
 
 363-26 
 371.07 
 
 378.93 
 
 386.84 
 394.80 
 402.82 
 
 410.89 
 419.01 
 
 427.18 
 
 435-41 
 443.69 
 
 452.02 
 
 Diff. 
 
 683 
 687 
 691 
 
 696 
 
 700 
 705 
 
 710 
 
 714 
 718 
 
 723 
 728 
 
 732 
 
 737 
 742 
 746 
 
 752 
 756 
 761 
 
 766 
 771 
 776 
 
 781 
 786 
 791 
 
 796 
 
 802 
 807 
 
 812 
 817 
 823 
 
 828 
 ^33 
 839 
 
 I{v) 
 
 I0.38I4T 
 : 0.38295 
 ; 0.38450 
 
 0.38606 
 0.38762 
 0.38919 
 
 0.39077 
 0.39235 
 0.39394 
 
 0.39554 
 0.39715 
 0.39877 
 
 0.40039 
 0.40202 
 0.40366 
 
 0.40530 
 0.40695 
 0.40861 
 
 0.41028 
 0.41196 
 0.41364 
 
 0.41533 
 0.41703 
 0.41874 
 
 0.42046 
 0.42218 
 0.42392 
 
 0.42566 
 0.42741 
 0.42917 
 
 0.43093 
 0.43271 
 
 0.43449 
 
 Diff. 
 
 154 
 155 
 156 
 
 156 
 157 
 158 
 
 158 
 
 159 
 160 
 
 161 
 162 
 162 
 
 163 
 164 
 164 
 
 165 
 166 
 167 
 
 168 
 168 
 169 
 
 170 
 171 
 172 
 
 172 
 174 
 174 
 
 175 
 176 
 176 
 
 178 
 178 
 180 
 
 T(v) 
 
 7.229 
 7.249 
 
 7.270 
 
 7.290 
 
 7-311 
 
 7-332 
 
 7-354 
 7-375 
 7-396 
 
 7.418 
 
 7-439 
 7.460 
 
 7.481 
 7.503 
 
 7-524 
 
 7-546 
 7-568 
 7-590 
 
 7.612 
 7-635 
 7-657 
 
 7-679 
 7.701 
 
 7-723 
 
 7-745 
 7-768 
 
 7-790 
 
 7-813 
 7.836 
 
 7-858 
 
 7.881 
 
 7-904 
 7.928 
 
TABLE I.— Continued. 
 
 S{v) 
 
 Diff. 
 
 0426.9 
 0446.2 
 0465.6 
 
 [0485.0 
 [0504.4 
 0523-9 
 
 0543-4 
 0563.0 
 0582.7 
 
 [ 0602. 4 
 0622,1 
 [0641.9 
 
 0661.7 
 0681.6 
 0701.6 
 
 0721.6 
 0741.6 
 0761.7 
 
 :o78i.8 
 :o8o2.o 
 :o822.2 
 
 :o842.5 
 0862.8 
 : 0883. 2 
 
 10903.6 
 0924.1 
 0944.6 
 
 0965.2 
 0985.8 
 1006.5 
 
 1027.2 
 1048.0 
 1068.8 
 
 193 
 T94 
 194 
 
 194 
 195 
 195 
 
 196 
 197 
 197 
 
 197 
 198 
 198 
 
 199 
 
 200 
 200 
 
 200 
 201 
 201 
 
 202 
 202 
 203 
 
 203 
 204 
 204 
 
 205 
 205 
 206 
 
 206 
 
 207 
 207 
 
 208 
 208 
 209 
 
 Aiv) 
 
 460.41 
 468.85 
 477.35 
 
 485.90 
 
 494.51 
 503-18 
 
 511.90 
 520.69 
 529-52 
 
 538.42 
 547-38 
 556.39 
 
 565-47 
 574.61 
 583-80 
 
 593-05 
 602.37 
 611.75 
 
 621.20 
 630.70 
 640.27 
 
 649.90 
 659-60 
 669.36 
 
 679.19 
 689.08 
 699.04 
 
 709.07 
 719.16 
 729.32 
 
 739-55 
 749-84 
 760.21 
 
 Diff. 
 
 844 
 
 850 
 855 
 
 861 
 867 
 
 872 
 
 879 
 
 896 
 901 
 908 
 
 914 
 919 
 925 
 
 932 
 938 
 945 
 
 950 
 957 
 963 
 
 970 
 976 
 
 983 
 
 989 
 
 996 
 
 1003 
 
 1009 
 1016 
 1023 
 
 1029 
 1037 
 1043 
 
 /{v) 
 
 0.43629 
 0.43809 
 0.43990 
 
 0.44172 
 0.44354 
 0.44538 
 
 0.44722 
 0.44908 
 
 C.45094 
 
 0.45282 
 0.45470 
 0.45659 
 
 0.45849 
 
 0.46040 
 0.46231 
 
 0.46424 
 0.46618 
 0.46812 
 
 0.47008 
 
 0.47205 
 
 0.47402 
 
 0.47601 
 0.47800 
 0.48001 
 
 0.48202 
 0.48404 
 
 0.48608 
 0.48812 
 
 0.49018 
 
 0.49225 
 0.49432 
 
 0.49641 
 
 0.49850 
 
 Diff. 
 
 180 
 181 
 182 
 
 182 
 184 
 184 
 
 186 
 186 
 
 188 
 189 
 190 
 
 191 
 191 
 T93 
 
 194 
 194 
 196 
 
 197 
 197 
 199 
 
 199 
 201 
 201 
 
 202 
 204 
 204 
 
 206 
 
 207 
 207 
 
 209 
 209 
 211 
 
 T(v) 
 
 7-95T 
 7-974 
 7-997 
 
 8.021 
 8.044 
 8.068 
 
 8.091 
 8.115 
 8.139 
 
 8.163 
 8.187 
 8.211 
 
 8.235 
 8.259 
 8.284 
 
 8.308 
 ^'333 
 8.357 
 
 8.382 
 8.407 
 8.432 
 
 8.457 
 8.482 
 
 8.507 
 
 8.533 
 8.558 
 8.584 
 
 8.610 
 
 8-635 
 8.661 
 
 8.687 
 8.713 
 8.739 
 
 Diff. 
 
TABLE I.-rCONTINUED. 
 
 Siv) 
 
 798 
 
 797 
 
 796 
 
 795 
 794 
 793 
 
 792 
 791 
 790 
 
 789 
 
 788 
 787 
 
 786 
 785 
 784 
 
 783 
 782 
 
 781 
 
 780 
 
 779 
 
 778 
 
 777 
 776 
 
 775 
 
 774 
 773 
 
 772 
 
 771 
 
 770 
 769 
 
 768 
 767 
 766 
 
 1089.7 
 1 1 10. 7 
 1131.7 
 
 1152.7 
 1173.8 
 1195.0 
 
 1216.2 
 
 1237.5 
 1258.8 
 
 1280.3 
 1301.8 
 1323-4 
 
 1345-0 
 1366.6 
 
 1388.2 
 
 1409.8 
 1431-5 
 1453-3 
 
 I475-0 
 1496.8 
 1518.6 
 
 1540.4 
 1562.2- 
 1584.1 
 
 1606.0 
 1627.9 
 1649.9 
 
 1671.9 
 1693.9 
 1716.0 
 
 1738.0 
 1760. 1 
 1782.3 
 
 Diff. 
 
 210 
 210 
 210 
 
 211 
 212 
 
 212 
 
 213 
 213 
 215 
 
 215 
 216 
 216 
 
 216 
 216 
 216 
 
 217 
 
 218 
 217 
 
 218 
 218 
 218 
 
 218 
 219 
 219 
 
 219 
 
 220 
 220 
 
 220 
 221 
 
 220 
 
 221 
 
 222 
 222 
 
 A (7') 
 
 1770.64 
 1781.15 
 1791.72 
 
 1802.37 
 1813.10 
 1823.89 
 
 1834.76 
 1845.70 
 1856.71 
 
 1867.87 
 1879.08 
 1890.36 
 
 1901.70 
 1913.1i 
 
 1924.57 
 
 1936.10 
 1947.70 
 1959.36 
 
 1971.08 
 1982.87 
 1994.72 
 
 2006.64 
 2018.62 
 2030.68 
 
 2042.80 
 2054.98 
 2067.24 
 
 2079.56 
 2091.95 
 2104.41 
 
 2116.94 
 2129.54 
 2142.21 
 
 Diff. 
 
 051 
 057 
 065 
 
 073 
 079 
 087 
 
 094 
 
 lOI 
 
 116 
 
 121 
 
 128 
 134 
 
 141 
 146 
 
 153 
 
 160 
 166 
 172 
 
 179 
 
 185 
 192 
 
 198 j 
 
 206 i 
 212 I 
 
 1 
 
 2l8| 
 
 226 I 
 
 232 1 
 
 239 
 
 246 
 
 253 
 
 260 
 267 
 
 274 
 
 7(7.) 
 
 I 0.50061 
 10.50273 
 I 0.50486 
 
 ! 0.50700 
 0-50915 
 0-51131 
 
 0.51348 
 0.51566 
 
 0-5 
 
 786 
 
 0.52008 
 0.52231 
 
 0.52454 
 
 0.52678 
 0.52904 
 0.53130 
 
 0.53357 
 0.53585 
 0.53813 
 
 0.54043 
 0.54273 
 0.54504 
 
 0.54736 
 0.54969 
 0.55203 
 
 0.55438 
 0.55674 
 0.55911 
 
 0.56148 
 0.56387 
 0.56626 
 
 0.56867 
 0.57108 
 0.57350 
 
 Diff. 
 
 212 
 213 
 214 
 
 215 
 216 
 217 
 
 218 
 
 220 
 222 
 
 223 
 223 
 224 
 
 226 
 226 
 
 227 
 
 228 
 228 
 230 
 
 230 
 231 
 232 
 
 233 
 234 
 
 235 
 
 236 
 
 237 
 237 
 
 239 I 
 
 239 
 241 
 
 241 
 
 242 
 
 244 
 
 T(v) 
 
 8.765 
 8.791 
 8.818 
 
 8.844 
 8.871 
 8.897 
 
 8.924 
 8.951 
 8.97.8 
 
 9.005 
 9.032 
 9.060 
 
 9.087 
 9.114 
 9.T42 
 
 9.170 
 9.197 
 9.225 ! 
 
 9-2531 
 9.281 ! 
 
 9-309 I 
 
 9-337 I 
 9365 i 
 9-394 i 
 
 9.422 j 
 
 9-450 
 
 9-479 
 
 9-507 
 9-536 
 9-565 
 
 9-593 
 9.622 
 
 9-651 
 
TABLE I.— Continued. 
 
 S{v) 
 
 765 
 764 
 
 763 
 
 762 
 761 
 760 
 
 759 
 
 758 
 
 757 
 
 756 
 755 
 754 
 
 753 
 752 
 751 
 
 750 
 749 
 748 
 
 747 
 746 
 
 745 
 
 744 
 743 
 742 
 
 741 
 740 
 
 739 
 
 738 
 737 
 736 
 
 735 
 734 
 733 
 
 1804.5 
 1826.7 
 1848.9 
 
 1871.1 
 1893.4 
 1915-7 
 
 1938.0 
 1960.4 
 
 2005.3 
 2027.7 
 2050.2 
 
 2072.8 
 
 2095-3 
 2117.9 
 
 2140.5 
 
 2163. 1 
 2185.8 
 
 2208.5 
 
 2231. 2 
 2253-9 
 
 2276.7 
 2299.6 
 2322.4 
 
 2345-3 
 2368.2 
 
 2391-1 
 
 2414.1 
 
 2437-1 
 2460.1 
 
 Diff. 
 
 222 
 222 
 222 
 
 223 
 223 
 223 
 
 224 
 224 
 
 225 
 
 224 
 225 
 226 
 
 225 
 226 
 226 
 
 226 
 
 227 
 
 227 
 
 227 
 227 
 228 
 
 229 
 228 
 229 
 
 229 
 229 
 
 230 
 
 230 
 230 
 231 
 
 2^1 
 
 2483.2 
 2506.31 231 
 2529.4' 232 
 
 A{v) 
 
 Diff. 
 
 2154-95 
 2167.76 
 2180.64 
 
 2193-59 
 2206.62 
 2219.7 r 
 
 2232.88 
 2246.12 
 2259.44 
 
 2272.83 
 2286.30 
 2299.84 
 
 2313-45 
 2327.14 
 2340.91 
 
 2354-75 
 2368.67 
 2382.66 
 
 2396.74 
 2410.89 
 2425.12 
 
 2439-44 
 2453-83 
 2468.30 
 
 2482.86 
 
 2497-49 
 2512.21 
 
 2527.01 
 2541.89 
 2556.86 
 
 2571.91 
 
 2587.04 
 2602.25 
 
 281 
 288 
 295 
 
 303 
 309 
 3^7 
 
 324 
 332 
 339 
 
 347 
 354 
 361 
 
 369 
 
 377 
 384 
 
 392 
 
 399 
 
 408 
 
 415 
 423 
 432 
 
 439 
 447 
 456 
 
 463 
 472 
 
 /(v) 
 
 480 0.64271 
 
 488 
 
 497 
 
 505 
 
 513 
 521 
 
 530 
 
 0-57594 
 0.57838 
 0.58083 
 
 0.58330 
 
 0.58577 
 0-58825 
 
 0.59074 
 0.59324 
 0-59575 
 
 0.59827 
 0.60080 
 0.60334 
 
 0.60589 
 0.60845 
 0.61 103 
 
 0.61361 
 0.61620 
 0.61880 
 
 0.62142 
 0,62404 
 0.62667 
 
 0.62932 
 0.63198 
 0.63464 
 
 0.63732 
 0.64001 
 
 0.64542 
 0164814 
 
 0.65087 
 
 0.65361 
 0.65637 
 0.65913 
 
 Diff. 
 
