VENTILATION OF DARK-ROOM. 



149 



LOADING SHELF 



f ft. 9 in. 



DOOR \ 



Fig. 135.* 



in use much of the time, some 

 The writer accomplishes this 

 by an electric fan placed in the 

 mouth of an air-shaft which 

 extends from the ceiling to 6 or 

 8 feet above the roof. These 

 shafts are cylindrical, i foot in 

 diameter, made of heavy sheet- 

 iron and surmounted by a broad, 

 mushroom - shaped cap. The 

 interior is painted a dead black, 

 and as an additional precaution 

 against the entrance of light it 

 carries a sleeve of the fonn 

 shown in fig. 131. This effectu- 

 ally cuts out light. The air is 

 pumped out so rapidly by a de- 

 vice of this sort that not the 

 least inconvenience is experi- 

 enced in working all day in a 

 very small room. 



If only one or two persons 



The very convenient heavy camera 

 shown in fig. 124 may also be used 

 for natural-size work, arranged as 

 shown in fig. 129. In this connection 

 the Starrett cross-level shown in fig. 

 130 will be found very convenient 

 for leveling the back of the camera. 



Very excellent cameras are made 

 by the Century Camera Company. 

 Their Long-focus Century Grand 

 leaves little to be desired in the way 

 of a convenient, perfect-working in- 

 strument. 



The dark-room for development is 

 an important subject. The chamber 

 must be light-tight. At the same 

 time it ought to be roomy and well 

 ventilated. If the room is small and 

 means of removing the foul air becomes imperative. 



5; 

 o 



I 



Fig. I36.t 



*Fic. 135. Diagram of small dark-room shown in fig. 134. Standing in the middle, a man can 

 touch the walls in either direction. In the ceiling is a foot-wide pipe extending 6 feet beyond the 

 roof and capped with a broad mushroom top. In the lower end of this pipe is an electric fan, 

 which pumps foul air out of the room. Light is prevented from entering by partial cross-septa 

 projecting from opposite sides of the air-shaft, and also by blacking its inner surface. 



fFic. 136. Wall case for preserving from dust and scratches the enameled iron plates used for 

 squeegeeing silver prints. 



