The avenue which had been cleared through a dense forest from the monument to a distance of 12 miles north of it by the surveyors in 1817 was easily recognized by the new and thick growth of young timber, which, having a width of from 40 to 50 feet, now occupied it.  Axmen were at once set at work to reopen this avenue, under the supposition that the due north line would at least fall within its borders for a distance of 12 miles.  In the meantime the first astronomical station and camp were established, and the transit instrument set up at a distance of 4,578 feet north of the monument, upon an eminence 45-1/2 feet above the level of its base.  This position commanded a distinct view of the monument to the south, and of the whole line to the north for a distance of 11 miles, reaching to Parks Hill.  Whilst the work of clearing the line of its young growth of timber was progressing a series of astronomical observations was commenced at this first camp, and continued both day and night without intermission (except when interrupted by unfavorable weather), with the sextant, the repeating circle of reflection, and the transit instrument, until the latitude and longitude of the monument and of this first camp were satisfactorily ascertained, and also the direction of the true meridian from the said monument established.  For this latter purpose several observations were in the first place made upon the polar star ([Greek:  alpha] Ursae Minoris) when at its greatest eastern diurnal elongation, and the direction thus obtained was afterwards verified and corrected by numerous transit observations upon stars passing the meridian at various altitudes both north and south of the zenith.  These were multiplied with every degree of care, and with the aid of four excellent chronometers, whose rates were constantly tested, not only by the transit observations, but also by equal altitudes of the sun in the day, to correct the time at noon and midnight, and by observed altitudes of east and west stars for correcting the same at various hours of the night.

The direction of this meridian, as thus established by the commissioner, was found to vary from the experimental line traced by the surveyors of 1817 by running in the first place to the west of their line, then crossing it, and afterwards deviating considerably to the east of it.

At the second principal station erected by the party, distant 6 miles and 3,952 feet north of the first camp, or 7 miles and 3,240 feet north of the monument, it found itself 60 feet to the west of the line of 1817.  This appeared to be the maximum deviation to the west of that line as near as its trace could be identified, which was only marked by permanent objects recognized by the party at the termination of each mile from the monument.  Soon after passing this station the line of 1817 was crossed, and the party did not afterwards touch it, but deviated more and more to the east of it as it progressed north by an irregular proportion to the distance advanced.