714 
in the accumulation and tabulation of replies to its 
circular letter relative to photographs of Halley’s 
comet. From these replies there has been con- 
structed a card catalogue exhibiting in chronolog- 
ical order the material available for a photo- 
graphic history of this comet during its appearance 
of 1910. At present this catalogue consists of 
about a thousand titles, but it can not be regarded 
as complete, owing to the absence of reports from 
several important sources. 
Correspondence is being conducted in the en- 
deavor to supply as far as may be the missing 
data, but it is already apparent that the existing 
gaps can not be completely filled. A period of 
very great activity in photographing the comet 
accompanies the date of its nearest approach to 
the earth, but this is preceded by an epoch of 
comparative neglect and is followed, in July, 1910, 
by an apparently complete cessation of photo- 
graphic work upon the comet, continuing until 
December, when some exposures were made at the 
Lick Observatory and reported to the committee. 
It is earnestly hoped that these lacune will be 
filled by observations not yet reported to the 
committee. 
As soon as the card catalogue can be regarded 
as reasonably complete it is the purpose of your 
committee to select from it such data for repro- 
duction as will best serve its purpose of construct- 
ing a graphic history of the comet’s appearance in 
the years 1909-10. 
Report of the Committee on Photographic As- 
trometry: EF. SCHLESINGER (chairman). 
The chairman reported briefly on the progress 
made since the meeting at Ottawa four months 
earlier, at which a full report had been read. It 
appears that the most immediate duty of this com- 
mittee is to study the movements of a pier during 
the course of a night, and if possible to devise 
some method by which a pier can be kept station- 
ary within small amounts. For this purpose a 
10-inch photographie telescope of 100 inches focal 
length has been constructed, and is now being 
mounted upon a pier at the Allegheny Observatory. 
The pier and telescope are to be kept at a nearly 
constant temperature in a basement room at the 
observatory. At frequent intervals throughout the 
night, short exposures are to be made upon the 
region of the pole, access to this part of the sky 
being obtained through a window of plane parallel 
glass. Dr. Schlesinger also referred briefly to the 
progress made by Dr. Ross with the photographie 
zenith-tube designed by the latter and mounted by 
SCIENCE 
[N.S. Vou. XXXV. No. 905 
him at the International Latitude Station at 
Gaithersburg. The material thus far secured indi- 
cates a considerable reduction in accidental errors, 
as compared with the best work of the zenith tele- 
scope by Talcott’s method. This instrument had 
been in operation during a few months only, and 
consequently no information is as yet forthcoming 
as to the freedom of the method from systematic 
error. 
A verbal report by Professor C. L. Doolittle, 
chairman of the committee on cooperation in the 
teaching of astronomy, was followed by an ex- 
tended and profitable discussion. 
Late in the afternoon of Friday, December 29, 
the society adjourned to reassemble at the Alle- 
gheny Observatory, Pittsburgh, in the following 
August. 
R. H. Curtiss, 
Editer for the Meeting 
ANN ARBOR, 
February, 1912 
SOCIETIES AND ACADEMIES 
THE ACADEMY OF SCIENCE OF ST. LOUIS 
THE meeting of the Academy of Science of St. 
Louis was held at the Academy building on Mon- 
day, March 18, 1912, at 8 P.M., President Engler 
in the chair. 
_ Professor C. A. Waldo, of Washington Univer- 
sity, addressed the academy on ‘‘The Problems of 
Coal Exhaustion. ’’ 
““Miniature Flint Arrows’’ was the subject of 
a short paper by Dr. H. M. Whelpley, who illus- 
trated his remarks with over 2,000 specimens, 
varying in length from .06 to 1 inch. In form 
they represent all of the common types of ordinary 
arrows and were evidently made by the same proc- 
ess of pressure chipping. Specimens have been 
found in England, Spain, Belgium, India, Pales- 
tine, Egypt and the United States. These arti- 
facts belong to the Neolithic age. It has been 
suggested, but without evidence, that they were 
made by a pygmy race of human beings. It is 
also claimed that they were barbs for harpoons, 
tattooing instruments, fish snags or drills for skin 
and shell work. Dr. Whelpley concludes that the 
medium size and larger miniature arrows, such as 
are very plentiful along portions of the Missouri 
and Meramee Rivers, were used as arrow heads. 
The most minute ones he considers examples of 
skill in flint chipping, the same as the miniature 
baskets made by the Pomo Indians to-day are 
merely examples of skill in basketry. 
