The first was an equinoctial, the second a solstitial armilla.
Von Humboldt and Aime Bonpland, Personal Narrative of Travel to the Equinoctial Regions of America (3 vols., London); M.
277) onwards accused the Jews of disregarding the (Christian) equinoctial limit, and of sometimes placing the Paschal full moon before it; and it is possible that in the time of Christ the 14th of Nisan might have fallen as far back as the 17th of March.
Bradley had already perceived, in the case of the two stars previously scrutinized, that the apparent difference of declination from the maximum positions was nearly proportional to the sun's distance from the equinoctial points; and he realized the necessity for more observations before any generalization could be attempted.
The influence of daylight is presumably the principal cause of the difference between the phenomena during November, December and January at Cape Thorsden and Jan Mayen, for in the equinoctial months the results from these two stations are closely similar.
Gunter's Quadrant, an instrument made of wood, brass or other substance, containing a kind of stereographic projection of the sphere on the plane of the equinoctial, the eye being supposed to be placed in one of the poles, so that the tropic, ecliptic, and horizon form the arcs of circles, but the hour circles are other curves, drawn by means of several altitudes of the sun for some particular latitude every year.