High Frequency Apparatus Page xv

CONTENTS High Potential Transformer. Design for a Four-Kilowatt Magnetic Leakage Instrument. Building the Core. Forms for Winding Primary and Secondary. Insulation. Assembly of the Transformer. Construction of the Rotary Spark Gap. Spark Gap Muffler. The Oscillation Condenser. Coating the Plates. Building Up Units. Connections. Setting Up and Operating the Apparatus. The Switch Board. Prevention of Kick Back. Tuning and Adjustment of the Apparatus. Chapter XIX. LARGE TESLA AND OUDIN COILS FOR THE STAGE Specifications for Large Oscillation Transformers of the Portable Air-Insulated Type. Tesla Transformer for the Production of a Fifty-Inch Spark. Details of Construction. Oudin Resonator for the Production of a Short but Very Thick Discharge. Mounting the Apparatus. Provisions for Packing and Shipment. Chapter XX. CONSTRUCTION OF A WELDING TRANSFORMER Transformer to Deliver a Current of Low Voltage and very Great Amperage. Heating a Quarter-Inch Iron Rod to Incandescence. Building the Transformer. Suggestions for Handling the Heavy Secondary Wire. Insulation. Assembly and Mounting. Experiments Using a Current of 250 Amperes. Special Copper Tongs or Pliers. Making Flexible Cable to Carry the Heavy Current. Burning Up a Heavy Bar of Steel. Welding Two Pieces of Iron Rod Held in the Hands. Spot Welding of Sheet Iron. Melting Metals in a Crucible to Show Principle of Electric Furnace. Suggestions for Effective Stage Setting. Particularly Startling and Spectacular Experiments to Close the Entertainment. Chapter XXI. HINTS FOR THE ELECTRICAL ENTERTAINER Preparation of the Lecture. Snap and Vigor Necessary. Education of the Public Far Advanced in Recent Years. Class of Audience Must Receive Careful Consideration. Comparison of Well-Read Chautauqua AsXV 204 212 221