of reference with which they are sometimes loaded, is often the most perplexing part of the subject, and particularly when one figure is made to answer several purposes, and is placed at a distance from the explanation. To avoid this difficulty, the author has introduced additional figures to illustrate the different parts of the subject, instead of referring back to former ones, so that the student is never perplexed with many letters on any one figure. The figures are also placed under the eye, and in immediate connexion with their descriptions, so that the letters of reference in the text, and those on the diagrams, can be seen at the same time. In respect to the language employed, it has been the chief object of the author to make himself understood by those who know nothing of mathematics, and who indeed had no previous knowledge of Natural Philosophy. Terms of science have therefore been as much as possible avoided, and when used, are explained in connexion with the subjects to which they belong, and it is hoped, to the comprehension of common readers. This method was thought preferable to that of adding a Glossary of scientific terms. The author has also endeavored to illustrate the subjects as much as possible by means of common occurrences, or common things, and in this manner to bring philosophical truths as much as practicable within ordinary acquirements. It is hoped, therefore, that the practical mechanic may take some useful hints concerning his business, from several parts of the work. Hartford, May, 1830. RECOMMENDATIONS. The attention of Teachers, and other gentlemen interested in education, is requested, to the following notices of this "System of Philosophy,” which are from the most respectable sources: From John Griscom, LL. D. Principal of the New-York High School. ESTEEMED FRIEND, New-York, June 19th, 1830. I have received and examined thy book on Natural Philosophy, with much satisfaction; I have no hesitation in saying, that I consider it better adapted to the purposes of School Instruction, than any of the Manuals hitherto in use with which I am acquainted. The amiable author of the Conversations threw a charm over the different subjects which she has treated of, by the interlocutory style which she adopted, and thus rendered the private study of those Sciences more attractive; but this style or manner, being necessarily diffuse, is not so well adapted to the didactic forms of instruction pursued in Schools. Hence also, more matter can be introduced within the same compass, and I find, on comparing thy volume with either of the editions of the Conversations now in use, that the former is much better entitled to the appellation of a System of Natural Philosophy, than the latter. The addition also of E.ectricity and Magnetism, is by no means unimportant in a course of instruction in the Physical Sciences. I am, with great respect, JOHN GRISCOM. P. S. I have recommended thy book to all the pupils of our High School, who at tend to Natural Philosophy, and it is the only Book which we shall now use as a Class Book. From H. Potter, Professor of Mathematics and Natural Philosophy, in Washing. ton College, Hartford, Conn. DEAR SIR, I have examined a portion of your work on Natural Philosophy, and am happy ta say that I am, in general, well pleased with the plan you have adopted. With the exception of a few errors, which will doubtless be corrected in a subsequent edition, your mode of treating your subjects seems to be sufficiently scientific for a work so very elementary in its character-and at the same time, it is so popular, as to present few difficulties to an uneducated person of ordinary understanding. The diagrams are generally well drawn, and the plan of introducing them on the same page with the explanation, will contribute greatly to the comfort and advantage of your readers. Very truly Yours, II. POTTER. DR. J. L. COMSTOCK. From the Right Rev. T. C. Brownell, D. D., LL. D., President of Washington College. From a cursory examination of the work, I willingly concur in the above recom mendation. I know of no similar Book, which, for plan and arrangement, is so well calculated for the use of Schools. T. C. BROWNELL' DR. J. L. COMSTOCK. DR. COMSTOCK, I have examined your Treatise on Natural Philosophy with considerable attention, having used it as a Text Book in the Grammar School, immediately on its publication. With this knowledge of its contents, I have no hesitation in pronouncing it the best work on this subject, for the use of Schools and Academies, with which I am acquainted, and therefore hope to see it extensively introduced. Hartford, June 26, 1830. DR. COMSTOCK, E. P. BARROWS, Principal Hartford Grammar School Dear Sir,-I have carefully examined your System of Natural Philosophy, and am of opinion that it is far superior to any work of the kind now in use. As particular excellencies of this System, I would mention its happy illustrations—the perspicuity, variety, arrangement, and originality of its diagrams, and the addition of much new, interesting, and useful matter. It appears, indeed, to have been a principal object with you, to give the Student correct and definite ideas, and in this attempt I think you have been peculiarly successful. I have been highly pleased with the work my self, and can heartily recommend it to the attention and patronage of the public. OLIVER HORSON, Principal of the Select School. Hartford, June 1, 1830. From the Teacher of Mathematics and Natural Philosophy in the High School, at Ellington, Conn. Dear Sir,—I have examined your "System of Natural Philosophy," and used it as a text-book for one class. I consider it better adapted to the purposes of elementary instruction than any work of a similar kind with which I am at present acquainted. ZEBULON CROCKER. Ellington School, Aug. 10, 1830. GENTLEMEN, I have examined "Comstock's Natural Philosophy," and think it is a book excel. lently adapted to communicate a competent knowledge of the various subjects on which it treats. It does not enter into that depth of Scientifical and Mathematical illustration, of which the subjects are susceptible; but it illustrates, in a familiar way, most of the principles of Natural Philosophy, and is enriched with a statement of practical details in that science. It is a book well calculated to be highly useful in our Schools and Academies. GENTLEMEN, Most respectfully Yours, &c. ROBERT BRUCE, President of Western University, Penn. I have examined many of those Treatises of Natural Philosophy that have been prepared for the younger classes of Students-Dr. Comstock approaches more nearly to the idea I have formed of what such a work should be, than any I have met with. It is rich in Philosophical facts, its explanations are popular, its illustrations practical, and its language perspicuous. It is perfectly adapted to those students at school that do not take an extensive course of Mathematics, and to those that do, it will serve the important purpose of an Introduction. Yours, respectfully, J. H. FIELDING, President of Madison College. |