Page:Great Neapolitan Earthquake of 1857.djvu/315

Rh A knowledge of the magnetic declination, as affecting all my determinations, rendered frequent observations to ascertain its amount important; unfortunately, from the season of the year, and inclemency of the weather in these mountain regions, the observation of the sun or pole star was practicable but seldom. I therefore, in addition to such solar or stellar observations as were possible, took magnetic bearings, from many elevated known points, of others visible from them, and recognizable again upon the two great maps of the country, Zannoni's and Bachler D'Albe's, so that, by comparing the observed bearings with those of the maps, the declination might be checked. I took the following bearings at Auletta:—

These give from 14° to 14° 50' declination W.

On the 13th February I was able to see the sun's disc, though not perfectly clear, and take observations. At 9h. 0m. Greenwich time by chronometer, the centre of the sun's disc bears 24° E. by compass. Taking Auletta to be in lat. 40° 30' N., long. 15° 23' E.

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