Transcriber’s Note
Text printed in italics has been transcribed between _underscores_.
Small capitals have been replace with ALL CAPITALS. Superscript texts
are transcribed as ^{text}.
Sidenotes are surrounded by ~tildes~.
More Transcriber’s Notes may be found at the end of this text.
CLASS BOOK
FOR
THE SCHOOL OF MUSKETRY
HYTHE.
PREPARED FOR THE USE OF OFFICERS.
BY
COLONEL E. C. WILFORD,
_Assistant-Commandant and Chief Instructor_.
HYTHE:
W. S. PAINE, STATIONER, POST OFFICE, HIGH STREET.
1861.
INTRODUCTION.
The School of Musketry was founded in 1853, by the then
Commander-in-Chief, the late Viscount Hardinge, as a normal school of
instruction in Musketry.
It has for its especial object the formation of officers and
non-commissioned officers to act as instructors in the several
battalions throughout the Army.
In the book of “Regulations for conducting the Musketry Instruction of
the Army,” promulgated by order of His Royal Highness the
Commander-in-Chief, it is ordered at page 33, and paragraph 35, that,
“The Commanding Officer is to assemble the officers of the battalion at
least once in each half-year, and to cause the non-commissioned officers
and men to be assembled occasionally by squads or companies, at other
times than when the annual course is proceeding, when the
officer-instructor, having previously explained the theoretical
principles detailed in the foregoing lessons, will be at liberty to
advance deeper into the subject, developing to a degree proportionate to
the rank and intelligence of his auditors, the whole history of small
arms, from the first invention of gunpowder, and the successive steps by
which the rifle-musket has attained its present efficiency; in order
that the officers and soldiers, by acquiring a thorough knowledge of the
subject theoretically, may take a greater interest in the practical part
of this most important branch of their duty.”
The following Lectures have been prepared for the use of officers
qualifying at the School of Musketry for the positions of Instructors in
their respective Regiments. They are not to be considered as complete
treatises or histories, but merely as “aids” to instruction, which can
be expanded by the Instructor in viva voce Lectures, and if bound with
an alternate ruled blank leaf, they may be corrected and enlarged when
desirable, to suit the various improvements in arms, &c., introduced
from time to time.
These Lectures are a mere compilation, extracted from a vast amount of
interesting and valuable matter, systematically arranged. The names of
the various authors upon whom wholesale plunder has been committed are
mentioned in the course of the work, and the compiler hopes this general
confession may secure their pardon.
The Theory of Gunnery has been very slightly touched upon: it cannot be
pursued by any persons unless well grounded in Mathematics, and the
short time passed by officers at Hythe wholly precludes so abstruse a
study. Our School is decidedly a practical institution; to acquire an
art or skill is our object, and we only broach the subject of Theory to
soldiers, so far as to enable them to understand the reasons for all
those rules which have to be attended to in practice.
E. C. WILFORD,
COLONEL.
HYTHE, _January, 1861_.
CONTENTS
PAGE.
History of Gunpowder 1
Manufacture of Gunpowder 7
Foreign Gunpowder 20
Explosive force of Gunpowder 29
Experiments with Gunpowder 36
Magazines 23
Lightning Conductors 24
Greek Fire 4
Ancient Engines of War 39
On Artillery 62
Portable Fire Arms 73
The Rifle 86
The Bayonet 83
Accoutrements 84
Breech-loaders 92
On Rifling 95
On Rifle Projectiles 101
Theoretical Principles 110
Gravity 113
Atmosphere 115
Form of Bodies 119
Causes of Deviation 121
Windage 121
Rotation 122
On Eccentric Projectiles 124
Extended Table of Contents
ERRATA.
Page 6, para. 5, line 6, for “_have before stated_” read “_shall
state_.”
Page 20, last line but one, for “_altogether_” read “_all together_”
Page 25, para. 3, line 5, for “_descriptive_” read “_disruptive_.”
Page 30, para. 3, line 9, for “_expansive_” read “_expansion_.”
Page 31, para. 3, line 1, for “_art_” read “_act_.”
Page 32, para. 7, line 9, for “_considerable_” read “_considerably_.”
Page 32, para. 7, line 10, for “_Robert_” read “_Piobert_.”
Page 35, para. 3, line 1, for “_sulphurate of Potassia_” read
“_sulphide of Potassa_.”
Page 36, para. 4, lines 1 and 2, for “_which is a mortar_” read “_the
chamber being_.”
Page 40, last line but 3, for “_Polyreetes_” read “_Polyorcetes_.”
Page 41, para. 4, line 10, for “ix” read “xii.”
Page 53, para. 2, line 9, for “_incredible_” read “_incredibly_.”
Page 66, para. 6, line 2, after “_has_” insert “_a_”
Page 78, para. 5, line 3, for “753in.,” read “·753in.”
Page 78, para. 5, line 3, for “16” read “14¹⁄₂.”
Page 79, line 4, for “600” read “6,000.”
Page 84, para. 2, line 1, for “_Latinat_” read “_Catinat_.”
Page 84, para. 3, line 1, for “_masquitairy_” read “_mousquetaires_.”
Page 86, para. 10, line 2, for “_Carabins ragees_,” read “_Carabines
rayées_.”
Page 86, para. 12, line 1, for “_subaltern officers_” read
“_Non-Commissioned Officers_.”
Page 89, line 3, for “_range_” read “_rayé_.”
Page 89, line 3, for “_ball culot_” read “_balle à culot_.”
