3i8 



SMITHSONIAN MISCELI,ANE0US COLLECTIONS VOL. 52 



Velocity of the Sources of the Light Showing the Doppler Effect. 



Maximum velocity varies from 30 per cent to 85 per cent of the velocity 

 of the canal rays computed from the cathode fall and the probable 

 value of e/m: Ps2(257) ; SHK(464) ; 813(36, 417) ; 819(399)- 



Sources of the H series lines: Ps2(252) ; 813(36, 417)- See Fig. 61. For 

 low voltages the displaced line is composed of two lines whose maxi- 

 mum shifts are to each other as i : 1 2 



2,000 4.000 6,000 



14.000 



18,000 V0LT5. 



Fig. 61. — Range of velocities of sources of H lines as a function of the cathode 

 fall in volts. Full lined curves are calculated, using formula (l). 



Sources of O spark lines: Ps3(263) ; 823(815). See Fig. 62. Phenomenon 



seems similar to that with H, data not so complete. 

 Sources of He lines : 



Maximum velocity half that calculated for the canal rays assuming 

 e/m = 2500, m = 4: Di(59o). 

 Sources of C lines : 



Maximum velocity 0.9 times that calculated for canal rays assuming 

 e/m = 800, m = 12 : Kn3 (36) . 

 Specific Charge, e/m. 



From magnetic deflection, equations (7) and (10), maximum values are: 



In air. e/m=io'' (H2 carefully eliminated): Tm3(569). Other 



values obtained range from 3x10": W2(i2) ; W3(449), 



and 3.6x10°: W5(56i, 264), to 3.6x10*: W4(432, 435)- 



In H.. e/m =10': W8(66o, 662, 663) ; Tm3(57i) ; Raul (422). 



In O2. e/m = 10* (approximately): W5(562, 265): W8 (663) ; 



Ew3(306). 

 In He. e/m = io': Tm3(57i) ; cf. Raui(522). 

 In Ar. e/m =10*: Tm3(S73). 



At extremely low pressure, deflection strip divides into two patches, 

 the maximum deflection of second giving for all gases 

 (H, He, Air, Ar, Ne) e/m = sxio': Tm3(57i) ; 

 Tm8(664). 



