﻿Electricity on Streams of Water Drops. 1G1 



IB E is charge sufficient to raise the isolated spherical drop 

 to say, -f 100 volts, 



E = Vr = ^-- E.s. unit. 



.'. F=-'552x o 4xl0 2 =--0Gl dyne (attraction). 



30 2 J 



4 

 The weight of one drop = ^ irr^pg = approx. 4 dynes. 



Electrical force is then — - of the weight o£ drop. 

 400 



2. Suppose two unequal drop?, a = '2 cm., & = •! cm., and 

 c — -3?> cm. If the quantity on smaller drop would raise it to 

 }00 volts if it were isolated, and if D = E, 



E = ot-.e.s. unit. 



From equation (11), 



„ 2/3DE-*D 2 - 7 E 2 ( -0455 xlO 2 , n _ . 



J? = — 3 — = H ttt^ = + 'OOd dyne 



?" 30" y 



(repulsion). 



(2) The question now arises "Is there any ground for 

 believing that in the cases before us we have really two drops 

 bearing charges for which the ratio becomes very large ? " 

 Here it would be well to examine the conditions at the 

 point of breaking of the stream. 



From such photographs as shown in figs. 2, 8 c, 9 c, we see, 

 as to size and distance apart, the relation between drops as 

 they break from the stream. From what has been said 

 above we must conclude that there will be strong forces 

 between the drop which has just left and the one that is just 

 forming, and that the charge on the drop leaving will have an 

 influence on the size of the charge on the drop just forming. 

 Suppose A and B to be two consecutive drops which, tor 

 simplicity, we shall first suppose equal to one another and of 

 radius r cm. They are forming at the 

 ^-v a centre of: a ring maintained at a poten- 



tial + V volts. The potential at centre 

 of ring will be, approximately, 2/ttY, 

 say 2/3V. If A has just left the 

 stream at potential zero, and no drops 

 are close above it, it will have a nega- 

 tive charge approximately sufficient to 

 give it a potential — 2/3V if it were 

 far removed from all other conductors. The charge on A is 

 Phil. Mag, S. 6. Vol. 23. No. 133. Jan. 1912. M 



