Chapter VI—ELECTRICAL MEASURING INSTRUMENTS. Galvanometers, Ammeters, Voltmeters, etc. Chapter VII—CURRENT CONTROL DEVICES. How to Make a Pole Changing Switch or Current Reverser. How to Reverse Small Motors. Battery Rheostats. Chapter VIII—HOW TO MAKE A TELEGRAPH KEY AND SOUNDER. How to Install a Telegraph Line and Learn to Operate. Learning the Morse Code. Chapter IX—HOW TO MAKE AND INSTALL A TELEPHONE. Chapter X—MEDICAL COILS AND SHOCKING COILS. Chapter XI—THE CONSTRUCTION OF SPARK COILS. A one-quarter inch Coil, a one-half inch Coil, a one inch Coil. Experiments with Spark Coils. VOLUME III 80 Pages 73 Illustrations Chapter XII—HOW TO MAKE A DYNAMO-MOTOR. Chapter XIII—HOW TO MAKE A TOY BATTERY MOTOR. Chapter XIV—HOW TO BUILD AN ELECTRIC ENGINE. Chapter XV—MINIATURE BATTERY LAMP LIGHTING. Chapter XVI—COHERER OUTFITS FOR WIRELESS TELEGRAPHY. Chapter XVII—HOW TO BUILD A TESLA HIGH FREQUENCY COIL. Experiments with High Frequency Currents. Chapter XVIII—AN EXPERIMENTAL WIRELESS TELEPHONE. Chapter XIX—MISCELLANEOUS APPARATUS. Electrolysis of Water. Electro-Plating. Electricity from Heat. A Handy Light. An Experimental Arc Lamp. A Magnetic Diver. Magnetic Fish. A Magnetic Clown. An Electric Breeze. A Static Motor. *Price Postpaid, 25 Cents per Volume* All three volumes can be supplied bound together with handsome cloth cover for $1.25 postpaid. *Parts and Materials* For Building the Apparatus Described in this Book We have received so many requests from our customers for information as to where they may obtain some of the materials required to build the apparatus described in this book, that we have made arrangements to supply same. Our business is essentially publishing, and we do not intend to go into the manufacture of, or to push the sale of apparatus or parts. Knowing, however, that many of our customers live where they are remote from cities or suitable supply houses, where they might obtain the necessary materials, we believe that the value of our books will be increased ten fold to the reader if we are in a position to furnish parts, etc. *M500* Complete Set of Parts for Dynamo illustrated in Figure 132 *$3.75* Shipping Weight, 5 lbs. *M631* Complete Set of Parts for Tesla Coil *4.50* Shipping Weight, 4 lbs. *M631A* Completed Tesla Coil *6.00* Shipping Weight, 10 lbs. *M631B* Complete Tesla Coil Outfit, consisting of Tesla Coil, two-inch Spark Coil, Spark Gap and Leyden Jars *25.00* Shipping Weight, 25 lbs. Please use list number when ordering. Include postage to pre-pay mailing charges, or we will ship by Express Collect. No parts supplied other than listed above. All prices subject to change without notice. Send for latest price list. *COLE & MORGAN, Inc.* P.O. Box 473, City Hall Sta. New York, N. Y.