Transcriber’s Notes:
Underscores “_” before and after a word or phrase indicate _italics_
in the original text.
Equal signs “=” before and after a word or phrase indicate =bold=
in the original text.
Small capitals have been converted to SOLID capitals.
Illustrations have been moved so they do not break up paragraphs.
Old or antiquated spellings have been preserved.
Typographical and punctuation errors have been silently corrected.
THE HAND-BOOK OF ARTILLERY.
BY CAPT. JOSEPH ROBERTS,
Fourth Regt. Artillery U. S. Army.
RICHMOND:
PRINTED BY RITCHIE & DUNNAVANT.
1861.
PROCEEDINGS.
The following Report was made by the Committee appointed at a meeting
of the staff of the Artillery School at Fort Monroe, Va., to whom the
commanding officer of the School had referred this work:
Your Committee to which has been referred the
consideration of the work of Captain Roberts,
proposed as a text-book for the Artillery School,
beg leave to submit the following Report, viz:
The work submitted by Captain Roberts, and entitled
“Hand-book of Artillery,” embraces sections on the
following subjects.
[For subjects see Table of Contents, page 7.]
Under each of these heads, except the last, the work contains a number
of questions and answers. Your Committee have carefully examined each
of these questions and their corresponding answers, and find that the
answers have been principally drawn from the following sources, viz:
Gibbon’s Artillerist’s Manual, Light and Heavy Artillery Tactics, and
the Ordnance Manual, all of which works have been authorized by the War
Department. Wherever the prescribed authorities furnish the means of
answering the questions, they appear to have been followed as closely
as possible.
The idea of the arrangement, and a few of the questions and answers,
appear to have been taken from “Burns’ Questions and Answers on
Artillery;” but that work has been so far deviated from, as fairly to
entitle the present work to be considered as an original compilation.
In the opinion of your Committee, the arrangement of the subjects and
the selection of the several questions and answers have been judicious.
The work is one which may be advantageously used for reference
by the officers, and is admirably adapted to the instruction of
non-commissioned officers and privates of Artillery.
Your Committee do therefore recommend that it be substituted as a
text-book in place of “Burns’ Questions and Answers on Artillery.”
(Signed) I. VOGDES,
CAPT. 1ST ART’Y.
(Signed) E. O. C. ORD,
CAPT. 3D ART’Y.
(Signed) J. A. HASKIN,
BVT. MAJ. AND CAPT. 1ST ART’Y.
The preceding Report was adopted, and the Staff recommended this work
as a book of instruction at the Artillery School, in lieu of “Burns’
Questions and Answers on Artillery.”
PREFACE.
The following compilation originated in an attempt to adapt Lieut.
Col. Burns’ “Questions and Answers on Artillery” to the United States
service. The British Artillery being very different from ours, it was
found necessary to omit many of Burns’ questions, and to introduce
others.
The compiler is under great obligations to several of his brother
officers at Fort Monroe (especially to Major Haskin, 1st Artillery),
for their kindness in assisting him in the compilation of this little
volume, and for important suggestions in the revision of many of the
“answers.”
_Fort Monroe, Va._, 1860.
CONTENTS.
The pages refer to the sidenotes in the margin of the text.
_Page._
Preface, 5
General Table of Contents, 7
Part I., Section 1. On Artillery in General, 9
“ “ 2. On Guns, 26
“ “ 3. On Howitzers, 28
“ “ 4. On Columbiads, 30
“ “ 5. On Mortars, 31
“ “ 6. On Sea-coast Artillery, 35
“ “ 7. Siege Artillery, 36
“ “ 8. Field Guns and Field Batteries, 40
Part II. “ 1. Pointing Guns and Howitzers, 51
“ “ 2. Pointing Mortars, 56
Part III. Charges, 60
IV. Ranges, 63
V. Ricochet, 73
VI. Recoil, 77
VII. Windage, 80
VIII. Gunpowder, 83
IX. Projectiles, 90
X. Laboratory Stores, 109
XI. Platforms, 118
XII. Artillery Carriages and Machines, 123
XIII. Practical Gunnery, 147
XIV. Miscellaneous, 151
Appendix—Rifle Cannon, 163
Index, 169
THE HAND-BOOK OF ARTILLERY.
PART I. SECTION I.
ARTILLERY IN GENERAL.
[Sidenote: 9]]
1. What is understood by the term _Artillery_?
Heavy fire-arms of every description.
2. How many kinds of Artillery are employed in the land service of the
United States?
Four, viz.: Guns, Howitzers, Columbiads, and Mortars.
3. How are these pieces distinguished?
According to their use as Sea-coast, Garrison, Siege, and Field
Artillery.
4. What metals are used in the construction of Artillery?
All heavy artillery, such as that for sea-coast, siege, and garrison
equipment, is made of iron; and that for field service, of bronze.
[Sidenote: 10]]
5. What is bronze for cannon?
An ALLOY consisting of 90 parts of copper and 10 of tin, allowing
a variation of one part of tin more or less. It is commonly called
_brass_.
6. Why is bronze used in preference to iron, for field pieces?
This metal, having greater tenacity and strength than iron, the pieces
can be made lighter.
7. In what respect does iron merit a preference?
Iron is less expensive than bronze, and is more capable of sustaining
long-continued firing with larger charges; such pieces are, therefore,
better calculated for the constant heavy firing of sieges.
=NOTE.=—In the sieges in Spain, bronze guns
could never support a heavier fire than 120 rounds
in twenty-four hours, and were never used to batter
at distances exceeding 300 yards; whereas, with iron
guns, three times that number of rounds were fired
with effect, from three times the distance, for
several consecutive days, without any other injury
than the enlargement of their vents. The comparative
power of conducting heat in iron and copper being
respectively as 3.743 to 8.932, taking gold at
10.000, it is evident that in practicing with iron
and bronze pieces of the same calibre, it would soon
become necessary to reduce the charges in the bronze
pieces, and, also to increase the time between the
discharges, to prevent their softening and drooping;
while with iron, full charges and rapid firing may be
kept up.
8. What additional objection has been urged to bronze for cannon?
The difficulty of forming a perfect alloy, in consequence of the
difference of fusibility of tin and copper.
9. What iron pieces are used in the land service?
[Sidenote: 11]]
12, 13, and 24-pdr. siege and garrison guns, 32 and 42-pdr. sea-coast
guns, 8-in. siege and 24-pdr. garrison howitzers, 8 and 10-in.
sea-coast howitzers, 8 and 10-in. columbiads, 8 and 10-in. siege, and
10 and 13-in. sea-coast mortars.
=NOTE.=—The 24-pdr. eprouvette is also of iron, and
used for the proof of powder.
10. What are the kinds of bronze pieces in use at present?
6 and 12-pdr. field guns; 12-pdr. mountain howitzer; 12, 24 and 32-pdr.
field howitzers; stone and 24-pdr. Coehorn mortars.
11. What is a battery?
This term is applied to one or more pieces, or to the place where they
are served.
12. What regulate the dimensions of cannon?
The tenacity and elasticity of the metals employed in their
fabrication. Their thickness must be proportioned to the effect
developed by the powder; and the length is determined by experiment,
and should not exceed 24 calibres. The exterior surface of a cannon is
composed of several surfaces, more or less inclined to the axis of the
bore, the forms of which have been determined by experiment.
13. Why is a piece made stronger near the breech than towards the
muzzle?
Because the elastic force of the inflamed gunpowder is there greatest,
constantly diminishing in intensity as the space increases in which it
acts.
14. What is the length of a piece?
The distance from the rear of the base-ring to the face of the piece.
[Sidenote: 12]]
15. What is the extreme length?
From the rear of the cascable to the face.
16. What is the _bore_ of a piece?
It includes the part bored out, viz: the cylinder, the chamber (if
there is one), and the conical or spherical surface connecting them.
17. What is understood by the _calibre_ of a piece?
The diameter of the bore.
18. How do you ascertain the number of calibres in a piece?
Divide the length of the cylinder, in inches, by the number of inches
in the calibre.
19. The number of calibres being known, how do you find the length of
the cylinder?
Multiply the number of calibres by the calibre in inches.
20. What is meant by the _sights_ of a piece?
Artificial marks on the piece for determining the line of fire.
21. How are the sights determined?
Usually by means of the gunner’s level, when the trunnions are
perfectly horizontal.
22. What is the _line of metal_ or the natural line of sight?
It is a line drawn from the highest point of the base-ring to the
highest point on the swell of the muzzle.
