CHAPTER XVIII.
APPARATUS FOR STATIC ELECTRICITY.
236. Static or Frictional Electricity. There are many interesting and instructive experiments in this branch of electricity. All that can be done here is to explain a few pieces of simple apparatus to show the presence of static electricity, it being taken for granted that you know how to produce it, and that you have some book of simple experiments.
237. Electroscopes are instruments for showing the presence of static electricity.
238. Thread Electroscope. A piece of ordinary thread may be used for this purpose. Tie one end of it to the back of a chair or other support.
Fig. 107.