I. HANDBOOK OF CHEMISTRY

IL HANDBOOK OF NATURAL PHILOSOPHY, $ 1.25. III. HANDBOOK OF THE STARS, $1.50.

Thèse books contain (aside from the Appendix) respe^mvely 159, 230, and 159 pages, in clear, open type, with no fine print, and they treat of ail the topics usually included in school

manuals of thèse sciences. The more theoretical portions of the subject are discussed briefly in Appendixes, and descriptions of apparatus and directions for performing experiments are added. Omittùig the Appendixes, the books are not too difficult for the upper classes in Grammar and District Schools. With the Appendixes, they are exactly adapted to the wants of those High Schools and Académies which have not time for larger books.

They are not abridgments of the larger works by the same authors, but are wholly nevv and independent books, differing from the others in the sélection, arrangement, and treatment of topics, so far as was necessary to fit them for a briefer and easier course of study. They are simple in style, and eminently practical, yet thoroughly scientific, and giving the results of the latest discovery and research. s They are sure of a hearty welcome from teachers who désire books that shall be brief without being dry, and easy withouëbeing puérile.

gg§=> E. S. Ritchie & Sons, of Boston, will furnish a set of apparatus for the thorough illustration of the Handbook of Chemistry for $30, and a set for the thorough illustration of the Handbook of N attirai Philosophy for $ 350.

%* Circulars, containing notices and testimonials from eminent teachers, will be furnished on application. Copies for examination will be supplied at one half the advertised price, with twenty-five cents additional for postage. Spécial terms will be given for first introduction of any of the books.

WOOLWORTH, AINSWORTH, & CO-,

117 Washington Street, Boston.