...with a candle or lain]) upon it, be placed at a distance of thirty or forty yards from the plumb-line, and in the same direction with it and the compass-sight....Now, if the elongation at the time of observation was west, and the north end of the needle is on the west side of the line, the azimuth, plus the angle...

...thirty or forty yards from the plumb-line, and in the same direction with it and the compass- sight. The line so determined makes, with the true meridian, an angle equal to the azimuth of the polestar; and from this line the variation of the needle is readily determined, even without tracing...

...thirty or forty yards from the plumb line, and in the same direction with it and the compass sight. The line so determined makes, with the true meridian,...Now, if the elongation at the time of observation was west, and the north end of the needle is on the west side of the line, the azimuth, plus the an;...

...reference, by driving pegs deeply into the ground and marking the exact point on each by a small nail. The line so determined, makes, with the true meridian, an angle equal to the azimuth of the pole.star; and, from this line, the variation of the needle is readily determined, even without tracing...

...thirty or forty yards from the plumb line, and in the same direction with it and the compass sight. The line so determined makes, with the true meridian, an angle equal to the azimuth of the pole-star; and from this line the variation of the needle is readily determined, even without tracing...

...assistant. The line passing through the tack a under the instrument and the tack b set in the forward stake makes with the true meridian an angle equal to the azimuth of the North Star at elongation. Now multiply the natural tangent of the azimuth by the distance between the...