 244 
 245 
 247 
 
 247 
 248 
 
 249 
 
 250 
 
 251 
 
 252 
 
 253 
 254 
 255 
 
 256 
 
 258 
 258 
 
 259 
 260 
 262 
 
 262 
 263 
 265 
 
 266 
 266 
 268 
 
 269 
 
 270 
 271 
 
 272 
 273 
 274 
 
 276 
 276 
 
 278 
 
 T{v) 
 
 9.680 
 9.709 
 9-738 
 
 9.767 
 
 9-797 
 9.826 
 
 9-855 
 9.885 
 5.914 
 
 9-944 
 
 9-973 
 
 10.003 
 
 10.033 
 10.063 
 10.093 
 
 10.123 
 
 10.153 
 10.184 
 
 10.214 
 10.244 
 
 10.275 
 
 10.306 
 10.336 
 10.367 
 
 10.398 
 10.429 
 10.460 
 
 10.491 
 10.522 
 10.554 
 
 10.585 
 10.616 
 10.648 
 
 Diff. 
 
 23 
 
TABLE I.— Continued. 
 
 S(v) 
 
 732 
 731 
 730 
 
 729 
 
 728 
 727 
 
 726 
 
 725 
 724 
 
 723 
 722 
 721 
 
 720 
 719 
 718 
 
 717 
 716 
 
 714 
 
 713. 
 712 
 
 711 
 710 
 709 
 
 708 
 707 
 706 
 
 705 
 704 
 
 703 
 
 702 
 701 
 700 
 
 2552.6 
 2575-8 
 2599.0 
 
 2622.3 
 2645.6 
 2668.9 
 
 2692.3 
 2715.6 
 2739.0 
 
 2762.5 
 2786.0 
 2809.5 
 
 2833.1 
 2856.7 
 2880.3 
 
 2903.9 
 2927,6 
 2951-3 
 
 2975-1 
 2998.9 
 
 3022.7 
 
 3046.5 
 3070.4 
 
 3094-3 
 
 3118.3 
 
 3142.3 
 3166.3 
 
 3190.3 
 3214.4 
 
 3238.5 
 
 3262.7 
 3286.9 
 3311.I 
 
 Diff. 
 
 232 
 232 
 233 
 
 233 
 233 
 234 
 
 233 
 234 
 235 
 
 235 
 235 
 236 
 
 236 
 236 
 
 236 
 
 237 
 237 
 238 
 
 238 
 238 
 238 
 
 239 
 239 
 
 240 
 
 240 
 240 
 240 
 
 241 
 241 
 242 
 
 242 
 242 
 
 242 
 
 A{v) 
 
 2617.55 
 2632.94 
 2648.41 
 
 2663.97 
 2679.61 
 2695.34 
 
 2711.16 
 
 2727.07 
 2743-07 
 
 2759.16 
 
 2775-33 
 2791.60 
 
 2807.96 
 2824.41 
 2840.96 
 
 2857.60 
 
 2874.33 
 2891.15 
 
 2908.07 
 2925.08 
 2942.19 
 
 2959-39 
 2976.09 
 
 2994.09 
 
 3011.58 
 3029.17 
 3046.86 
 
 3064,66 
 
 3082.55 
 3100.54 
 
 3118.64 
 3136.84 
 3155-H 
 
 Diff, 
 
 539 
 547 
 556 
 
 564 
 
 573 
 582 
 
 591 
 600 
 609 
 
 617 
 
 627 ; 
 636 I 
 
 645 
 
 6551 
 
 664 
 
 673 
 682 
 692 
 
 701 
 711 
 720 
 
 730 
 740 
 
 749 
 
 759 
 769 
 780 
 
 789 
 
 799 
 
 810 
 
 820 
 830 
 841 
 
 /{v) 
 
 0.66I9I 
 0.66470 
 0.66750 
 
 0.67031 
 
 0.67313 
 0.67596 
 
 0.67881 
 0,68167 
 0.68454 
 
 0.68742 
 0,69031 
 0.69322 
 
 0.69614 
 0.69907 
 0.70201 
 
 0,70496 
 
 0.70793 
 
 0,71091 
 
 0.71390 
 
 0.7I69I 
 
 0.71993 
 
 0.72296 
 0.72600 
 
 0.72905 
 
 0.73212 
 
 0.73520 
 0.73830 
 
 0.74I4I 
 0.74453 
 
 0.74766 
 0.75081 
 
 0.75397 
 0.75715 
 
 Diff, 
 
 279 
 280 
 281 
 
 282 
 283 
 285 
 
 286 
 287 
 
 289 
 291 
 292 
 
 293 
 294 
 295 
 
 297 
 298 
 299 
 
 301 
 302 
 303 
 
 304 
 305 
 307 
 
 308 
 310 
 311 
 
 312 
 313 
 315 
 
 316 
 318 
 319 
 
 T{v) 
 
 0.679 
 0.711 
 
 0.743 
 
 0.775 
 :o.8o7 
 
 0.839 
 
 0.871 
 
 0.903 
 0.936 
 
 :o.968 
 1. 00 1 
 1-033 
 
 1,066 
 1.099 
 1-132 
 
 1. 165 
 1. 198 
 1.231 
 
 1.264 
 1.297 
 1-330 
 
 1.364 
 1.398 
 1-432 
 
 1.465 
 1.499 
 1-533 
 
 1.567 
 1.60T 
 1.636 
 
 1,670 
 1,704 
 1-739 
 
 24 
 
TABLE I.— Continued. 
 
 S{v) 
 
 699 
 698 
 697 
 
 696 
 
 695 
 694 
 
 693 
 692 
 691 
 
 690 
 689 
 688 
 
 687 
 686 
 685 
 
 684 
 683 
 682 
 
 681 
 680 
 679 
 
 678 
 677 
 676 
 
 675 
 674 
 
 673 
 672 
 
 67. 
 
 670 
 
 669 
 668 
 667 
 
 3335-3 
 3359-6 
 3383-9 
 
 3408.3 
 3432.7 
 3457-1 
 
 3481.6 
 3506.1 
 3530.6 
 
 3555-2 
 3579-8 
 3604.4 
 
 3629.1 
 3653-8 
 3678.6 
 
 3703-4 
 3728.2 
 
 3753-1 
 
 3778.0 
 3802.9 
 3827.9 
 
 3852.9 
 3877-9 
 39030 
 
 3928.1 
 3953-3 
 3978.5 
 
 4003.7 
 4029.0 
 4054-3 
 
 4079.6 
 4105.0 
 4130.4 
 
 Diff. 
 
 243 
 243 
 
 244 
 
 244 
 244 
 
 245 
 
 245 
 245 
 246 
 
 246 
 246 
 
 247 
 
 247 
 248 
 248 
 
 248 
 249 
 249 
 
 249 
 
 250 
 250 
 
 250 
 
 25' 
 
 251 
 
 252 
 252 
 252 
 
 253 
 253 
 253 
 
 254 
 254 
 255 
 
 A (v) 
 
 3173-55 
 3192.06 
 3210.67 
 
 3229.39 
 3248.22 
 3267.15 
 
 3286.19 
 
 3305.33 
 3324.58 
 
 3343-95 
 3363-42 
 3383-00 
 
 3402.70 
 3422.50 
 3442.42 
 
 3462.45 
 3482.60 
 3502.86 
 
 3523-24 
 3543-73 
 3564.34 
 
 3585.07 
 3605.91 
 3626.88 
 
 3647.96 
 3669.17 
 3690.50 
 
 3711 94 
 
 373351 
 
 3755.21 
 
 3777.03 
 3798.98 
 3821.05 
 
 Diff. 
 
 1 85 I 
 1861 
 1872 
 
 1883 
 
 1893 
 1904 
 
 1914 
 1925 
 1937 
 
 1947 
 1958 
 1970 
 
 1980 
 1992 
 2003 
 
 2015 
 2026 
 2038 
 
 2049 ! 
 2061 I 
 
 2073 I 
 
 1 
 2084 
 2097 
 2108 
 
 2121 
 
 2133 
 2144 
 
 2157 
 2170 
 2182 
 
 2195 
 2207 
 2219 
 
 I{v) 
 
 0.76034 
 
 0.76354 
 0.76675 
 
 0.76998 
 
 0.77322 
 0.77648 
 
 0.77975 
 0.78304 
 0.78634 
 
 0.78966 
 0.79299 
 0.79633 
 
 0.79969 
 0.80306 
 0.80645 
 
 0.80985 
 0.81327 
 0.81670 
 
 0.82015 
 0.82362 
 0.82710 
 
 0.83059 
 0.83410 
 0.83762 
 
 O.84116 
 0.84472 
 0.84829 
 
 0.85188 
 
 0.85549 
 O.85911 
 
 0.86274 
 0.86639 
 0.87006 
 
 Diff. 
 
 320 
 321 
 3 3 
 
 324 
 326 
 
 327 
 
 329 
 330 
 332 
 
 333 
 334 
 336 
 
 337 
 339 
 340 
 
 342 
 343 
 345 
 
 347 
 348 
 349 
 
 351 
 
 352 
 354 
 
 356 
 357 
 359 
 
 361 
 362 
 363 
 
 365 
 367 
 369 
 
 T{v) 
 
 11.774 
 11.809 
 11.844 
 
 11.879 
 II. 914 
 11.949 
 
 11.984 
 
 12.020 
 12.055 
 
 12.091 
 12.126 
 12.162 
 
 12.198 
 12.234 
 12.270 
 
 12.306 
 12.342 
 12.379 
 
 12.415 
 
 12.452 
 12.489 
 
 12.526 
 
 12.563 
 12.600 
 
 12.637 
 12.675 
 12.712 
 
 12.750 
 12.787 
 12.825 
 
 12.863 
 12.901 
 12.939 
 
 25 
 
TABLE I.— Continued. 
 
 Siv) 
 
 666 
 665 
 664 
 
 663 
 662 
 661 
 
 660 
 
 659 
 658 
 
 657 
 656 
 
 655 
 
 654 
 
 653 
 652 
 
 65' 
 650 
 649 
 
 648 
 647 
 646 
 
 645 
 644 
 
 643 
 
 642 
 641 
 640 
 
 639 
 638 
 
 637 
 
 636 
 
 635 
 634 
 
 4155-9 
 4181.4 
 4206.9 
 
 4232.5 
 4258.1 
 4283.7 
 
 4309-4 
 
 4335.1 
 4360.9 
 
 4386.7 
 4412.6 
 
 4438.5 
 
 4464.4 
 4490.4 
 4516.4 
 
 4542.4 
 4568.5 
 4594-6 
 
 4620.8 
 4647.0 
 4673.2 
 
 4699.5 
 4725-9 
 
 4752.3 
 
 4778.7 
 4805.1 
 4831.6 
 
 4858.1 
 4884.7 
 4911.3 
 
 4938.0 
 4964.7 
 4991.4 
 
 Diff. 
 
 255 
 255 
 256 
 
 256 
 256 
 
 257 
 
 257 
 258 
 
 258 
 
 j 
 
 259 
 259 
 259 
 
 260 
 260 
 260 
 
 261 
 261 
 262 
 
 262 
 262 
 263 
 
 264. 
 264 
 264 
 
 264 
 265 
 265 
 
 266 
 266 
 267 
 
 267 
 267 
 268 
 
 A {7^) 
 
 3843-24 
 3865.57 
 3888.02 
 
 3910.60 
 
 3933-31 
 3956.16 
 
 3979-13 
 4002.24 
 4025.48 
 
 4048.86 
 4072.37 
 4096.01 
 
 4T19.79 
 
 4143-71 
 4167.77 
 
 Diff. 
 
 4340.12 
 
 4365-32 
 4390.67 
 
 4416.16 
 
 4441.81 
 4467.60 
 
 4493-55 
 4519.64 
 
 4545-89 
 
 4572.30 
 4598.86 
 4625.57 
 
 2233 
 
 2245 
 2258 
 
 2271 
 
 2285 
 2297 
 
 2311 
 2324 
 2338 
 
 2351 
 2364 
 
 2378 
 
 2392 
 2406 
 2419 
 
 4191.96 2434 
 4216.30 2448 
 4240.78 2462 
 
 4265.40 j 2476 
 4290.16 I 2491 
 4315.07 2505 
 
 2520 
 
 2535 
 2549 
 
 2565 
 2579 
 2595 
 
 2609 
 2625 
 2641 
 
 2656 
 2671 
 2687 
 
 /{v) 
 
 0-87375 
 0.87745 
 0.88II7 
 
 0.88490 
 
 0.88866 
 0.89243 
 
 0.89622 
 0.90002 
 
 0.90384 
 
 0.90768 
 
 0.9II53 
 0.9I54I 
 
 0.91930 
 
 0,92321 
 
 0.92715 
 
 0.931 10 
 0.93506 
 0.93904 
 
 0.94304 
 
 0.94706 
 
 0.95IIO 
 
 0.95516 
 0.95923 
 0.96333 
 
 0.96745 
 0.97158 
 0.97574 
 
 0.97991 
 
 0,98410 
 
 0.98831 
 0.99254 
 
 0.99680 
 1.00107 
 
 Diff. 
 
