326 Description and Use of the

degrees counted on the broad paper circlefrom T towards x will give ^ 5 0 i6 / forthat point of the ecliptic which is then riling,and the fame quantity counted from T to-wards y will fall upon X 5 0 16' whichpoint is then setting.

III. To find the angle E & T being thatwhich a vertical circle E H passing throughthe sun at that time makes with the eclip-tic; this is called the parallactic angle.

To represent this angle upon the globeit is necessary to have a flexible flip of brass,or a flip of parchment about the breadthof the quadrant of altitude, with the di-visions inscribed on it with a pen; if thisflip be applied to the point 0 and its gra-duated edge laid over the vertex E, andextended to the quadrant of altitude firstremoved to x 90 degrees from O it will in-tersect the quadrant at w, the quantity uponthe quadrant, from x to w, will be 56° 29',the measure of the parallactic angle E G T.The result of this problem is as follows:

That point of the ecliptic which culmi-minates on the meridian is in O 27° 6' itsdistance from the vertex 31 0 59', the highestor nonagesima! point of the ecliptic, rr

5 C 16',