These are the Tables mentioned in the 208th Article, and are so easy that they scarce require any farther explanation than to inform the reader, that if, in Table I. he reckons the columns marked with Asterisks to be minutes of time, the other columns give the equatoreal parts or motion in degrees and minutes; if he reckons the Asterisk columns to be seconds, the others give the motion in minutes and seconds of the Equator; if thirds, in seconds and thirds: And if in Table II. he reckons the Asterisk columns to be degrees of motion, the others give the time answering thereto in hours and minutes; if minutes of motion, the time is minutes and seconds; if seconds of motion, the corresponding time is given in seconds and thirds. An example in each case will make the whole very plain. EXAMPLE I. | EXAMPLE II. | In 10 hours 15 minutes 24 | In what time will 153 degrees seconds 20 thirds, _Qu._ How | 51 minutes 5 seconds of the much of the Equator revolves | Equator revolve through the through the Meridian? | Meridian? | | Deg. M. S. | H. M. S. T. Hours 10 150 0 0 | Deg. { 150 10 0 0 0 Min. 15 3 45 0 | { 3 12 0 0 Sec. 24 6 0 | Min. 51 3 24 0 Thirds 20 5 | Sec. 5 20 ------------ | ------------ _Answer_ 153 51 5 | _Answer_ 10 15 24 20 CHAP. XII. _Of Solar and Sidereal Time._ [Sidenote: Sidereal days shorter than solar days, and why.] 221. The fixed Stars appear to go round the Earth in 23 hours 56 minutes 4 seconds, and the Sun in 24 hours: so that the Stars gain three minutes 56 seconds upon the Sun every day, which amounts to one diurnal revolution in a year; and therefore, in 365 days as measured by the returns of the Sun to the Meridian, there are 366 days as measured by the Stars returning to it: the former are called _Solar Days_, and the latter _Sidereal_. [Sidenote: PLATE III.] The diameter of the Earth’s Orbit is but a physical point in proportion to the distance of the Stars; for which reason, and the Earth’s uniform motion on it’s Axis, any given Meridian will revolve from any Star to the same Star again in every absolute turn of the Earth on it’s Axis, without the least perceptible difference of time shewn by a clock which goes exactly true.