THE RESPIRATION APPARATUS. 



The blower consists of a cylinder A, perforated laterally by the open- 

 ings a and b for the entrance and exit of the air current. Inside 

 the cylinder and arranged eccentrically with it is a revolving drum B, 

 bearing on its axis the rod F which carries at each end a piston, 

 G and G 1 . The piston G has a tight connection with the rod, while 

 G 1 is cushioned on the springs H. As the drum B is revolved the rod 

 slides so that the pistons press against the inner face of the cylinder 

 and prevent a backward escape of air, and the current entering through 

 a is forced out through b into the absorber system. 



The box in which the blower is placed is made of cast iron and provided 

 with stuffing-boxes through which the shaft or axis of the revolving 

 drum B and the pipes a and b 

 pass. Any leakage of air in 

 the blower is instantly detected 

 by the bubbles of air in the 

 thick cylinder oil. The shaft 

 is oiled by unscrewing two long 

 rods, which are tapped into 

 oil-holes on each side of the 

 blower. Leather washers on 

 the rods insure tightness when 

 screwed down. To avoid es- 

 cape of air the blower is oiled 

 only when at rest. 



In order that no oil may 



be drawn into the absorbing FIG. 9. Rotary Blower. Air enters at a, is forced about 

 System a trap is provided, as ^e Drum B by Sliding Pistons G and Oi, and is driven 



shown in figure 10. The tube 



.t is prolonged into the blind passage s s. The oil collects in the bottom 

 of this tube, and by removing the plug h may be drawn off from time 

 to time. It is impossible to eliminate the use of a small amount of 

 lubricating oil from a blower of this type, but we have found that the 

 amount of oil mechanically carried forward by the air current is ex- 

 tremely small and is practically all collected in the trap. Furthermore, 

 before reentering the chamber the air passes through strong sulphuric 

 acid, by which any hydrocarbons would be absorbed. On the other 

 hand, the partial reduction of sulphuric acid to sulphurous acid as a 

 result of the absorption of hydrocarbons would do little harm, because 

 of the absorption of this gas by the soda lime. 



The efficiency of the blower was tested by connecting it with a gas- 

 meter for several weeks. It was found that the amount of air forced 

 through the meter was almost directly proportional to the speed of 



