_The Longitudes given in the subjoined Table are referred to the
meridian of Greenwich._
For the determination of astronomical positions, we were provided with
the following instruments:
One telescope, magnifying power 120.
One circle, by Gambey, Paris.
One sextant, by Gambey, Paris.
One sextant, by Troughton.
One box chronometer, No.7,810, by French.
One Brockbank pocket chronometer.
One small watch with a light chronometer balance, No.
4,632, by Arnold and Dent.
The rate of the chronometer, 7,810, is exhibited in the following
statement:
"NEW YORK, May 5, 1842
"Chronometer No. 7,810, by French, is this day at noon--
"_Slow_ of Greenwich mean time, 11' 4"
"_Fast_ of New York mean time, 4_h._ 45' 1"
"Loses per day 2".7
"ARTHUR STEWART, 74 Merchants' Exchange."
An accident among some rough ground in the neighborhood of the Kansas
river, strained the balance of this chronometer, (No. 7,810) and
rendered it useless during the remainder of the campaign. From the 9th
of June to the 24th of August, inclusively, the longitudes depend upon
the Brockbank pocket chronometer; the rate of which, on leaving St.
Louis, was fourteen seconds. The rate obtained by observations at Fort
Laramie, 14".05, has been used in calculation.
From the 24th of August until the termination of the journey, No. 4,632
(of which the rate was 35".79) was used for the same purposes. The rate
of this watch was irregular, and I place little confidence in the few
longitudes which depend upon it, though, so far as we have any means of
judging, they appear tolerably correct.
_Table of Latitudes and Longitudes, deduced from Observations made
during the Journey._
Date Station Latitude. Longitude.
1842 Deg. min. sec. Deg. min. sec.
May 27 St. Louis, residence
of Colonel Brunt,.......38 37 34
June 8 Chouteau's lower
trading-post; Kansas
river,..................39 05 57 94 25 46
16 Left bank of Kansas
river. 7 miles above
the ford,...............39 06 40 95 38 05
18 Vermilion creek.........39 15 19 96 04 07
19 Cold springs, near
the road to Laramie,..39 30 40 96 14 49
20 Big Blue river, ........39 45 08 96 32 35
25 Little Blue river, .....40 26 50 98 22 12
26 Right bank of Platte
river,..................40 41 06 98 45 49
27 Right bank of Platte
river...................40 39 32 99 05 24
28 Right bank of Platte
river, .................40 39 51
30 Right bank of Platte
river...................40 39 55 100 05 47
July 2 Junction of north and
south forks of the
Nebraska or Platte
river,..................41 05 05 100 49 43
4 South fork of Platte
river, left bank,
6 South fork of Platte
river, island...........40 51 17 103 07
7 South fork of Platte
river, left bank........40 53 26 103 30 37
11 South fork of Platte
river, St. Vrain's
fort ,..................40 22 35 105 12 12
12 Crow creek,.............40 41 59 104 57 49
13 On a stream, name
unknown ................41 08 30 104 39 37
14 Horse creek. Goshen's
hole? ..................41 40 13 104 24 36
16 Fort Laramie, near
the mouth of Laramie's
fork, ..................42 12 10 104 47 43
23 North fork of Platte
river...................42 39 25 104 59 59
24 North fork of Platte
river...................42 47 40
25 North fork of Platte
river, Dried Meat camp..42 51 35 105 50 15
26 North fork of Platte
river, noon halt........42 50 08
26 North fork of Platte
river, mouth of Deer
creek,..................42 52 24 106 08 24
28 North fork of Platte
river, Cache camp,......42 50 53 106 38 26
29 North fork of Platte
river, left bank........42 38 01 106 54 32
30 North fork of Platte
river, Goat island......42 33 27 107 13 29
Aug. 1 Sweet Water river,
one mile below Rock
Independence,...........42 29 56 107 25 23
4 Sweet Water river.......42 32 31 108 30 13
7 Sweet Water river.......42 27 15 109 21 32
8 Little Sandy creek,
tributary to the
Colorado of the West,...42 27 34 109 37 59
9 New fork, tributary to
the Colorado,...........42 42 46 109 58 11
10 Mountain lake,... ......42 49 49 110 08 03
15 Highest peak of the
Wind River mountains,
19 Sweet Water, noon
halt,...................42 24 32
19 Sweet Water river,......42 22 22
20 Sweet Water river,......42 31 46
22 Sweet Water river,
noon halt,..............42 26 10
22 Sweet Water river,
Rock Independence,......42 29 36
23 North fork of Platte
river, mouth of Sweet
Water, .................42 27 18
30 Horse-shoe creek,
noon halt,..............42 24 24
Sept 3 North fork of Platte
river, right bank,......42 01 40
4 North fork of Platte
river, near Scott's
bluffs..................41 54 38
5 North fork of Platte
river, right bank,
six miles above
Chimney rock,...........41 43 36
8 North fork of Platte
river, mouth of Ash
creek,..................41 17 19
9 North fork of Platte
river, right bank.......41 14 30
10 North fork of Platte
river, Cedar bluff,.....41 10 16
16 Platte river, noon
halt....................40 54 31
16 Platte river, left
bank, ..................40 52 74
17 Platte river, left
bank,...................40 42 38
18 Platte river, left
bank, ..................40 40 21
19 Platte river, left
bank....................40 39 44
20 Platte river, noon
halt, left bank, .......40 48 19
20 Platte river, left
bank,...................40 54 02
21 Platte river, left
bank ...................41 05 37
23 Platte river, noon
halt, left bank.........41 20 20
23 Platte river, left
bank ...................41 22 52
25 Platte river, mouth
of Loup fork,...........41 22 11
28 Platte river, mouth
of Elk Horn river.......41 09 34
29 Platte river, left
bank,...................41 02 15
Oct. 2 Bellevue, at the post
of the American Fur
Company, right bank of
the Missouri river......41 08 24 95 20
4 Left bank of the
Missouri, opposite to
the right bank of the
mouth of the Platte.....41 02 11
5 Missouri river,.........40 34 08
6 Bertholet's island,
noon halt,..............40 27 08
6 Missouri river, mouth
of Nishnabatona river, .40 16 40
8 Missouri river, left
bank ...................39 36 02
10 Missouri river, mouth
of the Kansas river.....39 06 03
* * * * *