1064 



RECORD OF CURRENT RESEA.RCHES RELATING TO 



Fig. 128. 



United States Patent Office. 

 Eobert B. Tolles, of Boston, Massachusetts. 



Improvement in Microscopes. 



Specification forming part of Letters Patent No. 198,782, dated January 1, 1878 ; 

 application filed July 27, 1877. 



To all whom it may concern : 



Be it known that I, Egbert B. Tolles, of Boston, in the County of 

 Suffolk and State of Massachusetts, have invented certain new and 

 useful improvements in Microscopes, of which the following is a 

 specification, reference being had to the accompanying drawings, 

 making a part of the same, in which — 



Figure 128 represents a front elevati n of a portion of a Microscope- 

 stand with my improvements 

 applied thereto. Fig. 129 re- 

 presents a side elevation of the 

 same. Fig. 130 represents in 

 section a portion of the sub- 

 stage detached. Fig. 131 

 represents in side elevation a 

 portion of the substage illu- 

 mination apj)aratus detached 

 and drawn upon an enlarged 

 scale, and modified by con- 

 necting with it a graduated 

 arc ; and Fig. 132 represents 

 in end elevation the parts 

 shown in Fig. 131. 



My invention relates to 

 the combination of a circular 

 track in a plane parallel with 

 the optical axis of the instru- 

 ment and concentric with the 

 object to be examined, with 

 a substage carriage, upon 

 which said track is mounted 

 and carried on guides. 



It also relates to the said 

 circular track, provided with 

 graduations, in combination 

 with a carriage running 

 thereon, and carrying a con- 

 densing-lens and other acces- 

 sories, either singly or com- 

 bined. 



It also relates to a holder 

 to carry an achromatic illu- 

 minator or other accessory, in combination with a graduated arc and 

 clamping device, to fix the holder at any angle to the radius that may 

 "be desired, or in the radius of the circular track. 



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