420 R. H. Richards— Jet Aspirator for Laboratories. 
when the atmosphere is admitted it fee the _atmospheric 
ressure on top of the feed reservoir, and when it is not admit- 
ted, the whole atmospheric pressure is added to that of the 
column of water which exerts the force, increasing its power by 
15 lbs. on the square inch, and if there is need of further proof, 
it may be obtained from a set of perunene noted by the aster- 
isks below each set of trials. It will there be seen that more 
water came through the pepuaier when * was producing a vacu- 
um than when it was not, even though the pressure gauge read- 
ings were the same, which plainly indicates that with the vacuum, 
there is greater impelling force to the water than without it. 
ASPIRATOR No. 1. ae | hang ai oh 
a= ‘068” Barometer, 764 
w= *068 Air, 74" F: 
oO =: *250 Water, IZ" F. 
Record of experiments. 
G. G.. . h. H— le G;. use h. H—A. 
7a8 900. SE AR 8 41 tO 
000 730 18 712 811 415 ath 0 
Calculated results. 
With vacuum. With so-vadenin) 
Water P. Air tension. Water P. Air tension. 
1448™™ 7414™™ 100077 0 
137i 112 867 0 
Asprator No. 2. w* -0*—1: 14. 
a— 075" Barometer, 7667" 
w= °0612 Air, 75° F, 
o = *240 Water, 78° F. 
Record of experiments. 
G,. Go. H; A. H—A: G,. ce h. H—A. 
1740 900 744 1 743 727 415 415 0 
1740 1000* 742 3 739 775+ = 415 415 0 
1740 §=1050 689 71 +618 825 415 415 0 
Calculated results. 
With vacuum. With no vacuum. 
Air tensio. Water P. Air tension 
14572" 74g7™ 1057" 
1305 739 954 0 
1121 618 850 0 
: “£10006. of water nese per nuts + 1708 ¢.c. of water passed per minute. 
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