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NATURE 
117 
THURSDAY, JUNE 10, 1886 
THE 43-TON GUN EXPLOSION 
HE bursting of the 43-ton gun on board the Col/ing- 
wood has naturally attracted considerable attention 
from men of science as well as from the general public, 
and it may not be out of place at the present time to 
compare the ideas of scientific men with the data given 
in text-books published by authority and put into the 
hands of artillery officers for purposes of instruction. 
The latest gunnery text-book is that compiled by Major 
Mackinlay, R-A., and published in 1883. In it is a table 
compiled by another artillery officer, in which is given 
the calculated and actual results obtained from all classes 
of ordnance, among them being the 12” B.L. gun of 43 
tons, Mark II., the gun which burst on board the 
Collingwood. : 
The powder charge is given as 286 lbs. prismatic, pro- 
jectile 720 lbs. ; the total work theoretically producible 
from the expansion of the charge in the bore 22,884 foot 
tons ; the actual work produced in muzzle energy of pro- 
jectile 17,180 foot tons. There is therefore, according to 
the table, a loss of 5704 foot tons to be expended— 
externally in expelling the powder gases, displacing the 
atmosphere, and recoil ; internally in heating and stretch- 
ing the gun, in friction of the gas check and gases, and 
rotating the shot. 
In a lecture delivered in January 1885, just after the 
bursting of the Acézve’s 6” gun, Mr. Wm. Anderson pointed 
out that the lost work was very much greater than was 
usually imagined, and he went through a calculation on 
thermo-dynamical principles of the forces produced in a 
1o" B.L. gun. Taking Mr. Anderson’s formule and 
adapting them to the 12” B.L. gun, we shall not have to 
proceed far before finding out how erroneous is the table 
given in the text-book. We will only examine the forces 
external to the gun (¢.e. those producing recoil), as Mr. 
Anderson’s accuracy on these points has been indorsed 
by Col. Moncrieff, C.B., F.R.S., and we shall neglect 
internal forces employed in friction stretching and heat- 
ing the gun—forces difficult to estimate, and on which 
there is some difference of opinion. 
As to the energy of the projectile there can be no 
question, but taking the terminal pressure at 3 tons (we 
believe it has risen as high as 5°5 to 6 tons) the energy of 
the expelled gases is 12,208 foot tons, that expended in 
lifting the atmosphere 2501 tons, together 14,714 foot 
tons ; so that, neglecting internal forces altogether—and 
these are no small quantity—we have 14,714 foot tons of 
energy against 5704 in the text-book. 
We can only conclude that the pressure corresponding 
to this difference, as well as that due to the forces 
expended inside the bore, have been entirely neglected by 
the designers of the guns. 
The powder with which the gun was burst was that 
known as “cocoa”; this powder, while diminishing the 
maximum pressure carries it further down the bore (a 
most dangerous thing for guns weak in the chase), and 
increases the mean and final pressures, and the muzzle 
velocity ; therefore the calculation we have given is 
VOL, XXXIv.—No. 867 
probably within the mark for an equal weight of cocoa 
powder. 
The reason for the errors we have pointed out may 
probably be found in the blind confidence placed in the 
indications of crusher gauges. It is well known that a 
certain length of time must be taken up in the com- 
pression of all metals, and it is extremely doubtful 
whether something near the two-hundredth part of a 
second in which the explosion takes place is sufficient for 
the compression of copper cylinders, especially when 
comparisons are made between those near the breech, 
which are longer under the influence of the powder gases, 
and those in the muzzle, which are not acted on for any 
appreciable time. 
The only item in the above estimates which has been 
ascertained by experiment is the muzzle velocity, the 
others are the result of calculation, and although Col. 
Moncrieff tells us they are to be trusted when measured 
in recoil, it would be far more satisfactory were they 
ascertained by direct experiment. 
Means for verification have been pointed out, and 
although we believe the Government is provided with the 
instruments nothing has yet been done with them. 
The failure of the Coddimgwood’s gun raised hopes in 
the minds of many that at last a proper inquiry into the 
question would be held ; but it has been referred back to 
the same Committee, associated with the same civilians 
(except Mr. Leece, who is dead), who recommended that 
the gun “should remain unaltered,” but that “the charge 
of 295 lbs. of cocoa powder should not be exceeded.” 
They therefore are to sit in judgment on themselves, 
and if they relied on the same data when recommending 
certain additional strength should be given to other guns, 
as they did when merely limiting the charge of the 
12”, what reason is there for supposing that the results 
with other guns will differ from this one except in loss of 
life and damage done ? 
GEOLOGY OF TURKESTAN 
Turkestan; a Geological and Orographical Description 
based upon Data collected during the Fourneys of 1874 
to 1880. By J. V. Moushketoff. Pp. 714. With Map 
and Engravings. Russian. (St. Petersburg, 1886.) 
OR several years past all who take an interest 
in Central Asia have followed with great interest 
the yearly reports published by Profs. Romanovsky and 
Moushketoff on their geological explorations in the 
mountains of the Tian-Shan, the high plateaux of the 
Pamir, and the lowlands of the Amu-daria. The ex- 
tensive character of these explorations, prosecuted for 
several consecutive years, and the practical experience of 
the two Russian geologists promised that new light would 
soon be thrown on several important but doubtful points. 
in the geology of this most interesting region; but the 
appearance of their works has been delayed for some 
years. We have, however, now before us the first volume 
of M. Moushketoff’s work, and when the whole, which 
will comprise three large volumes, as also M, Romanoy- 
sky’s work on the same subject, is published, we shall 
have an almost complete picture of the geology of this 
region which contains the key to so many important 
geological questions in Europe, 
G 
