Cambridge, Sept. 10, 1861. I have carefully examined the revised edition of Smith's Illustrated Astronomy, and find it fully brought up to the present state of the science, and more accurate in its details than any other elementary work subject with which I am acquainted. on the The plates are admirably calculated to interest the learner, and give him a clear idea of the celestial motion! Simon Newcomb, Assistant, U. S. Nautical Almanac, Also, Fellow of the American Academy of Arts and Sciences. he author would recommend that, whenever a lesson is given to a class, the her call their particular attention to the illustration, and explain, if necessary, the rams relating to the lesson given, at the same time questioning the whole class the subject; and inviting any pupil who does not fully understand the subject to any questions relating to it he may think proper. This will prepare the pupil, when = studying his lesson, to have a right conception of what he is learning. It is not ected by the author that the teacher will confine himself solely to the questions n in the book; but that he will ask many which may occur to him at that time, and h may lead the pupil off from the routine of the book, and induce him to apply the 66 19 17 23 66 which is equal to any Telescope in Europe. TEACHERS. He would also particularly recommend that the teacher, when hearing a rec change the question or put it in a different form, in all cases where it will admi For example: What is the attraction, by which all particles of matter tend toward each called? The attraction of gravitation. What is the attraction of gravitation? It is that attraction by which all parti matter tend toward each other. What is the point in the heavens directly over our heads called? The zenith What is the zenith? It is that point in the heavens directly over our heads. |