108 ANNUAL OF SCIENTIFIC DISCOVERY. 



recently invented by Merwin Davis, of New York City, which is intended to 

 supply a want of many small printing establishments, viz., a press expeditious 

 in its operations but of moderate cost. The bed of this press, which is flat, is 

 mounted on a strong column, oscillating from fixed bearings through the 

 intervention of a crank and connecting-rod. The bed. consequently, moves in 

 a circular path. By this arrangement the necessity of a " track" for the bed is 

 obviated, and a considerable amount of friction is avoided, thus rendering it 

 more easy to operate than any other press of equal capacity. The bed being 

 counterbalanced, its momentum is overcome without jar or unsteadiness. The 

 impression is produced by the segment of a cylinder, which also oscillates from 

 a fixed point. The "fingers" for holding the sheet are on the front of the 

 segment. In printing, the cylindrical surface of the segment and the plain or 

 flat surface of the bed move forward in concert, being geared together to pre- 

 vent "slurring;" but they disengage on the completion of the impression and 

 permit the segment to return (with the printed sheet) to its starting-point in 

 advance of the bed, which continues to move forward until the whole surface 

 of the "form" has passed under the inking-rollers. The "sheet-flyer" is 

 located on the column (which supports the bed), its upper edge lying against 

 the rear edge of the bed; and as the printed sheet hangs from the "fingers" 

 of the segment, it is caught by the "fly" in the backward osculation of the 

 bed and column. As the same " fingers" which draw in the blank sheet do 

 not relinquish the ir hold until the printed sheet is caught by the "fly," no 

 tapes are required, and of course no adjustment of tapes or fly in changing 

 from a large form to a small one, or vice versa. The distribution of the ink 

 on this machine is effected in a superior manner, and the hiking rollers ( rang- 

 ing in numbers according to the quality of execution desired) are so conveni- 

 ently arranged that they can be put in or taken out of the press in a moment. 



Ames's Polygraph, or Copying Machine. Mr. Nathan Ames of Saugus, 

 Mass., is the inventor of a "polygraph," or machine for writing several copies 

 at the same time. The device is simple and ingenious, and consists mainly of 

 light wire levers so connected together that whatever motion is given to one 

 will be communicated to the others with exact precision. A pen-handle is 

 connected by a flexible joint to the extremity of one lever, and the effect is 

 produced by a movement precisely like ordinary writing. Common gold pens 

 are employed, and ink is taken at intervals in the usual way, a sufficient 

 number of inkstands being suitably located for supplying both or all the pens 

 by the same movement. All the practical difficulties are admirably sur- 

 mounted, and perfect copies are produced with the utmost ease. 



Improvements in Copperplate Printing. The following is the claim of a 

 patent recently granted to S. "W. Lowe of Philadelphia, for improvements in 

 copperplate printing : "I claim coating the plain or uneugraved face or sur- 

 iiice of the plate (which is intended for leaving the white or unprinted surface 

 of the paper) with a mercurial amalgam, that will have the effect of prevent- 

 ing the ink used in printing therefrom, from adhering to or soiling the same, 

 while the figures engraved or etched thereon, readily receive the ink, and thus 

 admit of printing from the plate, by a letter or any other press, either from 

 the plate alone, or from the plate in the same ' form' with the type, without 



