398 



SUMMARY OF CUKRKNT RESEARCHES RELATING TO 



lens (6). The position of the latter should be such that the image 

 of the radiant is projected about 7 to 9 in. from the condensing 

 lens, and falls exactly in the centre of the mirror. The tube containing 

 the mantle can be rotated in the cradle (2) until the incandescent 

 material presents a convex surface to the flame. The relative position 

 of incandescent material to flame can be adjusted exactly by means of a 



1 — r 



Half Actual Size. 



fine-adjustment screw (?,). The milled head (C) regulates the supply of 

 gas, and the lever (D) the supply of air. The bull's-eye condenser sHdes 

 in sleeve (H), and is attached to the gallery of the lamp by clamping 

 screw (K). 



*| (4) Photomicrography. 



Wratten "M" Filters (Kodak, Limited, London, 1919, 12 pp.).— 

 A booklet has been issued by the Kodak Company in place ;of their 



