280 ON THE LIGHT OF THE MOON AND OF THE PLANET JUPITER. 
'The flames of the lamps were occasionally examined and found in good adjustment. 
The globe B, was placed within a hollow tin cone, near its apex. The cone was well 
blackened to cut off dispersed light, and the globe was frequently altered in position 
so as to expose different parts to the Sun. 
1860, March 28th. Sky nearly, though not perfectly clear, especially in the later 
experiments. Adjustments as on 26th. Globe B, in same position. Lamp $, dia- 
phragm Z. 
h m ft. ft. 
1 4 Sid. time. Bulb to lamp S, 7.70 Bulb to focus, 5.85 
lI o4 " e 7.70 ü 5.85 
I 14 " S 8.00 $ 5.85 
Aperture changed to 14^".94. 
n im ft. ft. 
134 Sid. time. Bulb to lamp S, 7.80 Bulb to focus, 5.85 
Di 7.80 ke 5.85 
se 5.05 a DO 
Lamp S exchanged to I. | 
~ 
h m ft. ft. 
1 44 Sid. time. Bulb to lamp Z 7.45 ` Bulb to focus, 5.85 
js 7.85 " 5.85 
> TOP " 5.85 
At the same distance, a screen of * Whatman's" drawing-paper painted with 
* Flake white" was set up, perpendicular to the Sun's rays, affording a surface of a 
pure white without gloss, sensibly more brilliant than new-fallen snow. 
h m ft. ft. 
1 59 Sid. time. Bulb to lamp Z 6.40 Bulb to focus, 5.85 
" 6.50 x 5.85 
Silvered globe B;, diameter 17.760, placed in the position described above for B, . 
k m ft. ft. 
2 19 Sid. time. Bulb to lamp 7, 6.08 Bulb to focus, 3.00 
: “ 5.80 WW 9.90 
A screen of black cloth, washed with a thin size of indigo, to destroy the gloss 
and afford a dead blue-black surface, was set up at the same distance. 
px ft. 
2 39 Sid. time. Bulb to lamp Z, 11.10 Bulb to focus, 8.10 
: Clouds troublesome. The clear intervals were used. 