23. What is the _axis_ of a piece?
An imaginary line passing through the centre of the bore.
24. What is the _natural angle of sight_?
It is the angle which the natural line of sight makes with the axis of
the piece.
[Sidenote: 13]]
25. What is the _dispart_ of a piece?
It is the difference of the semi-diameter of the base-ring and the
swell of the muzzle, or the muzzle-band. It is, therefore, the tangent
of the natural angle of sight to a radius equal to the distance from
the rear of the base-ring to the highest point of the swell of the
muzzle, or the front of the muzzle-band, as the case may be, measured
parallel to the axis.
26. Give the nomenclature of a piece?
The CASCABLE is the part of the gun in rear of the base-ring, and is
composed generally of the _knob_, the _neck_, the _fillet_, and the
_base of the breech_.
The BASE OF THE BREECH is a frustum of a cone, or a spherical segment
in rear of the breech.
The BASE-RING is a projecting band of metal adjoining the base of the
breech, and connected with the body of the gun by a concave moulding.
The BREECH is the mass of solid metal behind the bottom of the bore,
extending to the rear of the base-ring.
The REINFORCE is the thickest part of the body of the gun, in front
of the breech; if there be more than one _reinforce_, that which is
next the breech is called the _first reinforce_; the other the _second
reinforce_.
The REINFORCE BAND is at the junction of the first and second
reinforces in the heavy howitzers and columbiads.
The CHASE is the conical part of the gun in front of the reinforce.
The ASTRAGAL AND FILLETS in field guns, and the _chase ring_ in other
pieces, are the mouldings at the front end of the chase.
[Sidenote: 14]]
The NECK is the smallest part of the piece in front of the astragal or
the chase ring.
The SWELL OF THE MUZZLE is the largest part of gun in front of the
neck. It is terminated by the _muzzle mouldings_, which in field and
siege guns, consist of the _lip_ and _fillet_. In sea-coast guns and
heavy howitzers and columbiads, there is no fillet. In field and siege
howitzers, and in mortars, a _muzzle-band_ takes the place of the
_swell of the muzzle_.
The FACE of the piece is the terminating plane perpendicular to the
axis of the bore.
The TRUNNIONS are cylinders, the axes of which are in a line
perpendicular to the axis of the bore, and in the same plane with that
axis.
The RIMBASES are short cylinders uniting the trunnions with the body of
the gun. The ends of the rimbases, or the _shoulders_ of the trunnions,
are planes perpendicular to the axis of the trunnions.
The BORE of the piece includes all the part bored out, viz.: the
cylinder, the chamber (if there is one), and the conical or spherical
surface connecting them.
The CHAMBER in howitzers, columbiads, and mortars, is the smallest part
of the bore, and contains the charge of powder. In the howitzers and
columbiads,[1] the chamber is cylindrical; and is united with the large
cylinder of the bore by a conical surface; the angles of intersection
of this conical surface with the cylinders of the bore and chamber, are
rounded (in profile) by arcs of circles. In the 8-inch siege howitzer,
the chamber is united with the cylinder of the bore by a Spherical
surface, in order that the shell may when necessary, be inserted
without a sabot.
[1] The new columbiad is made without a chamber.
[Sidenote: 15]]
The BOTTOM OF THE BORE (to facilitate sponging) is a plane
perpendicular to the axis, united with the sides (in profile) by an arc
of a circle the radius of which is one-fourth of the diameter of the
bore at the bottom. In the columbiads, the heavy sea-coast mortars,
stone mortar, and eprouvette, the bottom of the bore is hemispherical.
The MUZZLE, or mouth of the bore, is chamfered to a depth of 0.15 inch
to 0.5 inch (varying with the size of the bore), in order to prevent
abrasion, and to facilitate loading.
The TRUE WINDAGE is the difference between the true diameters of the
bore and of the ball.
27. What is the vent?
The aperture through which fire is communicated to the charge.
28. What is to be observed in reference to the diameter of the vent?
It should be as small as the use of the priming wire and tube will
allow.
29. Why?
As the velocity of the gases arising from the combustion of the powder
is extremely great, a large amount escapes through the vent, which
contributes nothing to the velocity of the projectile. It therefore
follows, that the effect produced by a given charge will diminish as
the diameter of the vent increases. Besides, on account of the increase
of power in the current that escapes from them, large vents are more
rapidly injured than small ones.
[Sidenote: 16]]
30. What is the diameter of the vent?
0.2 of an inch in all pieces except the eprouvette, in which it is 0.1.
31. What is the position of the axis of the vent?
The axis of the vent, is in a plane passing through the axis of the
bore, perpendicular to the axis of the trunnions. In guns, and in
howitzers having cylindrical chambers, the vent is placed at an angle
of 80° with the axis of the bore, and it enters the bore at a distance
from the bottom equal to one-fourth the diameter of the bore. As this
inclination renders it easy to pull the friction tube out of the vent,
that of the new 12-pdr. field gun, and the new columbiads has been
placed perpendicular to the axis.
32. What are the _quarter-sights_ of a piece?
Divisions marked on the upper quarters of the base ring, commencing
where it would be intersected by a plane parallel to the axis of the
piece, and tangent to the upper surface of the trunnions.
=NOTE.=—Not used in our service.
33. To what use are the quarter-sights applied?
For giving elevations up to three degrees but especially for pointing a
piece at a less elevation than the natural angle of sight.
34. What is a _breech-sight_?
An instrument having a graduated scale of tangents, by means of which
any elevation may be given to a piece.
[Sidenote: 17]]
35. How are the divisions of the tangent scale found?
By taking the length of the piece, from the rear of the base-ring to
the swell of the muzzle, measured on a line parallel to the axis, and
multiplying it by the natural tangent of as many degrees as may be
required; and then deduct the dispart. Thus, for 5° elevation, and the
gun supposed to be 5 feet, or 60 inches long, multiply .08748, which
is the natural tangent of 5°, by 60; the product gives 5.2488 inches;
supposing the dispart to be 1 inch, the graduating of the tangent scale
will be 4.2488 inches.
36. With what pieces are breech-sights used?
Guns and howitzers.
37. What is a _pendulum hausse_?
It is a tangent scale, the graduations of which are the tangents
of each quarter of a degree of elevation, to a radius equal to the
distance between the muzzle-sight of the piece, and the axis of
vibration of the hausse, which is one inch in rear of the base-ring.
At the lower end of the scale is a brass bulb filled with lead. The
_slider_ which marks the divisions on the scale is of thin brass, and
is clamped at any desired division on the scale by means of a screw.
The scale passes through a slit in a piece of steel, with which it is
connected by a screw, forming a pivot on which the scale can vibrate
laterally. This piece of steel terminates in pivots, by means of which
the pendulum is supported on the _seat_ attached to the gun, and is
at liberty to vibrate in the direction of the axis of the piece. The
_seat_ is of metal, and is fastened to the base of the breech by
screws, so that the centres of the steel pivots of vibration shall be
at a distance from the axis of the piece equal to the radius of the
base-ring.
[Sidenote: 18]]
A MUZZLE-SIGHT of iron is screwed into the swell of the muzzle of guns,
or into the middle of the muzzle-ring of howitzers. The height of this
sight is equal to the dispart of the piece, so that a line joining the
muzzle-sight and the pivot of the tangent scale is parallel to the axis
of the piece.
38. What is a _gunner’s level_, or gunner’s perpendicular?
An instrument made of sheet-brass; the lower part is cut in the form of
a crescent, the points of which are made of steel; a small spirit-level
is fastened to one side of the plate, parallel to the line joining the
points of the crescent, and a slider is fastened to the same side of
the plate, perpendicular to the axis of the level.
39. What is it used for?
To mark the points of sight on pieces.
40. What is a _plummet_?
A simple _line_ and _bob_ for pointing mortars.
41. What is a _gunner’s quadrant_?
It is a graduated quarter of a circle of sheet-brass, attached to a
brass rule 18 inches long. It has a vernier turning on a pivot, to
which is attached a spirit-level. To get a required elevation, the
vernier is fixed at the indicated degree, the brass rule is then
inserted in the bore parallel to the axis of the piece; the gun is then
elevated or depressed until the level is horizontal.
There is another graduated _quadrant_ of wood, of 6 inches radius,
attached to a rule 23.5 inches long. It has a _plumb-line_ and _bob_,
which are carried, when not in use, in a hole in the end of the rule,
covered by a brass plate.
