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 94 strokes, 24 revolutions of 
eccentric G, and 1 revolution of the speculum, the stroke, &c., 
being adjusted to a 9-inch speculum. 

Myr. Lassell’s Machine. 
The power is applied in this machine to the pully I I, 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 O 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. 