 370 
 372 
 373 
 
 376 
 377 
 379 
 
 380 
 382 
 384 
 
 385 
 388 
 389 
 
 391 
 394 
 395 
 
 396 
 398 
 
 400 
 
 402 
 404 
 406 
 
 407 
 410 
 412 
 
 413 
 416 
 
 417 
 
 419 
 421 
 423 
 
 426 
 
 427 
 429 
 
 T{v) 
 
 977 
 015 
 053 
 
 092 
 130 
 169 
 
 208 
 
 247 
 286 
 
 326 
 365 
 
 404 
 
 444 
 484 
 524 
 
 564 
 604 
 
 644 
 
 684 
 
 725 
 766 
 
 806 
 847 
 
 929 
 971 
 
 012 
 
 053 
 095 
 137 
 
 4 179 
 4.221 
 4-263 
 
 Diff. 
 
 26 
 
TABLE I.— Continued. 
 
 V 
 
 S{zi) 
 
 Diff. 
 
 i 
 
 A (7-) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T(v) 
 
 Diff. 
 
 633 
 
 632 
 
 63. 
 
 15018.2 
 
 i5C'45-o 
 15071.9 
 
 268 
 269 
 269 
 
 4652.44 
 
 4679.47 
 4706.65 
 
 2703 
 2718 ' 
 
 2735 
 
 1.00536 
 1.00967 
 1. 01401 
 
 431 
 
 434 
 436 
 
 14.305 
 14.348 
 14.390 
 
 43 
 42 
 43 
 
 6.'?o 
 629 
 
 628 
 
 15098.8 
 15125.8 
 15152-8 
 
 270 
 2701 
 
 270 i 
 
 4734.00 
 4761.51 
 4789.18 
 
 2751 
 2767 
 
 2784 
 
 1. 01837 
 1.02274 
 
 I.027I3 
 
 437 
 439 
 
 442 i 
 
 14.433 
 14.476 
 
 14.519 
 
 43 
 43 
 
 43 
 
 627 
 626 
 625 
 
 15179-8 
 15206.9 
 15234.0 
 
 271 
 271 
 
 272 
 
 4817.02 
 4845.02 
 4873.18 
 
 2800 
 2816 
 2833 
 
 I 03155 
 J. 03598 
 
 1.04044 
 
 443 
 446 
 
 448 
 
 14.562 
 14.605 
 14.648 
 
 43 
 43 
 
 44 
 
 624 
 623 
 622 
 
 15261.2 
 15288.4 
 15315-7 
 
 272 
 273 
 273 
 
 4901.51 
 4930.00 
 4958.67 
 
 2849 
 2S67 
 2883 
 
 1.04492 
 
 1.04943 
 1.05395 
 
 451 
 
 452 
 
 455 
 
 14.692 
 14.735 
 14.779 
 
 43 
 44 
 44 
 
 621 
 620 
 619 
 
 15343.0 
 15370.3 
 15397.7 
 
 273 
 274 
 274 
 
 4987.50 
 
 1 5016.51 
 
 5045-69 
 
 2901 
 2918 
 
 2935 
 
 1 1.05850 
 1.06307 
 1.06766 
 
 457 
 459 
 461 
 
 14.823 
 14.867 
 14.91 1 
 
 44 
 44 
 45 
 
 618 
 617 
 616 
 
 15425. 1 
 15452.6 
 15480.1 
 
 275 
 
 275 
 276 
 
 5075-04 
 5104.57 
 5134-27 
 
 2953 
 2970 
 2988 
 
 1.07227 
 1.07690 
 1. 08156 
 
 463 
 466 
 468 
 
 ,14.956 
 
 15.000 
 
 15.045 
 
 44 
 45 
 
 45 
 
 615 
 614 
 
 613 
 
 15507.7 
 15535.3 
 15563.0 
 
 276 
 
 277 
 277 
 
 5164.15 
 5194.21 
 5224.44 
 
 3006 
 3023 
 3042 
 
 1.08624 
 1.09095 
 1.09568 
 
 471 
 473 
 475 
 
 15.090 
 
 15-135 
 15.180 
 
 45 
 45 
 45 
 
 612 
 611 
 610 
 
 T5590.7 
 15618.4 
 15646.2 
 
 277 
 
 1 278 
 
 278 
 
 5254-86 
 
 i 5285.46 
 
 5316.24 
 
 3060 
 3078 
 3097 
 
 1 10043 
 
 1. 10520 
 
 I.IIOOO 
 
 477 
 48c 
 482 
 
 15-225 
 15.270 
 T5-316 
 
 45 
 46 
 45 
 
 609 
 608 
 607 
 
 1 15674.0 
 15701.9 
 15729.8 
 
 279 
 279 
 
 280 
 
 5347-21 
 5378.36 
 5409-71 
 
 31^5 
 3135 
 3153 
 
 1 I.II482 
 I.II966 
 1. 12452 
 
 484 
 486 
 
 489 
 
 15-361 
 
 15-407 
 15.453 
 
 46 
 46 
 46 
 
 606 
 605 
 604 
 
 15757-8 
 15785.8 
 15813-9 
 
 280 
 i 281 
 1 281 
 
 1 
 
 ! 5441.24 
 
 5472.95 
 5504.86 
 
 3171 
 
 3191 
 3210 
 
 I.I294I 
 
 1. 13433 
 
 1 1.13927 
 
 492 
 494 
 497 
 
 ■ 
 15-499 
 15-546 
 15.592 
 
 47 
 46 
 46 
 
 603 
 602 
 601 
 
 15842.0 
 15870. 1 
 15898.3 
 
 281 
 282 
 
 ' 283 
 
 1553696 
 i 556926 
 '5601.75 
 
 3230 
 
 3249 
 3268 
 
 1. 14424 
 1. 14923 
 1-15425 
 
 499 
 
 502 
 
 504 
 
 15.638 
 15.685 
 15.732 
 
 47 
 47 
 47 
 
 27 
 
TABLE I.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. I 
 
 1 
 1 
 
 A (v) Diff. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 600 
 
 599 
 598 
 
 15926.6 
 
 15954.9 
 15983-2 
 
 283 
 283 
 284 
 
 5634.43 I 3288 
 5667.31 J3309 
 5700.40 3329 
 
 1. 15929 
 1. 16435 
 1.16944 
 
 506 
 509 
 
 5'2 
 
 15.779 
 15.826 
 
 15.873 
 
 47 
 47 
 48 
 
 597 
 596 
 595 
 
 160IT.6 
 1 6040. 1 
 16068.6 
 
 285 
 285 
 
 285 1 
 
 5733-69 
 
 5767.18 
 5800.87 
 
 3349 
 3369 
 3389 
 
 1. 17456 
 1. 17970 
 
 1. 18487 
 
 5H 
 517 
 519 
 
 15.921 
 15.968 
 16.016 
 
 47 
 48 
 48 
 
 594 
 593 
 592 
 
 16097. 1 
 16125.7 
 16154-4 
 
 286 
 
 287 
 287 
 
 5834-76 
 5868.85 
 5903.16 
 
 3409 
 3431 
 3451 
 
 1. 19006 
 1. 19528 
 1.20053 
 
 522 
 525 
 
 527 
 
 16.064 
 16. 113 
 16. 16 I 
 
 49 
 
 48 
 48 
 
 591 
 590 
 589 
 
 16183.I 
 16211.8 
 16240.6 
 
 287 1 
 
 288 
 
 288 
 
 5937-67 
 
 5972.39 
 6007.32 
 
 3472 
 3493 
 3515 
 
 T. 20580 
 I.2IIIO 
 1. 21643 
 
 530 
 533; 
 
 535 , 
 
 16.209 
 16.258 
 16.307 
 
 49 
 49 
 49 
 
 588 
 
 587 
 586 
 
 16269.4 
 16298.3 
 16327.2 
 
 289 
 289 
 290 
 
 6042.47 
 
 6077.83 
 6113.41 
 
 3536 
 3558 
 3579 
 
 I. 22178 
 I. 22716 
 1.23257 
 
 538 
 541 
 544 
 
 16.356 
 16.405 
 
 16.454 
 
 49 
 49 
 50 
 
 585 
 584 
 583 
 
 16356.2 
 16385.2 
 16414.3 
 
 290 
 291 
 291 
 
 6149.20 
 6185.22 
 6221.46 
 
 3602 
 3624 
 3646 
 
 I. 23801 
 1.24348 
 1.24897 
 
 547 
 549 
 552 
 
 16.504 
 
 16.553 
 16.603 
 
 49 
 
 50 
 50 
 
 582 
 581 
 580 
 
 16443.4 
 16472.6 
 16501.8 
 
 292 
 292 
 293 
 
 6257.92 
 6294.61 
 6331-52 
 
 3669 
 3691 
 3714 
 
 1.25449 
 1.26004 
 1.26562 
 
 555 
 558 
 561 
 
 16.653 
 16.704 
 16.754 
 
 51 
 
 50 
 51 
 
 579 
 
 578 
 
 577 
 
 16531.1 
 16560.4 
 16589.8 
 
 293 
 294 
 294 
 
 6368.66 
 6406.01 
 6443-63 
 
 3735 
 3762 
 
 3783 
 
 1. 27123 
 
 1.27687 
 1.28253 
 
 564 
 
 566 
 
 570 
 
 16.805 
 16.855 
 16.906 
 
 50 
 51 
 
 52 
 
 576 
 
 575 
 574 
 
 16619.2 
 16648.7 
 16678.2 
 
 295 
 295 
 296 
 
 6481.46 
 
 65^9.52 
 
 6557.82 
 
 3806 
 3830 
 3854 
 
 1.28823 
 1.29396 
 I. 29971 
 
 573 
 575 
 579 
 
 16.958 
 17.009 
 17.060 
 
 51 
 51 
 
 52 
 
 573 
 572 
 571 
 
 16707.8 
 16737.4 
 16767. 1 
 
 296 
 
 297 
 298 
 
 6596.36 
 
 6635.14 
 6674.16 
 
 3878 
 3902 
 3926 
 
 1.30550 
 I.3II3' 
 I.31716 
 
 581 
 
 585 
 588 
 
 17.112 
 
 17.164 
 
 i 17.216 
 
 52 
 52 
 52 
 
 570 
 
 569 
 568 
 
 16796.9 
 16826.7 
 16856.6 
 
 298 
 
 299 
 299 
 
 671342 
 
 6752.93 
 6792.68 
 
 3951 
 3975 
 4000 
 
 1.32304 
 1-32895 
 1-33489 
 
 591 
 594 
 597 
 
 17.268 
 17.320 
 17-373 
 
 52 
 52 
 
 28 
 

 TABLE I.— Continued. 
 
 S{v) 
 
 567 
 566 
 
 565 
 
 564 
 563 
 562 
 
 561 
 560 
 
 559 
 
 558 
 557 
 556 
 
 555 
 554 
 553 
 
 552 
 
 551 
 550 
 
 549 
 548 
 547 
 
 546 
 
 545 
 544 
 
 543 
 542 
 541 
 
 540 
 539 
 538 
 
 537 
 536 
 535 
 
 6886.5 
 6916.4 
 6946.4 
 
 6976.5 
 7006.6 
 7036.8 
 
 7067.0 
 7097.3 
 7127.6 
 
 7158.0 
 7188.4 
 7218.9 
 
 7249.4 
 7280.0 
 7310.7 
 
 7341-4 
 
 7372.2 
 7403.0 
 
 7433-9 
 7464.8 
 
 7495-8 
 
 7526.8 
 7557.9 
 7589-1 
 
 7620.3 
 7651.6 
 7682.9 
 
 77H-3 
 7745-8 
 7777-3 
 
 7808.9 
 
 7840-5 
 7872.2 
 
 Diff. 
 
 299 
 300 
 301 
 
 301 
 
 302 
 302 
 
 303 
 303 
 304 
 
 304 
 
 305 
 305 
 
 306 
 307 
 307 
 
 308 
 308 
 309 
 
 309 
 310 
 310 
 
 311 
 312 
 312 
 
 313 
 313 
 314 
 
 315 
 315 
 316 
 
 316 
 317 
 317 
 
 Aiv) 
 
 6832.68 
 6872.93 
 6913-43 
 
 6954.18 
 6995.19 
 7036.46 
 
 7077.99 
 7119.78 
 7161.83 
 
 7204.15 
 7246.73 
 7289.58 
 
 7332.71 
 7376.11 
 7419.78 
 
 7463.74 
 7507-97 
 7552.48 
 
 7597.28 
 7642.36 
 7687.73 
 
 7733-39 
 7779-34 
 7825.58 
 
 7872.12 
 7918.96 
 7966.12 
 
 8013-55 
 8061.30 
 8109.36 
 
 8T57-73 
 8206.41 
 8255.41 
 
 Diff. 
 