[Sidenote: 19]]
42. What is an _elevating arc_, and its use?
It is an arc attached to the rear part of the cheek of a gun-carriage,
having its centre in the axis of the trunnions; the arc is graduated
into degrees and parts of a degree. By placing the axis of the piece
horizontal, and marking the breech at any one of the divisions on the
arc, any elevation or depression required will be noted by the number
of degrees below or above this mark. It turns on a pivot which admits
of the arc, when not in use, being placed inside the cheek to which it
is attached.
43. What is the use of the knob of the cascable?
To facilitate the handling of the piece in mounting and dismounting it,
and moving it when off its carriage.
44. Of what use are the trunnions of a piece?
By means of them the piece is attached to its carriage; and by being
placed near the centre of gravity, it is easily elevated or depressed.
45. What are the dolphins of a piece?
Two handles placed upon the piece with their centres over the centre of
gravity, by which it is mounted or dismounted.
46. Are all pieces provided with dolphins?
Only the 12-pdr. brass guns, and the 24 and 32-pdr. brass howitzers.
47. What is understood by the preponderance of a piece?
It is the excess of weight of the part in rear of the trunnions over
that in front; it is measured by the weight which it is necessary to
apply in the plane of the muzzle to balance the gun when suspended
freely on the axis of the trunnions.
48. Why is this preponderance given?
To prevent the sudden dipping of the muzzle, in firing, and violent
concussion on the carriage at the breech.
[Sidenote: 20]]
49. What is bushing a piece of artillery?
Inserting a piece of metal about an inch in diameter (near the bottom
of the bore), through the centre of which the vent has been previously
drilled. It is screwed in.
50. What kind of metal is used for bushing bronze pieces?
Pure copper always, which is not so liable to run from heat as gun
metal.
51. What is the object of bushing a piece?
To prevent deterioration of the vent, or provide a new one when this
has already occurred.
52. Is all new artillery bushed?
No, only bronze pieces, and iron pieces, only when repeated firing has
rendered it absolutely necessary.
53. How is artillery rendered unserviceable?
I. Drive into the vent a jagged and hardened steel spike
with a soft point, or a nail without a head; break it off
flush with the outer surface, and clinch the point inside by
means of the rammer.
II. Wedge a shot in the bottom of the bore by wrapping it
with felt, or by means of iron wedges, using the rammer or
a bar of iron to drive them in.
III. Cause shells to burst in the bore of bronze guns.
IV. Fire broken shot from them with large charges.
V. Fill the piece with sand over the charge, to burst it.
VI. Fire a piece against another, muzzle to muzzle, or the
muzzle of one to the chase of the other.
VII. Light a fire under the chase of a bronze gun, and
strike on it with a sledge, to bend it.
VIII. Break off the trunnions of iron guns; or burst them by
firing them at a high elevation, with heavy charges and
full of shot.
[Sidenote: 21]]
54. State how to unspike a piece.
If the spike is not screwed in or clinched, and the bore is not
impeded, put in a charge of powder ⅓ of the weight of the shot, and ram
junk wads over it; laying on the bottom of the bore a slip of wood,
with a groove on the under side containing a strand of quick-match,
by which fire is communicated to the charge. In a brass gun, take out
some of the metal at the upper orifice of the vent, and pour sulphuric
acid into the groove, and let it stand some hours before firing. If
this method, several times repeated, is not successful, unscrew the
vent piece if it be a brass gun; and if an iron one, drill out the
spike, or drill a new vent.
55. Explain how to drive out a shot wedged in the bore.
Unscrew the vent piece, if there be one, and drive in wedges so as
to start the shot forward; then ram it back again in order to seize
the wedge with a hook; or pour in powder, and fire it after replacing
the vent piece. In the last resort, bore a hole in the bottom of the
breech, drive out the shot, and stop the hole with a screw.
56. What is scaling a piece of artillery?
Flashing off a small quantity of powder to clean out the bore; about
1-12 of the shot’s weight. The practice is discontinued.
[Sidenote: 22]]
57. How are cannon in our service marked?
As follows, viz: The _number of the gun_ and the _initials of the
inspector’s name_ on the face of the muzzle,—the numbers in a separate
series for each kind and calibre at each foundry; the initial letters
of the _name of the founder_, and of the foundry, on the end of the
right trunnion; _the year of the fabrication_ on the end of the left
trunnion; _the foundry number_ on the end of the right rimbase, above
the trunnion; _the weight of the piece in pounds_ on the base of the
breech; the letters U. S. on the upper surface of the piece, near the
end of the reinforce.
58. What marks are used to designate condemned pieces?
Pieces rejected on inspection are marked X C on the face of the muzzle;
if condemned for erroneous dimensions which cannot be remedied, add X
D; if by powder proof, X P; if by water proof, X W.
59. What are the kinds of proof which artillery must undergo, before
being received into the service?
1st. They are gauged as to their several dimensions,
internal and external; as to justness and position of the
bore, the chamber, vent, trunnions, &c.
2d. They are fired with a regulated charge of powder and
shot, being afterwards searched to discover irregularities
or holes produced by the firing.
3d. By means of engines, an endeavor is made to force water
through them.
4th. They are examined internally, by means of light
reflected from a mirror.
[Sidenote: 23]]
60. Are brass cannon liable to external injury, caused by service?
They are little subject to such injury, except from the bending of the
trunnions sometimes, after long service or heavy charges.
=NOTE.=—Recent experiments at Fort Monroe show that
brass guns, when _rifled_, and fired with large
charges and heavy shot, expand so much that the
projectile does not take the grooves.
61. What are the causes of internal injury?
Internal injuries are caused by the action of the elastic fluids
developed in the combustion of the powder, or by the action of the shot
in passing out of the bore.
62. Name the injuries of the first kind.
_Enlargement of the bore_ by the compression of the metal; _corrosion
of the metal_ at the inner orifice of the vent, or at the mouth of the
cylindrical chamber; _cracks_, from the yielding of the cohesion of the
metal; _cavities_, cracks enlarged by the action of the gas, and by the
melting of the metal, observable especially in the upper surface of the
bore.
63. Name those of the second kind.
[Sidenote: 24]]
The _lodgment of the shot_,—a compression of the metal on the lower
side of the bore, at the seat of the shot, which is caused by the
pressure of the gas in escaping over the top of the shot. There is a
corresponding _burr_ in front of the lodgment; and the motion thereby
given to the shot causes it to strike alternately on the top and
bottom of the bore, producing other _enlargements_, generally _three_
in number: the first, on the upper side a little in advance of the
trunnions; the second, on the lower side about the astragal; the third,
in the upper part of the muzzle; it is chiefly from this cause that
brass guns become unserviceable. _Scratches_, caused by the fragments
of a broken shot, or the roughness of an imperfect one; _enlargement of
the muzzle_ by the striking of the shot in leaving the bore; _external
cracks_, or longitudinal slits, caused by too great a compression of
the metal on the inside.
64. When is a piece said to be honeycombed?
When the surface of the bore is full of small holes or cavities.
65. To what is this due?
To the melting and volatilization of a portion of the tin in the alloy;
tin being much more fusible than copper.
66. Do _lodgments_ cause an inaccuracy of fire?
They do.
67. How may this in a measure be remedied?
By using a wad over the cartridge, in order to change the place of
the shot; or by wrapping the shot in woollen cloth or paper, so as to
diminish the windage. In field guns, the paper cap which is taken off
the cartridge should always be put over the shot.
68. To what injuries are iron cannon subject?
To the above defects in a less degree than brass, except the corrosion
of the metal, by which the vent is rendered unserviceable from
enlargement. The principal cause of injury to iron cannon is the
rusting of the metal, producing a roughness and enlargement of the
bore, and an increase of any cavities or honeycombs which may exist in
the metal.
69. How may you judge of the service of an iron gun?
Generally by the appearance of the vent.
[Sidenote: 25]]
70. What rules are laid down for the preservation of artillery?
Cannon should be placed together, according to kind and calibre, on
skids of stone, iron, or wood, laid on hard ground well rammed and
covered with a layer of cinders or of some other material to prevent
vegetation. In case of _guns and long howitzers_, the pieces should
rest on the skids in front of the base ring and in rear of the
astragal, the axis inclined at an angle of 4° or 5° with the horizon,
the muzzle lowest, the trunnions touching each other; or the trunnion
of one piece may rest on the adjoining piece, so that the axis of the
trunnions may be inclined about 45° to the horizon; the vent down,
stopped with a greased wooden plug, or with putty or tallow. The pieces
may be piled in two tiers, with skids placed between them exactly over
those which rest on the ground; the muzzles of both tiers in the same
direction and their axes preserving the same inclination. In case
of _short howitzers and mortars_, the pieces should stand on their
muzzles, resting on thick planks, the trunnions touching, the vents
stopped.
