162 



CLYDE C. HAMILTON. 



have an inlet opening (A} and an outlet opening (B), each three 

 eighths of an inch in diameter. On the upper side of each half 

 of the cylinder are two openings (E) and (F) which are one fourth 

 of an inch in diameter. These openings connect by rubber tubing 

 to ends (X} and (F) respectively of the inclined manometer. 



FIG. i. Showing the three gages in position and connected with the gradient 

 cage. The metal hood with symmetrical electric lights is removed. The valves 

 make it possible to measure the pressure on either side of the diaphragm separately 

 and thus check the results when both sides are connected. 



The liquid used in the manometer was a red oil but the scale was 

 corrected to read in millimeters of water. The amount of air 

 entering chamber (i) through opening (A) is regulated by a 

 screw-clamp (T) on the rubber tubing (5). The opening (C) 

 in the diaphragm (D) should be in the center and may be any 

 size smaller than openings (A) and (B). Since opening (C} is 

 smaller than opening (^4) the air cannot escape from the chamber 