Page 91, para. 4, last line, for “⁷⁄₁₀₀” read “¹⁄₁₀₀”
Page 93, para. 8, line 1, for “_wounds_” read “_rounds_.”
Page 98, para. 1, lines 6 and 7, for “_possible. For_,” read
“_possible; for_”
Page 103, para. 3, line 7, for “_proportionary_” read
“_proportionate_.”
Page 103, para. 5, line 4, for “_reserved_” read “_reversed_.”
Page 105, para. 6, line 3, for “_horn-wood_” read “_hora, wood_.”
Page 112, para. 1, line 8, after “_direction_,” insert “_b_.”
Page 114, para. 2, line 7, for “16-48-80” read “16+48+80.”
Page 115, para. 2, line 2, for “_sine_” read “_tangent_.”
Page 115, para. 2, for “_plate_ 21, _fig._ 3,” read “_plate_ 22,
_fig._ 3.”
Page 119, para. 3, line 1, after “_moving_,” insert “_in_.”
Plate 21, fig. 5, should be lettered as fig. 4. plate 22.
HISTORY OF GUNPOWDER.
The History of Gunpowder may well form a prelude to that of Fire Arms,
as the existence of the latter is wholly dependent on the discovery of
the former. Of all the discoveries which have been made, there is,
perhaps, none which has produced more important consequences to mankind
than the discovery of Gunpowder, as by introducing fire-arms, and a new
method of fortifying, attacking, and defending Towns, it wrought a
complete change in the whole art of war.
~Knock’s opinion.~
The invention of Gunpowder is completely involved in obscurity, and this
very fact is one great proof of its antiquity. Knock observes that the
invention of Gunpowder comprises several discoveries, which it is
necessary to distinguish from each other.
~Order of discovery.~
1st.--The discovery of Nitre, the principal ingredient, and the cause of
its detonation.
2nd.--The mixture of nitre with sulphur and charcoal, which, properly
speaking, form gunpowder.
3rd.--The application of powder to fire-works.
4th.--Its employment as a propelling agent for throwing stones, bullets,
&c.
5th.--Its employment in springing mines and destroying fortifications.
All these discoveries belong to different periods.
~Mr. Duten’s account.~
Mr. Dutens carried the antiquity of gunpowder very high; and refers to
the accounts given by Virgil, and others, of Salmonens’ attempt to
imitate thunder, presuming from hence that he used a composition of the
nature of Gunpowder.
~Known in China, A. D. 85.~
It has been said that it was used in China as early as the year A. D.
85, and that the knowledge of it was conveyed to us from the Arabs, on
the return of the Crusaders to Europe.
~Known in India, A. D. 250.~
The Brahmas and Indians, whose practice is recorded by Philostratus, in
his life of Appolonius Tyanœus, written about 1600 years ago. “These
truly wise men,” says he, “dwell between the rivers Hyphasis and Ganges;
their country Alexander never entered, their cities he never could have
taken, for they come not out to the field to fight those who attack
them, but they overthrow their enemies with tempests and thunderbolts,
shot from their walls.”
This is a most striking illustration of the antiquity of Gunpowder, for
if some such composition be not implied in the foregoing quotation, it
must remain for ever perfectly unintelligible.
Saltpetre, which is the principal ingredient of Gunpowder, is found in
its natural state in the East, and from this it seems highly probable
they were acquainted with the composition of Gunpowder before the
Europeans.
~Powder at siege of Mecca, A. D. 690.~
The Arabs are said to have employed Gunpowder at the siege of Mecca,
A. D. 690.
~Oldest book on gunpowder A. D. 900.~
There is a manuscript book still extant, entitled Liber Ignium, written
by Marcus Græcus, who lived about the end of the eighth century, and the
composition there prescribed is 6lbs. saltpetre, 2lbs. charcoal, 1lb.
sulphur, to be well powdered and mixed in a stone mortar.
~Work on gunpowder in Escurial Collection A. D. 1249.~
There is in the Escurial Collection a treatise on Gunpowder, written in
1249.
~Roger Bacon on powder, A. D. 1267.~
Our countryman, Roger Bacon, who was born 1214, and published works at
Oxford 1267, expressly mentions the ingredients of Gunpowder, not as any
new discovery, but as a well known composition, used for recreation. He
describes it as producing a noise like thunder, and flashes like
lightning, but more terrible than those produced by nature; and adds
that it might be applied to the destruction of an army or a city. Bacon,
in his treatise “De Secretis Operibus,” says that from saltpetre,
sulphur, and wood coals, we are able to make a fire that shall burn at
any distance we please.
~Tradition of Schwartz, A. D. 1320.~
~Mortar.~
The common tradition of Bartholdus Schwartz having invented Gunpowder
and Artillery, about 1320, is without the slightest foundation, but he
might possibly have suggested the simplest application of it to warlike
purposes, in consequence of some accidental explosion while mixing the
ingredients in a mortar. Indeed, the name, as well as the form of the
old species of artillery, which was employed to throw large bullets at
an elevation, strongly corroborate this conjecture; but Schwartz cannot
lay any claim to originality of invention.
~Powder made in the reign of Richard II. 1378.~
Gunpowder was made in England in the fourteenth century, as Richard II.
commissioned Sir Thomas Norwich to buy, in London, or in any other
place, certain quantities of “sulphur, saltpetre, and charcoal,” for
making Gunpowder.
