COMPUTATION OF ALTITUDES. 355 
Table D being calculated in this manner from observations made at Fort Benton in May, 1854, 
and table Е from observations made at Cantonment Stevens in September of the same year. 
TABLE D.—Abnormal corrections. 
Temperature at— 
Date. T a. m. .2 p. m. 9 p. m. 
Та. m 2 p.m 9 p.m 
1854. | 
May 11 + 154 + 220 + 204 52 67 50 
|; Rope cH ee + 251 + 165 + 124 45 63 45 
13 + 072 + 105 + 024 44 63 51 
14 — 032 — 083 —114 52 62 56 
15 -- 112 — 122 — 104 44 65 54 
16 — 106 — 069 -- 051 52 73 62 
1T — 071 + 008 + 012 60 76 60 
18 ~ —177 — 127 — 052 60 73.5 69 
19 — 132 — 170 — 182 63 74 57.5 
20 = 300° ^ — 043 + 054 ' 69 72,5 66 
21 + 030 + 062 + 076 63 81.5 64 
22 + 061. + 095 + 126 69 87.5 66 
ЕСТЕ Е of abnormal corrections which were used in computing the altitudes from the observa- 
tions made from May 11 to May 22, 1854, between Fort Benton and Badger river, along the 
eastern base of the Rocky mountains, was obtained as follows: The simultaneous observations 
made at Cantonment Stevens, at each particular hour during the above period, viz: from May 
11 to May 22, being reduced to the freezing point and corrected for horary variation by the table 
previously given, were added together and a mean of their several sums taken, the abnormal 
corrections being the difference between these means and each of the several observations. 
Observations were made at Fort Benton during the same period, but as they were made at 
the hours of 7 a. m., 2 р. m., and 9 p. m., they were useless for the purpose of comparison for 
determining the abnormal oscillations. 
TABLE E.—Abnormal corrections. 
Date. Та. m. 9 a. m. 2 p. m, 7 p. m. 
1854. 
September 6 шше — . 066 --.072 —.041 --.051 
6 --.058 --.084 --.024 
Тоо е аш --.062 --.071 55,04 
Ез ааа ааа --.057 --.050 = 042 iht 
‚Ж зел --.010 --.022 + .069 024 
I8... + . 044 + .020 4-.013 + .007 
11 + .076 + . 054 + . 053 + .050 
I iouis coutra oe ae 1.093 + .080 + .038 + .024 
La SIS --.068 —.097 —.074 --.073 
14 ----...... иса 058 --.049 4.009 + .040 
15 — . 058 4.052 4.027 --.013 
16 — , 053 —.094 —.024 = 
17 o EM —.038 —.025 —.14 
