794 
the red stars of classes K5 and M are usually less 
than one fiftieth as bright as the sun. On the 
average, the stars of each spectral class are seven 
times as bright as those of the following class. 
This rule holds true both for the stars relatively 
near us, whose individual distances can be meas- 
ured, and for those belonging to clusters whose 
distances are known. 
There exist, however, many stars of great bright- 
ness, of all spectral types, which are almost all so 
remote that their distances can not be accurately 
measured. From the best available data, these 
stars appear to be on the average from 100 to 250 
times as bright as the sun, without much difference 
between the different spectral types. 
Among the stars redder than the sun, these two 
groups, of different brightness, are widely sepa- 
rated; but among the whiter stars they run to- 
gether, and become identical for the whitest stars 
(elass B), which average more than 250 times as 
bright as the sun. 
In the cluster of the Pleiades (whose distance 
has so far been unknown) all spectral classes from 
B5 to G are represented, and the relative bright- 
ness of the different types follows very closely the 
law which holds good for the fainter stars already 
mentioned. If it is assumed that the stars of the 
Pleiades also follow the same law as regards their 
actual brightness, the distance of the cluster is 
found to be such that their light takes 600 years 
to reach us. 
From a study of double stars it is found that 
the stars of the brighter class do not greatly 
exceed those of the fainter class in mass, and 
hence that they are either much less dense, or 
much brighter per unit of surface, or both. The 
average density of the stars of classes B and A 
can be found with the aid of certain stars which 
eclipse one another, and it follows that these stars 
give off much more light per square mile of sur- 
face than the sun does. It can also be shown that 
the faint red stars give out much less light per 
square mile than the sun. 
If the same is true of the other kind of red 
stars (which several lines of argument make very 
probable) these stars must be of enormous size, 
but very low density. 
An arrangement of all these groups of stars in 
order of increasing density would begin with the 
bright red stars of the type of Antares, run up 
the series of stars of great brightness to those of 
spectrum B, and then down the series of fainter 
stars, past those like the sun, to the faintest and 
SCIENCE 
[N.S. Vou. XXXV. No. 907 
reddest stars. It seems probable that this arrange- 
ment represents the evolutionary history of a star, 
which at first becomes heated more and more by 
its own contraction, and finally, as it becomes too 
dense to admit of further shrinkage, cools off like 
a solid body. 
At the annual dinner on Saturday evening at 
the Bellevue-Stratford nearly eighty members and 
guests were present, the toasts being responded to 
as follows: 
““The Memory of Franklin,’’ by Professor John 
Bassett Moore. 
‘“Our Sister Societies,’’? by Professor Chas. F. 
Chandler. 
‘‘Our Universities,’’ by Professor Ernest W. 
Brown. 
‘*The American Philosophical Society,’’ by Pro- 
fessor Francis B. Gummere. 
An important feature of this occasion was the 
presentation of the Henry M. Phillips prize of 
two thousand dollars to the author of the crowned 
essay on ‘‘The Treaty-making Power of the United 
States and the Methods of its Enforcement as 
Affecting the Police Powers of the United States.’’ 
The successful competitor was Charles H. Burr, 
Esq., of Philadelphia, the judges of award being 
Joseph Choate, former ambassador to Great 
Britain; Judge John C. Gray, of Harvard College; 
Henry Wade Rogers, dean of the Yale Law 
School; J. M. Dickinson, former Secretary of 
War; and Joseph Brown Scott, of the Department 
of State at Washington. 
In their sealed verdict the judges declared that 
they found great difficulty in deciding the essay 
of Mr. Burr and that of Edward S. Corwin, of 
Princeton University. 
ARTHUR WILLIS GOODSPEED 
SOCIETIES AND ACADEMIES 
THE TENNESSEE ACADEMY OF SCIENCE 
Own March 9, 1912, a meeting was held in Nash- 
ville, Tennessee, to make plans and prepare a 
constitution for a Tennessee Academy of Science. 
The meeting was called by Dr. Geo. H. Ashley, 
then state geologist. 
The first general meeting, which was largely 
attended, was held at the Carnegie Library, Nash- 
ville, on April 6, at which time the following 
officers were elected: C. H. Gordon, president; 
J. I. D. Hinds, vice-president; Wilbur A. Nelson, 
secretary, Capitol Annex, Nashville; S. M. Barton, 
treasurer, and EH. S. Reynolds, editor; after which 
the following papers were read: 
