Horological disquisitions concerning the nature of time, and the reasons why all days, from noon to noon, are not alike twenty four hours long [electronic resource] : in which appears the impossibility of a clock's being always kept exactly true to the sun : with tables of equation, and newer and better rules ... how thereby precisely to adjust royal pendulums ... : with a table of pendulums, shewing the beats that any length makes in an hour ... / by John Smith ... ; to which is added The best rules for the ordering and use both of the quick-silver and spirit weather-glasses, and Mr. S. Watson's rules for adjusting a clock by the fixed stars.