A treatise on the various lengths of the days, nights, and twilights, [electronic resource] : with tables of the latitude and longtitude of the most eminent towns, harbours, Headlands, and Islands, in the world, and their Bearings and Distance from London; with a short Discourse on Heat, Cold, and Twilight. The Whole being very plain and easy, diverting and instructive. Illustrated with a Copper-Plate, shewing The Length of the Days, Nights, and Twilights, at Bridge-Town, in Barbadoes, when the Sun is on the Tropicks and Equator. Also, A moveable Planisphere, neatly engraved on Copper, which, with a Semi-Circle of Sinical Hours, sheweth the Time of the Sun's Rising, Setting, and Length of the Days, Nights, and Twilights in all Parts of the Globe, when the Sun is in the Summer and Winter Solstices, and the Vernal and Autumnal Equinoxes; with its Description and Use. Likewise A moveable Orthographical Projection on the Plain of the Equator, with a moveable Index, neatly engraved on Copper, which will shew the Situation of any Place on the Globe; and also the Difference of Longitude and Time, between any two Places; and will solve several entertaining Questions the Globe; with its Description and Use at large. By Richard Mihill, Late Midshipman on Board his Majey's Ship Elizabeth.