Page:Popular Science Monthly Volume 92.djvu/171

 Electrical Wizardry at Home

Some weird effects that you can obtain with a Tesla coil and some of your apparatus

By E. R. Thomas

��TO begin with, if you have an oscilla- tion transformer the secondary will make a suitable primary for a Tesla or Oudin Coil.

To construct a Tesla coil that will. give a 10 to 12-in. spark, procure a tube 4 in. in diameter and 16 in. long. This may be made of two tubes 8 in. long and joined together as shown in Fig. 2. Some cereals come in tubular containers which will answer very well for this purpose. The pieces A and B are of wood; shellac is used to join the parts together. Avoid

��the use of nails in this construction.

After applying two coats of shellac to the secondary tube, wind it closely within ^ in. of either end with double cotton- covered No. 25 wire. Then give two coats of shellac to the windings, being sure the first coat is absolutely dry be- fore applying the second.

The base and uprights should be made of well seasoned wood which should also be shellacked. Make the dimensions to suit the individual requirements. Fasten four glass push-pins to the base as shown

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��Details in the construction of a Tesla or Oudin coil and diagram of the hook-up for the experiments shown in the lower part of the illustration. These experi- ments as well as X-ray photographs may be made by the use of this coil

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