CONTENTS.

PART I.

		Page
Chap. I.	—Rules for finding the mean places The average position of a celestial body, assuming a perfectly circular orbit at a constant speed. of planets,	1
II.	—Rules for finding the true places The actual observed position of a planet, accounting for its elliptical orbit and varying speeds. of planets,	55
III.	—Rules for solving Problems concerning the points of the Horizon, the position of places, and time,	102
IV.	—Of Lunar Eclipses,	149
V.	—Of Solar Eclipses,	172
VI.	—On the Projection The mathematical or graphical representation of an eclipse on a flat surface. of Lunar and Solar Eclipses,	193
VII.	—On the conjunction When two celestial bodies appear close together in the sky. of planets,	209
VIII.	—On the conjunction of planets with stars,	233
IX.	—On the rising and setting of planets,	245
X.	—On the Phases of the Moon and the position of the Moon's cusps The pointed ends or "horns" of a crescent moon.,	257
XI.	—Rules for finding the time at which the declinations The angular distance of a celestial body north or south of the celestial equator. of the Sun and Moon become equal,	273


XII.	—Matters cosmographical The science dealing with the general features of the universe, including the earth and heavens.,	294
XIII.	—On the construction of the armillary sphere A model of objects in the sky consisting of a spherical framework of rings representing lines of celestial longitude and latitude. and other astronomical instruments,	346
XIV.	—Of Measures of time,	369