424 fi. H. Richards—Jet Aspirator for Laboratories. 
Taste V. 
Ratio air 
Aspirator. Water pres. Air ten. water volume. Time. 
No, 1 EY bee 740% 5 1 min, 
No. 2 639 76 4°015 $ 
No. 3 771 76 2°123 * 
No. 4 1686 120 1°826 - 
No. 5 1749 98 1°602 he 
No. 6 2133 76 1°466 i 
No.1 1125 414 6°825 . 
No. 2 977 . 10°110 . 
No. 3 1109 - 6°524 ” 
No. 4 1980 = 4°551 - 
No. 5 2065 — 2°351 - 
No. 6 2467 ved 2°357 e 
C, is at the same instant opened. The manometer is pre- 
vented from rising and indeed held exactly on its desired read- 
ing by means of cock C,. At the instant the minute is up, ? 18 
removed and C, closed; then 7 contains the whole of the water 
used, and the number of cubic centimeters of water required to 
| ain represents the amount of air drawn. ‘To be sure, 
there is a slight error from having the levels of water in K and 
F different, but this is entirely Insignificant when compared 
with the forces at issue. 
Experiment to ascertain the length of time required to pro- 
duce a vacuum ina vessel of given size. Aspirator a? : w?=5:1. 
Water pres. H—A. Time. Water pres. H—h. Time. 
2774 714 1 min.* Q774 637 5 min. 
“ 1 14 cc 8 6* (74 662 6 “ 
“ "31 Q % * “ se 
