104 



Mr. Samuel Hunter, 



one-third the dimensions, and on which I have frequently worked 

 to an excellent figure a 9-inch speculum, is given in figure 5, 

 where you have the result of 9J strokes, 2J revolutions of 

 eccentric G, and 1 revolution of the speculum, the stroke, &c, 

 being adjusted to a 9-inch speculum. 



Fig. 5. 



Mr. LasselVs Machine. 

 The power is applied in this machine to the pully 1 1, which 

 drives the worm spindle H K, this drives the wheel L of 77 

 teeth, and by means of the band G, a similar wheel C, on which 

 the speculum rests. The spindle M turns with L, carrying the 

 arm S P ; the wheel is fixed to the frame N, so that as the arm 

 S P is carried round the pinion Q of 16 teeth works in O of 72 ; 

 R of 72 revolves with Q, working in the pinion T of 16 ; T carries 

 with it the eccentric V ; T and V can be adjusted by means of 

 the slots as shown in the figure. A pin at V carries round the 

 polisher J. 



