259 
TRANSVERSE ELECTROSTATIC FIELD. 
The magnet was then removed and the deflection of the discharge 
studied in an electrostatic field. With the apparatus as previously de- 
scribed and with the electrostatic plates, the points and the electroscope 
shunted in parallel circuit, the four series of photographs I, J, K and L 
were taken. The following is a record of the potential and the current 
in each case, the forms of discharge for series I, J, IX and L corresponding 
to those of A, B, C and D respectively : 
Distance between points, 18.05 mm. 
TABLE 3. 
Charge | ; ; 
Woo an a Sign of | Potential Current 
Berna bottom Right in in 
Plate |hand point Volts Amperes 
| 1) none + 17859 | 00019 
WD itm aet + 17700 00019 
3 — ~ 17600 00016 | 
Pilea he ndue = 16270 00016 | 
| 5 = = 15150 00015 
6 = —_ 16270 .00015 
1| none + | 18900 | 00027 
2 + + 19425 00036 | 
J 3 = | =F 19500 00036 
4 none | — 14700 00026 | 
5 ae —_ 17400 .00026 
6 = — 17250 .00026 
| a = — = 
@igtione oe =e 16800 | .00039 
2} + 4 17700 | .00051 
K 3 = + 19200 .00052 Changed to brush. 
4 none — 15600 00052 
5 + —_ 17900 .00052 
6 — — 18370 00051 Partjally changed to brush. 
1| none JE 16725 | 00092 
2) = + 18000 | 00089 
LI 3 -- -f 17700 00091 
4 none = 13950 00088 
5| + _ 16875 00094 
6 — 16800 .00090 
The variation of the potential and current in any series in the above 
table except for (8 and 6) K, was due to a decrease of speed of the motor. 
This was caused by a drop in potential when a large current was used in 
