60 ANNUAL OF SCIENTIFIC DISCOVERY 



cules, I think we may consider the polarized state of the outer surface of 

 the ball suddenly cooled as continuous in its action. The attraction of the 

 interior molecules for this part is seen in the formation of a void space ; 

 and when the vibrations of impinging points induced a movement, the 

 molecules united their dissimilar poles in the ordinary way of building- 

 up a crystalline aggregate. The natural crystal of this alloy being pris- 

 matic, room for the radiations which this form must exhibit would be found 

 only by an enlargement of the exterior crust, which owing to the slight de- 

 gree of malleability in this case, occurred without fracture. Unequal aggre- 

 gation of crystals formed would produce the concretionary and mammillary 

 masses into which the balls were converted ; and it seems probable that the 

 taking on of this form was but one step in passing to one still more simple, 

 in which the natural crystalline form of the alloy would have been presented 

 in a single crystal." 



ON THE STKENGTH OF RAILROAD CAR AXLES. 



A thorough test of the strength of railroad materials has recently been 

 made at Detroit, at which the railroad axles made by different manufac- 

 turers were submitted to a trial which was not only fair but searching and 

 conclusive. Each axle tested was selected by the manufactures from quan- 

 tities on sale, and not made especially for the occasion, as is too often the 

 case in such matters, and the process was thorough and conclusive. Each 

 axle was confined on a firm anvil with the end projecting over and un- 

 supported for about twelve inches. In this position a hammer weighing 

 150 pounds was dropped twelve feet, striking the end of the axle, each one 

 of which was four and a half inches in diameter. Ten blows were struck, 

 then the axle was turned over and the same number of blows given on the 

 opposite side, and so continued until the axle was broken. The following 

 is the result : E. Corning & Company's axles, made of laggoted bar, iron- 

 hammered, stood 193 blows ; Wyandott axles, made from Lake Superior 

 iron, stood fourteen blows ; Cleveland axles, made from scrap iron, stood 

 eleven blows ; showing a very wide difference in the strength of the differ- 

 ent axles. 



ON THREAD OR FIBRE GILDING. 



The following is an abstract of a paper recently read before the Royal 

 Institution, London, by Mr. F. Bennoch, on the operations of fibre gilding, 

 and upon some new improvements recently effected in this department of 

 art. 



The author first described the mode of manufacture adopted in India, in 

 the city of Pactun, situated on the river Godavery, famed for its manufac- 

 tures in gold and silver tissues. 



The long shawls which are thrown over the shoulders of the native 

 princes on state occasions frequently cost as much as 300 each. The 

 weft is composed of very fine cotten-thrcad, generally scarlet or green, 

 the warp being of silk of a similar color. The shawls are formed of 

 long strips of about an inch in width, and placed alternately a strip of 



