DECEMBER 11, 1913] 
NATURE 
437 
countries were in opposite directions in all seasons, 
as indicated by the correlation coefficient, but the 
results were much more definite for the first and last 
quarters of the year, when the values of r were 
—o'72 and —o43 respectively. Mr. Craig then pro- 
ceeded to calculate the values of r between Egypt and 
other European stations, and by using the values 
found he drew lines of equal correlation. A little 
thought shows what a powerful method he has in- 
augurated for dealing with the problem of centres of 
action and for localising the centres in a definite 
manner. It will be for each country in the future to 
work out the monthly or seasonal iso-correlational 
lines with itself as base, and to use the charts ob- 
tained in determining what information will be useful 
to it in making its own seasonal forecasts. 
Mr. E. Gold and Mr. F. J. W. Whipple showed some 
curves of frequency of temperature for Kew and 
Valencia Observatories, which exhibited a double 
maximum in the annual curve. Roughly speaking, 
the year may be divided as regards temperature into 
three seasons, winter, summer, and equinoctial, each 
season including four months. If the temperature of 
a particular day of the year were always the same in 
different years, we should get a relatively large 
number of warm days at the time of the summer 
maximum, when temperature changes but slowly from 
day to day and of cold days at the time of the 
winter minimum. Actually, the temperature of a 
particular day of the year varies considerably, and 
the result is that the temperatures occurring most 
frequently are not the extremes, but are closer to the 
mean, and it may happen that they meet and give one 
single temperature of most frequent occurrence if 
the annual variation is small enough compared with 
the variability of a particular day. It may be noted 
for places similar to Kew in their temperature varia- 
tions, that in order to experience the largest number 
of days of temperature 60° F., say, it is necessary to 
select a place with a mean maximum temperature, 
either 4° or 5° above 60° F. or 4° or 5° below 60° F. 
Dr. J. S. Owens discussed the conditions to be ful- 
filled by an approved method of measuring atmo- 
spheric pollution, and considered in turn nine different 
methods, none of which were entirely free from 
objection. One of the simplest, that of collecting the 
deposit from the atmosphere ip a gauge of known 
area, has been adopted by the Committee for the 
Investigation of Atmospheric Pollution. 
Dr. Vaughan Cornish described a simple method of 
determining the period of waves at sea by observing 
the interval between the times when a patch of spent 
foam is on the crest of successive waves. The 
method appears to be an excellent one, and ought to 
be brought to the notice of marine meteorologists, but 
it is desirable that observations should be made, in 
connection with the method, to determine what cor- 
rection is necessary owing to the effect of wind on 
the foam. 
Prof. H. H. Turner, in presenting the report of 
the seismological committee, referred to the great loss 
which seismology had sustained through the death 
of Prof. Milne, who had invariably given some account 
of the year’s work and progress at the annual meet- 
ing of the association ever sincs the committee was 
formed nearly twenty years ago. Since his death the 
committee had had an anxious time; it was agreed 
that the work must be carried on, and the committee 
had decided that for the present it could not do better 
than arrange for the collection and discussion of 
records to be carried on at Shide so far as possible 
without alteration. Mr. J. J. Shaw, who gave a 
description of his instrument which was working in 
the basement of the building, had succeeded in 
NO. 2302, VOL. 92] 
making a satisfactory damping arrangement for the 
Milne seismograph; this removed the most serious 
objection which had been raised to the Milne instru- 
ment, and it was hoped that the network of stations 
reporting to Shide would be able to add a “damped” 
instrument to their equipment. 
The Rev. H. V. Gill, S.J., read a paper on the dis- 
tribution of earthquakes in space and time. He con- 
cluded that at least 60 per cent. of recorded earth- 
quakes were associated with others in their neigh- 
bourhood. 
The Rev. W. O’Leary, S.J., discussed the sources of 
disturbance of seismometers which are especially 
sensitive to convection currents. A statement that 
certain periodic variations were due to the beating 
of the waves on the west coast of Ireland was chal- 
lenged by Dr. Vaughan Cornish, who pointed out 
that the resultant effect of the waves on an irregular 
coast-line would not have the wave-period; it would 
probably not be periodic at all. 
The Rev. A. L. Cortie, S.J., discussed the connection 
between sun-spots and terrestrial magnetic disturb- 
ances, and suggested that the equatorial rays of the 
solar corona might represent the stream lines of the 
solar influence, active in magnetic storms. 
Dr. S. Chapman gave an account of an investiga- 
tion into the periodic variations of magnetic force, 
by which he sought to test and extend Schuster’s 
suggestion that the changes are due to the motion 
of ionised air across the vertical magnetic field. He 
dealt particularly with variations of lunar period, and 
found that he got eight complex curves for different 
phases of the moon, which could be resolved into a 
semi-diurnal variation, and a diurnal variation of 
which the epoch changed during the month—a change 
which he attributed to variation in the ionisation of 
the upper atmosphere due to the variation in the 
solar-hour angle. 
In a joint meeting with Section E, important 
geodetic questions were discussed. An account of this 
discussion is given in the report of the proceedings of 
Section E. 
On Monday the meteorologists and other cosmical 
physicists met together for the annual ‘‘ meteorological 
luncheon,”’ and taking to heart Sir Joseph Larmor’s 
comment on the results achieved at the Mount Wilson 
Solar Observatory, that ‘tif the meteorologists were 
not careful we should soon know more about the 
sun’s atmosphere than we did about the earth’s,” 
the meteorologists accorded the place of principal 
guest to Prof. Hale’s representative, Mr. C. E. 
St. John, who promised to remember them at his 
mountain shrine. 
GEOGRAPHY AT THE BRITISH 
ASSOCIATION. 
ye the conclusion of the president’s address in 
Section E (Geography), Dr. W. S. Bruce pre- 
sented his newly completed map of Prince Charles 
Foreland, Spitsbergen—an island of about 250 square 
miles, half of which is below the too-foot contour line 
and one-fifth covered by glaciers. The rest consists 
of mountains and huge moraines. The height of 
Saddle Mount was fixed at 1406 ft., and the Devil’s 
Thumb at 2602 ft. Ona later day he gave an account 
of the economic resources of Spitsbergen, chief among 
which is an excellent steam coal bordering a splendid 
harbour, at present mined chiefly by Americans. In 
view of negotiations from Russia for the purchase of 
these coal measures, lying only fifty-three hours by 
cruiser from our coasts, he urged the immediate 
annexation of the island by the British Government. 
Mr. N. Dracopoli described his journey across 
