Universal Projectoscope For Lantern Slides, Microscopic Work, Opaque and Vertical Projection THE THE ONLY LANTERN on the market that meets in a satisfactory manner the diversified requirements of educational work. It covers practically the entire field of projection. Every device calculated to facilitate rapid passage from one method of projection to the other has been adopted and from the standpoints of efficiency, economy, solidity of construction, rapidity and simplicity of operation it leaves nothing to be desired. To pass from opaque or vertical projection to regular or microscopic, and vice versa, it is merely necessary to drop or raise the mirror in the interior of the dark chamber. The change from lantern slide to microscopic projection is made by the simple act of swinging in or out of alignment the desired arm of the right angled objective or microscope holder. We have a pamphlet describing our full line of projection apparatus which we will be glad to send upon application. C. H. STOELTING CO. SCIENTIFIC APPARATUS AND LABORATORY SUPPLIES 39 W. Randolph Street :: :: CHICAGO, ILL. Please mention School Science and Mathematics when answering advertisements. EVER before has SO vast an NEV amount of knowledge made fascinating for children, been brought together as in the Every Child Should Know Books. It is the richest and most fascinating series for children that can be imagined. For the little student the series spreads a vivid, compelling, neverto-be-forgotten tale of the world-its mythology, its poems, its wars, its heroes, its facts, and its fancies. Features that recommend the series especially are the MODERATE PRICES at which they are sold, and the uniformly ATTRACTIVE BINDINGS and DECORATIONS. The subjects are as follows-the books sold separately or boxed in multiples of three: Check Those You Want Poems Every Child Should Know Songs Every Child Should Know Water Wonders Every Child Should Know Easy to Own You can get any one of the above books upon remittance of a Dollar bill, with the exception of the book on "Birds" ($1.20 postpaid) and "Water Wonders" ($1.10 postpaid). You can get three volumes (any titles) handsomely boxed, for Three Dollars ($3.00) or nine together, boxed, at the very special price of Eight Dollars ($8.00). The books may also be purchased on the instalment plan, $2.00 down, and $1.00 a month, until Nine Dollars have been paid for the set of Nine volumes. WRITE TO-DAY. Check the volumes you want on the above list, and fill in the following blank. Books will be shipped at once. CUT OFF HERE. DOUBLEDAY, PAGE & COMPANY, 133-137 East 16th Street, New York, N. Y. Please send via.... the books checked on the above list for which I enclose $. Name... Sch. Sci. & Math. 10-07 Address..... Please mention School Science and Mathematics when answering advertisements. PHYSICS IN THE SECONDARY SCHOOL-T. Quincy Browne TUNGSTEN SOME NOTES ON CHEMICAL LABORATORY EQUIPMENT Fletcher 717 724 729 730 733 744 745 748 750 751 ON THE DEVELOPMENT OF ELEMENTARY GEOMETRY 752 756 ..... AN APPARATUS FOR DERIVING LAWS OF PENDULUMS 760 THE TEACHING OF MATHEMATICS IN CALIFORNIA 762 GIFTS 769 GRAPHICAL ILLUSTRATIONS OF CONVERGENCE OF 770 A HIGH SCHOOL BOY'S PROOF OF THE PYTHAGOREAN 777 AN EXTENSION OF THE PYTHAGOREAN THEOREM-H. 778 PROBLEM DEPARTMENT—Ira M. DeLong 779 A METRIC CARAT-R. P. Williams .. 783 MAIL-STUDY AT THE UNIVERSITY OF WISCONSIN................ Read Our Advertising Pages We Have Several Special Bargains Advertised MEMBER OF THE EDUCATIONAL PRESS ASSOCIATION OF AMERICA PRICE. The subscription price is Two Dollars a year, if paid in advance, otherwise $2.50; single copies 25 cents. ALL REMITTANCES should be made payable to the order of SCHOOL SCIENCE AND MATHEMATICS. Remittances should be made by Post Office Money Order, Express Order, or Bank Draft. If personal checks are sent, please add ten cents for collection. SCHOOL SCIENCE AND MATHEMATICS is the "official organ" of the following associations and is sent free to all members who have paid their dues. The Central Association of Science and Mathematics Teachers, Eastern Association of Physics Teachers, Indiana State Science Teachers' Association, The Physics Club of New York, Missouri Society of Teachers of Mathematics, The Pacific Coast Association of Chemistry and Physics Teachers, Mathematics Section of the California Teachers' Association, Colorado Mathematics Society, Central Iowa Association of Science ana Mathematics Teachers. POSTAGE IS PREPAID for all subscriptions in the United States and Mexico. For Canada add 25 cents for postage. For all other countries in the Postal Union, add 50 cents. CHANGE OF ADDRESS. Subscribers should promptly notify the publishers of any change of address; otherwise they are held responsible for magazines sent to their former address, until ordered stopped or address changed. DISCONTINUANCES. According to the general custom of educational papers this magazine will be sent to subscribers until notice of discontinuance is received and all arrearages paid. MANUSCRIPTS. Contributions on Science and Mathematics Teaching are invited. Articles must be written on one side of the sheet ONLY. All illustrations must be drawn or written in jet black ink on a separate sheet of manuscript. Contributors are requested to write scientific and proper names with particular care. Manu. scripts should be sent to the Editor of SCHOOL SCIENCE and MATHEMATICS, 5406 Madison Ave., Chicago, or to the proper departmental Editor. Books and pamphlets for Review should be sent to the Editor. MISSING NUMBERS will be replaced free only when claim is made within thirty days after receipt of the number following. REPRINTS, if desired, must be ordered in advance of publication. Reprints of leading articles will be printed as ordered, the actual cost (with cover, if desired) to be paid for by the author. Reprints must be paid for when ordered. The table below shows the approximate cost of reprints consisting of plain text or text with line engravings. The actual cost may vary from the figures given, and will depend upon the amount of work in re-making the pages into forms, press work, paper, binding, etc. ALL CORRESPONDENCE regarding subscriptions, advertisements, and bills rendered, should be addressed to SCHOOL SCIENCE AND MATHEMATICS Please mention School Science and Mathematics when answering advertisements. THE PUBLISHERS of SCHOOL SCIENCE AND MATHEMATICS purpose to issue the magazine on the 20th of the month preceding the date of publication. Material to appear in any number must be in the Editor's hands not later than the first of the second month immediately preceding. No numbers published for July, August and September. REQUEST. It is hoped that our friends and readers will try to increase the circulation of School Science and Mathematics among their friends and acquaintances. Sample copies will gladly be mailed to addresses furnished. Back numbers of School Science, School Mathematics, and School Science and Mathematics may be had for 25 cents a single copy. The Mathematical Supplements for 15 cents a copy. School Mathematics and Supplement, Vol. I, five numbers... $1.50 2.00 2.00 .75 2.00 2.00 1.00 Volume I,, No. 2, April, 1901, Volume I., No. 9, February, 1902, and Volume III., No. 1, April, 1903, of SCHOOL SCIENCE AND MATHEMATICS are out of print. For copies returned in good condition 50 cents will be paid in cash, or credit of $1.00 allowed on subscription. COLUMBIA OPTICAL DISK including 2 slotted plates, 4 lenses, 2 prisms and mirrors.... Above with refraction tank. .$14.95 17.50 Send for descriptive circulars. Let us quote on your Indianapolis Indiana 1330 THE NATURE STUDY LIBRARY Bound in Morocco This work was recently from the press of Doubleday, Page & Co. C. M. TURTON, 440 Kenwood Terrace, Chicago, Ill. Please mention School Science and Mathematics when answering advertisements. |