i68 



RAJDIOMETRY. 



Table VII Continued. 



Observer. 



Rubens: Wied. Ann., 45, p. 

 238; 1892 



Rubens and Snow (Wied. 

 Ann., 46, p. 529; 



1892) 



Snow (Phys. Rev., 1, p. 31; 



1893) 



Aschkinass (Wied. Ann., 

 55, p. 401; 1895).. 



Donath (Wied. Ann., 58, 

 p. 609; 1896) 



Paschen (Wied, Ann., 48, 

 p. 272; 1893) 



Coblentz 



Rubens Thermopile . 

 Coblentz Radiometer 



Resist- 

 ance. 



ohms. 

 80 



I50 

 140 



*6o 



*6o 



20 



5-2 



5-2 



Galvanometer. 



Full 

 period. 



20 

 20 



20 



7 



15 



3 

 34 



10 

 16 



14 



70 



150 



Current 



sensitiveness 

 for 1 mm. 

 deflection. 



3-2XIO" 



I.8X10- 11 

 1. 5X10-H 



6X10-H 

 6X10-1 2 



Bolometer. 



Resist 

 ance. 



2.3X10-" 

 3-3X io- 

 1.6X io-n 

 8.3X10-1 2 



2.5X10-1 

 1.5X10-1 



1.4X10' 



-10 



ohms. 

 80 



80 



75 



13 



5 



12 

 8 



2.8 



3-5 



Area. 



sq. mm. 

 O.09X 12 



O.09X 12 

 0.05 X 7 



Bolometer 

 current. 



amp. 



O.O25 



0.04 



3X0.5X15 



0.25 X7 



0.22X 10 



0.8X20 



0.5X9 



0.5X9 



0.01 to 0.02 



0.03 



.02 



0.02 



Galvanometer; 4 coils 40 mm. external and 5 mm. internal diameter, 1,200 turns of graded wire in each coil; 

 moving system, 13 magnets in each group, 1 to 1.5 mm. long, on both sides of glass staff, and 0.3 mm. apart; 

 mirror 2 mm. diameter X 0.03 mm. thick. Total weight of system = 5 mg. 



