The following is taken from Notes of a Military Reconnoissance...,
by William H. Emory. Spelling
and punctuation are as they appear in the original.
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WASHINGTON, September 1,
1847
To Col. J. J. Abert,
Chief of the Corps of Topographical Engineers:
Sir: The following order was received by me June 5th, 1846:
BUREAU OF TOPOGRAPHICAL
ENGINEERS,
Washington, June 5, 1846.
SIR: You will repair, without delay, to Fort
Leavenworth, and report yourself and party to Colonel Kearny, 1st dragoons,
as field and topographical engineers of his command. In addition
to yourself, the party will consist of---
First Lieutenant Warner, now at Washington;
Second Lieutenant Abert,
do.
Second Lieutenant Peck.
Lieutenant Peck is a West Point, but he has been
ordered to repair to St. Louis, and report to you at that place.
Should Colonel Kearny be at St. Louis, which you will ascertain on passing
through that place, you will report to him at St. Louis.
Although ordered to report as field and topographical
engineers, under the regulations, you will not consider these in the light
of exclusive duties, but will perform any military duty which shall be
assigned to you by Colonel Kearny in accordance with your rank.
Should Colonel Kearny have moved on the prairies
with his command, you will make every effort to overtake him.
Respectfully, sir, your obedient servant,
J. J. ABERT,
Colonel Topographical Engineers.
To Lieut. W. H. EMORY, Top. Eng. |
Anticipating that the route of
Colonel Kearny's command would be through unexplored regions, your suggestions
required, that in all cases where it did not interfere with other and more
immediate military demands of the service, the attention of myself, and
the officers assigned to duty with me, should be employed in collecting
data which would give the government some idea of the regions traversed.
The column commanded by Colonel Kearny, to which
we were attached, styled "The Army of the West," to march from Fort
Leavenworth, was destined to strike a blow at the northern provinces of
Mexico, more especially New Mexico and California.
It was supposed we would barely reach Fort Leavenworth
in time to join the army, and but twenty-four hours were allowed us in
Washington to collect the instruments and other conveniences for such an
expedition. This was quite sufficient for all the objects appertaining
directly to our military wants, but insufficient for the organization and
outfit of a party intended for exploration. In submitting the following
notes, they should be received as observations made at intervals snatched
from other duties, and with an expedition whose movements were directed
by other considerations than those which would influence the views and
conveniences of an explorer.
We left Washington on the 6th of June, unable
to procure a pocket chronometer, or telescope of power sufficient to observe
eclipses; but through your intercession, and by the kindness of the
Chief of Hydrography, U. S. N., we were provided with two excellent box
chronometers, No. 783 and No. 2,075, by Parkinson and Frodsham, and we
received from the bureau two of Gambey's 81/2-inch
sextants.
Crossing the Alleghanies the stage capsized with
us, and placed the chronometers in great danger, but the prudence of Mr.
Bestor, who carried them in a basket on his arm, saved them from destruction.
Their rates were changed very materially by the accident, but on reaching
Fort Leavenworth, the chronometers were again found to have changed their
rates materially, owing to the peculiarly unsteady and jarring motion of
the steamer upon which we ascended.
The meridian of Fort Leavenworth, as determined
by Mr. Nicollet, is therefore taken as that to which all the determinations
of longitude as far as Bent's fort, by the chronometer, are referred, and
any change which subsequent observations may make in the longitude of Fort
Leavenworth, will be common to them. The travelling rates of chronometer
783 were, as the observations will show, very uniform, and longitudes deduced
from it, compared with direct measurements of lunar distances made at various
points, give satisfactory comparisons as far as camp 70, October 9th, on
the Rio del Norte. At this point we left the wagons, thence crossing
the mountains to the Gila river, some irregularity in the rates is discoverable,
until we reach camp 83, October 26th on the Gila river.
From that point (camp 83) to San Diego, on the
Pacific, the rates were very uniform. Assuming Captain Belcher's
determination of that point, 7h. 48m. 44s., west from Greenwich,
and carrying my longitudes back, they compare well with the longitudes
derived from the direct measurements of lunar distances made at different
points of the route.
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