~Tartaglia on Powder, A. D. 1500.~
Tartaglia, at the commencement of the sixteenth century, sets down
twenty-three different compositions, made use of at different times, the
first of which, being the most ancient, consists of equal parts of
nitre, sulphur, and charcoal.
~Ancient gunpowder weak.~
Gunpowder, for some time after the invention of artillery, was of a
composition much weaker than what we now use, or than that ancient one
mentioned by Marcus Græcus; but this, it is presumed, was owing to the
weakness of their first pieces, rather than to the ignorance of a better
mixture.
~Graining.~
The change of the proportion of the materials composing it was not the
only improvement it received. The invention of graining it is doubtless
a considerable advantage to it; for powder, at first, was always in the
form of fine meal, such as it was reduced to by grinding the materials
together. It is doubtful whether the first graining of powder was
intended to increase its strength, or only to render it more convenient
for the filling into small charges, and the charging of small arms, to
which alone it was applied for many years, whilst meal-powder was still
made use of in cannon. But at last the additional strength which the
grained powder was found to acquire from the free passage of the fire
between the grains, occasioned the meal-powder to be entirely laid
aside.
~Tartaglia wrote, 1537.~
~William Bourne, 1577.~
That powder was first used in meal, and continued in its old form for
cannon long after the invention of graining it for small arms, are facts
not to be contested. Tartaglia expressly asserts that in his time
cannon-powder was in meal, and the musket-powder grained. And our
countryman, William Bourne, in his “Art of Shooting in great Ordnaunce,”
published forty years after Tartaglia, tells us, in chap. I, that
serpentine powder, (which he opposes to corn, or grained-powder) should
be as fine as sand, and as soft as flour: and in his third chapter he
says that two pounds of corn-powder will go as far as three pounds of
serpentine-powder.
~Tartaglia on the proportions.~
We learn from Tartaglia, that the cannon-powder was made of four parts
saltpetre, one part sulphur, and one part charcoal; and the
musket-powder of forty-eight parts saltpetre, seven parts sulphur, and
eight parts charcoal; or of eighteen parts saltpetre, two parts sulphur,
and three parts charcoal. These compositions for musket powder are very
near the present standard; the first having, in one hundred pounds of
powder, about one pound of saltpetre more than is at present allowed,
and the second three pounds more.
~Nye’s treatise on the proportions.~
Nye, in his treatise on fireworks, gives the proportions of the
ingredients, and the dates when they are used, thus in 1380 equal parts
of each were employed. This would be about as efficient as a common
squib of the present time. In 1410, three parts saltpetre, two sulphur,
and two charcoal. In 1520, for the best powder, four parts saltpetre,
one sulphur, and one charcoal, and afterwards, five saltpetre, one
sulphur, and one charcoal.
~Early gunpowder mere mixture.~
In fact, Gunpowder was merely those substances, combined, with little or
no purification. It was not at first corned or grained, as at present,
but remained in its mealed state, and was called “serpentine powder,” in
several accounts of stores in the time of Edward VI., and Elizabeth.
~Two kinds.~
Soon after this two kinds of powder were used for the same gun, one in
its mealed state (for priming only) as being more readily ignited by the
match, the other, corned or grained, for the charge in the gun barrel.
~Powder first used to explode mines in 15th century.~
The application of powder to mines, and to the destruction of
fortifications, does not appear to have been in practice before the end
of the fifteenth century.
~Elizabeth had powder made, 1558 to 1603.~
Camden, in his life of Queen Elizabeth, says that she was the first who
procured Gunpowder to be made in England, that she might not pray and
pay for it also to her neighbours; but it has been stated that it was
previously made in the reign of Richard II.
~Charles I. from A. D. 1625 to 1649.~
Sir Henry Manwayring, in his Seaman’s Dictionary, presented to the Duke
of Buckingham, in the time of Charles 1st, under the word powder, tells
us, “There are two kinds of powder, the one serpentine-powder, which
powder is dust (as it were) without corning. The other is “corn-powder;”
though he informs us the serpentine-powder was not used at sea. Indeed,
when that book was written, it is believed powder was usually corned,
for the foreign writers on artillery had long before recommended its
general use.
~Causes which checked the progress of Fire-Arms.~
~Fire-Arms supposed to extinguish bravery, and to be contrary to
humanity.~
~Fire-Arms expensive and powder difficult to procure.~
Various circumstances tended to check the progress of fire-arms, and the
improvement of artillery, for a long period after the invention of
gunpowder. Custom made most people prefer the ancient engines of war.
The construction of artillery was very awkward and imperfect; and the
bad quality and manufacture of gunpowder, so that it could produce but
little effect; and there was a general aversion to the newly invented
arms, as calculated to extinguish military bravery, and as being
contrary to humanity; but above all, the knights (whose science was
rendered completely useless by the introduction of fire-arms) opposed,
with all their might, this invention, to which may be added the great
cost and difficulty of procuring gunpowder.
~Rockets in India.~
It is known that iron rockets have been used in India as military
weapons, time out of mind. (See plate 4, fig. 3.)
GREEK FIRE.
~Discovered by Callinicus. A. D., 617.~
The Greek Fire has been highly extolled for its wonderful effects, but
it owed much of its effect to the terrors and imagination of the
beholders. It is said by the Oriental Greeks, to have been discovered by
Callinicus, an architect of Heliopolis or Balbeck, in the reign of the
Emperor Constantine Pogonatus, who, it is said, forbad the art of making
it to be communicated to foreigners, but it was at length known, and in
common use, among the nations confederated with the Byzantines.