71. What additional precautions should be observed in case of iron
pieces?
They should be covered on the exterior with a lacker impervious to
water; the bore and the vent should be greased with a mixture of _oil_
and _tallow_, or of _tallow_ and _beeswax_ melted together and boiled
to expel the water. The lacker should be renewed as often as necessary,
and the grease at least once a year. The lacker and grease should be
applied in hot weather. The cannon should be frequently inspected, to
see that moisture does not collect in the bore.
[Sidenote: 26]]
PART I. SECTION II.
ON GUNS.
1. What are _Guns_?
Long cannon without chambers.
2. How are guns denominated?
By the weight of their respective shot.
3. What are the principal parts of a gun?
The cascable, breech, reinforce, chase, and muzzle.
4. What proportion usually exists between the length and calibre of a
gun?
It varies from 15 to 23 calibres.
5. What proportion does the dispart of a gun bear generally to its
length?
About a sixtieth part in field guns, about a thirtieth part in
sea-coast, and about a thirty-eighth part in siege and garrison guns.
6. What is the natural angle of sight in siege and garrison guns?
One degree and thirty minutes.
7. What is it in field guns?
One degree.
8. Why have sea-coast guns no natural line of sight?
Because the swell of the muzzle is not visible when the eye is on a
level with the base ring.
9. Upon what are guns mounted?
On field, siege, barbette or casemate carriages.
[Sidenote: 27]]
10. What projectiles are used with guns?
Solid shot, spherical case, grape, and canister.
11. About what are the weights of the different guns?
6-pdr., 884 lbs.; brass 12-pdr., 1,757 lbs.; iron 12-pdr., 3,590 lbs.;
18-pdr., 4,913 lbs.; 24-pdr., 5,790 lbs.; 32-pdr., 7,200 lbs.; 42-pdr.,
8,465 lbs.
12. Give the entire length of the several guns?
6-pdr. field-gun, 65.6 inches; 12-pdr. field-gun, 85 inches; 12-pdr.
iron gun, 116 inches; 18-pdr., 123.25 inches; 24-pdr., 124 inches;
32-pdr., 125.2 inches; 42-pdr., 129 inches.
[Sidenote: 28]]
PART I. SECTION III.
ON HOWITZERS.
1. What is a _Howitzer_?
A chambered piece, of larger calibre than a gun of like weight, and
mounted in a similar manner.
2. What form of chamber is given to howitzers?
That of a cylinder.
3. How is it united with the large cylinder of the bore?
By a conical surface, except in the 8-inch siege howitzer, where it is
united with the cylinder of the bore by a _spherical_ surface, in order
that the shell may—when necessary—be inserted without a sabot.
4. What advantages are gained by the employment of howitzers?
They project larger shells than the guns with which they are
associated, are well adapted for ricochet fire, the destruction of
field works, breaking down palisades, and setting fire to buildings.
5. What projectiles are used with howitzers?
Shells usually, spherical case, canister, grape and carcasses.
[Sidenote: 29]]
6. Give the entire length of the several howitzers.
Iron 10-inch, 124.25 inches; 8-inch sea-coast, 109 inches; 8-inch siege
and garrison, 61.5 inches; 24-pdr. garrison, 69 inches; 32-pdr. field,
82 inches; 24-pdr. field, 71.2 inches; 12-pdr. field, 58.6 inches;
mountain, 12-pdr., 37.21 inches.
7. What is the weight of a howitzer of each kind?
10-inch, 9,500 lbs.; 8-inch sea-coast, 5,740 lbs.; 8-inch siege and
garrison, 2,614 lbs.; 24-pdr. garrison, 1,476 lbs.; 32-pdr. field,
1,920 lbs.; 24-pdr. field, 1,318 lbs.; 12-pdr. field, 788 lbs.; 12 pdr.
mountain, 220 lbs.
8. What is the natural angle of sight in siege and garrison and field
howitzers?
One degree.
9. What in mountain howitzers?
Thirty-seven minutes.
10. Why have sea-coast howitzers no natural line of sight?
Because the swell of the muzzle is not visible when the eye is on a
level with the base ring.
[Sidenote: 30]]
PART I. SECTION IV.
ON COLUMBIADS.
1. What is a _Columbiad_?
A gun of much larger calibre than the ordinary gun, used for throwing
solid shot or shells.
2. What are some of the peculiarities of this gun, when mounted in
barbette?
Its carriage gives a vertical field of fire from 5° depression to 39°
elevation; and a horizontal field of fire of 360°.
3. Are these pieces chambered?
Those of the old pattern have chambers; but they are now cast without
any.
4. Give the weight of this piece?
10-inch, 15,400 lbs.; 8-inch, 9,240 lbs.
5. What is the entire length of this gun?
10-inch, 126 inches; 8-inch, 124 inches.
6. What is the natural angle of sight in this piece?
8-inch, 1° 23´; 10-inch, 1° 21´.
[Sidenote: 31]]
PART I. SECTION V.
ON MORTARS.
1. What is a _Mortar_?
The shortest piece in service; the trunnions are placed in rear of the
vent at the breech; the bore is very large in proportion to the length,
and is provided with a chamber.
2. What are the principal advantages obtained by the employment of
mortars?
Reaching objects by their vertical fire—such as a town, battery, or
other place—whose destruction or injury cannot be effected by direct or
ricochet fire; dismounting the enemy’s artillery; setting fire to and
overthrowing works; blowing up magazines; breaking through the roofs
of barracks, casemates, &c.; and producing havoc and disorder amongst
troops.
3. What do you mean by vertical fire?
That produced by firing the mortar at a high elevation.
4. What are its advantages?
The shell having attained a great elevation, descends with great force
on the object, in consequence of the constant action of the force of
gravity on it.
[Sidenote: 32]]
5. Why are mortars constructed stronger and shorter than other pieces?
Because greater resistance is required in consequence of the high
elevation under which they are fired; and were they longer, the
difficulty experienced in loading them would become too great.
6. Why is a mortar constructed with a chamber?
In consequence of employing various charges, some very small, it
becomes necessary to use a chamber to concentrate the charge as much
as possible, so that the shell may be acted on by the entire expansive
force of the powder.
7. What form of chamber is given to mortars?
Usually that of a frustum of a cone. The bottom is hemispherical in
the sea-coast, stone, and eprouvette mortars. In siege mortars it is a
plane surface, the angles of intersection being rounded in profile by
arcs of circles.
8. What is this form of chamber called?
Gomer Chamber.
9. What is the advantage of the conical over the cylindrical chamber?
Cylindrical chambers are objectionable, as the projectile is frequently
broken in consequence of the small surface exposed to the action of the
charge. This defect is obviated by large chambers, and particularly by
those that are conical, in which the charge is expended upon nearly a
hemisphere.
10. What form of chamber has the eprouvette?
That of a cylinder, it being the only mortar whose chamber is of this
shape.
11. How are mortars mounted?
On beds of wood or iron.
[Sidenote: 33]]
12. What is the object of mounting mortars on beds in preference to
wheel carriages?
On account of the high elevation at which they are usually fired, when
the recoil, instead of forcing the piece backwards, tends to force it
downwards, and this tendency becomes so great at the higher angles that
no wheel carriage could long sustain the shock.
13. What is the entire length of each mortar?
13-inch, 53 inches; 10-inch sea-coast, 46 inches; 10-inch siege, 28
inches; 8-inch, 32.5 inches; stone mortar, 31.55 inches; coehorn, 16.32
inches.
14. What are the weights of mortars?
13-in., 11,500 lbs.; 10-in. sea-coast, 5,775 lbs.; 10-in. siege, 1,852
lbs.; 8-in., 930 lbs.; stone mortar, 1,500 lbs.; coehorn, 164 lbs.;
eprouvette, 220 lbs.
15. What are the weights of the different mortar beds?
8-in. siege, 920 lbs.; 10-in. siege, 1,830 lbs.; coehorn, 132 lbs.;
eprouvette, 280 lbs.
