MECHANICS AND USEFUL ARTS. 65 



of muslin many times, and with a small punch and mallet perforating 

 it with numerous holes at a very short distance apart. Much of the 

 substance of the muslin is removed by the punch, and it is rendered 

 sieve-like or reticulated in appearance. It makes an admirable, light 

 and airy dressing for wounds, and several thicknesses may, if neces- 

 sary, be used to absorb purulent discharges. It has the great advan- 

 tage for military surgery of cheapness, and ready preparation from 

 materials which can always be conveniently at hand. London Lan- 

 cet. 



WOODEN SUBSTITUTE FOR WHALEBONE. 



Many unsuccessful attempts have been made to obtain a perfect 

 substitute for whalebone for the manufacture of the ribs of umbrellas 

 and parasols. A Mr. Ball has found that by selecting the butt end 

 of white oak timber, of what is termed the " second growth," and of 

 straight rib and free from knots or curls, and in no case using more 

 than six feet from the ground or stump, and subjecting it to a certain 

 process of curing, it is made to serve not merely as a substitute for 

 whalebone, but is converted into an altogether superior article, as it 

 is not only tougher and possesses greater tenacity than whalebone, 

 but the ribs made from it always resume their straight condition after 

 exposure to the weather. London Chemical News. 



CURIOUS ILLUSTRATION OF THE CAPACITY OF THE LONDON 



RAILROADS. 



A recent English authority states, as an illustration of the rapid 

 expansion of the English railroad system, that while the railroads 

 centring in London in 1851 were only equal to bringing or carrying 

 away forty-two thousand persons daily, they can now actually bring 

 and carry away two hundred and forty thousand visitors ; so that the 

 modern Babylon could be emptied of its inhabitants in about ten 

 days. 



MACHINE FOR CRYPTOGRAPHY. 



Mr. R. A. Brooman, of London, has patented a Cryptographic Ma- 

 chine, or apparatus for carrying on secret correspondence. 



The object of this invention is to provide a machine or apparatus 

 by. means of which secret correspondence, for diplomatic and other 

 purposes, may be carried on conveniently, and so as effectually to 

 prevent the deciphering of the despatches by any person not in pos- 

 session of the key to the same. The main feature of the invention 

 consists in the employment of several pairs of alphabets, one alphabet 

 of each pair being capable of longitudinal motion along the other, 

 so as to bring different letters of the two alphabets opposite each 

 other. By arranging the several pairs of alphabets according to po- 

 sitions indicated by means of a " key-word " and a standard pair of 

 alphabets, and transmitting in succession the letters found on one of 

 the two alphabets opposite to the proper letters of the dispatch on 

 the other, the several pairs of alphabets being successively used, a 

 dispatch in cipher may be sent, which dispatch may be readily in- 

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