 4025 
 4050 
 4075 
 
 4101 
 4127 
 4153 
 
 4179 
 4205 
 4232 
 
 4258 
 4285 
 
 43^3 
 
 4340 
 4367 
 4396 
 
 4423 
 4451 
 4480 
 
 4508 
 
 4537 
 4566 
 
 4595 
 4624 
 
 4654 
 
 4684 
 4716 
 4743 
 
 4775 
 4806 
 
 4837 
 
 4868 
 4900 
 4932 
 
 /{v) 
 
 34086 
 34686 
 35290 
 
 35897 
 36507 
 37120 
 
 37736 
 38356 
 38979 
 
 39606 
 
 40236 
 
 40869 
 
 41506 
 
 42146 
 
 42789 
 
 43436 
 
 44087 
 44741 
 
 45399 
 46060 
 
 46725 
 
 47394 
 48066 
 
 48742 
 
 49422 
 50106 
 50793 
 
 51484 
 52179 
 52878 
 
 53581 
 54287 
 54998 
 
 Diff. 
 
 600 
 604 
 607 
 
 610 
 613 
 616 
 
 620 
 623 
 627 
 
 630 
 
 637 
 
 640 
 643 
 647 
 
 651 
 654 
 
 658 
 
 661 
 665 
 669 
 
 672 
 676 
 680 
 
 684 
 687 
 691 
 
 695 
 699 
 
 703 
 
 706 
 711 
 715 
 
 Tiv) 
 
 7.425 
 7-478 
 7-531 
 
 7-584 
 7.638 
 7.691 
 
 7.745 
 7-799 
 7.853 
 
 7-908 
 7.962 
 8.017 
 
 8.072 
 8.127 
 8.183 
 
 8.238 
 8.294 
 8.350 
 
 8.406 
 8.462 
 8.519 
 
 8.576 
 
 8.633 
 8.690 
 
 8.747 
 8.805 
 
 8.921 
 
 8.979 
 9.038 
 
 9.096 
 9-155 
 9-215 
 
 Diff. 
 
 29 
 
TABLE I.— Continued. 
 
 S{v) 
 
 534 
 533 
 
 532 
 
 531 
 
 530 
 529 
 
 528 
 527 
 526 
 
 525 
 524 
 523 
 
 522 
 
 521. 
 520 
 
 519 
 518 
 
 517 
 
 516 
 
 5^5 
 514 
 
 513 
 512 
 
 511 
 
 510 
 509 
 508 
 
 507 
 506 
 
 505 
 
 504 
 503 
 502 
 
 7903.9 
 
 7935-7 
 7967.6 
 
 7999-5 
 8031.5 
 8063.5 
 
 8095.6 
 8127.8 
 8160.0 
 
 8192.3 
 
 8224.7 
 8257.1 
 
 8289.6 
 8322.1 
 8354-7 
 
 8387-4 
 8420.1 
 8452.9 
 
 8485.7 
 8518.6 
 
 8551-6 
 
 8584-7 
 8617.8 
 8651.0 
 
 8684.2 
 8717-5 
 8750-9 
 
 8784.3 
 8817.8 
 8851.4 
 
 8885.0 
 8918.7 
 8952.5 
 
 Diff 
 
 318 
 319 
 319 
 
 320 
 320 
 321 
 
 322 
 322 
 323 
 
 324 
 324 
 325 
 
 325 
 326 
 
 327 
 
 327 
 328 
 328 
 
 329 
 330 
 
 33^ 
 
 33'^ 
 332 
 332 
 
 333 
 334 
 334 
 
 335 
 33^ 
 33^ 
 
 337 
 33^ 
 338 
 
 A'iv) 
 
 8304.73 
 8354.36 
 8404.32 
 
 8454.61 
 8505.22 
 8556.16 
 
 8607.44 
 8659.06 
 8711.01 
 
 8763.30 
 8815.94 
 8868.92 
 
 8922.25 
 
 8975.93 
 9029.97 
 
 9084.36 
 9139.11 
 9194.23 
 
 9249.71 
 
 9305.56 
 9361.79 
 
 9418.39 
 9475-38 
 9532.74 
 
 9590.49 
 9648.62 
 9707.15 
 
 9766.06 
 9825.38 
 9885.09 
 
 9945.21 
 10005.74 
 10066.67 
 
 Diff. 
 
 4963 
 4996 
 5029 
 
 5061 
 
 5094 
 5128 
 
 5162 
 
 5195 
 5229 
 
 5264 
 5298 
 5333 
 
 5368 
 5404 
 5439 
 
 5475 
 5512 
 
 5548 
 
 5585 
 5623 
 5660 
 
 5699 
 5736 
 
 5775 
 
 5813 
 5853 
 5891 
 
 5932 
 
 5971 
 6012 
 
 6053 
 6093 
 
 6134 
 
 I{v) 
 
 55713 
 56431 
 57154 
 
 57881 
 
 58612 
 
 59347 
 
 60086 
 60830 
 61578 
 
 62330 
 63086 
 63847 
 
 64612 
 65381 
 66155 
 
 66933 
 67716 
 68504 
 
 69296 
 70092 
 70894 
 
 71700 
 72510 
 73326 
 
 74146 
 
 74971 
 75801 
 
 76636 
 77476 
 78321 
 
 79171 
 80026 
 80886 
 
 Diff. 
 
 718 
 
 723 
 
 727 
 
 731 
 735 
 739 
 
 744 
 748 
 752 
 
 756 
 761 
 
 765 
 
 769 
 
 774 
 778 
 
 783 
 788 
 792 
 
 796 
 802 
 806 
 
 810 
 816 
 820 
 
 825 
 830 
 835 
 
 840 
 
 845 
 850 
 
 855 
 860 
 
 865 
 
 T{v) 
 
 19.274 
 J9.334 
 19-394 
 
 ^9-454 
 19.514 
 19-574 
 
 19-635 
 19.696 
 
 19-757 
 
 19.819 
 19.881 
 19.943 
 
 20.005 
 20.067 
 20.130 
 
 20.193 
 20.256 
 20.319 
 
 20.383 
 20.447 
 20.511 
 
 20.575 
 20.640 
 20.705 
 
 20.770 
 20.835 
 20.901 
 
 20,967 
 21.033 
 21.099 
 
 21.166 
 21.233 
 
 21,300 
 
 30 
 
TABLE I.— Continued. 
 
 501 
 500 
 
 499 
 
 498 
 
 497 
 496 
 
 495 
 494 
 493 
 
 492 
 491 
 490 
 
 489 
 488 
 487 
 
 486 
 485 
 484 
 
 483 
 482 
 481 
 
 480 
 
 479 
 478 
 
 477 
 476 
 
 475 
 
 474 
 
 473 
 472 
 
 471 
 
 470 
 469 
 
 ■S(v) 
 
 3 
 
 9020.2 
 9054.2 
 
 9088.2 
 9122.3 
 9156.4 
 
 9190.6 
 9224.9 
 9259-3 
 
 9293.8 
 
 9328.3 
 9362.9 
 
 9397.6 
 
 9432.3 
 9467.1 
 
 9502.0 
 
 9536.9 
 9572.0 
 
 9607.1 
 9642.2 
 9677-5 
 
 9712.8 
 9748.2 
 9783.6 
 
 9819. 1 
 
 9854.7 
 9890.4 
 
 9926.2 
 9962.0 
 9997-9 
 
 20033.9 
 20070.0 
 20106,2 
 
 Difif. 
 
 339 
 
 340 
 340 
 
 341 
 341 
 342 
 
 343 
 344 
 345 
 
 345 
 346 
 347 
 
 347 
 348 
 349 
 
 349 
 351 
 351 
 
 351 
 353 
 353 
 
 354 
 
 354 
 355 
 
 356 
 
 357 
 358 
 
 358 
 
 359 
 360 
 
 361 
 362 
 362 
 
 A{v) 
 
 0128.01 
 0189.78 
 0251.9 
 
 0314.5 
 0377.6 
 0441.0 
 
 0504.9 
 
 0569-3 
 0634.1 
 
 0699.3 
 0765.0 
 0831. 1 
 
 0897.6 
 0964.7 
 1032.2 
 
 1 100. 1 
 1168.6 
 1237-5 
 
 1307.0 
 1376.9 
 1447-2 
 
 1518.1 
 1589.4 
 1661.3 
 
 1733-7 
 1806.6 
 1880.0 
 
 1953-9 
 
 2028.4 
 2103.4 
 
 2178.9 
 2254.9 
 2331-5 
 
 Diff. 
 
 6177 
 
 6219 
 
 626 
 
 631 
 634 
 639 
 
 644 
 
 648 
 
 652 
 
 657 
 661 
 665 
 
 671 
 
 675 
 679 
 
 685 
 689 
 
 695 
 
 699 
 
 703 
 709 
 
 •713 
 719 
 
 724 
 
 729 
 734 
 739 
 
 745 
 750 
 755 
 
 760 
 766 
 771 
 
 /{v) 
 
 .81751 
 
 .82622 
 
 .83498 
 •84379 
 
 -85265 
 -86157 
 
 •87054 
 -87957 
 .88865 
 
 .89778 
 
 .90697 
 
 .91622 
 
 •92552 
 -93488 
 .94430 
 
 •95378 
 .96332 
 .97292 
 
 .98258 
 
 .99230 
 
 2.00207 
 
 2.0II90 
 2.02180 
 2.03176 
 
 2.04179 
 2.05188 
 
 2,06203 
 
 2.07225 
 
 2.08253 
 
 2.09288 
 2.10329 
 
 2.II376 
 
 2.12430 
 
 Diff, 
 
 871 
 876 
 
 886 
 892 
 897 
 
 903 
 908 
 
 913 
 
 919 
 
 925 
 930 
 
 936 
 942 
 948 
 
 954 
 960 
 966 
 
 972 
 977 
 983 
 
 990 
 
 996 
 T003 
 
 1009 
 1015 
 
 1022 
 
 1028 
 
 1035 
 1041 
 
 1047 
 
 1054 
 1061 
 
 T{v) 
 
 21.367 
 
 21.435 
 21.503 
 
 21.572 
 21.641 
 21.710 
 
 21.779 
 21.848 
 2T.918 
 
 21.988 
 22.058 
 22.128 
 
 22.199 
 22.270 
 22.341 
 
 22.413 
 22.485 
 22.557 
 
 22,630 
 22,703 
 22.776 
 
 22.849 
 22.923 
 22.997 
 
 23.071 
 23.146 
 23.221 
 
 23.296 
 23.372 
 23.448 
 
 23-524 
 23.601 
 23.678 
 
 Diff. 
 
 31 
 
TABLE I.— Continued, 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 /{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 468 
 467 
 466 
 
