_Having the Latitude of the Place; to find the time when a Star rises and sets_ Heliacally 172 PROB. XLV. _To find the Place of any Planet upon the Globe, so by that Means to find its Place in the Heavens; also to find at what Hour any Planet will rise or set, or be on the Meridian, at any Day in the Year_ 173 PROB. XLVI. _To find all that space upon the Earth where an Eclipse of one of the Satellites of_ Jupiter _will be visible_ 175 _The_ DESCRIPTION _of the_ ORRERY 177 _Of the Motions of the Planets in general_ 183 _Of the Stations and Retrogadations of the Planets_ 186 _Of the Annual and Diurnal Motion of the Earth_ 194 _Of the Phases of the Moon, and of her Motion in her Orbit_ 201 _Of the Eclipses of the Sun and Moon_ 208 _Of the Eclipses of_ Jupiter’_s Satellites_ 212 [Illustration] THE INTRODUCTION, CONTAINING A Brief Account of the SOLAR SYSTEM, and of the FIXED STARS. SECT. I. _Of the Order and Periods of the Primary Planets revolving about the Sun; and of the Secondary Planets round their respective Primaries._ [Sidenote: _Planets._] The Sun is placed in the midst of an immense space, wherein six opaque spherical bodies revolve about him as their center. These wandering globes are called the _Planets_, who, at different distances, and in different periods, perform their revolutions from West to East, in the following order: 1. ☿ _Mercury_ is nearest to the Sun of all the planets, and performs its course in about three months. 2. ♀ _Venus_ in about seven months and a half. 3. ♁ The _Earth_ in a year. 4. ♂ _Mars_ in about two years. 5. ♃ _Jupiter_ in twelve. And lastly, ♄ _Saturn_, whose[1]_Orbit_ includes all the rest, spends almost 30 years in one revolution round the Sun. The distances of the Planets from the Sun are nearly in the same proportion as they are represented in _Plate_ 1. _viz._ Supposing the distance of the Earth from the Sun to be divided into 10 equal parts; that of _Mercury_ will be about 4 of these parts; of _Venus_ 7; of _Mars_ 15; of _Jupiter_ 52; and that of _Saturn_ 95. The Characters placed before the names of the Planets, are for brevity’s sake commonly made use of by Astronomers, instead of the words at length, as ♀, for _Venus_, &c. [Illustration: Plate 1. THE SOLAR SYSTEM Or the Orbits of the Planets _according to their mean distances from the Sun_.] [Sidenote: _Nodes._]