~Known in China, 917.~
It is also said to have been known in China in 917, being 300 years
after Constantine Pogonatus, under the name of “The oil of the
cruelfire,” and was carried thither by the Kitan Tartars, who had it
from the King of Ou.
~Wild fire from the Saracens.~
It was thrown by machines, by the hand, and by cross bows, fastened to
the heads of arrows. The Crusaders obtained a knowledge of a sort of
wild fire from the Saracens, which could only be extinguished by dust or
vinegar. It was composed of the gum of resinous trees, reduced to powder
with sulphur, to which was added naptha, and other bitumens, and
probably nitre.
~Wild fire in the Holy Wars.~
~Geoffrey de Vinesauf’s account.~
~Father Daniel’s account.~
~Used at the siege of Dieppe.~
It is much spoken of in all the Holy Wars, as being frequently employed
by the Saracens against the Christians. Procopius, in his history of the
Goths, calls it Media’s oil, considering it an infernal composition
prepared by that sorceress. Geoffrey de Vinesauf, who accompanied
Richard I. to the Crusades, says that it could not be extinguished by
water, but that sand thrown upon it abated its virulence, and vinegar
poured upon it put it out. Father Daniel says this wild fire was not
only used in sieges, but even in battles, and that Philip Augustus, King
of France, having found a quantity of it ready prepared at Acre, brought
it with him to France, and used it at the siege of Dieppe, for burning
the English vessels in that harbour.
~Greek fire and gunpowder, both used at the siege of Ypres, 1383.~
The Greek fire was used long after the invention of firearms; when the
Bishop of Norwich besieged Ypres, 1383, the garrison is said by
Walsingham to have defended itself so well, with stones, arrows, lances,
and certain engines called guns, that they obliged the English to raise
the siege with such precipitation, that they left behind them their
great guns, which were of inestimable value.
Greek fire was probably a more recent invention than Gunpowder.
* * * * *
~Powder used by Arabs, 14th century.~
It is ascertained that Gunpowder was employed by the Arabs as an agent
for throwing bolts and stones, about the commencement of the fourteenth
century, and that the Moors first availed themselves of its advantages
in their wars with the Spaniards. From Spain, the use of Gunpowder and
Artillery gradually extended itself to France, and thence over the other
States of Europe.
* * * * *
Some idea of the importance of Gunpowder may be formed by the estimate
of the enormous quantity employed in sieges, and warfare generally.
~Quantity used in sieges.~
At the siege of Ciudad Rodrigo, January, 1812, 74,978lbs. were consumed
in 30¹⁄₂ hours; at Badajos, March, 1812, 228,830lbs. in 104 hours, and
this from the great guns only.
~San Sebastian and Zaragoza.~
At the two sieges of San Sebastian, 502,110lbs. At Zaragoza, the French
exploded 45,000lbs. in the mines, and threw 16,000 shells.
~Sebastopol.~
During the siege of Sebastopol, extending over a period of eleven
months, the enormous quantity of 2,775,360lbs., or 1,239 tons of
gunpowder, were expended by ourselves alone; 9,076 tons of shot and
shell having been launched by us on that memorable occasion, from 476
pieces of heavy ordnance; of which only 11 actually burst, though 269
were rendered unserviceable.
~Quantity made.~
Some of our private manufactories make from 8 to 10,000 barrels of
powder a year in time of peace, and from 10 to 14,000 during war.
~Quantity proved by Government.~
~Quantity in store in 1783.~
The quantity of powder received and proved from Faversham, at the Royal
Magazines, and from the several powder makers contracting with
Government, amounted, during the several years from 1776 to 1782
inclusive, to 244,349 barrels of 100 lbs. each, being equal, on an
average, to 3,490,700lbs. annually. The quantity of powder in store in
Great Britain, Guernsey, Jersey, and the Isle of Man, in 1783, was about
80,000 barrels.
~Gunpowder used for works of peace.~
Sir George Staunton observes, that gunpowder in India and China seems
coeval with the most distant historic events, and that the Chinese have
at all times applied it to useful purposes, as the blasting of rocks,
and also in the preparation of fireworks, in which they greatly excel
other nations.
~Powder used at Woodhead tunnel.~
In blasting the Woodhead tunnel, in the county of Chester, not less than
three thousand five hundred barrels of gunpowder, weighing about one
hundred and sixty tons, were used in its formation. The average number
of men employed was about a thousand; and during the six years the works
were in progress, twenty-six men were killed. There were about 400 minor
accidents, many of them attended with loss of limb, and the sum total of
the casualties, in proportion to the men employed, was greater,
according to Mr. Edwin Chadwick, than was suffered by the British army
in the battles of Talavera, Salamanca, Vittoria, and Waterloo.
~Powder used on S. Eastern Railway.~
In the formation of the South-Eastern Railway, the blasts of the cliffs
between Dover and Folkestone have astonished even scientific men. On one
occasion 18,500 pounds of gunpowder were ignited by galvanic action at
the same instant, which severed from the Round-down cliff, the height of
which is 375 feet above the level of the sea, more than 1,000,000 tons
of chalk. The fallen mass extended 1200 feet into the ocean, and covered
a space of 18 acres. By another statement, the quantity of earth moved
by the explosion was 400,000 cubic yards, and was a saving to the
Company of £7,000.
