OcTOBER 27, 1899. ] 
Mr. Chesnut exhibited utensils used by the 
Indian women in the preparation of acorn meal. 
WILLIAM H. Krue, Secretary. 
ASTRONOMICAL NOTES. 
CLOCK RATES AND BAROMETRIC PRESSURE. 
ENSIGN EVERETT Haypen, U. S. Navy, 
publishes in the Publications of the Astronom- 
ical Society of the Pacific, No. 68, an interest- 
ing investigation of the effect of variations in 
barometric pressure upon the rates of clocks 
and chronometers. This study was made at the 
Mare Island Observatory, where chronometers 
are rated for the U.S. Navy, and where the 
time observations are regularly made, which 
are supplied by the Western Union Telegraph 
Company to that part of the country west of 
Ogden, Utah. The paper gives in detail the re- 
sults for the Mean Time Clock of the observatory 
and for three Negus chronometers. The method 
is empirical, depending upon the rates actually 
observed under varying pressure and tempera- 
ture, and the numerical results are obtained 
graphically. From tests of the Mean Time 
Clock extending through two hundred days, it 
is believed that had the rate-curves been used 
without any time observations the errors of 
the noon signal would at no time have ex- 
ceeded six-tenths of a second, and seldom have 
exceeded one-tenth of a second, and at the end 
of the period would have been correct within a 
few hundredths of a second. The barometric 
and temperature curves of the sidereal and 
mean time clocks are now used in the current 
work of the observatory, and the author is of 
the opinion that a first rate pendulum clock is 
a much better instrument than usually sup- 
posed, and actually comparable in uniformity 
with the axial rotation of the earth, if account 
is taken of these variations. The experiments 
on chronometers lead the author to believe 
that the use of a barometric curve in actual 
practice at sea is worthy of trial, and the navi- 
gator of one of our naval vessels now in the 
Pacific will report upon his experience with the 
three chronometers whose rates are discussed 
in the paper. 
STELLAR PARALLAX BY PHOTOGRAPHY. 
A CONTRIBUTION to this subject is made by 
SCIENCE. 
617 
Osten Bergstrand of the observatory at Upsala. 
The author discusses the theory of the reduc- 
tion of measures on the photographic plates 
and the instrumental errors of the Repsold ap- 
paratus employed. The parallax of 21516 A 
is found to be 0.7080 +0.//011 and of A—QOe. 
11677, which has a proper motion of nearly 3/’, 
to be 0.//192 + 0.7018, These determinations 
were made on account of the discrepancies in 
the results of other observers. The paper is in 
Swedish but an abstract in French is supplied. 
JUPITER’S FIFTH SATELLITE. 
PROFESSOR BARNARD has added to our knowl- 
edge of the period of this satellite the results 
of his observations in the last two oppositions 
of Jupiter made with the 40-inch equatorial of 
of the Yerkes Observatory. Combining these 
with the earlier observations at the Lick Obser- 
vatory, the period is 11 h. 57 min. 22.647 sec. 
and is not in error exceeding 0.01 sec. The 
discordancies in the separate determinations are 
very small and the measures show the great 
accuracy attainable in micrometric observations 
with these large refractors upon difficult objects. 
WINnsLow UPTon. 
PROVIDENCE, R. I., Oct. 14, 1899. 
CURRENT NOTES ON METEOROLOGY. 
KITE AND BALLOON METEOROLOGY IN FRANCE. 
Two communications have been made to the 
French Academy of Sciences during the past 
summer by Teisserenc de Bort on the kite and 
balloon work carried on at the Observatory of 
Trappes. Altitudes of 3,940, 3,590 and 3,300 
meters were reached on June 14th, June 15th, 
and July 3d, respectively. The results obtained 
by means of the kite meteorographs during more 
than 100 ascents show that in anti-cyclones the 
rate of decrease of temperature aloft becomes 
slower at a distance of a few hundred meters 
above the ground, and inversions of temperature 
are often observed. In cyclonic areas the de- 
crease of temperature is more rapid. In fine 
weather, with high pressure, the wind velocity 
generally decreases with increasing distance 
from the ground up to an altitude between 
1,500 and 3,000 meters. On the other hand, 
on cloudy days, with low pressure, the velocity 