 20142.4 
 20J78.7 
 20215.0 
 
 363 
 365 
 
 12408.6 
 
 '12486.3 
 
 12564.6 
 
 777 
 783 
 788 
 
 2.13491 
 2.14559 
 2.15635 
 
 ic68 i 
 1076 i 
 1082 
 
 23.755 
 23.833 
 23.911 
 
 78 
 78 
 78 
 
 465 
 464 
 
 463 
 
 20251.5 
 20288.0 
 20324.7 
 
 365 
 367 
 367 
 
 12643.4 
 12722.8 
 12802.7 
 
 794 
 799 
 805 
 
 2.16717 
 2.17806 
 2.18902 
 
 1089 1 
 1096 
 1 104 
 
 23.989 
 24.068 
 24.147 
 
 79 
 79 
 79 
 
 462 
 461 
 460 
 
 20361.4 
 20398.1 
 20435.0 
 
 367 
 369 
 369 
 
 12883.2 
 12964.3 
 13045-9 
 
 811 
 816 
 822 
 
 2.20006 
 2.21116 
 
 2.22233 
 
 i 
 1110 
 
 1117 
 
 1124 
 
 24.226 
 24.306 
 24.386 
 
 80 
 80 
 80 
 
 459 
 458 
 457 
 
 20471.9 
 20508.9 
 20546.0 
 
 370 
 371 
 371 
 
 13128. 1 
 13211.O 
 13294.4 
 
 829 
 
 834 
 841 
 
 2.23357 
 
 2.24489 
 2.25629 
 
 1132 
 1140 
 1147 
 
 24.466 
 
 24.547 
 - 24.628 
 
 81 
 81 
 
 82 
 
 456 
 455 
 454 
 
 20583.1 
 20620.4 
 20657.7 
 
 373 
 373 
 
 374 
 
 13378.5 
 
 134633 
 13548.6 
 
 848 
 853 
 859 
 
 2.26776 
 
 2.27931 
 
 2.29094 
 
 1155 
 1163 
 1171 
 
 24.710 
 24.792 
 24.874 
 
 82 
 82 
 82 
 
 453 
 452 
 451 
 
 20695.1 
 20732.6 
 20770.2 
 
 375 
 376 
 377 
 
 13634.5 
 13721.1 
 13808.3 
 
 866 
 
 872 
 878 
 
 2.30265 
 
 2.31443 
 2.32628 
 
 1178 
 1185 
 1193 
 
 24.956 
 
 25-039 
 25.122 
 
 ^3 
 83 
 84 
 
 450 
 449 
 448 
 
 20807.9 
 20845.6 
 20883.4 
 
 377 
 378 
 380 
 
 13896.1 
 13984.6 
 14073.7 
 
 885 
 891 
 898 
 
 2.33821 
 2.35022 
 2.36232 
 
 1201 
 1210 
 1218 
 
 25.206 
 
 1 25.290 
 
 25.374 
 
 84 
 84 
 85 
 
 447 
 446 
 
 445 
 
 20921.4 
 20959.4 
 20997.4 
 
 380 
 380 
 382 
 
 '4163.5 
 
 14254.0 
 
 14345. i 
 
 905 
 911 
 919 
 
 2.37450 
 
 2.38676 
 2.39911 
 
 1226 
 1235 
 1243 
 
 1 25.459 
 25.544 
 25.629 
 
 85 
 85 
 86 
 
 444 
 
 443 
 442 
 
 21035.6 
 21073.9 
 21112.2 
 
 385 
 
 14437.0 
 
 14529.5 
 14622.7 
 
 925 
 932 
 939 
 
 2.41154 
 2.42405 
 2.43665 
 
 1251 
 1260 
 1268 
 
 i 25.715 
 25.801 
 25.888 
 
 86 
 87 
 87 
 
 441 
 440 
 439 
 
 21150.7 
 21189.2 
 21227.8 
 
 385 
 386 
 
 387 
 
 14716.6 
 14811.2 
 14906.5 
 
 946 
 
 953 
 960 
 
 2.44933 
 
 2.46209 
 
 2.47494 
 
 1276 
 1285 
 1294 
 
 25.975 
 26.062 
 26.150 
 
 87 
 88 
 88 
 
 438 
 437 
 436 
 
 21266.5 
 
 213^5-3 
 2i34'4-2 
 
 388 
 389 
 389 
 
 15002.5 
 
 15099.3 
 15196.8 
 
 968 
 
 975 
 982' 
 
 2.48788 
 2.50091 
 
 2.51404 
 
 1303 
 1313 
 1322 
 
 26.238 
 
 26.327 
 
 ' 26.416 
 
 89 
 89 
 89 
 
 32 
 
TABLE I.— Continued. 
 
 S{v) 
 
 21383. 1 
 21422.2 
 21461.4 
 
 21500.6 
 21540.0 
 21579-4 
 
 21618.9 
 21658.5 
 21698.2 
 
 21738.0 
 21777.9 
 21817.8 
 
 21857.9 
 21898.1 
 21938.4 
 
 21978.7 
 22019.1 
 22059.6 
 
 Diff. 
 
 22100.2 
 22140,9 
 22 
 
 81.8 
 
 22222.7 
 22263.7 
 22304.8 
 
 22346.1 
 
 ^2387.4 
 22428.8 
 
 22470.4 
 225 12.0 
 
 22553-7 
 
 22595.6 
 22637.5 
 22679.6 
 
 391 
 392 
 392 
 
 394 
 394 
 395 
 
 396 
 397 
 398 
 
 399 
 399 
 
 401 
 
 402 
 403 
 403 
 
 404 
 
 405 
 406 
 
 407 
 409 
 409 
 
 410 
 411 
 413 
 
 413 
 414 
 416 
 
 416 
 417 
 419 
 
 419 
 421 
 
 422 
 
 A{v) 
 
 5295-0 
 5394.0 
 5493-7 
 
 5594-2 
 5695-4 
 5797-3 
 
 5900.0 
 6003.5 
 6107.9 
 
 6213. 1 
 6319.1 
 6425.9 
 
 6533-5 
 6641.9 
 6751.2 
 
 6972.2 
 7084.1 
 
 7196.8 
 7310.5 
 7425.0 
 
 7540.5 
 7656.8 
 
 7774.1 
 
 7892.2 
 8011.3 
 813^-3 
 
 8252.4 
 
 8374.4 
 8497.4 
 
 8621.4 
 8746.4 
 8872.3 
 
 Diff. 
 
 990 
 
 997 
 
 1005 
 
 012 
 019 
 
 027 
 
 035 
 044 
 052 
 
 060 
 068 
 076 
 
 084 
 093 
 
 T09 
 119 
 127 
 
 137 
 145 
 155 
 
 163 
 
 173 
 181 
 
 191 
 200 
 211 
 
 220 
 230 
 240 
 
 250 
 
 259 
 270 
 
 I{v) 
 
 2.52726 
 
 2.54057 
 2.55397 
 
 2.56746 
 2.58104 
 2.59471 
 
 2.60848 
 2.62235 
 
 2.63632 
 
 2.65039 
 2.66456 
 
 2.67883 
 
 2.69320 
 2.70767 
 
 2.72225 
 
 2.73692 
 2.75169 
 
 2.76658 
 2.78158 
 
 2.79668 
 2,81190 
 
 2,82723 
 2.84267 
 
 2.85822 
 
 2.87388 
 2.88965 
 2.90554 
 
 2.92155 
 2.93768 
 
 2.95393 
 2.97030 
 
 2.98679 
 
 3.00341 
 
 Diff. 
 
 33^ 
 
 340 
 349 i 
 
 358 
 367 
 
 377 
 
 387 
 397 
 407 
 
 417 
 
 427 
 
 437 
 
 447 
 
 458 
 467 
 
 477 
 489 
 500 
 
 510 
 
 522 
 
 533 
 
 544 
 
 555 
 566 
 
 577 
 589 
 601 
 
 613 
 625 
 
 637 
 
 649 
 662 
 
 674 
 
 T{v) 
 
 26.505 
 
 26.595 
 26.685 
 
 26.776 
 26.867 
 26.959 
 
 27.051 
 
 27.143 
 27.236 
 
 27.329 
 27.423 
 27.517 
 
 27.612 
 
 27.707 
 27.803 
 
 27-899 
 27-995 
 28.092 
 
 28.189 
 28.287 
 28.385 
 
 28.484 
 28.583 
 28.683 
 
 28.783 
 28.884 
 28.985 
 
 29.087 
 29.189 
 29.292 
 
 29-395- 
 29.499 
 29,603 
 
 33 
 
TABLE I.— Continued. 
 
 V 
 
 Siv) 
 
 Difif. 
 
 A{v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 Tiy) 
 
 Diff. 
 
 402 
 401 
 400 
 
 22721.8 
 22764.0 
 22806.4 
 
 422 
 424 
 424 
 
 18999.3 
 19127.3 
 19256.2 
 
 1280 
 1289 
 
 1300 
 
 3.02015 
 I 3-03701 
 ' 3-05399 
 
 1686 
 1698 
 1710 
 
 29.708 
 29.813 
 29.919 
 
 105 
 106 
 106 
 
 34 
 
TABLE II. 
 
 For Spherical Projectiles. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A(v) 
 
 Diff. 1 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 2000 
 
 
 
 25 
 
 0.00 
 
 I i 
 
 0.00000 
 
 40 
 
 0.000 
 
 12 
 
 1990 
 1980 
 
 25 
 49 
 
 24 
 
 25 
 
 O.OI 
 
 0.02 
 
 I ! 
 2 
 
 00040 
 00080 
 
 40 
 41 
 
 0.012 
 0.025 
 
 13 
 
 12 
 
 1970 
 i960 
 1950 
 
 74 
 
 99 
 124 
 
 25 
 25 
 26 
 
 0.04 
 0.08 
 0.13 
 
 4 
 
 5 
 
 51 
 
 0.00121 
 00163 
 00205 
 
 42 
 42 
 43 
 
 0.037 
 0.050 
 0.063 
 
 13 
 13 
 13 
 
 1940 
 1930 
 1920 
 
 150 
 175 
 201 
 
 25 
 26 
 
 25 
 
 0.18 
 0.25 
 0.33 
 
 7J 
 8 1 
 
 9 
 
 0.00248 
 00292 
 00336 
 
 44 
 44 
 45 
 
 0.076 
 0.089 
 0.102 
 
 13 
 
 13 
 14 
 
 I9IO 
 1900 
 1890 
 
 226 
 
 252 
 278 
 
 26 
 26 
 26 
 
 0.42 
 
 0.53 
 0.65 
 
 13 
 
 0.00381 
 00427 
 00473 
 
 46 
 46 
 
 47 
 
 0.1 16 
 0.129 
 0.143 
 
 13 
 14 
 14 
 
 1880 
 1870 
 i860 
 
 304 
 
 357 
 
 26 
 
 27 
 26 
 
 0.78 
 0.92 
 1.07 
 
 14 
 15 
 17 
 
 0.00520 
 00568 
 00617 
 
 48 
 49 
 49 
 
 0.157 
 0.171 
 0.185 
 
 14 
 14 
 14 
 
 1850 
 1840 
 1830 
 
 383 
 409 
 
 436 
 
 26 
 
 27 
 27 
 
 1.24 
 
 1.43 
 1.63 
 
 19 
 
 20 
 
 21 
 
 0.00666 
 00716 
 00767 
 
 50 
 51 
 
 52 
 
 0.199 
 0.214 
 0.228 
 
 15 
 14 
 15 
 
 1820 
 181O 
 1800 
 
 463 
 490 
 
 517 
 
 27 
 
 27 
 28 
 
 1.84 
 2.07 
 2.31 
 
 23 
 24 
 26 
 
 0.00819 
 00872 
 00926 
 
 53 
 
 0.243 
 0.258 
 0.273 
 
 15 
 15 
 15 
 
 1790 
 
 1780 
 1770 
 
 545 
 572 
 600 
 
 27 
 28 
 28 
 
 2.57 
 2.84 
 
 3.14 
 
 27 
 30 
 31 
 
 0.00981 
 01036 
 01093 
 
 55 
 57 
 57 
 
 0.288 
 0.304 
 0.319 
 
 16 
 
 15 
 16 
 
 1760 
 
 1750 
 1740 
 
 628 
 656 
 684 
 
 28 
 28 
 28 
 
 3.45 
 3-78 
 4-13 
 
 35 
 37 
 
 0.01150 
 01209 
 01268 
 
 59 
 59 
 61 
 
 0.335 
 0.351 
 0.367 
 
 16 
 16 
 16 
 
 1730 
 1720 
 I7IO 
 
 712 
 741 
 769 
 
 29 
 28 
 
 29 
 
 4.50 
 4.89 
 5-30 
 
 39 
 41 
 43 
 
 0.01329 
 01390 
 01453 
 
 61 
 
 (>z 
 
 64 
 
 0.383 
 0.400 
 0.416 
 
 17 
 16 
 
 17 
 
 35 
 
TABLE IL— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff; 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 1700 
 1690 
 1680 
 
 798 
 827 
 856 
 
 29 
 29 
 30 
 
 5-73 
 6.18 
 6.65 
 
 45 
 47 
 50 
 
 O.OI5I7 
 01582 
 01648 
 
 65 
 
 66 
 67 
 
 0.433 
 0.450 
 0.468 
 
 17 
 
 18 
 
 17 
 
 1670 
 1660 
 1650 
 
 886 
 915 
 945 
 
 1 
 29 
 
 30 
 30 
 
 7.15 
 7.67 
 8.21 
 
 52 
 54 
 56 
 
 O.OI7I5 
 
 01783 
 01853 
 
 68 
 70 
 71 
 
 0.485 
 
 0-503 
 0.521 
 
 18 
 18 
 t8 
 
 1640 
 1630 
 1620 
 
 975 
 1005 
 1036 
 
 30 
 3T 
 30 
 
 8.77 
 9-35 
 9-97 
 
 58 
 62 
 64 
 
 0.01924 
 01996 
 02070 
 
 72 
 74 
 75 
 
 0.539 
 0.558 
 0.576 
 
 19 
 18 
 
 19 
 
 I6I0 
 1600 
 
 1590 
 
 1066 
 1096 
 T127 
 
 30 
 31 
 31 
 
 10.61 
 11.27 
 11.96 
 
 66 
 69 
 
 72 
 
 0.02145 
 02222 
 02300 
 
 79 
 
 0.595 
 0.614 
 0.633 
 
 19 
 19 
 
 20 
 
 1580 
 1570 
 
 1560 
 
 1158 
 1189 
 
 1220 
 
 31 
 31 
 
 32 
 
 12.68 
 
 1344 
 14.22 
 
 76 
 
 78 
 82 
 
 0.02379 
 02460 
 
 02542 
 
 81 
 
 82 
 84 
 
 0.653 
 0.673 
 0.693 
 
 20 
 20 
 20 
 
 1550 
 
 1540 
 1530 
 
 1252 
 1284 
 1316 
 
 32 
 32 
 32 
 
 15-04 
 15.90 
 16.78 
 
 86 
 88 
 92 
 
 0.02626 
 02712 
 
 02799 
 
 86 
 87 
 89 
 
 0.713 
 0.734 
 0.755 
 
 21 
 21 
 21 
 
 1520 
 I5I0 
 1500 
 
 1348 
 1380 
 
 1413 
 
 32 
 
 17.70 
 18.65 
 19.63 
 
 95 
 98 
 
 100 
 
 0.02888 
 02979 
 
 03072 
 
 91 
 93 
 94 
 
 0.776 
 0.797 
 0.819 
 
 21 
 22 
 22 
 
 1490 
 1480 
 
 1470 
 
 1446 
 1479 
 1512 
 
 Z2> 
 7>Z 
 34 
 
 20.63 
 21.68 
 
 22.77 
 
 105 
 109 
 114 
 
 03166 
 03262 
 03360 
 
 - 96 
 98 
 
 ICI 
 
 0.841 
 0.863 
 0.885 
 
 22 
 22 
 23 
 
 1460 
 
 1450 
 1440 
 
 1546 
 1580 
 1614 
 
 34 
 34 
 34 
 
 23.91 
 
 i 25.10 
 26.34 
 
 ! 
 
