A treatise on astronomy, in which the elements of the science are deduced in a natural order, from the appearances of the heavens to an observer on the earth; demonstrated on mathematical principles, and explained by an application to the various phenomena
A mathematical astronomy textbook by Olinthus Gregory, published in London by G. Kearsley in 1803 for students working through the science from observed appearances to geometric proof. The plates group numbered figures on open pages: line-engraved circles, ellipses, ray cones, shaded planetary spheres and orbital diagrams, useful as sparse technical linework, eclipse shadow cones and grids of labelled geometric figures.
