Simple Experiments in Static Electricity - A Series of Instructive and Entertaining Experiments in Static Electricity for Students and Amateurs

By Percival G. Bull

Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce and increasingly expensive. We are republishing these classic works in affordable, high quality, modern editions, using the original text and artwork.

• Language: English
• Publisher: Read Books Ltd.
• Release date: Sep 6, 2016
• ISBN: 9781473353763

Book preview

CHAPTER I

PRODUCTION OF ELECTRICITY BY VARIOUS MEANS

EXPERIMENT NO. 1

Friction on India-rubber (fig. 1).—Take a sheet of vulcanised rubber and with the thumb-nail scratch a word on its surface. Shake up in a muslin bag, or piece of dry paper, a mixture of powdered sulphur and red lead, previously well dried, and sprinkle it on the india-rubber. The word now appears in red letters on the surface of the rubber. The red lead when shaken with the sulphur in the bag becomes electrified positively, and is attracted to that part of the surface of the rubber which has been electrified negatively through friction by the thumb-nail. The sulphur is not attracted, and can be blown away.

FIG. 1.

EXPERIMENT NO. 2

Friction of Mercury in Glass Tube (fig. 2).—Take a glass tube about 18 in. long and 1 in. wide, dry it thoroughly, and after pouring in some mercury, cork it up, and shake it briskly. Hold the tube now to a gold-leaf electroscope and the leaves will diverge. Discharge the electroscope and place on it a small cup (fig. 3). Then pour the mercury from the tube into the cup. Again the leaves of electroscope will be seen to diverge.

FIG. 2.

FIG. 3.

EXPERIMENT NO. 3

Cleavage of a Card and of Talc.—Take a large card, and having warmed it well, double it in two, and tear it sharply in half. Test each portion of the card at the fractured edge, and the one will be found positively, and the other negatively, electrified. A piece of dry warm talc also, if split asunder quickly, will become electrified in a similar manner. A sheet of stiff brown paper may also be tried.

EXPERIMENT NO. 4

The Cone of Sulphur (fig. 4).—Procure a large tapering wineglass and cover part of the outside portion with tinfoil. Round this twist a wire with two pith balls attached to the end, suspended by cotton threads. Place the glass on an insulating stand, and pour some melted sulphur into it, immersing a glass rod therein to serve as a handle. Allow the sulphur to congeal and harden, and connect the tinfoil to earth during the process. When the sulphur has hardened, lift it up by the glass handle, when the pith balls will be seen to diverge. Let the sulphur drop down again into the glass, and the balls will collapse. Again raise the sulphur and then lower it. The same effects will be observed.

FIG. 4.

EXPERIMENT NO. 5

Combustion of Charcoal (fig. 5).—A convenient method of showing this is to twist a piece of copper wire around a bit of charcoal 6 in. in length and connect it with the lower plate of a condensing electroscope. The upper plate is connected with the earth. Now with a spirit-lamp