The nature and construction of a solar eclipse explained and exemplified in that which will happen on April 1st, A.D. 1764. Containing, I. The geometrical construction of a general eclipse of the sun, exhibiting its phases and affections, by scale and compasses. II. The same by trigonometrical calculation. III. The construction and phases of a solar eclipse for any particular place, exemplified for the city of London. IV. Of the form and dimensions of the moon's dark shadow on the Earth's surface considered not as a sphere but as a spheroid. V. The method of exhibiting all the phases of a solar eclipse in the best manner, by a reflecting telescope, in a room not darkened. By Benjamin Martin.