Celejlial and 'Terrestrial Globes . 249

point of Libra, where the sun must neces-sarily be at every autumnal equinox, andplace the artificial moon upon the first pointof Aries, where she must be, if a full moonshould happen at that time.

Rectify the globe to the position of a rightsphere, art. 214. which answers to the inha-bitants of the equator; bring the center ofthe artificial fun to the western edge of thebroad paper circle, and the horary index inthis cafe being the graduated edge of thestrong bra fs meridian, will cut the time ofthe fun’s setting, and the moon’s rising zhence it is obvious the moon will rife whenthe fun sets, which will be at VI o’clock, be-cause they are both supposed to be in thecelestial equator, but in opposite signs.Therefore on that day the fame phœnome-non will happen in all latitudes betweenthe equator and either pole.

But as the moon’s motion in her orbit,which we shall at present consider as coin-cident with the ecliptic, is about 13 deg.10 min. every day, which retards her diur-nal motion about 51 min. 56 sec. of timewith respect to the first point of Aries, thisdaily difference as it relates to the fun is

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