454 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



demanded on account of its supposed superiority, neverthe- 

 less its superior quality, when it existed, would be found to 

 be due to the use of purer and better materials. In substan- 

 tjiation of his opinions he exhibited specimens of fluid-com- 

 pressed steel. For guns, torpedoes, boilers, etc.. Sir Joseph 

 stated that the quality of elongation was of the first impor- 

 tance, as well as generally, wherever severe strains were sud- 

 denly employed. He said that it w^as now possible by 

 the compression of fluid metal to produce with certainty 

 steel that would bear a tensile strain of forty tons to the 

 square inch, and which elongated thirty per cent, of its length 

 before breaking. He urged, in conclusion, that guns should 

 be constructed of steel, and steel only. He detailed the re- 

 sults obtained in the experiments with his breech-loading 

 guns, and added that the War Department were now making 

 guns of enormous size and weight, but maintained that this 

 great size was unnecessary, for the reason that, if monster 

 guns were w^anted, they could be made by means of the 

 Siemens-Martin furnace and fluid compression at much less 

 cost, while with regard to the quality of materials employed 

 every thing favored the modern processes. On the subject 

 of projectiles, the speaker asserted that long projectiles gave 

 greater penetration at both long and short ranges, and also 

 a much lower trajectory, except at the lowest elevations, for 

 short distances, and he declared in favor of the polygonal 

 system of shot over the French studded system adopted at 

 Woolwich. 3^, VI., 139. 



KANGE-FINDER FOR ARTILLERY PRACTICE. 



The range-finder of Captain Nolan of the Royal Artillery 

 has been in use to a limited extent for some years, but a full 

 account of the instrument, with tables for its use and instruc- 

 tions for its employment, both by infantry and artillery, has 

 only lately been published by him. This simple instrument 

 can, according to him, give the correct distance of an object 

 in such a way and so quickly as to be perfectly applicable to 

 the use of a battery in the field. Its success seems to have 

 been so great in England that it is improbable that any 

 instrument diff"ering essentially in construction from it will 

 be likely to supplant it. The cost of the artillery practice 

 at unknown range, while manoeuvring rapidly, shows that a 



