1875.] The British Association. 545 
A meteor burst with a loud detonation over Paris on the roth February, of 
great size and brilliancy, and left a cloud like a streak of light in its track for 
nearly half an hour. No duplicate observation of it was obtained in England. 
Another fireball fell at Orleans on the gth March, and of this two good obser- 
vations were obtained in England—in London and Essex. The problem of the 
connection between comets and meteors had now become so great as to pass 
beyond the power of the Association to grapple with it in its fullest extent. 
There was a great deal of work yet to be done, and he was glad to state that 
Professor Le Verrier, of Paris, had made arrangements with some six thou- 
sand gentlemen who in different parts of France and her colonies would devote 
night after night to the study of meteoric astronomy. 
Professor Herschell added some particulars of the work of the committee 
with regard to the connection between meteors and comets, and stated that the 
aérolites were stone bodies differing very little from volcanic rocks. 
Sir William Thomson said the evidence they had with regard to the mass of 
comets was altogether negative. There was nothing in observations to justify 
the assertion of their being so extremely small as sometimes said. It would 
be interesting to obtain some definite knowledge of the mass of a comet, by 
comparison with some other body of the solar system. The whole subject still 
presented great difficulty, and the whole of the wonderful phenomena were not 
fully explained, but he thought that on the whole they might consider it quite 
established that the comet’s tail was really a train of meteors. 
Mr. G J. Symons presented the report of the Rainfall Committee. During 
the past fifteen years the number of stations has been raised from 241 to 
nearly 2000. 
Relative to the rainfall in Monmouthshire and the Severn Valley on July the 
14th, Mr. Symons said the rainfall was simply a mass of vapour that came up 
from the west, and it commenced at Tenby between midnight and one a.m. on 
the morning of the r4th July. It travelled at the rate of about 18 miles an 
hour, and at four p.m. in the same day it passed off by the north coast to Nor- 
folk. As to its breadth it took about 36 hours to pass over any given points. 
The quantity of water that fell varied very much over the whole country, and 
was deepest the west side of a line drawn from the Isle of Wight to the Isle 
of Sheppey, and thence to the north-east. Some stations in Monmouthshire 
and Glamorganshire had a rainfall of over 3 inches; at fourteen stations 
the rainfall exceeded 4 inches; at six it was over 5 inches; and at Tintern 
Abbey, usually considered a dry station, the rainfall was 5°31 in 24 hours. 
This was followed with storms in which from 2 to 3 inches of rain fell. At 
Tamunk there was the extraordinary fall of g} inches in 8 days, or one-third of 
the average rainfall for a year. 
Professor Hennessy read a paper on “ The Influence of the Physical Proper- 
ties of Water on Climate.” The author believes that of all substances largely 
existing in nature water is the most favourable to the absorption and distribu- 
tion of solar heat throughout the external coating of the earth. 
The same author also read a paper ‘“‘ On the Possible Influence on Climate 
of the Substitution of Water for Land in Central and Northern Africa.” 
Captain Abney, R.E.,ina paper ‘‘ On the Increase of AGtinism due to Differ- 
ence of Motive Power in the Electric Light,” described the results which had 
been observed in some experiments made for Government upon magneto- 
electric machines. 
Prof. H. A. Rowland, of Baltimore, described his method of testing the dis- 
tribution of magnetism in iron bars and also his experiments on the magnet- 
ising function of iron, nickel, and cobalt. 
The report of the Committee on the Thermal Conductivity of Rocks 
affirms that quartz is the best and coal the worst conductor. 
A paper was contributed by Prof. Osborne Reynolds ‘‘ On the Force caused 
by the Communication of Heat between a Surface and a Gas.” 
The following papers were also read by M. Janssen “ On the Eclipse of April 
5th, 1875,” ‘“ On the Actual Position of the Magnetic Equator in the Gulf of 
Siam and the Gulf of Bengal,” ‘‘ On Mirage at Sea.” 
