|
Main
- books.jibble.org
My Books
- IRC Hacks
Misc. Articles
- Meaning of Jibble
- M4 Su Doku
- Computer Scrapbooking
- Setting up Java
- Bootable Java
- Cookies in Java
- Dynamic Graphs
- Social Shakespeare
External Links
- Paul Mutton
- Jibble Photo Gallery
- Jibble Forums
- Google Landmarks
- Jibble Shop
- Free Books
- Intershot Ltd
|
books.jibble.org
Previous Page
| Next Page
Page 41
The spring, j, is bent into a loop and its lower end is inserted in a
wooden plug driven into a hole in the base piece, f.
In the upper part of Fig. 2 are shown two telegraph instruments less
the bobbins. Each instrument (Fig. 14) consists of a wooden base, k, a
right angled soft iron bar, l, having the central part of its upper
end brought to an obtuse angle, an armature, m, fitted loosely to the
angled end of the bar, a notched brass standard, n, for limiting the
movement of the armature, a retractile spring for lifting the
armature, a spring key, o, pivotally secured to the base by a common
wood screw, and a contact point projecting from the base under the
key.
Besides these there is a D shaped block, to answer as a frame to the
galvanometer, a common pocket compass, E, fitted to a circular cavity
in the top of the block, D, a permanent U magnet, F, a bundle of soft
iron wires, G, and two copper strips, H.
[Illustration]
DECOMPOSITION OF WATER.
To illustrate the decomposition of water, connect the copper strips, H
H, to the poles of the battery by means of wires, as shown in Fig. 3,
and insert them in a tumbler of water acidulated with a few drops of
sulphuric acid. Instantly bubbles will rise from the copper strips,
showing that gas is being disengaged from the water. The strip
connected with the carbon plate will disengage oxygen, while the strip
connected with the zinc plate will disengage hydrogen.
[Illustration: FIG. 3.--DECOMPOSITION OF WATER.]
SOLENOID.
By connecting one of the coils, A, with the battery by means of the
wires, the action of a helix or solenoid is shown. When so connected,
the helix will draw up with itself a barrel pen, or any light iron or
steel object. (See Fig. 4.) This is not a true solenoid, but it is
generally known by that name. In a true solenoid one of the terminals
is passed back through the center of the coil.
[Illustration: FIG. 4.--SOLENOID.]
MAGNETIZATION OF STEEL.
By inserting in the solenoid a knitting needle, or any bar of hardened
or tempered steel, and sending a current through the coil, the steel
will become permanently magnetized.
ELECTROMAGNET.
By placing the two coils, A, upon the magnet frame, B, and connecting
one terminal of each with the battery, the remaining terminals being
connected together, as shown in Fig. 5, an electromagnet is formed
which will lift several pounds.
[Illustration: FIG. 5.--ELECTROMAGNET.]
ELECTRIC MOTOR.
By placing the magnet thus formed upon the motor base, C, in front of
the armature, h, as shown in Fig. 6, and connecting one terminal of
the magnet with the battery and the other with the clamping screw, e,
of the magnet, and by connecting the commutator spring, j, with the
remaining pole of the battery, the motor will be made to rotate
rapidly.
COMPASS AND MAGNETIC EXPERIMENTS.
By placing one end of the bar magnetized by the solenoid near the
compass contained by the cabinet (Fig. 7) it will be seen that one end
of the compass needle is attracted. When the opposite end of the bar
is presented to the same end of the needle, that end of the needle
will be repelled and the opposite one attracted, showing that like
poles repel each other while unlike poles attract.
Previous Page
| Next Page
|
|