Part 7 (2/2)

”I determined to give a week's strict attention to each of the virtues successively. Thus, in the first week my great guard was to avoid every the least offence against _Temperance_, leaving the other virtues to their ordinary chance, only marking every evening the faults of the day. Thus, if in the first week I could keep my first line, marked T, clear of spots, I supposed the habit of that virtue so much strengthened, and its opposite weakened, that I might venture extending my attention to include the next, and for the following week keep both lines clear of spots. Proceeding thus to the last, I could go through a course complete in thirteen weeks, and four courses in a year. And like him who having a garden to weed does not attempt to eradicate all the bad herbs at once, which would exceed his reach and his strength, but works on one of the beds at a time, and, having accomplished the first, proceeds to the second, so I should have, I hoped, the encouraging pleasure of seeing on my pages the progress I made in virtue, by clearing successively my lines of their spots, till in the end, by a number of courses, I should be happy in viewing a clean book, after a thirteen weeks' daily examination.”

Uncle Fritz said that this plan of Franklin's had been quite a favorite plan of different people at the end of the last century. Richard Lovell Edgeworth, and Mr. Day, and a good many of the other reformers in England, and many in France, really thought that if people only knew what was right they would all begin and do it. They had to learn, by their own experience or somebody's, that the difficulty was generally deeper down.

There was a man, named Droz, who published a little book called ”The Art of being Happy,” with tables on which every night you were to mark yourself, as a school-mistress marks scholars at school, 10 for truth, 3 for temper, 5 for industry, 9 for frugality, and so on.[7]

”But in the long run,” said Uncle Fritz, ”there may be too much self-examination. If you really look up and not down, and look forward and not back, and loyally lend a hand, why, you can afford to look out and not in, in general.”

Fergus brought the talk back to the lightning-rod, and asked where was the earliest hint of it.

The history seems to be this. In the year 1747 a gentleman named Collinson sent to Franklin, from England or Scotland, one of the gla.s.s tubes with which people were then trying electrical experiments.

Franklin was very much interested. He went on repeating the experiments which had been made in England and on the Continent of Europe. With his general love of society in such things, he had other gla.s.s tubes made, and gave them to his friends.

He had one immense advantage over the wise men of England and France, in the superior dryness of our air, which greatly favors such experiments.

Almost any one of the young Americans who will read this book has tried the experiment of exciting electricity by shuffling across a Brussels carpet on a dry floor, and then lighting the gas from a gas-jet by the spark. But when you tell an Englishman in London that you have done this, he thinks at first that you are making fun of him. For it is very seldom that the air and the carpet and the floor are all dry enough for the experiment to succeed in England. This difference of climate accounts for the difficulty which the philosophers in England sometimes found in repeating Dr. Franklin's experiments.

When it came to lightning and experiments about that, he had another very great advantage; for we have many more thunder-storms than they have. In the year 1752, when Mr. Watson was very eager to try the lightning experiments in England, he seems to have had, in all the summer, but two storms of thunder and lightning.

Franklin made his apparatus on a scale which now seems almost gigantic.

The ”conductor” of an electrical machine such as you will generally see in a college laboratory is seldom more than two feet long. Franklin's conductor, which was hung by silk from the top of his room, was a cylinder ten feet long and one foot in diameter, covered with gilt paper. In his ”Leyden battery” he used five gla.s.s jars, as big as large water-pails,--they held nine gallons each. One night he had arranged to kill a turkey by a shock from two of these. He received the shock himself, by accident, and it almost killed him. He had a theory that if turkeys were killed by electricity, the meat would perhaps be more tender.

He acknowledges Mr. Collinson's present of the gla.s.s tube as early as March 28, 1747. On the 11th of July he writes to Collinson that they (”we”) had discovered the power of points to withdraw electricity silently and continuously. On this discovery the lightning-rod is based.

He describes this quality, first observed by Mr. Hopkinson, in the following letter:--

”The first is the wonderful effect of pointed bodies, both in _drawing off_ and _throwing off_ the electrical fire.

