ae H. J. Clark on the Microscope. 
~ 
° 
second ring (6), the innermost one (2), being above the horizon — 
of the field, was invisible; and, again, when the outermost and 
lowest ring (¢) was reached, the middle one (6) also vanished. _ 
ere this outermost ring as distinct as the others, it might | 
after day, plunged into the hitherto unknown depths o: 
ife. I say this 
life. after having tested from time to time some of: 4 
ae ee fe eS 
the best En lish microsco which have been made since the — 
n, 
“Great Exhi and therefore am not to be supposed to 
