24 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Jl 



This tank was used under three conditions : 



1st. Tank empty, with the elbow E to direct the gas into a swirl 

 such that the gas, while in motion, would not tend to return up the 

 pipe P. In this case, some rebound was to be expected from this 

 elbow. This expectation was realized in practice. 



2d. Tank empty, and elbow cut off along the dotted line Eq. In 

 this case, more rebound Avas to be expected than in Case i, which was 

 borne out in practice. 



3d. Elbow E cut at Eq, and tank half filled with ^-inch square- 

 mesh wire fencing. Two separate devices constructed of this wire 

 fencing were used one above the other. The gas first passed through 

 an Archimedes spiral, J, of 2-foot fencing, comprising eight turns. 