”For example, place an iron shot, of three or four inches diameter, on the mouth of a clean, dry gla.s.s bottle. By a fine silken thread from the ceiling, right over the mouth of the bottle, suspend a small cork ball about the bigness of a marble; the thread of such a length, as that the cork ball may rest against the side of the shot. Electrify the shot, and the ball will be repelled to the distance of four or five inches, more or less, according to the quant.i.ty of electricity. When in this state, if you present to the shot the point of a long, slender, sharp bodkin, at six or eight inches distance, the repellency is instantly destroyed, and the cork flies to the shot. A blunt body must be brought within an inch and draw a spark, to produce the same effect. To prove that the electrical fire is _drawn off_ by the point, if you take the blade of the bodkin out of the wooden handle, and fix it in a stick of sealing-wax, and then present it at the distance aforesaid, or if you bring it very near, no such effect follows; but sliding one finger along the wax till you touch the blade, the ball flies to the shot immediately. If you present the point in the dark, you will see, sometimes at a foot distance and more, a light gather upon it, like that of a firefly or glow-worm; the less sharp the point, the nearer you must bring it to observe the light; and at whatever distance you see the light, you may draw off the electrical fire, and destroy the repellency.

If a cork ball so suspended be repelled by the tube, and a point be presented quick to it, though at a considerable distance, it is surprising to see how suddenly it flies back to the tube. Points of wood will do near as well as those of iron, provided the wood is not dry; for perfectly dry wood will no more conduct electricity than sealing-wax.

”To show that points will _throw off_ as well as _draw off_ the electrical fire, lay a long, sharp needle upon the shot, and you cannot electrize the shot so as to make it repel the cork ball. Or fix a needle to the end of a suspended gun-barrel or iron rod, so as to point beyond it like a little bayonet; and while it remains there, the gun-barrel or rod cannot, by applying the tube to the other end, be electrized so as to give a spark, the fire continually running out silently at the point.

In the dark you may see it make the same appearance as it does in the case before mentioned.”

The next summer, that of 1748, the experiments went so far, that in a letter of Franklin's to Collinson he proposed the electrical dinner-party, which was such a delight to Harry and Lucy:--

”Chagrined a little that we have been hitherto able to produce nothing in this way of use to mankind, and the hot weather coming on when electrical experiments are not so agreeable, it is proposed to put an end to them for this season, somewhat humorously, in a party of pleasure on the banks of the _Skuylkill_. Spirits, at the same time, are to be fired by a spark sent from side to side through the river, without any other conductor than the water; an experiment which we some time since performed, to the amazement of many. A turkey is to be killed for our dinner by the _electrical shock_, and roasted by the _electrical jack_, before a fire kindled by the _electrified bottle_; when the healths of all the famous electricians in England, Holland, France, and Germany are to be drank in _electrified b.u.mpers_, under the discharge of guns from the _electrical battery_.”

It was in a letter to Collinson of the next year, 1749,--as I suppose, though it is not dated,--that the project of the lightning-rod first appears. It is too long to copy. The paragraphs most important in this view are the following:--

”42. An electrical spark, drawn from an irregular body at some distance, is scarcely ever straight, but shows crooked and waving in the air. So do the flashes of lightning, the clouds being very irregular bodies.

”43. As electrified clouds pa.s.s over a country, high hills and high trees, lofty towers, spires, masts of s.h.i.+ps, chimneys, &c., as so many prominences and points, draw the electrical fire, and the whole cloud discharges there.

”44. Dangerous, therefore, is it to take shelter under a tree during a thunder-gust. It has been fatal to many, both men and beasts.

”45. It is safer to be in the open field for another reason. When the clothes are wet, if a flash in its way to the ground should strike your head, it may run in the water over the surface of your body; whereas, if your clothes were dry, it would go through the body, because the blood and other humors, containing so much water, are more ready conductors.

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