182 Prof. J. Brocklesby on the Influence of Color on Dew. 
With the view of discovering, whether these varying results 
were the legitimate effects of color alone, unconnected with other 
causes ; I cut a piece of fine, evenly wove, yellow flannel into 
four portions, ahd prepared them in the same manner as in table 
A. I thus obtained as far as possible, uniformity in every dis- 
cernible a apaitt: The place of joo i was the same, and the 
ig precautions observed, as in 
e following are the results of four trials, the first two being 
eds upon the grass, the last two upon the elevated board. 
TABLE : ae 
| July 5th. | haa 17t July 21st July fuly 24th. | 
- < 3 2 | Ba j Seale 
£3 e ne FE 2e| 22 | ied 
ag GSAS] oa ¢8) as Ab e& 
ipches-| grs. -jinches. grs. linches.| grs.| grs. 
Ry . Pig's S4'/ 3319-3 | 94’) 33 io" | 123 94- Bb 
: 7 tc + 1 33 “c Q if 24- 
= vaso, m6 aitt “ £33 “c ¥ i “ e 93 
U, : 5 ic | S38 73 ll “ 94 24 
rs 
Average of four experiments: 
. 4 
| grs. 
R, ] = r 25:25 
S ed oo 
’ ‘ i a, ADO: 44 
U, ’ * 23-50 
By recurring to table A, it will be seen, that the amount of 
dew gained by the yellow and-white is greater than that acquired 
by the black, beth in the general and particular averages, an 
when single ‘experiments are compared, the gain of the yellow 
exceeds that of the black in every case ; the highest being one- 
seventh of the quantity deposited upon the yellow. In like man- 
ner the white preponderates over the black in ten out of eleven 
instances, and in the eleyenth their gain is alike. The greatest 
gain, ue one-eighth of the moisture contracted by the white. 
The n possesses likewise an advantage over the black in every 
en but the red dees not ; while in the comparison of sin- 
gle experiments they, follow no law, 5. da time falling below the 
black, and at another ranging as high as the white and yello rs 
The average of the blue is the telat of all in the last three ex: 
perments, and sinks below the black in every instance in respect 
to the quantity of deposited moisture. The results of this in- 
vestigation point to conclusions at variance with the commonly 
received opinions in regard to the radiation of heat as modified 
by color, and are directly opposed to the experiments of Dr. 
Stark. But are these variations in the amount of dew contracted, 
to their fudl oe the legitimate effects of difference in color * 
The details given in table B, throw light upon this question. 
e first series of experiments. 
