The next time you see a dog with his nose in the can, close the switch connected to the primary circuit. What happens will not hurt the dog, but he will travel for home as fast as four legs can carry him.
Experiment 9—How to Make an Electric Spark Photograph Itself.
This experiment must be conducted in a dark room with the aid of a photographer’s ruby lamp so that the photographic plates used will not become "light struck" and spoiled.
Place an ordinary photographic plate on a piece of sheet metal with the coated or sensitive side up. Connect the piece of sheet metal to one of the secondary terminals of the spark coil by means of a wire.
Then sift some dry starch powder, flour of sulphur or talcum powder through a thin piece of gauze on to the plate. Lead a sharp pointed wire from the other secondary terminal of the coil. Complete the primary circuit of the coil just long enough to make one single spark.
Wipe the powder off the plate thoroughly and develop it in the usual manner. The negative will show a peculiar electric discharge looking very much like sea moss. No two photographs will be alike. The test results are obtained when only one or two sparks are allowed to pass.
Arts and Science Series No. 9
Home-made
Electrical Apparatus
A Practical Handbook for Amateur