494 ANNUAL KECOKD OF SCIENCE AND INDUSTRY. 



into any desired shape after the printing has been accom- 

 plished. The establishment where this printed tin is worked 

 up also has a method of lining tin canisters with a solution 

 of silica, which produces a coating favorable for the preser- 

 vation of fruits or articles that contain acids. 3 A^ January 

 27, G8. 



HYDRO-EXTRACTOR. 



An apparatus called the hydro-extractor has been devised 

 for the purpose of separating liquid substances from any more 

 solid matters with which they have been mixed, and is said 

 to be especially applicable to the manipulation of liquid col- 

 ors, such as are used in a printing-office. The arrangement 

 in question consists of a cylinder, formed of fine brass wire, 

 which is made to rotate within another cylinder of sheet-iron 

 which terminates below in a kind of funnel. -If the substance 

 to be treated be introduced inside the sieve cylinder, and 

 then made to revolve with considerable velocity, the finer 

 and more liquid parts will be thrown out through the meshes 

 of the gauze, and, striking against the outer cylinder, will 

 trickle down and pass off through the funnel into any recep- 

 tacle, the solid parts remaining behind. This process is ex- 

 tremely useful in the case of the colors just mentioned, which 

 it is usually very difficult to strain. The principle involved 

 is not by any means a new one, since it is employed in vari- 

 ous branches of industry, but it is claimed to be especially 

 convenient in preparing the liquid colors used in printing. 

 5(7,1870,503. 



STEEL' TYPE. 







Some notice has already appeared of a recent French pat- 

 ent for making steel type, which, even if not likely to be 

 practically useful, is yet sufficiently curious to make it a sub- 

 ject of interest to some of our readers. For this purpose a 

 quadrangular wire, of the dimensions of the proposed type, is 

 prepared, of very soft iron, and this is introduced into a ma- 

 chine which cuts it off at the proper length, and punches the 

 letters in the end. The principal features of this machine are 

 the arrangement for cutting off the proper lengths with per- 

 fect accuracy, and a stamp of hardened steel which lias sunk 

 into it the letters to be produced. After passing through 