16. What are the diameters of the bores of the stone, coehorn, and
eprouvette mortars?
Stone mortar, 16 inches; coehorn, 5.82 inches; eprouvette, 5.655 inches.
17. What is the length of the bore, exclusive of the chamber, of the
different mortars?
13-in., 26 inches; 10-in. sea-coast, 25 inches; 10-in. siege, 15
inches; 8-in., 12 inches; stone mortar, 19.8 inches; coehorn, 8.82
inches; eprouvette, 11.5 inches.
18. What is the length of the chamber of the different mortars?
13-in., 13 inches; 10-in. sea-coast, 10 inches; 10-in. siege, 5 inches;
8-in., 4 inches; stone mortar, 6.75 inches; coehorn, 4.25 inches;
eprouvette, 1.35 inches.
[Sidenote: 34]]
19. For what purpose is the eprouvette used?
For determining the relative strength of gunpowder.
20. To what purpose is a stone mortar applied?
To throw stones a short distance, from 150 to 250 yards; and also 6-pr.
shells from 50 to 150 yards.
21. In what manner are the stones disposed in this mortar?
They are put into a basket fitted to the bore, and placed on a wooden
bottom which covers the mouth of the chamber.
22. What use is made of coehorn mortars?
They are fired either from behind intrenchments like other mortars, or
they may accompany troops in effecting lodgments in towns and fortified
places.
23. What kind of projectiles are thrown from mortars?
Shells, fire-balls, carcasses, and stones.
24. How rapidly may siege mortars be fired?
At the rate of twelve rounds per hour continuously; and in case of need
with greater rapidity.
[Sidenote: 35]]
PART I. SECTION VI.
SEA-COAST ARTILLERY.
1. How are _Sea-Coast_ pieces mounted?
On barbette, casemate, flank-casemate, and columbiad carriages; and
the carriage upon which the mortar is mounted—called its _bed_.
These carriages do not subserve the purpose of transportation; the
barbette carriage may, however, be used for moving its piece for short
distances, as from one front of the work to another.
2. What number and kind of pieces are required for the armaments of
forts on the sea-board?
In our service they are prescribed by the War Department, according to
the character and extent of the work.
3. What disposition should be made of heavy and light pieces in a
fortification?
Heavy pieces should be employed on the salients of the work, or for
enfilading channels where a long range is required; light pieces, where
the range is shorter.
[Sidenote: 36]]
PART I. SECTION VII.
SIEGE ARTILLERY.
1. How are siege-guns mounted?
Usually on travelling-carriages, with limbers.
2. Of what number and kind of pieces is a siege train composed?
This must altogether depend on circumstances; but the following
general principles may be observed in assigning the proportion of
different kinds and calibres, and the relative quantity of other
supplies for a train of 100 pieces:
GUNS. { 24-pdr., about one-half the whole number, 50
{ 18-pdr. or 12-pdr., one-tenth, 10
HOWITZERS. 8-in. siege, one-fourth, 25
MORTARS. { 10-in. siege, one-eighth, 12
{ 8-in. siege, 3
STONE-MORTARS, { } 6
COEHORN MORTARS, {in addition to the 100 pieces,} 6
WALL PIECES, 40
[Sidenote: 37]]
CARRIAGES.
For 24-pdr. guns, and 8-in. howitzers, one-fifth spare, 90
For 18-pdr. and 12-pdr. guns, 12
For 10-in. mortars and stone-mortars, one-sixth spare, 21
For 8-in. mortars, 4
_Mortar-wagons_, 1 for each 10-in. mortar and bed, for each
stone mortar and bed, and for three 8-in. mortar and beds, 38
_Wagons_ for transporting implements, intrenching and miner’s
tools, laboratory tools and utensils and other stores,
each loaded with about 2,700 lbs., say, 140
_Carts_ (carrying balls, &c. on the march), 50
_Park battery-wagons_, fully equipped, 28
_Park forges_, “ “ 8
_Sling carts_, large, 5
_Do._ hand, 4
DRAUGHT HORSES.
For each gun and howitzer, with its carriage, 8
“ Spare gun-carriage, 6
“ Mortar wagon, 8
“ Battery wagon, 6
“ Forge, 6
“ Cart, 2
“ Sling-cart, large, 2
“ Spare horses, 1-10th
——————
Total, about 1,900 horses.
[Sidenote: 38]]
PROJECTILES AND AMMUNITION.
{ Round-shot, 800 to each 24-pdr.,
{ 1,000 to each 18 and 12 pdr.
For Guns. { Grape and canisters strapped, 20 rounds to each piece.
{ Spherical case strapped, 20 rounds to each piece.
{ Shells, 800 to each 8-in. howitzer.
FOR HOWITZERS. { Canisters strapped, 5 to each.
{ Spher. case strapped, 20 to each.
{ 600 shells to each 10-inch.
FOR MORTARS. { 860 “ “ 8-inch.
{ 200 “ “ Coehorn.
_Gunpowder_, in barrels, 500,000 lbs.
Computing for each 24-pdr. round-shot, one-third the weight of shot.
“ “ 18 and 12 pdr. round-shot, one-fourth the
weight of shot.
“ “ grape, canister and spherical case, one-sixth
the weight of shot.
“ “ round of howitzer ammunition, }
5 lbs. }
“ “ round 10-in. mortar ammunition, } including
7 lbs. } charge of
“ “ round 8-in. mortar ammunition, } shell.
3 lbs. }
“ “ round Coehorn mortar ammunition, ½ lb.
“ “ round stone mortar ammunition, 1 lb.
3. What is the best position for guns in order to make a breach?
On the glacis, within 15 or 16 feet of its crest; but if the foot of
the revetment cannot be seen from thence, the guns must be placed in
the covered way, within 15 feet of the counterscarp.
[Sidenote: 39]]
4. In what manner should the fire of siege guns be conducted in order
to form a breach?
1st. Make a horizontal section the length of the desired breach along
the scarp, at one-third its height from the bottom of the ditch, and to
a depth equal to the thickness of the wall.
2d. Make vertical cuts through the wall, not farther than ten yards
apart, and not exceeding one to each piece of ordnance, beginning at
the horizontal section and ascending gradually to the top of the wall.
3d. Fire at the most prominent parts of the masonry left standing;
beginning always at the bottom and gradually approaching the top.
4th. Fire into the broken mass with howitzers until the breach is
practicable.
5. How long would it take to make a breach of 20 yards in length?
Breaches of more than 20 yards in length have been opened by way of
experiment, and rendered practicable in less than ten hours, by about
two hundred and thirty 24-pdr. balls and forty shells in one case, and
by three hundred 18-pdr. balls and forty shells in another.
6. How many discharges can an iron gun sustain?
An iron gun should sustain twelve hundred discharges, at the rate of
twelve an hour; but whatever may be the rate of fire, it is deemed
unsafe after that number of discharges. As many as twenty an hour have
been made for sixteen consecutive hours.
[Sidenote: 40]]
PART I. SECTION VIII.
ON FIELD GUNS AND BATTERIES.
1. What proportion of artillery should be allotted to an army in the
field?
The proportion of artillery to other troops varies generally between
the limits of one and three pieces to 1,000 men, according to the
strength of the army, the character of the troops composing it, the
strength and character of the enemy, the nature of the country which is
to be the theatre of the war, and the character and objects of the war.
2. What regulates the selection of the kinds of artillery and the
proportion of the different kinds in the train?
Similar considerations to those specified in the foregoing answer. The
following principles may be observed in ordinary cases:
{ ¼ are 12-pdrs.
3 pieces to { ⅔ guns, of which { ¾ “ 6-pdrs.
1,000 men. { { ¼ “ 24 or 32-pdrs.
{ ⅓ howitz., of which { ¾ “ 12-pdrs.
3. What is a field-battery?
A certain number of pieces of artillery so equipped as to be available
for attack or defense, and capable of accompanying cavalry or infantry
in all their movements in the field.
4. How many pieces are allotted to a field-battery?
Four guns and two howitzers.
[Sidenote: 41]]
5. Are all field batteries alike?
No; field batteries accompanying infantry are composed of the heavier,
and those accompanying cavalry of the lighter pieces, the first manned
by foot-artillery, and the latter by horse-artillery.
6. In what respect does a battery of horse-artillery differ from one of
foot-artillery?
The main difference consists in the cannoneers in a battery of
horse-artillery being mounted; in rapid evolutions of foot-artillery
they are conveyed on the carriages.
