Chemistry and Physics. 419 
that of d on Z; by rotation of ¢ the color, by turning of d the intensity 
of the flame is made equal to that of the star. This photometer can 
be attached to most telescopes. 
n his “ Photometrische Untersuchungen mit besonderer Ritcksicht auf 
die physische ‘Beschaffenheit der Himmelskorper, Leipzig, 1865,” Zéllner 
has given the results of his observations together with their bearing upon 
the theory of Kant-Laplace. The following intensities were obtained by 
comparing the sun or planets separately with « Aurige; he found 
Sun : Capella : ; 55,760,000,000 : 1 
* 
with a probable error of about 5 i cent; and hence for the intensity at 
the meat oppositio 
Prob. error. 
Sun = = 6,994,000.000 times rene “ 8 P. & 
Sun =  5,472,000,000 “ Jupi 
Sun = 130,980,000,000 “ dees (without the ring) 5 ie . 
un = 8,486,000,000,000 times Uran . 
Sun = 79,620,000,000,000 “ serine s ys 
Sun = 619,600 “ Full Moon, ay ga 
and by fies) stn surfaces, Sun = 618,000 times Full Moon, 1°6 p. c. 
Fro e above it follows, that our sun at a distance of 3°72 
Peters has actually found 0-046. If light suffers no absorption in the 
celestial spaces, Capella accordingly must send out much more light than 
our sun; and & Centauri seems to be equal to our sun. 
_ The reflecting power or albedo Zéllner found as follows : 
rob. error. Prob. error. 
Moon, 01736 -+-0-0035 | Saturn, 04981 =+0°0249 
ars, 02672 +0°0155 | Uranus, 0°6400 -+0°0544 
Jupiter, 06238 -+-0°0355 | Neptune, 0°4648 +-0°0372 
sake of comparison we add his determination of the albedo of 
terrestrial substances: (a.) diffuse reflected light—snow just fallen 0-783, 
white paper 0°700, white sandstone 0°237, clay-marl 0°156, quartz-por- 
phyry 0°108, moist soil 0°079, dark gray syenite 0°078. (4.) regular re- 
flection—mercury 0°648, speculum metal 0°535, glass 0°040, obsidian 
00382. Exist 0-021. 
In gard to the ney of lunar light in the different phases we 
and eriod of complete refrigeration. These periods he 3 cain 
in the cosmical history of the earth, and in the present aspect of the 
starry heave resentatives of the first period he considers the 
which latter is répresented by the invariable stars; our sun isin 
the third period ; to the fourth belong the ae stars; and the fifth 
is represented by Bessel’s dark stars. For a full exposition of these: a 
theses we must refer to the Seiviaibttionsd works of Zéllner. 