 119 
 124 
 
 128 
 
 03461 
 
 03564 
 03669 
 
 103 
 105 
 107 
 
 0.908 
 0931 
 0.955 
 
 23 
 24 
 24 
 
 1430 
 
 T420 
 I4I0 
 
 1648 
 1682 
 1717 
 
 34 
 
 35 
 35 
 
 27.62 
 1 28.95 
 
 133 
 138 
 143 
 
 0.03776 
 
 03885 
 03997 
 
 109 
 112 
 114 
 
 0.979 
 T.003 
 1.028 
 
 24 
 
 25 
 
 25 
 
 1400 
 
 1390 
 1380 
 
 1752 
 1787 
 1823 
 
 35 
 35 
 
 31.76 
 
 33-25 
 34-79 
 
 149 
 
 154 
 160 
 
 0.041 1 1 
 04227 
 04346 
 
 116 
 119 
 122 
 
 1.053 
 1.079 
 1. 105 
 
 26 
 .6 
 26 
 
 36 
 
TABLE II.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 1370 
 1360 
 
 1350 
 
 1858 
 1894 
 1931 
 
 36 
 37 
 36 
 
 36.39 
 38.03 
 39-73 
 
 164 
 
 170 
 
 175 
 
 0.04468 
 
 04592 
 04719 
 
 124 
 127 
 129 
 
 1. 131 
 
 1. 158 
 1. 185 
 
 27 
 27 
 27 
 
 1340 
 
 1330 
 1320 
 
 1967 
 2004 
 2041 
 
 37 
 
 37 
 37 
 
 41.48 
 43-29 
 45-14 
 
 181 
 
 185 
 191 
 
 0.04848 
 04981 
 
 05II7 
 
 136 
 139 
 
 1. 212 
 1.239 
 1.267 
 
 27 
 28 
 27 
 
 I3I0 
 1300 
 1290 
 
 j 2078 
 
 2Tl6 
 2T54 
 
 38 
 38 
 
 47-05 
 49.01 
 
 51-04 
 
 196 
 
 203 
 212 
 
 0.05256 
 
 05398 
 05542 
 
 142 
 144 
 
 148 
 
 1.294 
 1.322 
 I-351 
 
 28 
 
 29 
 30 
 
 1280 
 1270 
 1260 
 
 2192 
 2231 
 2269 
 
 39 
 38 
 39 
 
 53-16 
 
 55-37 
 57.67 
 
 221 
 230 
 240 
 
 0.05690 
 
 05842 
 05998 
 
 152 
 156 
 160 
 
 1.38T 
 1.411 
 1.442 
 
 30 
 31 
 31 
 
 1250 
 
 1240 
 1230 
 
 2308 
 
 2348 
 
 1 2388 
 
 40 
 40 
 40 
 
 60.07 
 62.56 
 65.14 
 
 249 
 258 
 267 
 
 0.06158 
 
 06323 
 
 06492 
 
 165 
 
 169 
 174 
 
 1.473 
 
 1-505 
 1.538 
 
 32 
 33 
 
 1220 
 
 I2IO 
 
 1200 
 
 2428 
 2470 
 2512 
 
 42 
 42 
 22 
 
 67.81 
 70.59 
 73-54 
 
 278 
 
 295 
 156 
 
 0.06666 
 
 06846 
 07033 
 
 180 
 
 187 
 
 97 
 
 1.571 
 1.605 
 1.640 
 
 34 
 
 35 
 18 
 
 I I 90 
 
 2534 
 2556 
 2578 
 
 22 
 22 
 22 
 
 75-IO 
 76.70 
 
 78.32 
 
 t6o 
 162 
 165 
 
 0.07130 
 07229 
 
 07329 
 
 99 
 100 
 
 102 
 
 1.658 
 1.676 
 1.694 
 
 18 
 18 
 18 
 
 I 180 
 
 II75 
 1170 
 
 1 2600 
 2623 
 2646 
 
 '23 
 23 
 23 
 
 79-97 
 81.66 
 
 83-39 
 
 169 
 
 173 
 177 
 
 0.07431 
 07535 
 
 07641 
 
 104 
 106 
 108 
 
 1.712 
 I-731 
 I-751 
 
 19 
 
 20 
 
 19 
 
 I165 
 I 160 
 
 i'55 
 
 j 
 
 i 2669 
 2692 
 2715 
 
 23 
 23 
 24 
 
 85.16 
 86.98 
 88.84 
 
 182 
 186 
 190 
 
 0.07749 
 
 07859 
 07972 
 
 no 
 113 
 115 
 
 1.770 
 1.790 
 1. 810 
 
 20 
 20 
 21 
 
 1150 
 
 1 145 
 
 1 140 
 
 2739 
 2763 
 2787 
 
 24 
 
 24 
 
 25 
 
 90.74 
 92.69 
 94.68 
 
 195 
 199 
 
 205 
 
 0.08087 
 08204 
 
 08324 
 
 117 
 120 
 122 
 
 1.831 
 1.852 
 1-873 
 
 21 
 21 
 
 22 
 
 1130 
 1125 
 
 2812 
 2837 
 2861 
 
 25 
 24 
 
 25 
 
 96.73 
 
 98.82 
 
 100.97 
 
 209 
 
 215 
 221 
 
 0.08446 
 08570 
 08697 
 
 124 
 127 
 130 
 
 1.895 
 
 1-917 
 1.940 
 
 22 
 23 
 23 
 
 37 
 
TABLE II.— Continued. 
 
 V 
 
 Si^v) 
 
 Diff. 
 
 A{v) 
 
 Diflf. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 II20 
 IITO 
 
 2886 
 2912 
 2938 
 
 26 
 26 
 26 
 
 103.18 
 
 J05-44 
 
 107.77 
 
 226 
 233 
 239 
 
 0.08827 
 08959 
 
 09094 
 
 132 
 
 '35 
 138 
 
 1.963 
 1.986 
 2.009 
 
 23 
 
 24 
 
 IIO5 
 IIOO 
 
 1095 
 
 2964 
 2991 
 3017 
 
 27 
 26 
 27 
 
 110.16 
 1 12,62 
 115-13 
 
 246 
 
 251 
 259 
 
 0.09232 
 
 09373 
 09516 
 
 141 
 '43 
 147 
 
 2.033 
 
 2.057 
 2.081 
 
 24 
 
 24 
 25 
 
 1090 
 1085 
 1080 
 
 3044 
 3071 
 
 3099 
 
 27 
 28 
 28 
 
 117.72 
 120.38 
 123.13 
 
 266 
 
 ■275 
 283 
 
 0.09663 
 09812 
 
 09965 
 
 149 
 
 153 
 156 
 
 2.106 
 
 2.132 
 2.158 
 
 26 
 26 
 26 
 
 1075 
 
 1070 
 1065 
 
 3127 
 
 3155 
 3184 
 
 28 
 29 
 29 
 
 125.96 
 128.87 
 131.87 
 
 291 
 300 
 308 
 
 0.10121 
 10280 
 
 10443 
 
 159 
 163 
 166 
 
 2.184 
 2.210 
 
 2.237 
 
 26 
 
 27 
 28 
 
 io6o 
 
 1055 
 1050 
 
 3213 
 3243 
 3273 
 
 30 
 30 
 30 
 
 134.95 
 138.12 
 141.38 
 
 317 
 326 
 
 338 
 
 0.10609 
 
 10-79 
 10952 
 
 170 
 
 173 
 177 
 
 2.265 
 2.293 
 2.321 
 
 28 
 28 
 29 
 
 1045 
 T040 
 
 1035 
 
 3364 
 
 30 
 31 
 31 
 
 144.76 
 148.22 
 151-77 
 
 346 
 355 
 364 
 
 0.11129 
 11310 
 1 1495 
 
 181 
 
 185 
 189 
 
 2.350 
 
 2.379 
 2.409 
 
 29 
 30 
 31 
 
 1030 
 1025 
 1020 
 
 3395 
 3427 
 3459 
 
 32 
 32 
 32 
 
 155-41 
 
 159-15 
 162.99 
 
 374 
 384 
 394 
 
 0.11684 
 
 II877 
 12074 
 
 193 
 197 
 
 202 
 
 2.440 
 2.471 
 2.502 
 
 31 
 31 
 32 
 
 1015 
 
 lOIO 
 
 1005 
 
 3491 
 
 3524 
 
 3557 
 
 Z2> 
 34 
 
 166.93 
 170.99 
 175-17 
 
 406 
 418 
 430 
 
 0.12276 
 12482 
 
 12693 
 
 206 
 211 
 215 
 
 2.534 
 2.566 
 
 2.599 
 
 32 
 
 1000 
 
 995 
 990 
 
 3591 
 3625 
 3660 
 
 34 
 
 35 
 35 
 
 179-47 
 183.90 
 188.46 
 
 443 
 456 
 
 470 
 
 0.12908 
 
 13128 
 13354 
 
 220 
 226 
 231 
 
 2.632 
 2.665 
 2.699 
 
 zz 
 
 34 
 ZS 
 
 985 
 980 
 
 975 
 
 3695 
 3731 
 3767 
 
 36 
 
 193.16 
 198.00 
 202.98 
 
 484 
 498 
 513 
 
 0.13585 
 13821 
 
 14062 
 
 236 
 241 
 246 
 
 2.734 
 
 2.770 
 2.806 
 
 36 
 37 
 
 970 
 
 965 
 960 
 
 3803 
 3840 
 
 3877 
 
 37 
 37 
 
 38 
 
 208.1 1 
 213.40 
 218.86 
 
 529 
 546 
 563 
 
 0.14308 
 14560 
 14818 
 
 252 
 
 258 
 264 
 
 2.843 
 2.881 
 2.920 
 
 38 
 39 
 39 
 
 38 
 
TABLE II.— Continued. 
 
 V 
 
 S{v) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 955 
 950 
 945 
 
 39^5 
 3953 
 3992 
 
 38 
 39 
 39 
 
 224.49 
 230.29 
 236.29 
 
 580 
 600 
 620 
 
 0.15082 
 
 15352 
 15628 
 
 270 
 276 
 283 
 
 2-959 
 2.999 
 
 3.040 
 
 40 
 
 41 
 
 42 
 
 940 
 
 935 
 930 
 
 4031 
 4070 
 41 10 
 
 39 
 
 40 
 
 41 
 
 242.49 
 248.86 
 255-43 
 
 637 
 657 
 676 
 
 O.I59II 
 
 I620I 
 16498 
 
 290 
 297 
 304 
 
 3.082 
 3-125 
 3.168 
 
 43 
 43 
 44 
 
 925 
 920 
 
 915 
 
 4151 
 4192 
 
 4234 
 
 41 
 
 42 
 
 43 
 
 262.19 
 269.17 
 276.37 
 
 698 
 720 
 743 
 
 0.16802 
 
 17113 
 
 17432 
 
 311 
 319 
 327 
 
 3-212 
 3-257 
 3-303 
 
 45 
 46 
 
 47 
 
 910 
 
 905 
 900 
 
 4277 
 4320 
 
 4363 
 
 43 
 43 
 44 
 
 283.80 
 291.47 
 299.40 
 
 767 
 
 793 
 819 
 
 0.17759 
 
 18094 
 
 18437 
 
 335 
 343 
 
 352 
 
 3-350 
 
 3-397 
 
 3.445 
 
 47 
 48 
 
 49 
 
 895 
 890 
 885 
 
 4407 
 
 4451 
 4496 
 
 44 
 45 
 46 
 
 307-59 
 316.04 
 
 324-77 
 
 845 
 873 
 901 
 
 0.18789 
 I9I49 
 I95I8 
 
 360 
 
 369 
 
 378 
 
 3-494 
 3.544 
 3.595 
 
 50 
 51 
 52 
 
 880 
 
 875 
 870 
 
 4542 
 
 4589 
 4636 
 
 47 
 47 
 48 
 
 333-78 
 343-06 
 352.67 
 
 928 
 961 
 997 
 
 0.19896 
 20283 
 20680 
 
 387 
 397 
 
 407 
 
 3-647 
 
 3.700 
 
 3-754 
 
 53 
 
 54 
 55 
 
 865 
 860 
 855 
 
 4684 
 4732 
 4781 
 
 48 
 49 
 49 
 
 362.64 
 372.96 
 
 1032 
 1064 
 1099 
 
 0.21087 
 
 21505 
 21933 
 
 418 
 428 
 439 
 
 3-809 
 3.865 
 3.922 
 
 56 
 
 57 
 58 
 
 850 
 
 845 
 840 
 
 4830 
 4880 
 4931 
 
 50 
 5» 
 
 52 
 
 394.59 
 405-96 
 417.71 
 
 "37 
 
 1175 
 1216 
 
 0.22372 
 
 22823 
 
 23285 
 
 451 
 462 
 
 476 
 
 3-980 
 
 4.039 
 4.100 
 
 59 
 61 
 61 
 
 835 
 830 
 
 825 
 
 4983 
 5036 
 5089 
 
 53 
 
 53 
 54 
 
 429.87 
 442.45 
 455-47 
 
 1258 
 1302 
 1347 
 
 0.23761 
 24248 
 24746 
 
 487 
 498 
 
 511 
 
 4. 161 
 
 4.224 
 4.288 
 
 64 
 
 820 
 
 815 
 810 
 
 5143 
 5198 
 5253 
 
 55 
 55 
 56 
 
 468.94 
 482.89 
 497-33 
 
 1395 
 1444 
 
 1495 
 
 0.25257 
 25783 
 
 26323 
 
 526 
 
 540 
 
 553 
 
 4-354 
 4-421 
 4.489 
 
 67 
 68 
 
 70 
 
 805 
 800 
 795 
 
 5309 
 5366 
 5424 
 
 57 
 58 
 59 
 
 512.28 
 
 527-77 
 543-81 
 
 1549 
 1604 
 1661 
 
 0.26876 
 27444 
 
 28031 
 
 568 
 
 587 
 601 
 
 4-559 
 4.630 
 4.702 
 
 71 
 
 72 
 74 
 
 39 
 
TABLE II.— Continued. 
 
