OF NATURAL PHILOSOPHY: EMBRACING THE GENERAL PRINCIPLES OF MECHANICS, HYDROSTATICS, ELECTRICITY, GALVANISM, MAGNETISM, AND ASTRONOMY. ILLUSTRATED BY SEVERAL HUNDRED ENGRAVINGS. DESIGNED FOR THE USE OF SCHOOLS AND ACADEMIES. BY LEONARD D. GALE, M. D. Professor of Geology and Mineralogy in the University of the City of New York, NEW YORK: COLLINS, KEESE & CO., 254 PEARL STREET, |