OIL LAMPS 99 



they are also carried on stands with clamp for adjustment 

 of height on a vertical pillar. Care must also be taken 

 to keep the jet clean ; a needle, to ensure this, forms part 

 of the burner. 



Fig. 30 



OIL LAMP WITH ADJUSTABLE CONDENSER AND SCREENS 



Oil Lamps. Even now, with all the advantages attend- 

 ing more intense illuminants, the oil lamp still holds a 

 prominent place. And, apart from its lack of brilliance, 

 it is as good as any illuminant for photomicrography. 

 A flat flame is always used, and when its edge is turned 



