. ON THERMOMETRIC OBSERVATIONS IN THE ALPS, ‘363 
On Thermometric Observations in the Alps. 
By J. Bau, M.RIA., FL.S., &c. 
At the Meeting of the British Association at Oxford in 1860, the writer 
laid before the Section of Mathematics and Physics a plan for the systematic 
observation of temperature in the chain of the Alps, and other mountain 
countries, in which several members of the Alpine Club had been induced to 
oin. 
Thermometers of uniform construction had been prepared for the purpose 
by one of our best makers, Mr. Casella, and forms were printed with the ob- 
ject of securing as far as possible a uniform and complete record of such 
observations as should be procured. - 
The conditions under which these observations were to be made, and the 
fact that most of the observers were not professed men of science, made it 
indispensable to limit the plan so as to include only such objects as might be 
accomplished without much expenditure of time and labour, and by means 
of very light and portable instruments. 
Four objects were suggested for inquiry :— 
1st. The determination of the minimum temperature on or near to the 
higher peaks of the Alps, and other mountains, by means of self-registering 
instruments fixed in suitable positions. 
2nd. To obtain comparative observations of the effects of the radiant heat 
of the sun upon black-bulb thermometers, 
3rd. To trace the propagation of disturbances of temperature throughout a 
mountain district by the multiplication of observations at a number of differ- 
ent points. 
4th. Observations on the temperature of the surface, and the upper layers 
of the soil, at great elevations, 
Unexpected circumstances have prevented the writer from visiting the 
Alps during the last two years, and have very much restricted his opportu- 
nities for carrying out his own share of the work ; and however moderate the 
expectations were which he had formed, the difficulties in the way of obtain- 
ing definite results have proved to be even greater than he anticipated; so 
that the plan has proved to be in some respects a complete failure, while in 
others a limited degree of success has attended it. 
1. In regard to the observations obtained by placing minimum thermo- 
meters at great heights, the principal share of merit in whatever has been 
accomplished is due to Mr. F. F. Tuckett, of Bristol, who is well known as a 
very active and successful mountaineer, and a careful observer. He has 
placed a considerable number of instruments at heights ranging from 7000 
to 14,000 feet, and has collected and arranged the observations made by 
various travellers upon the instruments so deposited by himself or by others. 
The following is a summary of the work done, and the results obtained, 
with which the writer has been favoured by Mr. Tuckett :— 
« Having been requested by the Committee of the Alpine Club to under- 
take the registration of such data as might result from the exposure of regis- 
- tering-thermometers on the loftiest summits of the Alps, I am able to supply 
the following brief account of what has been effected. 
“The conditions of success were (1) the cooperation of as large a number 
as possible of our mountaineers; (2) correctness and uniformity in the instru- 
ments employed ; (3) a judicious exposure which should secure them alike 
from the influence of radiation and the protective effect of heavy falls of 
snow, especially in winter; and (4) some mode of firm attachment which 
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