1875.] (543 ) 
THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF 
SCIENCE. 
| ae limited space at our disposal will not allow of more than a brief 
notice of the 1875 meeting of the British Association, which commenced 
on August 25th at Bristol. The local committee, of which Mr. W. Lant 
Carpenter and Mr. F. Clarke were secretaries, had made every possible 
arrangement for the comfort and convenience of the visitors. There were 
not wanting incidents to remind the members of the rapid progress in science 
during the 39 years which had elapsed since the previous meeting of the 
Association in Bristol. It was at Bristol in 1836 that the Mechanical Section 
was first instituted, and the President in his inaugural address drew attention 
to the fact that at a meeting of that section Dr. Lardner expressed the opinion 
that no steamboat would ever cross the Atlantic. Shortly after, however, the 
Sirius steamed from Bristol to New York in 17 days, and was soon fol- 
lowed by the Great Western, which made the homeward passage in 134 
days. We have also been reminded that at the Bristol meeting in 1836 
Andrew Crosse expressed the belief that by means of electricity instantaneous 
communication with all parts of the world would one day be accomplished. 
At the second sozrée this year a display of telegraphic instruments was made by 
the Post Office and telegraphic communications were maintained with Paris, 
London, and other places throughout the evening. 
In introducing Sir John Hawkshaw as President for the year, Prof. Tyndall said : 
“Tn him I doubt not you will have a wise and prudent head, a leader not likely to be 
caught up into atmospheric vortices of speculation about things organic or inor- 
ganic, about mind or matters beyond the reach of mind, but one who, struggling 
Anteus-like, with his subje& here to-night, will know how to maintain through- 
out arefreshing contact with his mother earth. I have looked forward for some 
time to the crowning ad still in prospect of his professional career, to give 
our perturbed spirits rest in crossing the Channel in visiting our fair sister 
Frarce. But pending that great achievement, it is his enviable lot to steer 
this British Association through calm waters to a haven of, at all events, 
temporary rest—rest all the more sweet and needful from the tempestuous 
weather which rasher navigators who preceded him thought it their duty to 
encounter rather than to avoid. To his strong hand I commit the helm of 
our noble barque, wishing him not only success, but triumph in that task he 
has undertaken, and which I now call upon him to fulfil.” 
Sir John Hawkshaw, F.R.S., delivered a long and able address on the 
origin, history, and progress of the science of engineering. 
Several of the sectional addresses possessed unusual merit; they do not, 
however, admit of sufficient compression for us to give abstracts of them. 
The papers on subjects connected with physical science were not so numerous 
as on some former occasions. Several of those read, however, were of great 
value. 
Professor Everett presented the report of the Underground Temperature 
Committee, which has now been in existence eight years. He gave an 
interesting account of investigations in the St. Gothard Tunnel. The dis- 
tance now penetrated is more than a mile and a half at each end, and the 
temperature is found to be higher in the Swiss than in the Italian end, although 
the thickness of rock overhead is less. The length of the tunnel when com- 
pleted will be nine miles, and the greatest depth beneath the surface two miles. 
Dr. Guthrie, F.R.S., read a paper ‘‘ On the Measurement of Wave Motion.” 
By means of cylindrical troughs, he shows that the rate of undulation varies 
inversely as the square root of the diameter. This confirms the assertion 
that the rate of wave progress varies directly as the square root of the wave 
length ; because the rate of recurrence must vary as the rate of progression 
divided by the path. 
Dr. J. Hopkinson read an important paper by Professor Stokes and himself 
** On the Optical Properties of Titano-Silicic Glass.”” The principal obje& 
for the experiments, viz., the production of a titano-silicic glass suitable for 
destroying the secondary spectrum in an achromatic combination, has not 
been attained. 
_ VOL. V. (N.S.) 32 