7. What is the composition of a field-battery on the war establishment?
KIND OF BATTERY. 12-PR. 6-PR.
GUNS. { 12-pdrs., mounted, 4
{ 6-pdrs., “ 4
HOWITZERS. { 24-pdrs., mounted, 2
{ 12-pdrs., “ 2
—————— 6 6
CAISSONS. { For guns, 8 4
{ For howitzers, 4 2
—————— 12 6
TRAVELING FORGES, 1 1
BATTERY WAGON, 1 1
—————— 2 2
—————————
Whole No. of carriages with a battery, 20 14
{ Shot, 560 560
{ For 4 guns, { Spher. case, 224 80
{ { Canisters, 112 160
{ ———————— 896 800
{ { Shells, 168 120
AMMUNITION. { For 2 howitzers, { Spher. case, 112 160
{ { Canisters, 42 32
{ ———————— 322 312
{ ——————————
{ Total No. rounds with a battery, 1218 1112
DRAUGHT HORSES. { 6 to each carriage, 120 84
{ Spare horses, 1-12, 10 7
————————
Total, 130 91
[Sidenote: 42]]
=NOTE.=—For two 32-pdr. howitzer carriages and four caissons, the
number of rounds of ammunition is:
Shells, 112
Spher. case, 84
Canisters, 14
———
Total, 210
8. What is the composition of a battery of mountain howitzers?
Howitzers, 6
Gun-carriages, 7
Ammunition-chests, 36
(48 rounds for each howitzer.)
Forge and tools, in 2 chests, 1
Set of carriage-makers’ tools in 2 chests, 1
Pack saddles and harness, 33
Horses or mules, 33
9. What composes the _Field-Park_?
The spare carriages, reserved supplies of ammunition, tools, and
materials for extensive repairs, and for making up ammunition, for the
service of an army in the field from the _Field-Park_, to which should
be attached also the batteries of reserve.
10. What determines the quantity of such supplies?
The quantities of such supplies must depend in a great measure on the
particular circumstances of the campaign.
11. How is the ammunition which cannot be transported by the batteries
carried?
With the park; in caissons, or in store wagons.
[Sidenote: 43]]
12. Do any other carriages and stores form part of the Field-Park?
Yes; spare gun-carriages, one to each field-battery,
_Traveling Forges_, }
_Battery-Wagons_, } one or more of each.
_Spare spokes_, 50 to each battery, }
_Spare fellies_, 20 to each battery, } in store wagons.
_Spare harness_, } in }
_Horse-shoes and nails_, } boxes. }
Gunpowder, saltpetre, sulphur, charcoal, laboratory paper,
cannon-primers (percussion and friction), fuzes and plugs
for field-service, stuff for cartridge bags, woollen yarn,
cotton yarn, glue.
13. Are any other pieces ever used for field service?
Yes: sometimes the 12 and 18-pdr. siege guns, and the 8-in. siege
howitzer.
14. For what particular service are these different pieces most
suitable?
The siege pieces for batteries of position; the 12-pdr. battery, for
following the movements of infantry, and the 6-pdr. battery for those
of cavalry.
=NOTE.=—These siege pieces should
be placed on the weakest points of a line, and on
heights which either form a key to the position, or
from whence the greatest and longest continued effect
may be produced.
15. What are the peculiar advantages of Horse-Artillery?
Possessing, from their lighter construction and mounted detachments,
much greater locomotive powers than other field batteries, they are
especially adapted for following the rapid evolutions of cavalry, for
sudden attacks upon particular points, and for supporting the advance
or covering the retreat of an army.
[Sidenote: 44]]
16. How is a field gun mounted?
Upon a four-wheel carriage, which answers for its transportation as
well as for its service, similar to a siege carriage, but lighter, and
the limber carrying an ammunition chest.
17. Where should a battery be placed before the commencement of an
action?
As much as possible under cover, by taking advantage of banks,
hollow-ways, buildings, woods, &c.
18. Is if advisable to move a battery at once into position in the
field?
No; but if unavoidable, it should be masked as much as possible until
ordered to open its fire.
19. How should a battery be masked?
If practicable, by covering it with cavalry, in preference to infantry,
as the former does it more effectually, and is sooner moved out of the
way.
20. In commencing an action, how should the fire of a battery be
directed?
When the enemy is in line, the fire should be directed over the whole
line, and not upon the real points of attack; but when in column, ready
to advance, it should be concentrated upon the real points of attack.
21. How should batteries be placed in relation to the troops with which
they are acting?
Upon the flanks of a line, but at such a distance as not to impede its
movements, and at the same time to be unfettered in their own; the
artillery may thus represent the faces of a bastion, and the line of
troops the curtain.
[Sidenote: 45]]
22. Is the front of a line of troops an advantageous position for a
field battery?
On the contrary, it is the worst possible, as offering a double object
to the enemy’s fire, and greatly obstructing the movements of the
troops; while a position in rear is nearly as bad, as the fire might
seriously injure, or at least, greatly disquiet them.
23. In supporting an attack, what precautions are necessary?
The battery should be carefully kept clear of the intended line of
march of our own troops, and such points occupied as may afford the
greatest annoyance to the enemy.
24. How should batteries be disposed with regard to the enemy’s troops?
Generally so as to secure a cross fire on his position, and on all
the ground over which he moves to the attack, endeavoring to take
him at all times in the direction of his greatest dimensions; that
is, obliquely or in flank when in line, and in front when formed
in columns. Moderate heights, commanding as much as possible the
surrounding country, should always be taken advantage of, but not such
as may prevent operations in advance if required.
25. Is it imperatively necessary to confine positions for field
batteries to the flanks of a line?
When, from particular circumstances, the front of the army is too
extended, and unavoidably divided into two lines, it may become
necessary to place one or more batteries in the centre, if those on
the flanks are unable to sweep the whole front; but great care must be
taken not to impede the advance or retreat of the troops when required.
[Sidenote: 46]]
26. Should the fire of field batteries be carried on at the same
uniform rate?
Certainly not; the destruction of the enemy being the object, it
follows that at distant ranges, a greater degree of care is required
in pointing the guns; the fire is slow and steady, and increasing
in rapidity as the enemy advances, without however, impairing its
precision.
27. Should the fire of field batteries be carried on in salvoes or
otherwise?
Never in salvoes; but in a regular manner, well sustained, and with
distinct intervals between every round, commencing slowly, and
increasing in rapidity as the range diminishes.
28. Is the fire of batteries more efficacious when dispersed than when
concentrated?
The effects of the fire will be in proportion to the number of guns
brought together, and therefore, in order to strike a decisive blow,
this should at once be done.
29. What projectiles are used with field guns?
Solid shot, spherical case, and canister.
30. At what distance from the enemy should the several kinds of
projectiles be employed with field battery pieces?
Solid shot from 350 yards and upwards; spherical case from 600 up
to 1000 yards, although it may be used within the first range; and
canister within 350 yards, or up to 400 against extended formations.
31. What number of rounds can be fired from a field gun in one minute?
Two solid shot or spherical case, or three of canister.
[Sidenote: 47]]
32. Why are more rounds of canister fired in a minute than of solid
shot or spherical case?
Because the latter are fired at greater distances than canister, and
require the piece to be carefully aimed, thus requiring more time.
33. What is the smallest number of guns that may with safety be
employed in the face of an enemy?
Never less than two, in order to secure a continuous fire and mutual
support.
34. Is the practice of employing field batteries against those of the
enemy recommended?
Only under peculiar circumstances; as for instance, when his troops are
well covered and his guns exposed, or their fire very destructive.
Their fire should be directed principally against columns of attack,
and masses, or upon positions which are intended to be carried.
35. In what time could a battery come into action in the field?
It could come into action and fire one round in 25 seconds, timing from
the order “action front,” to the discharge of one piece.
36. Suppose cavalry to be advancing to attack infantry, and first
observed at the distance of a mile, passing over the first half mile at
a trot; the next quarter of a mile at the manœuvring gallop; and the
remaining distance at an increased gallop, terminating with the charge;
occupying altogether about six minutes: during the last 1500 yards of
their advance how many rounds per piece might a battery fire in that
time?
Eleven rounds with effect, thus:
From 1500 to 650 yards, 3' 32"—spherical case, 7
“ 650 to 350 “ 0' 48"—solid shot, 2
“ 350 to close quarters, 0' 34"—canister, 2
[Sidenote: 48]]
37. What number of rounds could a battery fire against infantry,
supposing them to pass over 1500 yards in about 16¼ minutes?
