456 E. L. Nichols—Character and Intensity of the 
the last paragraph, and then the spectro-photometrie comparison 
; : 
an experiment pointed to a change of temperature in either 
wire, the experiment was set aside as imperfect. 
readings given in the following table will suffice to show 
the general character of the measurements. 
Taste IV.+ 
Scale-divisions. Readings. Mean. 90°—a. Intensity. 
37°-0) 
8 36 8} 37°-00 20° 36’ 0” "1238 
37-2 
36 0 
9 36 “34 36 “10 19 42 0 “1136 
36 0 
32 “5 
10 33 5h 32° 97 16 34 12 "08133 
32 -9 
30 -0 
i 30 0} 30 °33 13 56 0 "05798 
31-0) : 
29 -0 
12 28 -9 | 28 -97 12 34 12 04736 
29 -0 
21 Bb) 
13 27 -4} 27 -30 10 54 0 0°3576 
27 -0 
* For the lower temperatures used, the trum was not visible eveu t0 ise 
G, and measurements could only be carried oe oe to the scale-division nearest the 
limit of the visible rays. f the 
} The figures in the column marked “Readings” denote the position ert gs 
pointer attached to the ocular Nicol, Subtracting frost: the 
of the spectrum the position of the pointer when th 
quantity 90°— a is obtained. 90°— a being the angle betwee? 
of the two Nicols. 
