A tutor to astronomie and geographie, or, An easie and speedy way to know the use of both the globes, coelestial and terrestrial in six books : the first teaching the rudiments of astronomy and geography, the 2. shewing by the globes the solution of astronomical & geographical probl., the 3. shewing by the globes the solution of problems in navigation, the 4. shewing by the globes the solution of astrological problemes, the 5. shewing by the globes the solution of gnomonical problemes, the 6. shewing by the globes the solution of of [sic] spherical triangles : more fully and amply then hath ever been set forth either by Gemma Frisius, Metius, Hues, Wright, Blaew, or any others that have taught the use of the globes : and that so plainly and methodically that the meanest capacity may at first reading apprehend it, and with a little practise grow expert in these divine sciences / by Joseph Moxon ; whereunto is added Antient poetical stories of the stars, shewing reasons why the several shapes and forms are pictured on the coelestial globe, collected from Dr. Hood ; as also a Discourse of the antiquity, progress and augmentation of astronomie.

PROB. LII.

How to find the Hour of the Night, when the Moon shines on a Sun Dyal, by help of the Globe.

REctifie the Globe, and find by Prob. 54. or an Ephemeris, the Moons place at Noon: Bring it to the Meridian, and the Index of the Hour Circle to 12. and turn about the Globe till the Index of the Hour Circle points to the same Hour the shade of the Moon falls on, on the Sun Dyal. Then by Prob. 3. find the Suns place at Noon, and see how many degrees of Right Ascension are contained between the Suns place and the degree of the Equator at the Meridian, when the Index of the Hour Cir∣cle is brought to the Hour the Moon shines on in the Sun Dyal; for those number of degrees converted into Time, shall be the Time from Noon, or the Hour of the Night. Only note, Respect must be had to the motion of the Moon from West to East, for so swift is her mean motion, that it is accounted to be above 12. degrees in 24. Hours; that is 6 degrees in 12 Hours, 3 degrees in 6 Hours, &c. and this also converted into Time, as aforesaid, you must add proportionably to the Time found from Noon; and the sum shall give you the true Hour of the Night.

Example.

Here at London, I desired to know the Hour of the Night Ja∣nuary 6. this present Year 1658. The Moons place found by

an Ephemeris, or for want of an Ephemeris, by Prob. 54. is in ♊ 21. degree 22, minutes; Therefore I rectified the Globe to Lon∣dons Latitude, and brought ♊ 21. 22. minutes to the Meridian, and the Index of the Hour Circle to 12. then by Prob. 3. I found the Suns place in ♑ 26. degrees 46. minutes, and by Prob. 26. I found his Right Ascension to be 300 degrees; Then I turned about the Globe, till the Index of the Hour Circle pointed at 10 Hours, and at the degree of the Equator at the Meridian I made a prick; then I counted the number of degrees of the Equater contained between the foresaid 300 deg. and this prick and found them 111¼ degrees which converted into Time, by allowing 15 degrees for an Hour, gives 7 hours, 25 minutes, Time from Noon: which if the Moons motion were not to be considered, should be the immediate Hour of the Night: But by the Rule a∣foresaid, the Moons motion from West to East, in 7 hours 25 mi∣nutes is 3 degrees 42 minutes, and this 3 degrees 42 minutes be∣ing converted into Time, is 14 minutes more, which being added to 7 hours 25 minutes: make 7 hours 39 minutes, for the true Hour of the Night.