334 



MEMOIR OF DANIEL TKEADWELL. 



scqueiitly, the main lever swiugiug upuii the pivot,/, is raised at the hinder part, k, and de- 

 pressed at the front part, I. 



" Thus the descent of the lever at ?, by the means above described, throws a great weight 

 upon the platen, for the purpose of imprinting the sheet of paper previously (as above) placed 

 between it and the form of types, d, which is upon the table. 



Fig. 1. 



Fig 2. 



" By the descent of the treadle the instant before the impression is given, another action 

 is also obtained, for the purpose of bringing the hammer, m, into a perpendicular direction, 

 in order to meet the block, w, where the legs of the platen all unite. The rod, o, attached 

 at the bottom to the treadle, e, communicates also near its top by a connecting bar, p, 

 with the hammer, m. The top of the rod, o, is bent, and as it slides down through a 

 guide, 5, by the descent of the treadle, the connecting bar, p, moves the hammer, m, from 

 its inclined pendent position into a perpendicular, ready to press directly upon the block, n, of 

 the platen. 



" When the foot of the workman is removed from the treadle, e, it rises by the reaction of 

 the compressed parts aided by a spring, s ; at the same time the hammer, m, shifts from the 

 block, n, in order to allow the platen to rise, and the type to be inked afresh. 



" The platen and its arms being of considerable weight, a counterpoise, as it turns over, is 

 effected by the spring, s, and weight, *, acting upon the frame or lever, «, which by the rod, w, 

 hanging upon the bent arms, r r, of the platen, balance its weight, and render its motion easy 

 to the workman. 



" Figure 3 represents the platen, tympan, and frisket detached from the press, for the pur- 

 pose of exhibiting their parts and actions more distinctly, as respects the method of reversing 

 the sheet without removing it from between the double frisket ; c is the platen, upon the sides 

 of which are two pivots ; a; is a bar connected to two arms, y y, in which the double frisket is 



