364 British Service Ordnance. CJuly, 



steel, cut into shape and then hardened, will also curl 

 up under the blows of the fine particles of sand, unless pro- 

 tected by sheets of yielding material. Fine lace will protect 

 glass during the depolishing process, and leave its designs 

 in polished lines on a ground surface. 



At a recent meeting of the Photographic Society of Phila- 

 delphia, Mr. Tilghman submitted some specimens of engra- 

 ving on glass, prepared by this beautiful sand process. A 

 bichromatised gelatine negative is taken on glass from 

 an engraving. This is then subjected to a stream of sand 

 under a pressure of 1 to 4 inches of water. The 

 gelatine film protects the glass, the parts not covered by it 

 being cut by the sand. The process is complete in from 

 three to ten minutes. The finest specimens are produced 

 by using fine sifted sand at about 1 inch pressure, and 

 a longer time of exposure. 



VIII. BRITISH SERVICE ORDNANCE, 1870, 1871. 



By S. P. Oliver, Lieut. Royal Artillery. 



HE sixth annual " List of Service Ordnance and 

 Ammunition" for 1871 has just been published by 

 the Royal Artillery Institution, and by comparing it 

 with the list of June, 1870, we are able to note the progress 

 and change in the ever steadily advancing history of 

 British gunnery. 



The following abstract: of changes effected during the last 

 twelve months therefore may be worth noting. 



To the superficial observer, indeed, the two lists men- 

 tioned above would appear almost identical, but the initiated 

 soon detects important changes. 



To commence with the rifled guns. In June, 1870, we 

 had, and still retain in our service, two natures of 7-inch 

 breech-loading screw polygrooved guns (the old Armstrong 

 100-pounder), two 40-pounders, three 20-pounders, one 

 9-pounder, and one 6-pounder, all Armstrong guns; the 

 only other breech-loading guns in the service were, and 

 now are, the 64-pounder and 40-pounder wedge guns. As 

 regards all descriptions of breech-loading guns there has 

 been no change, and this section of -the list for 1870 

 remains unaltered in that for 1871. 



It is in the section relating to muzzle-loading rifled guns 

 alone that any change is to be noted. Of this description 

 there are two bronze guns, the 9-pounder and the 7-pounder, 