~No. of men employed at Waltham Abbey.~
~Quantity made.~
There are 134 men employed in the Government works at Waltham Abbey in
the manufacture of gunpowder, who make about 9,000 barrels a year. The
premises are near two miles long, consisting of detached mills, &c., on
a small stream, which runs through the whole length of the premises and
communicates with the Thames, whereby there is water-carriage to the
Government Powder Magazines at Purfleet. The barges conveying powder are
not allowed to anchor in the river off London during the night. Where
two buildings are adjacent, there are frequently heavy buttresses of
masonry between them, and lightning conductors are placed in great
numbers.
~Saving to Government.~
There is a great saving, amounting to upwards of £300,000, in the cost
of powder, when compared to the price paid to the merchants in seven
years of the war from 1809 to 1815, from the Government having Waltham
Abbey, Faversham, and Ballincollig.
~Improved Quality.~
At Waltham Abbey, in a very few years after it was constructed, the
powder was so improved, that the charge of powder to the weight of shot
was reduced from one-half to one-third; therefore two barrels were used
instead of three--an advantage in stowing on board ship as well as in
the field.
~Made by Contract.~
A great part of the powder for H. M. Government has at present to be
supplied by merchants. The contracts are made out sometimes for them to
supply their own saltpetre, and at others for the Government to furnish
it pure, at the rate of 77·5 lbs. per barrel of 100 lbs., they finding
the other materials and manufacture, a corresponding reduction in price
being made: as, however, it has to come up in nearly all respects to the
sample, the requirements of which we shall state, certain proofs have to
be undergone before being received for the different services.
NOTE.--The foregoing is mainly compiled from Robins’s _New Principles
of Gunnery_, by Hutton; _Engines of War_, by Wilkinson; and
_Projectile Weapons of War_, by J. Scoffern, M.B.
ON THE MANUFACTURE OF GUNPOWDER.
~Composition of powder.~
Gunpowder is an explosive propellant agent; a mechanical combination and
intimate mixture of saltpetre, charcoal, and sulphur, in certain fixed
proportions, the result of successive experiments.
~Ought to keep without deterioration.~
To be effective, Gunpowder should,
1st.--Preserve itself in a good state, whether in magazine or in
carriage.
~Leave no residue.~
2nd.--Leave as little residue as possible after ignition.
~Combine quickness and power.~
3rd.--Should combine a certain quickness of combustion with great
explosive force.
SALTPETRE, OR NITRE.
~Nitre.~
~Where found.~
~Unfit in natural state.~
The principal ingredient in Gunpowder is an abundant production of
Nature, and is a combination of nitric acid with the vegetable alkali.
It is never found pure, being always contaminated with other salts and
earthy matter. It is principally found in the East Indies, Ceylon, and
South America, and is sometimes produced from decayed animal and
vegetable matter. It is totally unfit for Gunpowder until it has been
refined; for, being combined with muriates of soda, lime, magnesia, and
other salts, which absorb moisture, the close contact of the ingredients
would be deranged by their presence, the strength of the powder
weakened, and the power of resisting the action of the atmosphere
greatly lessened. As for the efflorescent salts it may contain, they are
noxious only inasmuch as, possessing no particular useful property, they
interpose their atoms between the more combustible ingredients, and
impede the rapidity of deflagration.
~Two methods of refining.~
There are two methods of refining saltpetre at Waltham Abbey:--1st, the
Old Method, of re-crystallizing three times; and 2nd, the New Method,
which has only just been adopted, both of which we shall here briefly
describe.
OLD METHOD.
~Old method.~
~Saltpetre fuzes at 600°.~
About 35 cwt. of the grough saltpetre, as it is termed, viz., as it is
imported in its impure state, is put into a copper capable of holding
500 gallons, with 270 gallons of water, in the proportion of about
1¹⁄₂lbs. of nitre to 1lb. of water, (which proportion varies with the
quality of the saltpetre). This is allowed to boil, and the impurities
are skimmed off as they appear on the surface. Cold water is
occasionally thrown in to precipitate portions of the chloride, which
otherwise would remain on the top by the action of boiling. After being
allowed to boil from three and a half to four hours, the furnace doors
are thrown open, when the chlorides and salts fall to the bottom. In
about two hours, a copper pump is lowered into the liquor, which is
pumped out into a wooden trough, having four or five brass cocks, under
which are suspended canvas filtering bags in the shape of a V. The
solution is then filtered, and run off into pans, containing about 36
gallons, and allowed to remain for twenty-four hours, to crystallize,
when they are set up on edge, to drain off the liquor which remains
uncrystallized, and which is called mother liquor. The saltpetre thus
obtained is called once-refined, and undergoes the same process twice
again, the only difference being that there is a greater proportion to
the water each time, viz. 1³⁄₄lb. to 1lb. of water the second time, and
2lb. to 1lb. of water the third time: moreover, the third time, a small
quantity of ground charcoal is put into the solution, and it passes
through double filters, which brings it to a very fine pure white colour
when melted. The mother water which remains in the pans after each
crystallization is conveyed away by gutters to cisterns under the
building; it is then evaporated in iron pots to one quarter of its
original bulk, filtered, and allowed to crystallize. The saltpetre
obtained from the first mother water is considered one stage inferior to
grough; that from the second, equal to grough; that from the
treble-refined, equal to once-refined saltpetre. The water left from
every stage is treated in the same way, so that actually nothing is lost
of the pure material. Saltpetre treble-refined by this process is
perfectly pure, and fit for the manufacture of Gunpowder; and in order
to free it from moisture, as well as for the convenience of storage and
transport, it is melted in iron pots holding about 4 cwt., by raising it
to a temperature of 600° Fahrenheit, and cast into gun-metal circular
moulds holding about 38lbs. each. It must be observed that it requires
about two hours to bring the saltpetre into a liquid state, and that,
after this, the furnace doors are thrown open, to lower the heat to the
proper temperature for casting into the moulds. When the cakes are cold,
they are packed away in barrels containing 1 cwt., 1 qr. each, and put
into store. Care must be taken, in melting the saltpetre, not to raise
it to too high a temperature, as this would reduce the quantity of
oxygen, and form nitrite of potash, which would render it unfit as an
ingredient in the composition of Gunpowder.