 V 
 
 Siv) 
 
 Diff. 
 
 A{v) 
 
 Diff. 
 
 nv) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 79Q 
 
 785 
 780 
 
 5483 
 5542 
 5602 
 
 59 
 60 
 61 
 
 560.42 
 
 577-64 
 595-48 
 
 1722 
 1784 
 1849 
 
 0.28632 
 29249 
 29883 
 
 617, 
 
 634 
 
 650; 
 
 4.776 
 4.852 
 4-929 
 
 76 
 
 77 
 79 
 
 775 
 770 
 
 765 
 
 5663 
 
 5725 
 5788 
 
 62 
 
 63 
 64 
 
 613-97 
 653.01 
 
 1916 
 1988 
 2062 
 
 0.30533 
 31203 
 31891 
 
 670 
 688 
 
 707 
 
 5.008 
 5.088 
 5-170 
 
 80 
 82 
 84 
 
 760 
 
 755 
 750 
 
 5852 
 5917 
 5983 
 
 65 
 66 
 
 67 
 
 673-63 
 695.01 
 717 19 
 
 2138 
 2218 
 
 2303 
 
 0.32-598 
 33325 
 34073 
 
 727 
 748 
 770 
 
 5254 
 5-340 
 5-427 
 
 86 
 
 87 
 90 
 
 745 
 740 
 
 735 
 
 6050 
 6118 
 6187 
 
 68 
 69 
 69 
 
 740.22 
 764.11 
 788.91 
 
 2389 
 248c 
 
 2574 
 
 0.34843 
 35634 
 36448 
 
 791 
 814 
 837 
 
 5-517 
 5-608 
 
 S-701 
 
 91 
 93 
 96 
 
 730 
 
 725 
 720 
 
 6256 
 6327 
 6399 
 
 71 
 
 72 
 73 
 
 814.65 
 841.38 
 869.14 
 
 2673 
 2776 
 2882 
 
 0.37285 
 38146 
 39033 
 
 861 
 887 
 912 
 
 5-797 
 5.894 
 5-994 
 
 97 
 100 
 
 102 
 
 715 
 710 
 
 705 
 
 6472 
 6546 
 6621 
 
 74 
 
 75 
 77 
 
 897.96 
 927.92 
 959.07 
 
 2996 
 
 3115 
 
 3238 
 
 0.39945 
 
 40885 
 
 41853 
 
 940 
 968 
 
 995 
 
 6.096 
 6.200 
 6.306 
 
 104 
 106 
 109 
 
 700 
 
 695 
 690 
 
 6698 
 6776 
 685s 
 
 78 
 
 79 
 
 80 
 
 991.45 
 1025.2 
 1060.2 
 
 3366 
 350 
 364 
 
 0.42848 
 
 43872 
 44926 
 
 1024 
 
 1054 
 1089 
 
 6.415 
 6.526 
 6.640 
 
 III 
 ri4 
 116 
 
 685 
 680 
 
 675 
 
 6935 
 7016 
 7098 
 
 81 
 
 . 82 
 
 84 
 
 1196.6 
 
 1134.4 
 1173.8 
 
 378 
 394 
 409 
 
 0.46015 
 
 47143 
 48302 
 
 1128 
 
 1159 
 1192 
 
 6.756 
 6.875 
 6.997 
 
 1 
 
 119 
 122 
 125 
 
 670 
 665 
 660 
 
 7182 
 7267 
 7354 
 
 85 
 87 
 88 
 
 1214.7 
 
 1257.4 
 1301.8 
 
 427 
 444 
 463 
 
 0.49494 
 50722 
 
 51989 
 
 1228 
 1267 
 1307 
 
 7.122 
 
 7-249 
 7-380 
 
 127 
 
 131 
 134 
 
 655 
 650 
 
 645 
 
 7442 
 
 7531 
 7622 
 
 89 
 
 91 
 92 
 
 1348.1 
 
 1396.3 
 1446.5 
 
 482 
 502 
 523 
 
 0.53296 
 54645 
 56037 
 
 1349 
 1392 
 
 1436 
 
 7-5M 
 
 7-651 
 
 1 7.79T 
 
 137 
 140 
 
 143 
 
 640 
 
 635 
 630 
 
 7714 
 7808 
 7903 
 
 94 
 95 
 97 
 
 1498.8 
 
 1553.4 
 1610.2 
 
 546 
 568 
 592 
 
 0.57473 
 58955 
 60484 
 
 1482 
 1529 
 1579 
 
 7 934 
 ' 8.081 
 ' 8.231 
 
 147 
 150 
 154 
 
 40 
 
TABLE II.— Continued. 
 
 V 
 
 Siv) 
 
 Diff. 
 
 A {v) 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 625 
 
 620 
 
 6.5 
 
 8000 
 8098 
 8198 
 
 98 
 100 
 
 lOI 
 
 1669.4 
 1731.2 
 1795-6 
 
 618 
 644 
 673 
 
 0.62063 
 
 63696 
 65386 
 
 1633 
 1690 
 
 1737 
 
 8.885 
 
 8-543 
 8.705 
 
 158 
 162 
 166 
 
 610 
 605 
 600 
 
 8299 
 8402 
 8507 
 
 103 1 
 
 105 
 
 107 
 
 1862.9 
 
 I933-I 
 2006.4 
 
 702 
 733 
 765 
 
 0.67123 
 68922 
 70781 
 
 1799 
 
 1859 
 1923 
 
 8.871 
 9.041 
 9.215 
 
 170 
 
 174 
 179 
 
 595 
 590 
 
 585 
 
 8614 
 8722 
 8833 
 
 108 
 III 
 1 12 
 
 2082.9 
 2162.9 
 2246.5 
 
 800 
 836 
 872 
 
 0.72704 
 74692 
 76747 
 
 1988 
 
 2055 
 2126 
 
 9.394 
 9.577 
 9-765 
 
 183 
 188 
 192 
 
 580 
 575 
 570 
 
 8945 
 9059 
 9175 
 
 114 
 116 
 
 118 
 
 2333-7 
 2424.8 
 2520.2 
 
 911 
 954 
 998 
 
 0.78873 
 
 81072 
 
 83348 
 
 2199 
 2276 
 2356 
 
 10.957 
 10.154 
 
 10.357 
 
 197 
 
 203 
 208 
 
 565 
 560 
 
 555 
 
 9293 
 9413 
 9535 
 
 120 
 122 
 124 
 
 2620.0 
 2724.3 
 2833.4 
 
 1043 
 1091 
 1142 
 
 0.85704 
 88144 
 
 90670 
 
 2440 
 2526 
 2617 
 
 10.565 
 10.778 
 10.997 
 
 213 
 219 
 
 225 
 
 550 
 545 
 540 
 
 9659 
 9785 
 9914 
 
 126 
 129 
 131 
 
 2947.6 
 3067.2 
 3192.4 
 
 1196 
 
 1252 
 1312 
 
 0.93287 
 
 95998 
 98808 
 
 2711 
 2810 
 2913 
 
 11.222 
 
 11-453 
 11.690 
 
 231 
 237 
 243 
 
 535 
 
 - 530 
 
 525 
 
 10045 
 10178 
 
 135 
 138 
 
 3323-6 
 3461.0 
 3605.0 
 
 1374 
 1440 
 
 1509 
 
 I.OI72I 
 
 1.04740 
 1.07873 
 
 3019 
 3247 
 
 11-933 
 12.183 
 12.440 
 
 250 
 
 257 
 264 
 
 520 
 
 515 
 510 
 
 10451 
 10591 
 10734 
 
 140 
 
 143 
 146 
 
 3755-9 
 3914.1 
 4080.1 
 
 1582 
 1660 
 1743 
 
 I.III20 
 1. 14486 
 I.I7981 
 
 ZZ(^(> 
 3495 
 3633 
 
 12.704 
 
 12.975 
 13-254 
 
 271 
 
 279 
 
 287 
 
 505 
 500 
 
 495 
 
 10880 
 11028 
 11179 
 
 .48 
 151 
 
 '53 
 
 4254-4 
 4437-3 
 4629.3 
 
 1829 
 1920 
 2017 
 
 I.21614 
 
 1.25393 
 T. 29312 
 
 3779 
 3919 
 
 4070 
 
 13-541 
 13.836 
 14.138 
 
 295 
 302 
 312 
 
 490 
 
 485 
 480 
 
 11332 
 11488 
 1 1648 
 
 156 
 
 160 
 162 
 
 4831.0 
 5042.8 
 5265-4 
 
 2118 
 2226 
 2340 
 
 1.33382 
 I.37614 
 1. 42013 
 
 4232 
 4399 
 
 4575 
 
 14-450 
 14.770 
 15.100 
 
 320 
 330 
 340 
 
 475 
 470 
 
 465 
 
 11810 
 
 11975 
 12143 
 
 168 
 172 
 
 5499-4 
 
 5745-5 
 6004.3 
 
 2461 
 
 2588 
 2724 
 
 1.46588 
 1. 51348 
 1. 56301 
 
 4760 
 4953 
 5157 
 
 15-440 
 15-790 
 16.150 
 
 350 
 360 
 
 370 
 
 41 
 
TABLE II. —Continued. 
 
 V 
 
 S(v) 
 
 Diff. 
 
 A{v) 
 
 ■ 
 
 Diff. 
 
 I{v) 
 
 Diff. 
 
 T{v) 
 
 Diff. 
 
 460 
 455 
 450 
 
 12315 
 12490 
 12668 
 
 175 
 178 
 
 6276.7 
 6865.5 
 
 2868 
 3020 
 
 1. 61458 
 1.66826 
 
 ! 1. 72419 
 
 1 
 
 5368 
 5593 
 
 16.520 
 16.902 
 17.296 
 
 382 
 394 
 
 42 
 
TABLE III. 
 
 f) 
 
 (^) 
 
 Diff. 
 
 Tan^ 
 
 Diff. 
 
 e 
 
 (^) 
 
 Diff. 
 
