SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 3 
2. Section of Astronomy. 
December 19th, Section met at usual hour, Chairman Knight pre- 
siding. 
The meeting was opened with instructive remarks by the Chairman 
relative to the increase in the number of double stars that have been 
discovered, giving credit to many and notable discoveries at the Lick 
Observatory; justifying very amply the generous appropriations made 
for the maintenance of that noble institution. 
Mr, Knight then gave a resume of the knowledge now systematized 
relative to Phoebe, the ninth satellite of Saturn; claiming for it a 
diameter of about a thousand miles, a radius of revolution of about two 
million miles, and a period of perhaps three weeks. It is claimed by 
some that this planet moves about its principal in a direction reverse to 
that of the other satellites, but this theory is not fully accepted by the 
astronomical world. The question gave rise to a spirited discussion. 
The Chairman then introduced the speaker of the evening, Mr. 
B. R. Baumgardt, who entertained the section first by reference to some 
of the interesting facts relative to Encke’s comet. The period of the 
comet is 31-3 years, its orbit being an ellipse; and its present. situation 
is in the vicinity of Mercury. Mr. Baumgardt claims that there is no 
good authority for the theory that any comet of the solar system goes 
beyond the orbit of Jupiter. He stated that any comet which moves at 
a greater rate than twenty-six miles per second never returns, and must 
. move in a hyperbolic or parabolic course; that all apparently par- 
abolie or hyperbolic comets may be but such as move in ellipses of ex- 
treme eccentricity, the remote focus being almost at an infinite distance 
from the sun; all.such comets may yet return to our solar system. 
Mr. Baumgardt then proceeded to read a paper delivered at Cam- 
bridge by Professor Poynting, on solar radiation. The article consisted 
chiefly in the discussion of the significance of the fact that a black 
surface radiates more heat ‘than any other. The author analyzed the 
heating power of the sun, claiming for it the function of a full radiator. 
Professor Turner, of the Oxford Observatory, claims that the high- 
est heating power of the sun at its surface cannot exceed eight 'thousand 
degrees. Professor Poynting treated at length the effect of radiant 
energy as opposed in its effects to the gravitation of the sun, claiming . 
_ that were the planets small enough the repelling power of the sun’s 
radiant energy would counter-balance the attraction of gravity, or even 
overcome it. The paper was full of striking statements and closely logical 
argument, largely opposed to some formerly generally accepted theories. 
Mr. Knight read a brief extract from Professor Woodward suggest- 
ing the probability that light, heat, electricity, and magnetism would all 
be proved to be but forms of matter rather than modes of motion, 
Remarks were also made touching the extreme importance of the 
solar observatory ibeing constructed on Mt. Wilson. The eyes of the 
astronomical world are fixed with intense interest upon the possibilities 
to be expected from the operation of this newest enterprise for astronom- 
ical investigation. 
Attention of the Section was called to the interesting occultation of 
Aldebaran by the moon on the evening of the 20th of December. 
After some further discussion, the meeting adjourned. 
MELVILLE DOZIER, Secretary. 