~A neutral salt.~
Saltpetre is a neutral salt, the constituents of which are 46.55 potash,
and 53.45 nitric acid; the latter consisting of two volumes nitrogen and
five of oxygen. It is white, and of a fresh, sharp, and slightly bitter
taste. It crystallizes in six-sided prisms. Exposed to the air, it
remains permanent unless impure, or that the atmosphere is very moist.
NEW METHOD.
~New method.~
Forty cwt. of the grough saltpetre is put into a copper with 270 gallons
of water, and treated in precisely the same way as we have before
described for the first refining; it is then filtered and run off into
large troughs, about 10 feet long by 6 feet wide, and 9 inches deep,
lined with sheet copper; this liquor is then kept in a state of
agitation by a wooden rake, until nearly cold. By this process a large
quantity of very minute crystals are formed, which are collected as they
form by a wooden hoe, and shovelled with a spade on to a framework
covered with copper sieving resting on the opposite sides of the trough,
and allowed to drain. These fine white crystals, which have exactly the
appearance of snow, when they have drained sufficiently, are raked over
in a washing cistern adjoining, which is about 6 feet long, 4 feet wide,
and 3ft. 6in. deep, and fitted with a false wooden bottom that can be
removed at pleasure. Cold water is allowed to run on to the saltpetre in
this cistern till it is nearly level with the top. After remaining for
an hour it is drained off, and filled again with fresh water, which is
drained off after about another hour. The saltpetre thus obtained is
perfectly pure, and equal in every respect to the treble-refined by the
old method. The water remaining in the cisterns after agitation, is left
till the next morning, when a quantity of larger crystals are formed on
the bottom and sides; these are equal to once-refined by the old method,
and are used with grough; the mother-liquor is then drained off, and
evaporated in the usual way. The water from each washing is conveyed
into cisterns, and used with grough saltpetre instead of water; but, as
it contains a small portion of saltpetre in solution, a lesser quantity
of grough is used to make the proportions correct.
~Drying.~
The saltpetre flour, however, contains a certain degree of moisture,
which has to be dried off in the following way: two large copper trays,
about 10 feet by 6 feet, with a 3-inch rim, are fixed over flues heated
by a furnace, 4 inches of sand being between the flues and the bottom of
the trays; the saltpetre is spread about 2 inches deep all over, and
raked about till dry; it is then barrelled up for use. It takes about
two hours to dry 5 cwt.
~Comparison of the two methods.~
On comparing the two systems, there cannot for one moment be a doubt as
to the immense advantages of the latter over the former. As an example,
in the refinery where this new process is carried on, the result (that
is to say, pure saltpetre) is obtained in one day instead of six, with
less than one half the amount of labour and coals.
~Why new method best.~
On reflection, the reason of the great gain of time by this process will
suggest itself. In the former method, when allowed to remain quiet, the
crystals formed are very large, and the spaces left in them always
contain a certain amount of mother-water, which necessitates its being
crystallized three times to perfectly free it from the liquor. In the
latter, the crystals are so minute that there is practically no space
for the mother-water to collect; consequently, by careful washing, the
saltpetre is obtained perfectly pure.
CHARCOAL.
~Charcoal.~
~Object of charring.~
~Best wood for charcoal.~
Wood charcoal is the woody fibre that remains after the liquid and more
volatile parts have been driven off by the fire in the process of
charring. The temperature resulting from the combustion of charcoal is
much higher than that from burning wood, in consequence of the absence
of the large quantity of water which wood contains, amounting to between
50 and 60 per cent.; the object, therefore, of charring wood is the
removal of moisture, and also, what is of great importance, the
expulsion of those matters contained in it which become volatile before
they are burned, thus rendering a large amount of heat latent. The woods
generally used in this country in making charcoal for gunpowder are the
alder, willow, and dogwood. There are about 60 acres of wood grown for
charcoal at Waltham Abbey. The alder is cut every eight years, and the
willow in six years. It is used after one year. Other woods are
sometimes used by English and foreign manufacturers, but none produce a
powder of such quality as obtained from the above. It is usually
considered that better charcoal is distilled when the wood is allowed to
season for a time; but recent experience has shown that wood only lately
cut and peeled, after being desiccated in a hot chamber, will make
equally good charcoal with that which has been seasoning for three or
four years.
~First process.~
All the wood which is cut in the Government grounds or purchased from
merchants, is stripped of the bark, on account of its being impregnated
with salts and gummy substances, cut into lengths of 3 feet for the
convenience of loading the iron slips, which are a little above this
length, and stacked in the wood-yard.
