Thursday, October 06, 2005
Men Who Found Electricity - Part One
from the 1911 Book of Knowledge: The Children's Encyclopedia (The Grolier Society)
starting on page 2113
Electricity is one of the most wonderful forces placed ready for the service of mankind, yet it is one of the things which hid its secret longest from us. Men discovered how to turn the strength of animals to account; how to make the winds drive our ships across the seas; how to apply the power stored up in coal; how to raise steam, and with it change the face of the world. Yet electricity is greater than these. It can do almost anything. It can light a city, supply power for lifting the heaviest weights, drive trains and trolleys, cook a dinner, heal a sick child, and kill us if we are not careful. It is in almost everything, though it does not move. All that we have to do is to excite it, to bring it out, then catch it, so that we may use it as we need it. It is so valuable and does such marvels that it is hard to believe that it existed for thousands of years in the earth and in the air quite unknown to men.
The very name of electricity tells a story of the mystery in which it was hidden for thousands of years from men. A great man named Thales, of whom we read in another part of this book, who lived nearly seven hundred years before Christ was born, noticed that amber, when rubbed with another material, became heated, and that when in that condition it would draw towards itself little pieces of feathers and other tiny light articles. It is said that in the old time the women of Syria used amber to catch up leaves, straws, and other things clinging to their clothes.
A great writer named Pliny, who was born in the year 62 A.D. and died about 114, wrote about amber and its ways. He likened it to the loadstone, the properties of which were well known in his day. We all know that the loadstone is a certain ore which, if allowed to hang by a string, always has one of its points towards the North Pole and the other towards the South Pole, and will attract other metals towards itself. Another thing that Pliny knew was that the electric fish can give such sharp electric shocks as to make a man quite ill. But he never thought that there was any connection between the power of the amber, the fish, and the loadstone.
It was not until the sixteenth century was well advanced that the world began to take a real interest in electricity. Then William Gilbert, a thoughtful scholar, who was one of Queen Elizabeth's doctors, set himself to make experiments with a number of substances to see whether they, like amber, would, when warmed by friction, attract other bodies. He found that many, including sulphur, sealing-wax, gems, solid resin, rock-salt, and many other things, had the same power. They would attract metals, stones, earths, fluid, and even heavy smoke.
The Colchester Man Who Gave Electricity Its Name
As the first man to examine the question, he had to find a name to describe the condition which he excited in these objects. Now, as amber was the first substance known to possess this power of attraction, and as the Greek name for amber is elektron, Dr. Gilbert gave the name electricity to the condition which heat and friction excited in the things he tried. He is called the father of electrical science. Gilbert lived sixty-three years, dying in 1603; and his life was very valuable to the world, for every year sine he began his discoveries our store of learning concerning electricity has gone on increasing.
Gilbert was a Colchester man. He was followed by a famous Irishman, Robert Boyle, a son of the Earl of Cork. Boyle was born in Munster, in 1627, twenty-four years after the death of Gilbert. He was a wonderful scholar as a boy, and at ten learned algebra simply because he loved to exercise his mind. He invented a famous air-pump, and taught the world all about the condition and qualities of air. His work for electricity was to show that electricity remained for some time in a substance after rubbing had ceased; and to add new substances which could be electrified. The mere fact that he was noticing electricity was sufficient to set other men thinking about it, for his reputation was very high, especially with the great men on the Continent of Europe.
The Man Who Fastened Two Things Together With "Nothing"
Boyle died in 1691, five years after the death of Otto von Guericke. This clever man was born at Magdeburg, Prussia, in 1602, and after an excellent education visited England and became acquainted there with the scientists of that day. He invented the first air-pump, but that of Boyle's was so much better that the Prussian invention was soon forgotten. Guericke was the first man to show the immense power of a vacuum. He made two hemispheres of metal - that is, two large metal cups, the edges of which fitted together. There was a tape to each, through which the air could be drawn out by the air-pump. When this was done, so tightly did the two hemispheres cling together that not until the united strength of fifteen horses had been employed could they be pulled apart.
Guericke lived far too early. He discovered a way of making electric light, but nobody knew what it meant. Electric lighting did not become general until 1878. What Guericke did was to make a ball of sulphur inside a globe of glass, then break off the glass so as to expose the sulphur. This he rubbed in the dark, and found that it gave forth a light, accompanied by sound. He it was who discovered also that bodies which have not been electrified by friction become electrified when brought into contact with other bodies which have been electrified.
Sir Isaac Newton did one notable thing for electricity by showing that a disc of glass, when placed in a brass cylinder and electrified, would attract paper so strongly as to make it leap about in the cylinder.
The Man Who Showed That the Electric Spark was Like Lightning
Next came the experiments of Francis Hawksbee, who was famous in 1705 as a scientist, when he was elected a member of the Royal Society. It is not known when he was born, though the year of his death is given as about 1713. He made important experiments with air and mercury, and with a machine for producing electricity by rubbing a glass cylinder with the hand.
He, for the first time, drew attention to the fact that the electric sparks which he was able to produce, and the crackling noise they made, resembled lightning.
His son, Francis Hawksbee, who was born in 1687 and died in 1763, was a gifted maker of scientific instruments, and was the first man in London to lecture and at the same time make scientific experiments to illustrate his theories.
The elder Hawksbee wrote much about his discoveries, and his books, translated into French and Italian, were of great assistance to scientists on the Continent.
All this may seem unimportant, but each of these little discoveries led to other and more important discoveries.
A tree in a forest may not seem of much use as a dwelling for a man, but when the tree-feller and the carpenter and the builder have each done their share, that tree becomes an essential part of a house, all the parts of which have been pieced together, just like the building up of a great science. Now we come to the first step which brings us nearer to practical uses of electricity.
Stephen Gray was a Bluecoat boy in London at the beginning of the eighteenth century, and by some happy chance gave up his life to the study of electricity. He made a grand discovery. He found that we can divide matter into two classes - that which can be electrified by friction, and that which cannot be electrified by friction.
Then he went a step further and found that the non-electrics could be made electric by being placed in contact with those which were already electrified. This means, as we should say now, that he had discovered that some substances are conductors of electricity, and some are non-conductors of electricity.