986 
Mr. J. W. Froley then described some ‘ Ap- 
pliances for describing Oval and Circular Arcs 
of very large radius.’ The principal one de- 
pended on the fact that a uniform elastic bar, 
bent by equal oppositely directed forces takes 
the form of a circular are. The presentation 
was too mathematical to be condensed here. 
The Society then adjourned till October. 
CHARLES K. WEAD, 
Secretary. 
TORREY BOTANICAL CLUB. 
At the meeting of April 9, 1901, the scien- 
tific program consisted of a ‘Report on a Re- 
cent Visit to the Royal Gardens at Kew, Eng- 
land,’ by Mr. George V. Nash. Mr. Nash was 
absent about six weeks, nearly the entire time 
on the other side being spent at the Royal 
Gardens, Kew, securing specimens of living 
plants for the New York Botanical Garden. 
The collections were carefully inspected under 
the guidance of the officers of the institution, 
and such duplicate material picked out as was 
desired. In this way much valuable material 
was secured, both for the outside and con- 
servatory collections. Many of these were 
procurable only at a botanical garden, and a 
number of them were not obtainable elsewhere 
than at Kew. Of the large number of plants 
selected, over 1,000 species have already been 
received and incorporated in our collections. 
These include about 550 species of herbaceous 
plants, 350 shrubs and trees, and 150 succu- 
lents. The remainder of the material will fol- 
low as fast as the authorities at Kew can select 
it. 
Dr. Britton remarked that the favor ac- 
corded by Sir William Dyer in permitting Mr. 
Nash to select duplicates of living plants from 
the rich collections at Kew would be most 
gratefully appreciated not alone by the man- 
agers and members of the New York Botanical 
Garden, but by all American botanists. 
Dr. Britton presented a communication on 
a tree new to the American continent, a white 
birch from the Alaska region, collected by Mr. 
R. S. Williams and Mr. Tarleton and repre- 
sented in the U. 8. National Herbarium also 
by two specimens collected by Miss E. Taylor. 
At the meeting of April 24th a paper by 
Professor Francis E. Lloyd, entitled, ‘The 
SCIENCE. 
[N.S, Vou. XIII. No. 338. 
Genus Lycopodium: A Criticism,’ in the absence 
of the author, was read by the secretary pro tem. 
This was a review and criticism of the treat- 
ment of the genus Lycopodium by Pritzel in the 
recently published part of Engler and Prantl’s — 
‘Die naturlichen PAanzenfamilien’ dealing with 
the liycopodiaceae. The paper will be pub- 
lished in full in an early number of Torreya. 
Professor Underwood remarked on segrega- 
tions in the Selaginella rupestris group, stating 
that Dr. Hieronymus, of Berlin, had recently 
recognized twenty-seven species in this group, 
some of them American, outside of those 
recently proposed in this country. } 
MARSHALL A. HOWE, 
Secretary pro tem. 
THE ACADEMY OF SCIENCE OF ST. LOUIS. 
AT the meeting of May 20, twenty-six per- 
sons present, Professor George Lefevre pre- 
sented a comprehensive address on the ad- 
vance made in the science of zoology during 
the nineteenth century. 
Professor F. E. Nipher presented a paper de- 
termining the specific heat of a nebula, in pro- 
cess of gravitational contraction. It is found 
to be equal to the constant for the gas, provided 
by the mechanical equivalent of heat. This 
is also equal to the difference between the spe- 
cific heats, at constant pressure and at constant 
volume. The relation between pressure and 
volume of the gaseous mass during contraction 
is determined in terms of the fundamental 
constants, the gravitation constant, the con- 
stant of the gas and the mass of the contract- 
ing nebula. In the same way, the relation of 
pressure to temperature and of volume to tem- 
perature are determined. It is a matter of 
profound significance that a cosmical gaseous 
mass can apparently pull itself together, and at 
the same time become warmer, as it might if 
compressed by some external force. It raises 
the question whether the mass does really con- 
tract itself when it gravitates into a smaller 
volume, or is gravitation, after all, a force act- 
ing from without and upon the two bodies 
which seem to attract each other ? 
One person was elected to active membership. 
WILLIAM 'TRELEASE, 
Recording Secretary. 
