t practicable period in hopes of accomplishing these ends.

On the 18th day of November the party succeeded in erecting a station
opposite Mars Hill and very near the meridian line. It was thus proved
that the line would pass from nine-tenths of a mile to 1 mile east of
the eastern extremity of the base of the northeast peak of Mars Hill.

On the 30th of November a series of signals was commenced to be
interchanged at night between the position of the transit instrument
on Parks Hill and the highlands of the Aroostook. These were continued
at intervals whenever the weather was sufficiently clear until by
successive approximations a station was on the 9th of December
established on the heights 1 mile south of that river and on the
meridian line. The point thus reached is more than 50 miles from
the monument at the source of the St. Croix, as ascertained from
the land surveys made under the authority of the States of Maine and
Massachusetts. The measurements of the party could not be extended
to this last point, owing to the depth of the snow which lay upon the
ground since the middle of November, but the distance derived from the
land surveys must be a very near approximation to the truth. A permanent
station was erected at the position established on the Aroostook heights
and a measurement made from it due west to the experimental or exploring
line of 1817, by which the party found itself 2,400 feet to the east of
that line.

Between the 1st and 15th of December the observations were carried on
almost exclusively during the night, and frequently with the thermometer
ranging from 0 to 10 and 12 degrees below that point by Fahrenheit's
scale. Although frequently exposed to this temperature in the
performance of their duties in the open air at night, and to within a
few degrees of that temperature during the hours of sleep, with no other
protection than the tents and camp beds commonly used in the Army, the
whole party, both officers and men, enjoyed excellent health.

During the day the tents in which the astronomical computations were
carried on were rendered quite comfortable by means of small stoves,
but at night the fire would become extinguished and the temperature
reduced to within a few degrees of that of the outward air. Within
the observatory tent the comfort of a fire could not be indulged in,
in consequence of the too great liability to produce serious errors
of observation by the smoke passing the field of