Book Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1726 edition. Excerpt: ... may be Retrograde, Direct and Retrograde, but not a second Time Direct. Cor. II. 'Tts evident, there are in any Latitude innumerable Diverfities of inclinations of the DialPlane to the Horizon, and of the Stile to the Plane; also of Declinations of both Stile and Plane from the Meridian, whereby the Shadow may be made to go backward. Prap. VI. T H E Shadow cannot go back, while the Sun is nearer the zfqzzator, than the Top of the Stile to the Lqnator. And this holds good, whether the Sun and Top of the Stile be on the same, or different Sides of the Eqazztor. For the Planes of all Diurnal Circles, which are nearer to O 4. the the Equator, than the Top of the Stile, are cut by the Stile within their Perimeters, because the Stile passes thro' the Center of the Sphere. Cor. T H a nearer the Stile points to the Betrator, the more Days in the Year will the Shadow go back 5 but then, in any one Day, it will go back the less, oaeteris parihus. Prop. VII. THE" Shadow of a Stile pointing to any one Place of the Heavens, betwixt the A'quaror and either Tropiek, will go back all those Days, wherein the sun's Parallel is farther from the Equaror, than the Top of the Stile is from the Equator. And this holds, whether the Sun, and the Top of the Stile, be on the same, or diffferent Sides of the zfquator: But with this Pro-viszz, in both Cases, that the Point of Contact lie in the visible Diurnal Arc above the Plane. For Example, In our Latitude of Oxford, if a Stile Point as far North, as is the Beginning of the Sign Taurus; then the Shadow will be Retrograde every Day, Cancer, Leo. But while the Sun pasies through Virgo and Lihra, the Shadow is only Direct, or Forward, then in paffing thrdtfcorpio, Sagittarius, Capricorn and flquarirts, 'tis...