16 



The MiCKOscoPE. 

 NEW INVENTIONS. 



The Bausch and Lome Condenser and Sub-Stage. — The instru- 

 ment figured consists of a condenser and sub-stage, the latter 

 having five stops, diaphragms and blue glass. The lenses of 

 the condenser are of such a size as to utilize almost all the 

 rays of light which may pass through the sub- stage ring. In order 



that objectives having a large angular aperture may be used, the 

 condenser has been made with a numerical aperture of about 1.42 

 (another of 1.20 is also manufactured). Its volume of light is sufficient 

 with the highest amplification, and although it gives an intense light 

 at the focal point, it may be distributed over a large space by vary- 

 ing its distance from the object. It will work both dry and immer- 

 sion. The mounting of this condenser is new and simple, and is so 

 arranged that the instrument can be used where the sub-stage is 

 adjustable or fixed. The diaphragms are separate, and a click is 

 provided when one is in central position. It appears in all respects 

 one of the best condensers and sub-stages now in use, and is a 

 welcome addition to the microscopist's armamentarium. 



A New Self- Adjusting Fkog Plate. — James W. Queen & Co., 

 Bend us this little device. Much time can be saved through its use, 



as the tedious process of boring suitable holes and passing threads, 

 as in the usual way, is avoided. The modus operandi here 



