544 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



mains in its position the mirror is opaque, and reflects light ; 

 removing it, however, it becomes immediately transparent, 

 and the picture is seen behind it. 4 D, No. 301, 1869, 609. 







AMERICAN STERLING, A NEW ALLOY. 



A very valuable alloy, termed American sterling, has with- 

 in a few years been introduced in New York, where it is now 

 manufactured on a large scale by a company organized for 

 the purpose. It has not been patented, the inventors, per- 

 haps wisely, considering it best to keep to themselves the se- 

 cret of its composition. The crude alloy resembles nickel,' 

 but when worked up, according to the /Scientific American, 

 can scarcely be distinguished from silver, unlike which, how- 

 ever, it does not tarnish, nor is it affected by sulphurous va- 

 pors. Articles of food do not act upon it, and it is readily 

 cleaned by a slight rubbing. 



In the form of cutlery it takes a keen cutting edge, re- 

 quires little or no cleaning, and its lustre is seldom dimmed. 

 As compared with britannia metal, it is harder and one third 

 lighter, while it is superior to it in lustre, being scarcely dis- 

 tinguishable, indeed, from fine silver when made up. It can, 

 nevertheless, be used as a basis for electroplating, so that, 

 when the silver wears off, the subjacent alloy, being of the 

 same color, will not be observed. 



The strength of this alloy is very great, and, indeed, may 

 be substituted for steel in the manufacture of pistol barrels, 

 possessing, as it does, three times the tenacity. It is stated 

 that at present about 120 hands are employed in the works 

 at Naubuc, near Hartford, Connecticut, the buildings being 

 500 feet long and 50 feet wide. The alloy is said to be 

 workable in dies under a drop-press as easily as silver, and 

 much more easily than German silver, and on account of its 

 toughness is much less liable to become cracked in the proc- 

 ess of working. 6 Z>, October 19, 1872, 263. 



CLEANING WOOL BY SOLUBLE GLASS. 



The Journal of the Society of Arts gives an account of a 

 method for cleaning wool by means of soluble glass, which, 

 according to its inventors, Messrs. Baerle & Co., of Worms, 

 is far superior to any other now in use. For this purpose, 

 take forty parts of water, at the temperature of 122 to 135 



