ON THERMOMETRIC OBSERVATIONS IN THE ALPS. 365 
produce a ‘solution of continuity’ in the column of spirit, which has 
acquired amongst our mountaineers the expressive name of the ‘ bubble com- 
laint.’ 
x In one instance an observer, whose accuracy I have no reason to doubt, 
informs me that he could detect no trace whatever of spirit, nor any indication 
of fracture in the glass by which it could have escaped. The index lay 
‘high and dry’ at the bottom of the bulb. This extraordinary result he 
attributes to ‘a sort of volatilization of the contained spirit ;’ and though it 
seems difficult to understand how it could have taken place to the extent 
mentioned, there is little doubt that vaporization of the contained spirit to 
an extraordinary extent will occur, as pointed out by Dr. Hooker some years 
ago in the Appendix to his ‘ Himalayan Journal.’ If my informant’s state- 
ment appear exaggerated, I hope the probable truth which underlies it may 
draw attention to the question. 
«The causes just alluded to, and the comparatively short time which has 
elapsed since these observations were commenced, must be accepted as some 
justification of the meagreness of the results. 
‘«« The readings of the minimum temperature of the autumn and summer 
months at elevations of 9000 to 15,000 feet (Table III.) appear rarely to fall 
below —10° Cent., or if they do, the condition of the thermometer is generally 
stated by observers to be suspicious. The lowest winter reading registered is 
—41°C., in the case of a thermometer placed on the Col d’Argentiére at a 
height of upwards of 12,000 feet; but as when observed the spirit had separated, 
we have no right to assume that it had not done so before the index 
attained its actual position. We have, however, four observations which 
seem entitled to entire- confidence as far as the instrument is concerned, 
though one at least certainly does not represent the lowest temperature of 
the air. The minimum on the Becca di Nona, near Aosta, carefully deposited 
in a cairn at a height of 10,382 feet, has been found in perfect working 
order after the lapse of two years. My excellent friend M. Carrel informs me 
that the minimum temperature of the winter of 1860-61 and 1861-62 
was respectively — 27° and — 23°C. (— 17° and — 10° Fahr.). Again, 
a similar instrument on the Col d’Erin, at a height of 11,408 feet, was 
found in perfect preservation by Mr. Whately last autumn after exposure 
during one winter, that of 1860-61. Its minimum reading was — 21°C. 
(— 6°Fahr.); but as earlier in the season I was unable to find it, though 
it had been deposited by myself in 1860, there is no doubt that it must have 
been buried in the snow during either the spring or winter, and thus its indi- 
cations are probably considerably too low, since for the same period the tem- 
perature on the Becca di Nona (1000 feet lower) fell to — 27°. Lastly, a 
thermometer placed last year in a cairn on Scaw-Fell Pike appeared to be in 
good order this spring, and registered — 10°C, (+ 14° Fahr.) as the greatest 
winter cold. 
«To the above observations it may not be amiss to add one by M. Lizat on 
the Pic de Nethou, the highest point of the Pyrenees (11,168 English feet). 
This instrument, placed at the summit, registered — 24°:2 C, in the winter 
of 1857. If we compare the preceding observations with the registers kept 
at Geneva and the Great St. Bernard, we have during the winter 1859-60 
at Geneva the minimum readings of — 23° on 21st Dec. 1859, and — 11°1 
on 16th February 1860. Corresponding to these, the lowest temperatures 
recorded at the Great St. Bernard were — 27°:2 on 16th December 1859, 
and — 25°-3 on 10th March 1860. Even allowing that we are not certain 
that the instruments at levels higher than the Great St, Bernard were clear 
