Page:Description and Use of a New Celestial Planisphere.pdf/16

11 which is the Equinoctial Colure and Hour Circle of ix, thee two Circles do interect each other in the Pole of the world, and you will find the ituation and names of all thee Circles in the Planisphere; the next is the Circle of Months; and if you look on the horizon of any new Globe, or in any Almanac, you will there ee the Sun's place to every day of the year; then lay an index from the center of the Plane through every point of the Ecliptic into the Circle of Months, and mark the days accordingly, and it is done: the index conits of an Hour Circle, next to the Circle of Months; and, as you hold the South point from you, the left hand hours are the morning and forenoon hours, and the right hand are the afternoon hours, to twelve at night, which is at the bottom next to you, due North; then the Meridian reaches from 12 to 12 through the Pole, and on the outhern part is a cale of meridional Altitude from the Horizon up to the Zenith of London; and, on the northern part, is a cale of Declination, North and South; the Circle of the Horizon hath the points of the Compas, the Azimuth, and the Amplitude; and note, that the inward edge of the Circle is the enible and apparent Horizon; next is the Prime Vertical, or Azimuth of Eat and Wet, and on it is a cale of Altitude when due Eat or Wet, up to the Zenith; the next is the Equinoctial Colure and Hour Circle of ix; and above this is a mall index, or director, to be used, as will be taught among the Problems. This may uffice for a decription of the principle and contruction of the Planisphere. I mut now proceed to it's ues, as it relates to Atronomy: and