MECHANICS AND USEFUL ARTS. 91 



PRUSSIAN NEEDLE-GUN. 



The alteration of the Prussian needle-gun has been sanctioned 

 by the king, in consequence of which 2 or 3,000,000 of rifles 

 in the possession of this government will be remodelled. The 

 improvements introduced aim at simplifying the loading, and 

 increasing the force and range of the ball. For this purpose the 

 caoutchouc ring of the Chassepot has been adopted, which, help- 

 ing to close the breach by spontaneous action, renders it unneces- 

 sary to press the valves tightly down. In addition to this the 

 weight of the ball has been reduced from 31 to 21 grammes, 

 which, with the charge remaining at 4.9 grammes as formerly, 

 considerably augments the propelling force. To fit the reduced 

 ball for the old barrel the zund-speigel has been proportionately en- 

 larged, a proceeding the practicability of which was proved by a 

 similar alteration, adopted some time ago, and further attested by 

 a year's experiments with the weapon in its present latest form. 

 On the needle-gun being first taken into favor, in 1841, it had a ball 

 of 15.43 millimetres, but the heaviness and consequent want of 

 speed observable in the missile caused it soon to be reduced to 

 13.6 millimetres, which size has now been further diminished to 

 12 millimetres. The total weight of the new cartridge is 32 

 grammes, instead of 40, as heretofore, so that the soldier will 

 henceforth carry 95 instead of 75 cartridges, without experiencing 

 an additional burden. Besides this, the needle is now made to 

 move in a narrow hole, into which it fits exactl} 7 , instead of the 

 wider one of the old gun, and a piece of oiled paper is placed at 

 the bottom of the cartridge to clean the needle after each dis- 

 charge, and serve some other purposes of minor importance. 

 Van Nostrand. 



PHOTOGRAPHY APPLIED TO MILITARY PURPOSES. 



A writer in the " Nature," of July 21st, dwells upon the use 

 made of photography by the English military authorities. 

 Three establishments have been organized in connection with 

 the army, in which photography is extensively practised. 



Pictures are taken to illustrate the positions taken by a soldier in 

 different drill systems ; of pack mules, to illustrate the manner of 

 packing for the benefit of the India armies; in short, photographs 

 are used whenever mere descriptions would be prolix and am- 

 biguous. 



Great use is also made of this art in recording the results of 

 experiments in gunnery ; these photographs are made by the 

 carbon process. Editor. 



NEW ARMS. 



Sir Joseph Whit worth, Bart., at the meeting of the British As- 

 sociation, had had diagrams prepared to illustrate the Chassepot, 

 the Prussian, the Enfield, and the Whit worth bullets. The Chasse- 



