An Elementary Handbook for the Use of Amateurs and Students. By PERCIYAL MARSHALL, A.I.M.E-

Contents of Chapters.

I. - The Theory of the Accumulator. II. - How to make a 4-Volt Pocket Accumulator. III. - How to make a 32-Ampere-Hour Accumulator. IV. - Types of Small Accumulators, V. - Hew to Charge and Use Accumulate rs.

VI. - Applications of Small Accumulators, Electrical Novelties, etc. Glossary of Technical Terms

80 Pages, 40 Illus., 12mo, Cloth, 50c.

The Magneto-Telephone. Its Construction, Fitting Up And Adaptability To Every Day Use

By NORMAN HUGHES.

Contents of Chapters.

Some electrical considerations: I. - Introductory II. - Construction. III. - Lines, Indoor Lines. IV. - Signalling Apparatus. V. - Batteries. Open Circuit Batteries. Closed Circuit Batteries. VI. - Practical Operations. Circuit with Magneto Bells and Lightning Arresters. How to test the Line. Push-Button Magneto Circuit. Two Stations with Battery Bells. VII. - Battery Telephone. Battery Telephone Circuit. Three Instruments on one line. VIII. - General remarks. Index.

80 Pages, 93 Illustrations, 12mo, handsome cloth binding, $1.00, In paper covers, 50c.

SPON & CHAMBERLAIN, 123 Liberty street, NEW YORK CITY, U.S.A.