Sun’s observed and computed right ascensions , &c. 465 
Table VIII. — continued. 
Exposure of the Instrument, October 9. 
Times of Comparison. Thermometers under the cover Thermometers under the cover 
jj ]IU of the Black, or Western Axis. of the White, or Eastern Axis. 
12 43 54 °-° 54 °-° 
12 49 69 .0 54 .7 
12 5 1 73 0 54 - 8 
12 53 75 -° 55 ?° 
12 55 76 .0 55 .2 
12 57 76.5 vsT... 55 - 8 
12 59 . . . 78 -O 56 .O 
Mean = 74 .6 Mean ~ 55 .3 
Hence, difference of temperature == i9°.3. 
Thermometers placed under the covers of the black and white braces, did not vary 
from those applied to the axes, more than half, or three-quarters of a degree. 
During the observations not a cloud had been visible. 
Exposure of the Instrument, October 10. 
Times of Comparison. Thermometers under the cover Thermometers under the cover 
jj m _ of the Black, or Western Axis. of the White, or Eastern Axis. 
12 42 5o°.o 5o°.o 
12 49 68 .0 51 .0 
12 52 75-o 52 .0 
12 33 78 .0 52 .3 
I 2 55 79 0 5 2 -5 
12 57 81 .c 53 .0 
12 59 8 3 -o 53-5 
Mean =2 77 .3 Mean = 52 .4 
Hence, difference of temperature = 24°>9. 
Not a cloud visible, during the observations. Thermometers under the covers of the 
western and eastern braces, did not differ more than half a degree, from those 
applied to the axes. 
