94. REPORT—1840. 
the last Russian expedition, by whom the space between the 
sea of Asov (communicating through the Black Sea and Medi- 
terranean with the ocean), has been accurately levelled, and the 
depression of the Caspian found to be real, but amounting to 
only 81:5 English feet *, instead of 334 feet, as formerly sup- 
posedt+. But what is interesting is, that the barometrical 
observations made with the utmost care, and at multiplied 
intermediate stations (one German mile apart), confirm the 
older results obtained by the same means. The very same 
kind of anomaly as observed between Katherinenburg and St. 
Petersburg, occurs here, and even gives to the elevation of the 
Sea of Asov a negative sign at certain seasons. The Sea of 
Asov, though further south and lower than the Caspian, has a 
climate 30° Fahr. colder in the middle of January f. 
161. There seems to be very little doubt that the Dead Sea 
lies also below the level of the ocean. The very discordant, 
but almost simultaneous results, obtained by different travel- 
lers§, lead us to admit the fact as probable, and even to con- 
jecture that the depression may be considerable. 
162. M. Kamtz|| has given some very useful results as to 
variations of computed height depending on the hour of the 
day, which acts much in the way in which the season of the 
ear affects barometrical measurements. The maximum cal- 
culated height occurs at noon, or soon after; the minimum, about 
4a.m. The effect is far greater than the atmospheric tide would 
produce, amounting to 21— 27 toises upon 1100 (the difference 
of height of the Faulhorn and Zurich, or Geneva), and to 13 
upon 700 (Rigi and Zurich). Hence it appears that Ramond’s 
rule of employing the noon observations for deducing heights 
is not in this respect exact]. : 
163. We do not of course propose to give any results of baro- 
metrical measurements. ‘The temperature of boiling water is 
not unfrequently employed, but seldom with sufficient instru- 
ments. It has several practical difficulties; amongst others, 
that of obtaining sufficient heat at great elevations, and in ex- 
posed situations, to cause water to boil. M. Hugi, of Soleure, 
in his enterprising Alpine excursions**, has used the boiling 
point of alcohol with good effect. It may seem surprising that 
this should be tolerably constant, but such I have assured 
* Poggendorff, 1840, and Edin. Phil. Journal, July 1840. 
+ First Report, p. 239. t See Galle, ut sup. 
§ Edinburgh Philosophical Journal, 1840. 
|| Poggendorff, xxvii. 345, and Dove’s Repertorium, vol. iii. 
€ On the influence of winds on barometrical measurements, see Brandes, 
Beitrdge, p. 216. 
** Naturhistorische Alpenreise. 8vo. Solothurn, 1880. 
