Mr. Walker's lectures on natural philosophy. On Saturday the 14th of March will be published, printed in quarto, on a fine wove medium paper, to be completed in thirty-five numbers, published weekly, making two handsome volumes in Quat̕o, Number I. Price 1s. 6d. (with Two Copper-Plates, neatly engraved) of A system of familiar philosophy; in twelve lectures : Being The Course Usually Read By Mr. Walker, Of Conduit-Street, Hanover-Square: Containing the Elements, and the practical Uses to be drawn from the Chemical Properties of Matter; the Principles and Application of Mechanics, of Hydrostatics, of Hydraulics, of Pneumatics, of Magnetism, of Electricity, of Optics, and of Astronomy, including every material modern Discovery and Improvement to the present Time. To be illustrated by at least Fifty Copper-Plates, neatly engraved [electronic resource].