49 BAROMETRICAL OBSERVATIONS. Feb. 1827. 
the mercury 43°.* Unfortunately the day was very cloudy, 
and many squalls of sleet and rain, which obscured the hills, 
passed whilst I was taking bearings. To the N.E., towards 
the supposed Sebastian Channel, the horizon was too hazy to 
allow much view. A deep inlet was seen in that direction; 
but whether the land closed round, or whether a channel was 
at the bottom, we could not distinguish. A considerable body 
of water was observed to the southward of Cape St. Valentyn, 
behind Lomas Bay, but its extent was screened from our view 
by the intervention of the Lomas hills. It appeared to be a 
channel, the opposite or eastern side of it being formed by the 
high ranges previously seen from Point St. Mary. Cordova’s 
Ports San Antonio and Valdez were distinctly made out; but, 
to the southward, every thing was enveloped in mist. 
The bearings and observations, which occupied me nearly 
two hours, being completed, we all adjourned to a sheltered 
cleft in the rock close to our station, where we soon recovered 
the use of our fingers.+ 
* The result of the barometric observation for the height of Mount Tarn 
is as follows: 
9 ‘ 
{ Hath The 25065 
: f ascent eenotie ’ 
Do. two do. ‘descent, 596-7\f0e™ 2,608-0 
Height by one barometer 
2,602:2 
By angular measurement from Observation Cove, Port Famine, with 
theodolite, allowing 4 of the intercepted are for terrestrial refraction, the 
height is 2,850 feet. 
Another observation, with the sextant, made it 2,855 feet. The mean 
2,852 I consider more correct, from the difficulty of obtaining a correct 
reading of the barometer on the summit. 
+ By Daniell’s hygrometer, used in this sheltered spot, I found the 
temperature of the air to be 48°; dew point 41°: but upon exposing the 
instrument to the wind, the air was 393°, and the dew point 36°: the dif- 
ference in the former being 7°; and the latter 3°; from which the fol- 
lowing results are obtained : 
air. dewpt. diff exp. dryness. Weight of a cubic, 
oot of air. 
In the ravine 48 4] 7 292 776 - : 
Exposed to wind 394 36 } 248 898 2°871 
Difference 83 5 3h 44 122 0-452 
The 
