FIRST LESSONS IN Natural Philosophy FOR BEGINNERS. BY JOSEPH C. MARTINDALE, M.D., LATE PRINCIPAL OF MADISON GRAMMAR SCHOOL, PHILADELPHIA; AUTHOR OF A HISTORY OF THE UNITED STATES FOR SCHOOLS, ETC. [Illustration: Paddlewheel steamboat.] PHILADELPHIA: ELDREDGE & BROTHER, No. 17 North Seventh Street. 1881. Entered, according to Act of Congress, in the year 1872, by ELDREDGE & BROTHER, in the Office of the Librarian of Congress at Washington. J. FAGAN A SON, ELECTROTYPERS, PHILAD’A. [Illustration: KEYSTONE PRESS OF W^M. J. DORNAN] Preface. [Illustration: Decoration] In preparing this little work, our desire has been to afford both pleasure and profit to those who may read or study its pages. The most interesting, as well as the most useful things to us, are those with which we meet in every-day life; but we must have some knowledge of these things, ere we can contemplate them with much pleasure, or use them to our greatest profit. Simple truths in natural science may be learned at an early age; for it requires no more than the ordinary intelligence possessed by boys and girls to understand them. Such facts are not only valuable in themselves, but they are also useful in disciplining the mind by teaching it to observe the many changes constantly going on around us, and to reason and reflect in regard to the same. Habits of observation and reflection thus formed are likely to go with us through life; and they may prove a blessing in a thousand ways; for they will not only add to our comfort and our enjoyment, but they will also produce many a pleasing thought. We have endeavored to make a book that can be easily understood; but few scientific terms will be found in it, for its language is the language in familiar use; hence, it may serve to interest the fireside circle, and it may be referred to by intelligent boys and girls for answers to the many perplexing questions which are so often presented to their inquiring minds. Many pupils have not the chance to attend even an Academy or a High School. It is to such that this book is especially adapted, for it is believed to contain as much matter as can be taught with satisfaction and profit in our public or our private schools; but to other pupils, it will prove a valuable introduction to larger and more comprehensive works.