Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 1, Pt. 2

METEOROLOGICAL OBSERVATIONS.
Summary of Barometric and Temperature Oeservation8 at Fort Benton.
c~,
Barometric means corrected. Means and extremes of temperature.',
~ 0
Date.
7 A. M. 2 P. M. 9 P. M Mean. 7 A. M. 2 r. M. 9 P.M. Mean. Maximum. Minimum.,,
_Ynrhes.
September, 1853, (last 7 days) 27.336 27.302 27.309 27.316 56.70 63.00 63.90 60.90 75 51' 1.612
October, 1853..................284.239.251.258 47.13 61.58 50.80 53.07 81 10 0.187
November, 1853................235.212.235.227 12.90 27.40 18.13 19.48 58 -2 0.300
December, 1853................218.193.197.203 27.16 41.39 30.52 33.00 60 0 0.000
January, 1854..................264.232.245.247 13.74 22.52 13.26 16.52 61 -24 1.592
February,1854.................192.135.151.159 ]8.71 36.79 24.43 26.63 57 -6 3.410
March, 1854...................192.141.191.174 30.65 46.52 31.36 36.18 71 12 3.420
April, 1854.....................203.150.162.172 50.33 64.87 50.40 55.20 81 38 f0.400
May, 1854......................173.111.103.129 51.73 67.34 55.82 58.30 89 32 t1.100
June, 1854....................170.104.097.124 63.10 77.20 64.70 68.30 91 49 t0.450
July, 1854......................290.299.249.256 69.80 82.70 68.40 73.60 100 49 ~ -
August, 1854...................260.202.198.220 72.10 86.61 70.57 76.43 98 62 -
Mean of all............. 27.227 27.180 27.192 27.200
Means of temperature-spring, 49.89'; summer, 72.78'; autumn,~ 46.85'; winter, 18.38~; year, 48.72%.
Altitude of Fort Benton from these observations, 2662.9 feet.
* For the last seven days only.
f In part, several rains not measured.
t Two days on which rain fell.
!l Four days on which rain fell.
~ Mean for September assumed at 68~. See remarks for notice of the peculiar temperatures of the seasons.
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