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MINUTES OF PBOCEEDINGS OF 
Office, states that the want of mobility of this gun has prompted the 
French to adopt a lighter gun for their field batteries. 
Now this French gun is 2 cwt. lighter than the weight which Lieut. 
Jones, It.A., estimated in his recent lecture for thel6-pr. when carrying 
28 rounds in the limber (and this is a very moderate estimate) ; it is 
also rumoured that the gun is to be increased in weight to 12^ cwt., so 
that it seems likely it will be found necessary to limit its employment to 
the field batteries of reserve. 
In conclusion, it seems advisable in the selection of a new gun to 
consider first the weight of the projectile to be used, and the number of 
rounds requisite to be carried into action, due regard being had to 
efficiency and mobility. That being decided upon, the next step is to 
determine what calibre is best adapted to throw that shell with the 
greatest practical advantage, balancing the merits of long range, supe¬ 
rior accuracy and flatness of trajectory against that of large shell 
capacity. With regard to the trial of new guns before introduction 
into the service, it has been the custom for some years past to determine 
the muzzle velocity of the projectile. This was all that could be done 
with accuracy* till the invention of Professor BashfortlPs chronograph 
in 1865, to whom we are indebted for having determined with great 
precision the law of the resistance of the air to the motion of spherical 
and elongated projectiles; in fact all these tables of remaining velocities 
before you, have been calculated from his experiments carried on at 
Shoeburyness from October 1867 to May 1868. This chronograph has 
been reported upon by a Committee of Reference, consisting of Pro¬ 
fessors Stokes and Adams of Cambridge, and Captain Andrew Noble 
of Elswick, who state “ that the instrument is simple in principle, easy 
to work with, and not readily liable to get out of order, and we think 
it well adapted for general employment at schools of instruction in 
gunnery A 
This instrument measures the velocity at ten or more different in¬ 
tervals—so that it not only determines muzzle velocity, but also the loss 
of velocity over successive equal distances. This loss of velocity is due 
to the resistance of the air (which of course will increase with the 
unsteadiness of the shell), and affords a true criterion whereby the 
shooting powers of the gun (so far as range, accuracy and flatness of 
trajectory is concerned) may be estimated, which the determination of 
a single muzzle velocity does not . 
I may add that I have used an instrument designed by Mr. Bashforth 
similar in principle to the above at the rifle range in the Marshes to 
determine the velocity of the Martini-Henry, Chassepot, Snider and 
needle gun for the Small-Arms Committee, the results of which are 
embodied in Table II. 
But to return to the construction of guns : there are two methods of 
obtaining a powerful shooting gun to fire a shell of given weight:— 
(1) By getting a great muzzle velocity, i.e., by using a high charge 
of powder and comparatively light shell. 
(2) By lessening the resistance of the air, i.e., by using a smaller 
bore. 
* Vide p. 161 Reports on Experiments with Bushforth’s Chronograph. 