Thirty-six rounds with effect, viz:
From 1500 to 650, quick step, 9' 45"—spher. case, 19
“ 650 to 350, “ 3' 50"—solid shot, 7
“ 350 to 100, “ 2' 30"—canister, 8
“ 100 to close { double quick } 0' 40"—can. 2
quarters {and the charge.}
38. Should the enemy attempt to force the passage of a river, what is
the best position for artillery to oppose it?
Wherever the best cross fire can be obtained in order to obstruct and
harass him as much as possible, and if he has succeeded in passing
over any portion of his troops, it should be directed against their
formation.
39. When the enemy is making the passage of a river in retreat, where
should your guns be posted?
In such a position as to bear upon the batteries that cover the
retreat, and also upon his bridges.
40. In forcing the passage of a river, what is the most advantageous
position for artillery?
The bridge being generally laid in a re-entering angle, batteries
should be posted on each side of the bridge, and far enough from it to
secure a cross fire on the opposite bank.
41. Should the indiscriminate expenditure of ammunition be permitted in
the field during action?
Upon no account; ammunition should at all times be carefully husbanded,
particularly at the commencement of an action, as the want of it at the
close may decide the fate of the day; it should also be sparingly used
in skirmishes and minor affairs, especially when at a distance from
supplies, or in anticipation of a general action.
[Sidenote: 49]]
42. When should the reserve be employed?
When a particular point of the line requires additional support,
a favorable position is to be seized, an impression has been made
on the line by the enemy, a forward or retrograde movement is in
contemplation, or when a determined attack is to be made on him, then
the reserve should come up and take part in the action; and it is of
the utmost importance that this should be done as expeditiously as
circumstances will permit.
43. Where should the reserve be placed previous to an engagement?
In rear with the second line, out of the range of shot, and as little
exposed as circumstances will admit, but always in such a position as
to have ready access to the front or rear.
44. Should guns be lightly abandoned before an enemy?
Never until the VERY LAST EXTREMITY. An artilleryman must never forget
that his gun is his proper ARM; that here lies his strength; that here
is his post of honor and of duty; also, that the LAST DISCHARGES are
always THE MOST DESTRUCTIVE, and MAY POSSIBLY INSURE THE SAFETY OF THE
WHOLE ARMY, or TURN THE TIDE OF VICTORY IN THEIR FAVOR.
45. What is the position for cavalry when placed in support of a
battery?
On its flank, about the distance of 100 yards, and as much concealed as
possible.
[Sidenote: 50]]
46. What is the proper position of field batteries when infantry
squares are attacked by cavalry?
When infantry are formed in squares to resist the charge of cavalry,
the guns should be placed outside at the angles of the squares, the
limbers, horses, &c., inside. Should the detachments be driven from
their guns, they will retire into the square, after discharging their
pieces, and taking with them the sponges and other equipments; the
moment the enemy has retired, they recommence their fire. Supposing the
infantry formed in echelon of regimental squares, and that the time, or
small extent of the squares would not admit of the limbers, &c., being
placed inside, then the wagons and limbers should be brought up with
their broadsides to the front, so as to occupy, if possible, the space
between the guns, leaving no intervals for the cavalry to cut through:
the prolonge or drag ropes might also offer an effectual momentary
impediment to them, if properly stretched and secured.
[Sidenote: 51]]
PART II. SECTION I.
POINTING GUNS AND HOWITZERS.
1. What is meant by the term _pointing_ a piece?
To point a piece, is to give it such a direction and elevation, or
depression, that the shot may strike the object; and the rule (except
in case of mortars) is: First give the _direction_ and then the
_elevation_, or depression.
2. When a shot is fired from a piece, by how many forces is it acted on?
By three.—1st. The impulsive force of the powder, which urges it
forward.
2d. The resistance of the air, which tends to stop it.
3d. The force of gravity which causes it to descend.
3. Why is it necessary to give a certain degree of elevation to a piece?
Because a shot describes under the action of the above forces a curve
called a trajectory, which is situated below the prolongation of
the axis of the piece, the extent of its departure from _this line_
increasing with the time of flight. Therefore, the more distant the
object, the greater must be the elevation to enable the shot to reach
it.
4. How is the direction given to a gun or howitzer?
By directing the line of metal upon the object.
[Sidenote: 52]]
5. How is the elevation or depression given?
The elevation or depression, which depends upon the charge, the
distance, and the position of the object above or below the battery,
must be ascertained from tables or by experiment, and the proper degree
given by means of instruments.
6. When will the object be struck by merely directing the line of metal
upon it?
But in one case,—when it is at point-blank distance.
7. How must the line of metal be directed for all ranges less than the
point-blank range, in order to strike it?
So as to pass below the object.
8. Give a simple rule for firing at objects within point-blank.
Add to the point-blank range the difference between it and the required
range, set the scale to the elevation corresponding to this sum, as
shown by tables of firing. Then aim the gun directly at the object; now
apply the scale, and observe where the visual ray of the scale strikes
the ground, and having noted this point, aim the gun directly at it.
9. How must the line of metal be directed for ranges greater than the
point-blank range, in order to strike it?
Above it.
10. When the line of metal passes over the object, what instruments
must be employed for giving the proper elevation?
The gunner’s quadrant, or the breech-sight.
[Sidenote: 53]]
11. How is the quadrant used?
After the direction has been given, the quadrant is applied, either by
its longer branch to the face of the piece, or this branch is run into
the bore parallel with the axis, or it may be applied to the upper
surface of the lock-piece, making the allowance due to its inclination
with the axis of the piece, which ought to be previously determined,
and the elevating screw turned, or the quoin adjusted, until the
required degree is indicated.
12. How is the breech-sight used?
It is first set to the elevation corresponding to the distance; it is
then applied to the highest point of metal on the base-ring, and by the
elevating screw, or quoin, the notch of the breech-sight, the highest
point on the swell of the muzzle, and the object, are brought in the
same line.
13. What is a line thus determined called?
An artificial line of sight.
14. In the absence of instruments, how may the elevation be given?
By placing one or more fingers of the left hand upon the base-ring,
perpendicular to the axis, and using them as a breech-sight.
=NOTE.=—In practice, it is well to fire two or
three shot to determine the _range_ experimentally,
as _it_ is affected by divers causes.
15. Should the line of metal be always directed in the vertical plane
passing through the object?
No; as in practice there are circumstances (as, for instance, a strong
wind blowing across the field of fire) which will cause a ball to
deviate from this plane, it follows that to strike the object, in such
a case, the line of metal must be directed to its right or left; the
gunner judging of the distance by observing the striking of the shot.
[Sidenote: 54]]
16. Is the line of metal a permanent line under all circumstances?
No; in batteries for garrison and sea-coast defense, where the
platforms are fixed, the line of metal may be considered as nearly
permanent; but with siege guns, which are mounted on traveling
carriages, the wheels of which are liable to vary in position from
unevenness of ground, or unequal settling in newly constructed
platforms, this line is constantly changing. It approximates the higher
wheel in proportion to the difference of level between the wheels; and
hence, to secure the greatest accuracy of fire, it must be frequently
verified; the old marks, if not found correct, should be erased and new
ones substituted.
17. When the notches or sights, which are sometimes made upon the
base-ring and swell of the muzzle in field guns, for aiming the piece
are used, how is the error of direction remedied when the wheels are
not on the same level?
The piece must be aimed more or less to that side which corresponds to
the higher wheel, according to the inclination.
18. When the elevation or depression has once been ascertained for any
given distance, how may the firing at that distance be facilitated?
By noting some point on the elevating screw or quoin; adjusting some
fixed measurement from a point on the stock to another point on the
under side of the breech; or by a chalk mark drawn across the face of a
trunnion and its corresponding cheek.
[Sidenote: 55]]
19. When firing either within or beyond point-blank range, may
remarkable points on the ground be taken advantage of, in order to
furnish an object to aim at?
Yes; some fixed object may often present itself which will serve as
a point upon which to direct the line of metal. No means should be
neglected that may tend to secure accuracy of aim; for the shot that is
thrown away by carelessness in pointing, had better not be thrown at
all.
