The longitude demonstrated, [electronic resource] : by the use of a silent pendulum; that keeps true time at sea. And made plain (by an Index Instrument) to the meanest Capacity. With a new observatory for finding the meridian altitude of sun or stars, and a great Improvement of the Sun-Quadrant; which are more exact than any heretofore known: With fair Copper Cuts of the Machine, and all the other Instruments. And a table of the acceleration of fixed stars, more exact than any heretofore extant; with the Sun's Declination, Right Ascension, and Equation of Time; and other useful Tables fitted to this Work. An Experiment of what Proportion a Pendulum lengthens in the greatest Heat, where Animals can live, or Vegetables grow; and at several other Degrees of Heat, to red-hot. With a Method to make a Pendulum to fit all Climates; with several other uncommon Experiments. By Jonah Crathorne.