WHITING'S MATHEMATICAL AND PHYSICAL TABLES. Paper. 50 cents. _For elementary works see our list of books in Elementary Science._ D. C. HEATH & CO., Publishers, Boston, New York, Chicago Elementary Science. AUSTIN'S OBSERVATION BLANKS IN MINERALOGY. Detailed studies of 35 minerals. Boards 88 pages. 30 cents. BAILEY'S GRAMMAR SCHOOL PHYSICS. A series of practical lessons with simple experiments that may be performed in the ordinary school room. 138 pages. Illustrated. 50 cents. BALLARD'S THE WORLD OF MATTER. Simple studies in chemistry and mineralogy: for use as a text-book or as a guide to the teacher in giving object-lessons. 264 pages. Illus. $1.00. CLARK'S PRACTICAL METHODS IN MICROSCOPY. Gives in detail descriptions of methods that will lead the careful worker to successful results. 233 pages. Illustrated. $1,60. CLARKE'S ASTRONOMICAL LANTERN. Intended to familiarize students with the constellations by comparing them with facsimiles on the lantern face. With seventeen slides, giving twenty-two constellations. $4.50. CLARKE'S HOW TO FIND THE STARS. Accompanies the above and helps to an acquaintance with the constellations. 47 pages. Paper. 15 cents. ECKSTORM'S THE BIRD BOOK. The natural history of birds, with directions for observation and suggestions for study. 301 pages. Illustrated. 60 cents. GUIDES FOR SCIENCE TEACHING. Teachers' aids for instruction in Natural History. I. Hyatt's About Pebbles. 26 pages. Paper. 10 cts. II. Goodale's A Few Common Plants. 61 pages. Paper. 20 cts. III. Hyatt's Commercial and other Sponges. Illustrated. 43 pages. Paper. 20 cts. IV. Agassiz's First Lesson in Natural History. Illus. 64 pages. Paper. 25 cts. V. Hyates Corals and Echinoderms. Illustrated. 32 pages. Paper. 30 cts. IV. Hyates Mollusca. Illustrated. 65 pages. Paper. 30 cts. VII. Hyatt's Worms and Crustacea. Illustrated. 68 pages. Paper. 30 cts. XII. Crosby's Common Minerals and Rocks. Illustrated. 200 pages. Paper, 40 cts. Cloth, 60 cts. XIII. Richard's First Lessons in Minerals. 50 pages. Paper. 10 cts. XIV. Bowditch's Physiology. 58 pages. Paper. 20 cts. XV. Clapp's 36 Observation Lessons in Minerals. 80 pages. Paper. 30 cts. XVI. Phenix's Lessons in Chemistry. 20 cts. Pupils' Note-book to accompany No. 15. 10 cts. RICE'S SCIENCE TEACHING IN THE SCHOOL. With a course of instruction in science for the lower grades. 46 pages. Paper. 25 cents. RICKS'S NATURAL HISTORY OBJECT LESSONS. Information on plants and their products, on animals and their uses, and gives specimen lessons. 332 pages. Illustrated. $1.50 RICKS'S OBJECT LESSONS AND HOW TO GIVE THEM. Vol. I. Gives lessons for primary grades. 200 pages. 90 cents. Vol. II. Gives lessons for grammar and intermediate grades. 212 pages. 90 cents.