~Cylinder charcoal.~
~Quantity produced.~
~Qualities.~
~Kept dry.~
~Absorbs.~
Cylindrical cases of the required size, fitted with lids, are filled
with wood. These cases are made to fit easily, and slide horizontally
into iron retorts built in the wall, which admit of the accurate
regulation of heat (communicated to them by furnaces underneath)
throughout the operation of charring. A great saving of time and heat is
effected by their use, as when the wood has been properly charred the
case or slip containing it may be easily withdrawn, and another
containing a fresh charge at once introduced into the retort, without
allowing the latter to cool down, as would otherwise be necessary. When
it has been sufficiently charred (which is known by experience, in
watching the burning of the gas that is produced and is conducted into
the fire), the slip is withdrawn by tackling, and at once lowered down
into iron coolers or cases, which are immediately covered up with
close-fitting lids, and then allowed to remain until all fire is
extinguished. The goodness of charcoal is an essential point in the
manufacture of gunpowder. About twenty-five to thirty per cent. is
obtained; and one cord will produce about four cwt. of charcoal. If
properly charred, it should have a jet black appearance, and when
powdered a lustre resembling velvet; it should be light and sonorous
when gently dropped, and its fracture should exhibit the same appearance
throughout; it should be so soft as not to scratch polished copper, and
ought not to exhibit any alkali when treated with pure distilled water.
Charcoal is very porous, and absorbs very greedily gases and moisture
from the atmosphere; no large store therefore is ever kept, and
particular care is taken to prepare it only in proportion as it is
required for use. At all times it must be kept exceedingly dry; when
whole it will absorb about eight per cent. its weight of moisture, and
when in powder 15 per cent., so that the fresher the charcoal is the
better for the powder.
SULPHUR.
~Sulphur.~
~How purified.~
~Flowers of sulphur unsuitable.~
Sulphur is a simple, combustible, solid, non-metallic, elementary body.
It is found generally in great quantities in the neighbourhood of
volcanoes. It is also obtainable from metallic ores, and readily fuzes.
At 170° Fahrenheit it begins to evaporate; at 185° to 190° it melts; at
220° it is perfectly fluid; and at 600° it sublimes. Sulphur is purified
simply by melting: that which is supplied to Waltham Abbey has been once
refined, and the following is a description of the apparatus and method
for purifying and rendering it fit as an ingredient in Gunpowder. A
large iron pot is set about three feet off the ground, or about the
height that an ordinary boiling copper is placed, having a furnace
underneath. This pot has a movable lid, which is fixed into the top of
the pot with clay, and in which lid is an iron conical plug that can be
removed at pleasure. From the pot lead two pipes, one to a large
circular dome, and another to an iron retort, rather below its level.
The last-mentioned pipe has a casing, or jacket, round it, which can be
filled with cold water. The communication of these pipes with the
melting pot can be shut off or opened, as occasion requires, by a
mechanical arrangement. About 5¹⁄₂ to 6 cwt. of the once-refined sulphur
is broken up into small pieces, placed in the iron melting pot, and
subjected to the action of the furnace. The plug in the lid, and the
pipe leading to the dome are now left open, but the pipe to the retort
closed. After from two to three hours a pale yellow vapour rises, when
the plug is put in, and the vapour conducted into the dome, where it
condenses in the form of an impalpable powder, commonly called flowers
of sulphur. A small pipe leads from the bottom of the dome, on the
opposite side, into water, to allow the escape of the air, and sulphuric
acid is taken up by this water. In about one and a half to two hours
after, the vapour becomes of a deep iodine colour, when the
communication with the dome is shut, and the one to the retort opened;
at the same time, cold water from a tank above is allowed to pass into
the jacket we have before mentioned, surrounding this pipe. The vapour
then which distils over is condensed in the pipe, and runs into the
retort below in the form of a thick yellow fluid. When nearly all has
distilled, which can be known by the jacket getting cold, the
communication is again closed with the retort, and the fluid sulphur
left an hour, to get sufficiently cool to ladle out into moulds, the
furnace door and the communication with the dome at the same time are
again thrown open, that the rest of the vapour may pass into the latter.
The flowers of sulphur thus obtained are used for laboratory purposes,
being unfit for the manufacture of Gunpowder, from the acid they
contain, and the crystalline sulphur, after being allowed to cool in the
moulds, is barrelled up and used as the third ingredient in Gunpowder.
PULVERIZING THE INGREDIENTS.
~Grinding.~
~Screening.~
The three ingredients are now ground separately to a very fine powder.
The mills (vide plate 1) which effect this, and incorporate, are so
similar, that a description will be given under the head of
“Incorporation.” After being ground in this way, the saltpetre is
passed through a slope cylindrical reel, covered with copper sieving
wire of 60 meshes to the inch, which, as it revolves, sifts it to the
required fineness, being then received in a box or bin underneath. The
charcoal and sulphur are likewise passed through similar reels of 32 and
60-mesh wire respectively, and that which remains without passing
through, is ground again under the runners. A very excellent machine has
been invented by Mr. Hall, the engineer, of Dartford, for grinding
charcoal, which makes a most useful addition to the Gunpowder factory.
It consists of a conical drum, working in a conical box, on the same
principle as a coffee-grinding machine, the axis being vertical. The
mill is fed with charcoal by a hopper, and, as it passes through in fine
powder, falls into a revolving reel, which sifts it in the same manner
as before described, the whole being covered in, to prevent the great
annoyance of dust, which was felt until lately, from the old charcoal
mill. The three ingredients having been pulverized, are now fit for the
mixing process.
