The Pressure Due to Radiation. (Second Paper.)

E. F. Nichols, G. F. Hull
1903 Physical Review  
HE disc was calibrated for temperature in terms of the deflection -*• for a definite sensitiveness of the galvanometer G v For this purpose the disc was immersed in a kerosene bath and the galvanometer deflection measured for two different temperatures of the disc. One of these was about 18 0 C. above the comparatively steady temperature of the room, or calorimeter containing the standard temperature junctions (see Fig. 6 ), and the other about the same number of degrees below the room
more » ... re. These two temperatures were measured by a Fuess standard thermometer divided into tenths of a degree and calibrated at the Reichsanstalt. Two calibrations of the silver disc were made some days apart. One of these series appears in full in Table V . The first three columns of the table give the zero, direct and reversed reading of the galvanometer G v The fourth column gives the temperature of the bath in which the disc was immersed, and the fifth, that of the constant temperature calorimeter. The sixth column gives the deflections of G v The seventh column the means of the alternate deflections. The eighth, the mean of the two columns preceding it. The last column gives the difference in temperature between the two calorimeters in degrees C. For the total temperature range in the table, 39.11°, the deflection of G x was 393.8 scale divisions for a sensitiveness of G 1 = 996. A range of one degree would thus give a deflection of 10.03 divisions for a sensitiveness of G 1 = 1,000. The mean of two separate calibrations was 9.96 scale divisions for one degree temperature difference. Before beginning a series of intensity measurements the disc was suspended in an air-chamber containing phosphoric anhydride and 1 Concluded from July number.
doi:10.1103/physrevseriesi.17.91 fatcat:5xufohys4fc2rjtqhfowsqazny