 TanO 
 
 Diff. 
 
 o° oo' 
 o 20 
 40 
 
 0.00000 
 00582 
 01164 
 
 i 
 582 
 582 
 582 
 
 0.00000 
 00582 
 01164 
 
 582 
 582 
 582 
 
 ' 
 II 00 
 
 II 20 
 
 II 40 
 
 0.19560 
 20176 
 20794 
 
 616 
 618 
 621 
 
 0.19438 
 
 20042 
 20648 
 
 604 
 606 
 608 
 
 I 00 
 I 20 
 I 40 
 
 0.01746 
 02328 
 02910 
 
 582 
 582 
 583 
 
 0.01746 
 02328 
 02910 
 
 582 
 582 
 582 
 
 12 00 
 12 20 
 12 40 
 
 0.21415 
 22038 
 22663 
 
 623 
 625 
 627 
 
 0.21256 
 21864 
 
 22475 
 
 608 
 611 
 612 
 
 .2 00 
 2 20 
 2 40 
 
 0.03493 
 04076 
 04659 
 
 583 
 583 
 584 
 
 0.03492 
 
 04075 
 04658 
 
 583 
 583 
 583 
 
 13 00 
 13 20 
 13 40 
 
 0.23290 
 23920 
 24553 
 
 630 
 
 633 
 636 
 
 0.23087 
 23700 
 24316 
 
 613 
 616 
 617 
 
 3 00 
 3 20 
 
 3 40 
 
 0.05243 
 05827 
 06412 
 
 584 
 585 
 586 
 
 0.05241 
 05824 
 06408 
 
 583 
 584 
 585 
 
 14 00 
 14 20 
 14 40 
 
 0.25189 
 
 25827 
 26468 
 
 638 
 641 
 644 
 
 0.24933 
 25552 
 26172 
 
 619 
 620 
 
 623 
 
 4 00 
 4 20 
 4 40 
 
 0.06998 
 
 07585 
 08172 
 
 587 
 587 
 58S 
 
 0.06993 
 07578 
 08163 
 
 585 
 585 
 586 
 
 15 00 
 15 20 
 15 40 
 
 0.27112 
 
 27759 
 28409 
 
 647 
 650 
 654 
 
 0.26795 
 27419 
 28046 
 
 624 
 
 627 
 629 
 
 5 00 
 
 5 20 
 5 40 
 
 0.08760 
 09349 
 09939 
 
 589 
 590 
 591 
 
 0.08749 
 
 09335 
 09922 
 
 586 
 
 587 
 588 
 
 16 00 
 16 20 
 16 40 
 
 0.29063 
 29720 
 30380 
 
 657 
 660 
 663 
 
 0.28675 
 
 29305 
 29938 
 
 630 
 633 
 635 
 
 6 00 
 6 20 
 6 40 
 
 0.10530 
 II 122 
 11715 
 
 592 
 593 
 594 
 
 0.105 10 
 1 1099 
 11688 
 
 589 
 589 
 590 
 
 17 00 
 17. 20 
 17 40 
 
 0.31043 
 31710 
 32381 
 
 667 
 671 
 674 
 
 0.30573 
 31210 
 31850 
 
 637 
 
 640 
 642 
 
 7 00 
 7 20 
 7 40 
 
 0.12309 
 12905 
 13502 
 
 596 
 597 
 598 
 
 0.12278 
 12869 
 13461 
 
 591 
 592 
 593 
 
 18 00 
 18 20 
 18 40 
 
 0.33055 
 
 33733 
 34415 
 
 678 
 682 
 686 
 
 0.32492 
 33^36 
 33783 
 
 644 
 647 
 650 
 
 8 00 
 8 20 
 8 40 
 
 0.14100 
 14700 
 15301 
 
 600 
 601 
 603 
 
 0.14054 
 
 14648 
 
 1 15243 
 
 594 
 595 
 595 
 
 19 00 
 19 20 
 19 40 
 
 0.35101 
 
 35791 
 36486 
 
 690 
 
 695 
 699 
 
 0.34433 
 35085 
 35740 
 
 652 
 655 
 657 
 
 9 00 
 9 20 
 9 40 
 
 0.15904 
 16509 
 17116 
 
 605 
 607 
 608 
 
 0.15838 
 1 16435 
 
 1 17033 
 
 j 
 
 597 
 598 
 600 
 
 20 00 
 20 20 
 20 40 
 
 0.37185 
 37888 
 38596 
 
 703 
 
 708 
 
 713 
 
 0.36397 
 37057 
 37720 
 
 660 
 663 
 666 
 
 10 00 
 10 20 
 10 40 
 
 0.17724 
 
 18334 
 18946 
 
 610 
 612 
 614 
 
 0.17633 
 18233 
 18835 
 
 600 
 602 
 603 
 
 21 00 
 21 20 
 21 40 
 
 0.39309 
 40026 
 40748 
 
 717 
 
 722 
 728 
 
 0.38386 
 39055 
 39727 
 
 669 
 672 
 676 
 
 43 
 
TABLE III.— Continued. 
 
 . 
 
 m 
 
 Diff. 
 
 Tan 6/ 
 
 Diff. 
 
 6 
 
 (^) 
 
 Diff. 
 
 TanB 
 
 Diff. 
 
 22° Oo' 
 22 20 
 2 2 40 
 
 0.41476 
 42208 
 42946 
 
 732 
 738 
 744 
 
 0.40403 
 41081 
 41763 
 
 678 
 682 
 684 
 
 33 
 33 
 
 00' 
 
 20 
 
 40 
 
 0.69253 
 
 70245 
 71248 
 
 992 
 
 roo3 
 1015 
 
 0.64941 
 
 65771 
 66608 
 
 830 
 837 
 843 
 
 23 00 
 23 20 
 23 40 
 
 0.43690 
 
 44439 
 45193 
 
 749 
 754 
 760 
 
 0.42447 
 
 43136 
 
 43828 
 
 689 
 692 
 695 
 
 34 
 34 
 34 
 
 00 
 20 
 40 
 
 0.72263 
 73290 
 74330 
 
 1027 
 1040 
 
 1052 
 
 0.67451 
 68301 
 69157 
 
 850 
 856 
 864 
 
 24 00 
 24 20 
 24 40 
 
 0-45953 
 46719 
 
 47491 
 
 766 
 
 772 
 778 
 
 0.44523 
 45222 
 
 45924 
 
 699 
 
 702 
 
 707 
 
 35 
 35 
 35 
 
 00 
 20 
 40 
 
 0.75382 
 76447 
 
 77525 
 
 1065 
 1078 
 1092 
 
 0.70021 
 70891 
 71769 
 
 870 
 878 
 885 
 
 25 00 
 
 25 20 
 25 40 
 
 0.48269 
 49054 
 49845 
 
 785 
 791 
 
 798 
 
 0.46631 
 
 47341 
 
 48055 
 
 710 
 
 714 
 
 718 
 
 36 
 36 
 36 
 
 00 
 20 
 40 
 
 0.78617 
 79723 
 80843 
 
 1 106 
 1 120 
 1 1 34 
 
 0.72654 
 73547 
 74447 
 
 893 
 900 
 908 
 
 26 00 
 26 20 
 26 40 
 
 0.50643 
 51448 
 52260 
 
 805 
 812 
 818 
 
 0.48773 
 
 49495 
 50222 
 
 722 
 727 
 731 
 
 37 
 37 
 37 
 
 00 
 20 
 40 
 
 0.81977 
 83126 
 8429 1 
 
 1 149 
 1 165 
 1T82 
 
 0-75355 
 76272 
 77196 
 
 917 
 924 
 933 
 
 27 00 
 27 20 
 27 40 
 
 0-53078 
 53904 
 54738 
 
 826 
 
 834 
 842 
 
 0.50953 
 51688 
 
 52427 
 
 735 
 739 
 744 
 
 38 
 38 
 3^ 
 
 00 
 20 
 40 
 
 0.85473 
 86670 
 87883 
 
 1197 
 1213 
 1231 
 
 0.78129 
 79070 
 80020 
 
 941 
 950 
 958 
 
 28 00 
 28 20 
 28 40 
 
 0.55580 
 56429 
 57286 
 
 849 
 
 857 
 865 
 
 0.53171 
 53920 
 
 54073 
 
 749 
 
 753 
 758 
 
 39 
 39 
 39 
 
 00 
 20 
 40 
 
 0.89114 
 
 90363 
 91629 
 
 1249 
 1266 
 
 1285 
 
 0.80978 
 81946 
 82923 
 
 968 
 
 977 
 
 ^987 
 
 29 00 
 29 20 
 29 40 
 
 0.58151 
 59025 
 59907 
 
 874 
 882 
 892 
 
 0.55431 
 56194 
 56962 
 
 763 
 
 768 
 
 773 
 
 40 
 40 
 40 
 
 00 
 20 
 40 
 
 0.92914 
 94217 
 95541 
 
 1303 
 1324 
 1343 
 
 0.83910 
 84906 
 859'2 
 
 996 
 1006 
 1017 
 
 30 00 
 30 20 
 30 40 
 
 0.60799 
 61699 
 62608 
 
 900 
 
 909 
 919 
 
 0.57735 
 58513 
 59297 
 
 778 
 
 784 
 789 
 
 41 
 41 
 41 
 
 00 
 20 
 40 
 
 0.96884 
 98247 
 99632 
 
 •363 
 1385 
 1407 
 
 0.86929 
 
 87955 
 88992 
 
 1026 
 1037 
 1048 
 
 31 00 
 31 20 
 31 40 
 
 0.63527 
 
 64455 
 65394 
 
 928 
 939 
 949 
 
 0.60086 
 60881 
 61681 
 
 795 
 800 
 806 
 
 42 
 42 
 42 
 
 00 
 20 
 40 
 
 1.01039 
 02468 
 03920 
 
 1429 
 1452 
 U75 
 
 0.90040 
 91099 
 92170 
 
 1059 
 1071 
 
 T082 
 
 32 00 
 32 20 
 32 40 
 
 0.66343 
 67302 
 68272 
 
 959 
 970 
 981 
 
 0.62487 
 63299 
 64117 
 
 812 
 818 
 824' 
 
 43 
 43 
 43 
 
 00 
 20 
 40 
 
 1.05395 
 06894 
 08418 
 
 1499 
 1524 
 
 1550 
 
 0.93252 
 94345 
 95451 
 
 1093 
 1 106 
 1118 
 
 44 
 
TABLE III.— Continued. 
 
 44 oo 
 
 44 20 
 
 44 40 
 
 45 00 
 45 20 
 45 40 
 
 m 
 
 1.09968 
 
 I-II544 
 1.13148 
 
 1. 14779 
 1. 16439 
 1.18129 
 
 46 00 1. 19849 
 
 46 20 
 
 46 40 
 
 47 00 
 47 20 
 
 47 40 
 
 48 00 
 48 20 
 
 48 40 
 
 49 00 
 49 20 
 
 49 40 
 
 50 00 
 50 20 
 
 50 40 
 
 51 00 
 51 20 
 51 40 
 
 r. 21600 
 1.23384 
 
 1. 25201 
 
 1-27053 
 1.28940 
 
 1.30863 
 1.32823 
 1-34823 
 
 1.36863 
 1.38944 
 1. 41068 
 
 1.43236 
 
 1.45450 
 1. 47710 
 
 1. 50019 
 1-52379 
 I-54791 
 
 Diff. 
 
 1576 
 1604 
 1631 
 
 1660 
 1690 
 1720 
 
 1751 
 1784 
 1817, 
 
 1852 
 1887 
 1923 
 
 i960 
 
 2000 
 2040 
 
 2081 
 2124 
 2168 
 
 2214 
 2260 
 2309 
 
 2360 
 2412 
 2466 
 
 Tan S 
 
 0.96569 
 97700 
 98843 
 
 1. 00000 
 1.01170 
 1-02355 
 
 1-03553 
 1.04766 
 1.05994 
 
 1.07237 
 1.08496 
 1.09770 
 
 1.II06 
 1. 12369 
 1. 13694 
 
 1. 15037 
 r. 16398 
 1. 17777 
 
 1.19175 
 1-20593 
 1. 22031 
 
 1.23490 
 1.24969 
 1. 26471 
 
 Diff. 
 
 1131 
 1 143 
 1157 
 
 1170 
 1185 
 
 1213 
 1228 
 1243 
 
 1259 
 1274 
 129 
 
 1308 
 1325 
 1343 
 
 1361 
 
 T379 
 1398 
 
 1418 
 1438 
 1459 
 
 1479 
 
 1502 
 1523 
 
 52 00 
 
 52 20 
 
 52 40 
 
 53 00 
 53 20 
 
 53 40 
 
 54 00 
 54 20 
 
 54 40 
 
 55 00 
 55 20 
 
 55 40 
 
 56 00 
 56 20 
 
 56 40 
 
 57 00 
 57 20 
 
 57 40 
 
 58 00 
 58 20 
 
 58 40 
 
 59 00 
 59 20 
 
 59 40 
 
 60 00 
 
 (^) 
 
 Diff. 
 
 1-57257 
 1.59779 
 1.62357 
 
 1.64995 
 1.67696 
 1.70460 
 
 1. 73291 
 1.76191 
 1. 79162 
 
 1.82207 
 
 1-85329 
 1.88530 
 
 1.91815 
 1.95186 
 1.98646 
 
 2.02199 
 2.05849 
 2.09600 
 
 2.13456 
 
 2.1742 
 
 2.21500 
 
 2.25697 
 
 2.3001 
 
 2.34468 
 
 2-39053 
 
 Tan^ 
 
 Diff. 
 
 2522 
 
 2578 
 
 638 
 
 2701 
 2764 
 2831 
 
 2900 
 2971 
 
 3045 
 
 3122 
 3201 
 3285 
 
 3371 
 3460 
 
 3553 
 
 3650 
 3751 
 3856 
 
 3965 
 4079 
 4197 
 
 4321 
 
 4450 
 4585 
 
 4726 
 
 1.27994 1547 
 1. 29541 1569 
 1.31110 1594 
 
 1.32704 1619 
 
 1-34323 1645 
 1.35968 1670 
 
 1.37638 
 1.39336 
 1.41061 
 
 1.42815 
 1.44598 
 1.46411 
 
 1.48256 
 
 1.50133 
 1.52043 
 
 1.53986 
 1.55966 
 1.57981 
 
 1.60033 
 1. 62125 
 1.64256 
 
 1.66428 
 1.68643 
 1. 70901 
 
 1.73205 
 
 1698 
 1725 
 1754 
 
 1783 
 1813 
 
 1845 
 
 1877 
 1910 
 1943 
 
 1980 
 2015 
 2052 
 
 2092 
 2131 
 2172 
 
 2215 
 2258 
 2304 
 
 2351 
 
 45 
 
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