MIXING THE INGREDIENTS.
~Mixing and proportions.~
~Green charges.~
The ingredients are now weighed out very accurately, in the proportion
of 75 nitre, 15 charcoal, and 10 sulphur, in 42lb. charges, viz., nitre,
31lbs. 8oz., charcoal, 6lbs. 4oz. 13drs., sulphur, 4lbs. 3oz. 3drs., and
thoroughly mixed in a machine, which consists of a cylindrical gun-metal
or copper drum, about two feet in diameter, with an axle passing through
its centre, on which there are metal flyers, like forks. The machinery
is so arranged that the flyers and drum revolve in opposite directions
when in motion, at a rate of about one hundred revolutions per minute.
Five minutes is sufficient for a thorough mixture. The composition is
then drawn off by a slip into canvas bags the proper size to hold the
42lb. charges, which are tightly tied, and taken to small magazines.
These are called green charges, and are now ready for the next process,
incorporation.
THE INCORPORATING MILL.
~Incorporation.~
The Incorporating Mill consists of an iron or stone circular flat bed,
about seven feet in diameter, fixed very firmly in the floor of the
building which covers it, whereon two iron or stone cylindrical runners,
from five to seven feet in diameter, fourteen to eighteen inches wide,
and each weighing from 3 to 4¹⁄₂ tons, revolve. They have a common axle,
and a vertical shaft passing through the centre of the bed is connected
with this axle, and to machinery above or below, which communicates the
motion. These runners are not equidistant from the centre, by which
arrangement in their revolution every part of the composition on the bed
is subjected to their action, which is threefold, viz., crushing,
grinding, and mixing; crushing, from the weight of the cylinders;
grinding, from the twisting motion which they are forced into from so
large a diameter revolving in so small a circle; and mixing, from a
combination of the two former motions. To prevent the powder from
falling over the side of the bed, a wooden rim, about two feet in
height, is placed at an angle of forty-five degrees with it, like the
side of a funnel, and fitted closely all round its circumference. This
is called the “curb;” and in the centre of the bed a gun-metal ring, or
“cheese,” as it is termed, about two feet in diameter, and five inches
high, concentric with the bed, prevents the powder working beyond in
that direction. Moreover, two scrapers, or “ploughs,” connected by stays
with the horizontal axle, revolve with the runners, one rubbing against
the inner, and the other the outer circle. These ploughs are made of
hard wood, shod with leather and felt, and their use is continually to
disturb and rout about the composition, and keep it under the path of
the runners, so that every part should get its share of incorporation.
The houses or sheds which cover these buildings have hitherto been
constructed of wood, with either corrugated iron or wooden roofing. The
new incorporating mills in this factory, which are just completed, are
built with three sides of strong three-foot brickwork, and the fourth
side and roof of corrugated iron and glass. They are also placed in a
line contiguous to each other, the alternate ones only facing the same
way, so that an explosion from one would probably communicate no
further, and the lighter parts of the building would blow away, leaving
the rest entire. Most of the machinery in the factory is driven by
water-wheels; the motive power of these mills is steam. A horizontal
shaft, worked by the engine, passes underneath the entire length of the
building in a cast-iron tank, and a bevel wheel on this shaft is geared
into another one on the vertical shaft under the centre of each bed,
which, communicating with the runners, gives the necessary motion.
~Water-tanks to prevent explosions.~
In order, as much as possible, to guard against any explosion spreading,
above each bed, placed so as just to clear the runners, is suspended or
balanced a copper tank, holding about forty gallons of water. On one
side of the tank is fixed a small shaft, which communicates with similar
cisterns over the beds of the mills on either side. The other end of the
tank rests on a flat board, which is subjected to a great part of the
force of an explosion. This consequently lifts, disengaging the support
of the tank, the contents of which drench the bed which has just
exploded, thereby putting out all fire, and cooling the machinery,
besides having a similar effect on the mills right and left, preventing,
by this means, any extension of fire.
INCORPORATING THE INGREDIENTS.
~Incorporation.~
~Mill cake.~
~Proof of mill cake.~
The charge is spread pretty evenly over the surface of the bed, and
moistened with from four to six pints of distilled water; the quantity
varying according to the state of the atmosphere; the runners are then
set in motion, and run from seven to eight revolutions per minute for
three and a half hours, during which time the powder is often routed up
by a copper-shod spud, and watered slightly with a fine rose watering
pot, according to the experience of the millman; at the end of this time
the mixture is thoroughly incorporated, possesses all the chemical
properties of Gunpowder, and is taken off the bed in the form of a cake,
varying from a quarter to half an inch in thickness, and of a
blackish-grey colour. This is called “Mill Cake,” and when broken, the
fracture should exhibit the same uniform appearance, without presenting
any sparkling or yellow specks; should this, however, be the case, it is
a sign of the ingredients not being sufficiently incorporated. In this
stage it undergoes certain proofs; samples of the cake are taken from
every charge that is worked, dried in an oven, and granulated; half a
drachm of this is fired in a vertical eprouvette, which it ought to
raise 3.5 inches; and half an ounce is flashed on a glass plate. If very
little residue or ash is left, it is an additional proof of its being
well incorporated, and that the millman has done his work properly.
~Importance of incorporation.~
Incorporation is by far the most important process in the manufacture of
Gunpowder; for, however carefully the other part of the fabrication is
carried on, should there be a failing in this, the powder will be worth
nothing.
~Object of manufacture.~