OCR Text |
Show NOTE. THI Angles of the Triangulation were measured with a seven- inch theodolite, by Draper. The instrument was scarcely competent to the work, from the low power of its telescope, the great distance between most of the stations, the mirage, and the almost constant haze that pervaded the atmosphere. Many repetitions of the readings were consequently necessary to secure the requisite accuracy in the results. This was peculiarly the case in obtaining the Azimuth of the Base Line, which was fixed by observations of the Polar Star. The work is believed to be sufficiently accurate to correct the detailed measurements, as well as to form a basis upon which a triangulation may hereafter be extended over this great internal basin, should such a work ever be contemplated by the Government. The natural features of this desolate region, abounding as it does in lofty eminences, widely separated by intervening level plains, is admirably adapted to such an operation; although its execution could not but be attended with great labour and privation. Many of the deserts would furnish extended plains, absolutely level, upon which a degree of the Meridian could be measured to great advantage. |