The hill selected for the comparative measurement was, as far as could be judged, the highest, within convenient distance, of which the ascent was practicable, being rather above the general height of the hills on the western part of the north coast of Spitzbergen; the summit was distant less than two miles from the Observatory on the Inner Norway Island, in a direction very nearly due south, as the mark, which was placed to determine the point of measurement, was within the field of the meridian transit instrument: the hill was situated on the main land, and was divided from the island on which the Observatory was established, by a sea channel of little more than a mile across, making part of the harbour of Fair-haven. The annexed sketch of the harbour and of the adjacent coast will be sufficient to point out the positions of the hill and of the Observatory, and is the more necessary, as the plan of Fair-haven, published in Captain Phipps’s Voyage, (in which an endeavour might otherwise be made to trace them,) is so exceedingly inaccurate though purporting to be from actual survey, that after having been nearly three weeks on the spot, I am even more perplexed than on the day of arrival, to assign in the plan, the island which is intended to represent the one on which the Observatory is placed, or the position of the hill in question ; the latter, I apprehend must have been designed either by the one marked (
a
) in Captain Phipps's, (or rather in Mr. D’Auvergne's) plan, or by that marked
f
, although neither corresponds, even within ordinary limits, in height, or in relative position. The present sketch, Plate XIII. is taken principally from a manuscript survey of Captain Beechey's, when at Spitzbergen as a Lieutenant in Captain Buchan's expedition of 1818; Captain Beechey's Survey has been found remarkably correct wheresoever we have had an opportunity of verifying it. The shore of the main land to the north eastward of the hill forms a small bay, which being frozen over, afforded a perfectly level base, in which no correction was required for inequalities of surface, and the consequent liability to error introduced in the reduction was avoided. Having stationed a line of poles in such manner as to cover each other exactly, by means of a telescope placed at the one extremity, the distance between the extremes was carefully measured with a Gunter's chain, by Mr. Henry Foster, of His Majesty's Ship Griper, and myself, and was found to amount to 36 lengths, or 2376 feet; the chain was drawn along the surface of the ice at each remove, so that the links were prevented from entanglement; it was stretched at each repetition as tightly as two persons could draw against each other, and the spots marked by flat plates of iron, furnished with long spikes by which they were fixed securely in the ice; the temperature of the air was 35°, and of the chain 32°. In a second measurement, with the same precautions as on the first occasion, the difference did not amount to more than an inch and half. The extremities of the base, being abreast of two projecting points of land, one on the main shore, and the other on a small rocky island, offsets were made at right angles to the base, each of 38 feet, and the spots carefully marked, as containing between them the distance originally measured, with the additional advantage of a firm foundation at the extremities for future operations. This base is the line marked A B in the annexed plan, Plate XIV.
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