Horological disquisitions, [electronic resource] : discovering the true nature of time. Or, the reasons why all days from noon to noon are not alike twenty-four hours long. With Tables of Equation, that shew the different Length of all Natural Days, and Newer and Better Rules than any that have been yet made Publick, for the most Exact and Nice Adjusting of Pendulum Clocks and Watches. The second edition, much corrected, and many new particulars added. By John Smith, C. M. To which are annexed the best Rules for the Right Ordering and Use of Quicksilver and Spirit Weather Glasses; and Mr. Sam. Watson's Rule for Adjusting a Pendulum Clock by the Fixed Stars.