129 
TUBE I. 
ee SS 
Distance from 
Aperture’ beginning of 
Vv U 
Aand C open Band D open 
current 
Ay 9 | 549 509 
A 24 | 580 530 
B 54 | 518 510 
D | 100.3 590 566 
CPx, 146.6 567 | 581 
Bes 219.0 536 573 
F 292.2 | 498 568 
TUBE II. 
Fee | 292.2 567 550 
E’ 219.0 559 533 
Cae 154.8 554 540 
De 100.3 565 552 
B 51.4 520 588 
Si 9 457 573 
All numbers are expressed in cm. 
It seems worth while to graph the results. We begin with the 
case that the cocks A and C are open. Fig. 2 refers to this case. 
AanpC OPEN 
VELOCITY 
TEE 
j 
MEAN V=9591.9 
P MEAN VELOCITY OVER WHOLE TUBE 
948,1 
Proceedings Royal Acad. Amsterdam. Vol. XIX. 
