CH. Ill] MAGIC LANTERNS WITH MAZDA LAMPS 91 



FIG. 52. SIMPLE MAGIC LANTERN WITH INCANDESCENT 

 LAMP AS RADIANT. 



(Cut loaned by Williams, Brown & Earle). 



This is known as the "Society Incandescent Lantern No. 3 G." It is 

 especially designed for use with permanently mounted lantern slides (fig. 15). 



138. Centering and distance from the condenser. The 



centering along one axis is as with the arc lamp ( 51). 



In general the concentrated filament should be at the principal 

 focal distance from the condenser. One can determine the best 

 position by the use of a good lantern slide and changing the dis- 

 tance of light and condenser until the best position is found. It is 

 well to mark that position for future use. 



FIG. 53. MAGIC LANTERN WITH MAZDA LAMP. 

 (Balopticon B.; Cut loaned by the Bausch 6" Lornb Optical Co.}. 



This lantern can be used with the small arc lamp on the house lighting sys- 

 tem, with the Mazda incandescent lamp or with acetylene. 



