CHAP. XV.
To find out the Hours of the Night, by the Rays of the Moon. [ 60]
1. T'is to be supposed an Horizontal Sun-Dyal at hand, is either fixt or moveable; such as is usually carried about.
2. We suppose, joyn to the other a Moon-Dyal as they call it, framed of two Concentrick Cir∣les, in the one of which are set down the Days of the the Moons age, by a Globule applyed to the number 30. In the other the 12 Hours here and there set down.
3. Suppose the age of the Moon known, either by the Epact, or some other way. These things thus laid down, proceed as followeth by the be∣nefit of a Sun-Dyal applyed to the Lunar Beams in the same manner as used to be applied to those of the Sun. See what Hour the Moons Shadow points; As for Example, the 8th. Then place the Globule to that Hour set down in the Horary Circle. And Lastly have recourse to the age of the Moon, and that will give the Hour sought. For Example, If it be the 12th Day of the Moons age, it will declare the Hour to be about 5 ½. But if, as it often happens, a Lunar-Dyal be pro∣duc't, made up of 3 Concentrick Circles, whereof the last and biggest is that of the Lunary Days; the second and next to it is the Horary Circle; the inner∣most contains the Index. Apply that Index to the Day of the Moon; Then in the Circle of the Index seek the number of the Hour mark'd by the Lunary Shadow in the Sun-Dyal u, g, 8, the said Number will declare in the Horary Circle the Hour sought.