60 ANNUAL OF SCIENTIFIC DISCOVERY. 



of ordinary copper over type-metal is in the proportion of 100 to 1, 

 and the density of the copper used in the manufacture of type is 

 considerably increased by the compression which it undergoes in the 

 machinery. A London firm, employed to print stamps for gov- 

 ernment, is in the habit of using raised copper surfaces for the pur- 

 pose ; no less than 125,000,000 impressions having been taken from 

 a single plate. It is impossible so say, at present, to what extent 

 the new type will surpass that in use, as regards durability. They 

 can, however, be produced much cheaper than even under the pres- 

 ent system. In proportion as founts of type decrease in size, they 

 rise in price, but a decrease in weight, under the new system, will be 

 accompanied by a diminution in cost ; and when, ultimately, the 

 sharpness and clearness of the type has been, by long use, deteriorat- 

 ed, the metal will retain an intrinsic value far above what the present 

 composition of metals now used for printing-types does in similar 

 cases. The machine has received the name of the Apyrotype, and is 

 undoubtedly one of the most important and most desirable inventions 

 of the year. 



IMPROVEMENT IN GRAIN-SEPARATORS. 



THIS machine is the invention of Benjamin D. Sanders, of Vir- 

 ginia, and it is designed to separate the impurities in threshed grain, 

 upon a different principle from that of the common grain-separators. 

 Instead of forcing the chaff from the good grain by means of a blow- 

 er, a vacuum is created, the power of which can be regulated at will, 

 by which every thing specifically lighter than the good grain is raised 

 up into a receiver, while the latter is not raised off from the screens, 

 but passes over them, and falls into a granary below. As soon as the 

 vacuum is created, a current of air rushes from below, and its force 

 must be regulated according to the height to which the impurities are 

 to be raised. The good grain is thus deposited in a granary by itself, 

 while that which is light is forced up into a receiver, and the chaff is 

 entirely driven out from the machine. Scientific American. 



COTTON-SEED EXTRACTOR. 



THIS new invention of Mr. Stephen R. Parkhurst is said to be the 

 most perfect machine of the kind, and will prove of the greatest ad- 

 vantage to all branches of the cotton manufacture. The machine is 

 of the simplest construction, and it seems a wonder that the idea had 

 not been long since suggested. It is composed mainly of two cylin- 

 ders, closely set together, a feeder, and the ordinary fan. The cotton 

 containing the seed is thrown on the feeder, from which it is taken by 

 the cylinders, which extract the seeds whole, the cotton being passed 

 by the fan into a receiver. The quantity of cotton cleaned by this 

 machine will far exceed that of the ordinary saw-gin now in use, and 

 a third less power is required to keep it in operation. By this method 

 the texture and length of the fibre are completely preserved, the value of 

 the cotton will be greatly enhanced, and the intrinsic worth is increas- 