20. How may precision of fire be secured at night?
When a fixed object is to be fired at by night, the piece should be
directed during the day, and two narrow and well-dressed strips of
wood laid on the inside of the wheels, and two others outside of the
trail of a siege carriage, and nailed or screwed to the platform. In
case of a barbette carriage, the traverse-wheels should be chocked in
the proper position. To preserve the elevation, measure the height of
the elevating screw above its box, or take the measure between a point
on the gun, and another on the stock; cut a stick to this length and
adjust the gun on it at each fire.
21. Should night-firing with _guns_ be limited?
Yes; it should be limited to a small number of rounds, as it consumes
ammunition to little advantage.
[Sidenote: 56]]
PART II. SECTION II.
POINTING MORTARS.
1. What is the rule for pointing mortars?
First give the elevation, and then the direction.
2. How is the elevation given?
By applying the quadrant to the face of the piece, and adjusting the
quoin until the required number of degrees is indicated.
3. Are the same means employed for giving mortars their direction as
those which are used with guns and howitzers?
No; because mortars are usually masked from the object to be struck, by
an epaulment or parapet.
4. To what are all the methods employed for giving the direction to
mortars reduced?
To determining practically two fixed points, which shall be in line
with the piece and the object, and sufficiently near to be readily
distinguished by the eye. These points being covered by the plummet,
determine a vertical plane, which, when including the line of metal,
becomes the plane of fire.
5. What is the simplest manner of directing the mortar?
By means of _pointing-wires_.
[Sidenote: 57]]
6. Describe this method.
The two fixed points required are determined by planting two wires
upon the epaulment, one upon its crest, and the other about a yard in
advance of it, both as nearly as possible in the vertical plane passing
through the centre of the platform and the object. The points being
thus established, the direction is given to the mortar, by causing a
plummet held in rear of it, to cover the wires and the line of metal.
7. In what respects is this method defective?
Both in accuracy of aim, and the liability of the wires being deranged
by the shots of the enemy or by other causes.
8. Give a better method.
By means of _pointing-stakes_, by which one of the fixed points is
established upon the crest of the parapet, or at the toot of the
interior slope, and another in rear of the piece. Then by a cord called
the _pointing-cord_, stretched between these two points, with the
plummet suspended from it, a vertical plane is determined with which
the line of metal is made to coincide.
9. How are the stakes planted?
A stake, a foot or more in length, is driven into the crest of the
epaulment, as nearly as practicable in the vertical plane of fire
passing through the centre of the platform; sighting by this stake,
another long one is planted, three or four feet in front of it, in
line with the object. To this stake the cord is temporarily attached,
and stretched by the first stake, just grazing it, to a point on the
ground, one yard in rear of the platform. At this point a third stake
is driven. The cord is removed from the second stake, which may now be
taken away, and permanently attached to the first.
[Sidenote: 58]]
10. How is the mortar directed?
The cord is stretched to the rear stake, and as near the muzzle-band as
possible, with the left hand, while the plummet is suspended against
it with the right; or the plummet may be attached to the cord, just in
rear of the mortar.
11. How does it appear that the mortar is thus _properly_ directed?
Because the cord, the plummet, and the line of metal, are evidently in
the vertical plane of fire.
12. What is done in case the shell should strike constantly to the
right or left of the object?
The pointing-cord is shifted to some notch on the _pointing-board_, to
the right or left, until the shell falls at the desired point.
13. Describe the pointing-board.
This is a piece of wood one foot long, two or three inches wide, and
one inch thick, having a notch cut in the middle of one side, to fit on
the stake and which is graduated into equal divisions from its middle.
When not in use, the pointing-cord may be wound on it.
[Sidenote: 59]]
14. Describe another mode of planting the _pointing-stakes_.
The mortar being placed upon the middle of the platform, the gunner
mounts upon it, and suspends the plummet in front of the muzzle,
covering the object. Where the plummet thus suspended cuts the crest
of the epaulment, the first stake is driven. A second stake is then
driven in the same line between the mortar and the epaulment. The
pointing-cord being attached to the first stake and stretched to the
rear, over the point where the plummet touches the top of the mortar,
determines the point on the ground at which the rear stake is driven.
The first stake is then removed, and the cord attached permanently to
the second stake.
When the object cannot be seen from the mortar, owing to the
interposition of some obstacle, as a parapet or a hill, two persons in
sight of each other, one of whom can see the mortar, and the other the
object, must by successive changes of position, place themselves in the
vertical plane of fire, and at the points thus determined, stakes must
be driven, one of which will serve as the object.
15. How may precision of fire be secured at night with mortars?
The _direction_ is preserved by nailing or screwing two boards to the
platform outside of the cheeks; the _elevation_ is marked on the quoin,
or the quoin may be nailed in the proper position.
[Sidenote: 60]]
PART III.
CHARGES.
1. What is the charge of a piece of artillery?
The powder with which it is loaded.
2. What is the ordinary service charge of powder for heavy guns?
_One-fourth_ the weight of the shot.
3. What is it for firing _double shot_?
_One-sixth_ the weight of one shot.
4. What is the breaching charge?
_One-third_ the weight of the shot.
5. What kind of charges are used in hot shot firing?
Small charges from _one-fourth_ to _one-sixth_ the weight of the ball.
6. For what reason?
Because balls fired with small velocities split the wood in a manner
which is favorable to its burning; with a great velocity the hole
closes, the ball sinks deep, and, deprived of air, chars without
setting fire to the surrounding wood.
7. To what depth should hot shot penetrate?
Not deeper than ten or twelve inches.
8. In ricochet firing, what kind of charges are used?
Light charges generally; varying from _two-thirds_ to _one-eighth_ of
the ordinary charge.
[Sidenote: 61]]
9. In what manner are the charges of mortars regulated?
The charges vary with the elevation; or if the elevation be fixed at
any particular angle, they must be determined by the range.
10. What are the charges for field guns and field howitzers?
See Table, page 46.
11. What are the charges for heavy guns, columbiads, and howitzers?
See Table, page 46.
12. What are the greatest charges of the sea-coast, siege, and coehorn
mortars?
See Table, page 46.
13. What charge is used for projecting fire balls from mortars?
One _twenty-fifth_ the weight of the ball.
[Sidenote: 62]]
CHARGES FOR FIELD GUNS AND FIELD HOWITZERS.
===============================================================
|FOR GUNS.| FOR HOWITZERS.
KIND. +---------+----+----+----+--------
|12- |6- |32- |24- |12- |Mountain.
|pr. |pr. |pr. |pr. |pr. |
-----------------------------+----+----+----+----+----+---------
|lbs.|lbs.|lbs.|lbs.|lbs.| lbs.
For shot, |2.5 |1.25| | | |
For spher. case or canister, |1.5 |1.0 |2.5 |1.75|0.75| 0.5
For shells, { Small charge, | — | — |2.5 |2.0 |1.00| 0.5
{ Large charge, | — | — |3.25|2.50|1.00| 0.5
-----------------------------+----+----+----+----+----+---------
CHARGES FOR HEAVY GUNS, COLUMBIADS AND HOWITZERS.
====================================================================
GUNS. |COLUMBIADS | HOWITZERS.
-----+-----+-----+-----+-----+-----+-----+-----+-------+------------
42- | 32- | 24- | 18- | 12- | 10- | 8- |Siege| 24-pr.| Sea-Coast.
pr. | pr. | pr. | pr. | pr. |inch.|inch.|8-in.|Garri- |------+-----
| | | | | | | | son |10-in.|8-in.
-----+-----+-----+-----+-----+-----+-----+-----+-------+------+-----
lbs.| lbs.| lbs.| lbs.| lbs.| lbs.| lbs.| lbs.| lbs. | lbs. |lbs.
10.5| 8. | 8. | 6. | 4. | 14. | 8. | 4. | 2. | 12. | 8.
-----+-----+-----+-----+-----+-----+-----+-----+-------+------+-----
GREATEST CHARGES OF SEA-COAST, SIEGE AND COEHORN MORTARS.
=================================================================
SEA-COAST. | SIEGE. | COEHORN. | STONE MORTAR.
--------+--------+--------+-------+----------+----------+--------
18-inch.|10-inch.|10-inch.|8-inch.| | 120 pds. |15 6-pr.
| | | | |of stones.|shells.
--------+--------+--------+-------+----------+----------+--------
lbs. | lbs. | lbs. | lbs. | lbs. | lbs. | lbs.
20. | 10. | 4. | 2. | 0.5 | 1.5 | 1.
--------+--------+--------+-------+----------+----------+--------
[Sidenote: 63]]