Electricity for Boys | Page 4

electricity are the same, but that
they differ merely in their modes of motion.
FIRST HISTORICAL ACCOUNT.--The first historical account of
electricity dates back to 600 years B. C. Thales of Miletus was the first
to describe the properties of amber, which, when rubbed, attracted and
repelled light bodies. The ancients also described what was probably
tourmaline, a mineral which has the same qualities. The torpedo, a fish
which has the power of emitting electric impulses, was known in very
early times.
From that period down to about the year 1600 no accounts of any
historical value have been given. Dr. Gilbert, of England, made a
number of researches at that time, principally with amber and other
materials, and Boyle, in 1650, made numerous experiments with
frictional electricity.
Sir Isaac Newton also took up the subject at about the same period. In

1705 Hawksbee made numerous experiments; also Gray, in 1720, and a
Welshman, Dufay, at about the same time. The Germans, from 1740 to
1780, made many experiments. In 1740, at Leyden, was discovered the
jar which bears that name. Before that time, all experiments began and
ended with frictional electricity.
The first attempt to "bottle" electricity was attempted by
Muschenbr[oe]ck, at Leyden, who conceived the idea that electricity in
materials might be retained by surrounding them with bodies which did
not conduct the current. He electrified some water in a jar, and
communication having been established between the water and the
prime conductor, his assistant, who was holding the bottle, on trying to
disengage the communicating wire, received a sudden shock.
In 1747 Sir William Watson fired gunpowder by an electric spark, and,
later on, a party from the Royal Society, in conjunction with Watson,
conducted a series of experiments to determine the velocity of the
electric fluid, as it was then termed.
Benjamin Franklin, in 1750, showed that lightning was electricity, and
later on made his interesting experiments with the kite and the key.
DISCOVERING GALVANIC ELECTRICITY.--The great discovery
of Galvani, in 1790, led to the recognition of a new element in
electricity, called galvanic or voltaic (named after the experimenter,
Volta), and now known to be identical with frictional electricity. In
1805 Poisson was the first to analyze electricity; and when [OE]rsted of
Copenhagen, in 1820, discovered the magnetic action of electricity, it
offered a great stimulus to the science, and paved the way for
investigation in a new direction. Ampere was the first to develop the
idea that a motor or a dynamo could be made operative by means of the
electro-magnetic current; and Faraday, about 1830, discovered
electro-magnetic rotation.
ELECTRO-MAGNETIC FORCE.--From this time on the knowledge
of electricity grew with amazing rapidity. Ohm's definition of
electro-motive force, current strength and resistance eventuated into
Ohm's law. Thomson greatly simplified the galvanometer, and

Wheatstone invented the rheostat, a means of measuring resistance,
about 1850. Then primary batteries were brought forward by Daniels,
Grove, Bunsen and Thomson, and electrolysis by Faraday. Then came
the instruments of precision--the electrometer, the resistance bridge, the
ammeter, the voltmeter--all of the utmost value in the science.
MEASURING INSTRUMENTS.--The perfection of measuring
instruments did more to advance electricity than almost any other field
of endeavor; so that after 1875 the inventors took up the subject, and by
their energy developed and put into practical operation a most
wonderful array of mechanism, which has become valuable in the
service of man in almost every field of human activity.
RAPIDITY OF MODERN PROGRESS.--This brief history is given
merely to show what wonders have been accomplished in a few years.
The art is really less than fifty years old, and yet so rapidly has it gone
forward that it is not at all surprising to hear the remark, that the end of
the wonders has been reached. Less than twenty-five years ago a high
official of the United States Patent Office stated that it was probable the
end of electrical research had been reached. The most wonderful
developments have been made since that time; and now, as in the past,
one discovery is but the prelude to another still more remarkable. We
are beginning to learn that we are only on the threshold of that
storehouse in which nature has locked her secrets, and that there is no
limit to human ingenuity.
HOW TO ACQUIRE THE VAST KNOWLEDGE.--As the boy, with
his limited vision, surveys this vast accumulation of tools, instruments
and machinery, and sees what has been and is now being accomplished,
it is not to be wondered at that he should enter the field with timidity.
In his mind the great question is, how to acquire the knowledge. There
is so much to learn. How can it be accomplished?
The answer to this is, that the student of to-day has the advantage of the
knowledge