SEPTEMBER 24, 1897.] 
rate of variation of the specific heat of 
water were in agreement with those of 
Griffiths, but there was a difference of about 
one part in 400 in the absolute value at any 
point. This point was particularly referred 
to in the Report of the Hlectrical Standards 
Committee, and it was suggested that the 
discrepancy might be due to an error of 
0.1 % in the assumed value of the electro- 
chemical equivalent of silver. 
The last paper read was by Professor H. 
L. Callendar and N. N. Evans, ‘On the Be- 
havior of Argon in X-Ray Tubes.’ The 
authors had expected to find that pure 
argon, in consequence of its inertness and 
its supposed monatomic character, would 
give a very constant vacuum in such tubes. 
They found, however, that if the gas were 
very carefully dried, the resistance of the 
tube increased very suddenly, and the elec- 
trodes were melted or spattered over the 
walls as the vacuum approached the X-ray 
stage. ‘The presence of residual hydrogen 
appeared to be necessary to enable the dis- 
charge to pass from the cathode to the gas. 
These effects were substantiated by experi- 
ments with other gases. 
On Saturday the majority of the mem- 
bers dispersed on excursions to Niagara and 
various other places of interest, and with 
the exception of the Geological Section 
there were no meetings. 
On Monday the section divided into two 
departments, Meteorology and Mathe- 
matics, and those specially interested in 
electrical work repaired to Section G, which 
devoted itself on this day to electrical ques- 
tions. In the meteorological department 
papers were read by John Hopkinson ‘ On 
Monthly and Annual Rainfalls at Ten Sta- 
tions in the British Empire, 1877 to 1896.’ 
It appears doubtful, however, whether so 
listed a series of observations can be taken as 
representative of the pluviology of the Em- 
pire. By Dr. Van Rijckevorsel ‘On the Tem- 
perature of Hurope.’ From certain peculiar 
SCIENCE. 
469 
maxima and minima exhibited by the 
curves of daily temperature, he considers 
that the continent may be divided into two 
regions in which a different type of weather 
prevails. R. F. Stupart, the Director of the 
Meteorological Service of Canada, con- 
tributed a paper on the ‘Climatology of 
Canada.’ F. Napier Denison, from a com- 
parison of simultaneous records of changes 
of level in the Great Lakes and of smaller 
undulations in the atmospheric pressure by 
by means ofa sensitive barograph, concludes 
that the larger differences are due to differ- 
ence of atmospheric pressure over the ex- 
tremities of the lake, but may be greatly 
augmented by the action of the wind on the 
surface of the water. The smaller undula- 
tions appear to be due to atmospheric 
waves caused by currents in different strata 
traveling in opposite directions, as shown by 
Helmholtz. Papers were also contributed 
by Rotch and Marvin ‘On the Exploration 
of the Air by Kites,’ showing how it was 
possible by means of recording instruments, 
sent up to great elevations attached to a 
kite to obtain information with regard to 
the temperature and hygrometric condition 
of the air, which would be of use in forecast- 
ing. It would appear, however, that there 
is still much to be done in improving the 
recording hygrometer. 
In the department of mathematics there 
were several papers of esoteric interest. 
Alexander Macfarlane made an application 
of hyperbolic analysis to the solution of the 
cubic equation. Dr. Harris Hancock dis- 
cussed the history of the Abelian Functions. 
Professor O. Henrici proposed a convenient 
notation in Vector Analysis, upon which it 
would be difficult to express an opinion 
without extended use by different workers 
and authorities in the subject. Professor 
Michelson and A. W. Stratton described 
some new Harmonic Analyses, in which they 
had succeeded in carrying the process as far 
as 80 terms. Papers were also contributed 
