The Boy's Own Book of Indoor Games and Recreations / A Popular Encyclopædia for Boys

by C. Stansfeld Hicks; John Nevil Maskelyne; Gordon Stables

Electrical machines are not always as persistently popular as they might be, owing to their possessors being at a loss for novel experiments. The apparatus is put through its facings like soldiers at drill, the bells are rung, the little men are danced up and down between the plates, the lady’s hair is stiffened like quills upon the maligned porcupine, the sparks are extracted on the glass stool, a few shocks are given, and the round ends in a certain weariness, to be repeated at ever-lengthening intervals. The apparatus is always the same, the experiments are the same, and to a good many boys the constant repetition becomes monotonous. Some, of course, take sufficient interest in the matter to master the theory of the experiments and gain a living pleasure in what they do; the majority, less sturdily endowed, require to be led more gently on and have their paths made smoother. All, however, are invariably interested in using their hands as well as their heads, and for their benefit we offer the following hints, and relate how we last raised our storm in a teacup.

We took two pieces of glass tube and laid them side by side on a cup. The tubes had been bought for threepence from the druggist’s across the street, and had been used as peashooters, for which they are most excellently adapted. They are true, smooth, and to the ordinary tin peashooter very much what the modern rifle is to the old brown Bess. They carry a pea—but it suddenly occurs to us that we ought not to have said anything about such objectionable practices, which of course took place a good many years ago, as witness the ‘had been used’ with which the digression was introduced.

The pieces of glass tubing were then thoroughly dried and laid on the cup side by side. Over each of them a piece of tinfoil was pinched to represent the storm-clouds, and in one of the corners of each cloud, in order to make things easy for the electricity, we squeezed in a brass ball. To each cloud we attached a piece of silk twist out of the workbox, and then, by means of some copper wire—brass chain would have done just as well—we connected one cloud with the inside and one with the outside of a laden Leyden jar, or jar charged from the machine, whichever word-combination may appear preferable. We then proceeded to pull the silken strings, the tinfoil clouds slipped along their glassy ways, approached each other slowly, and then—a flash of lightning passed from each to each, and the thunder rolled in the form of the tiny snap which sounded as the discharge took place.

The theory of the thunderstorm suddenly awoke new interest in us, and having succeeded so well in the air, we resolved to advance further and do some damage. We took away one of the tubes, and resting the other on two cups—one at each end—placed a model house between for us to strike. The house was very loosely put together, the walls being only leant up against each other, and so arranged as to fall at the slightest jerk. In the chimney we placed a brass ball for the electricity to gather on instead of streaming off into the air, as it does on an ordinary lightning-conductor, and then, having joined up to the jar, we brought the cloud over and got our flash as we had hoped.

Then we soared to higher flights and put a pinch of gunpowder in the way of the flash, in the hope that we should have a little blow up, but, alas! the flash went through so quickly that the powder was scattered. Then we remembered the wet string with which our lecturer used to operate, and placing that in the path of the current, we slowed the rate, kept the flash in the powder long enough to ignite it, and blew down the walls of our house in grand style.

Then we worked up to our crowning success in the experiment line. We had a small model of a ship, and we resolved to strike it by lightning. We hung our cloud over a basin. Into the basin we put our ship, having first connected the foremast with our jar, and placed the least pinch of powder in a hole, where it entered the deck. The jar was charged, the cloud hung in the sky, the ship came ‘sailing, sailing o’er the sea;’ it neared the storm; it passed into it; it came within striking distance; there was a flash, a crack, and ‘the saucy frigate floated on the bosom of the waves’—in the wash-hand basin—‘a helpless wreck.’

‘What was the use of all that?’ Well, the use was that we clearly understood what before we had half doubted because we had only taken it for granted. We left off talking about the ‘electric fluid’ and ‘thunderbolts;’ we no longer looked upon electricity as something liquid which dropped out of a cloud with a bang; we ceased to imagine that lightning-conductors should be insulated, ‘to lead the fluid.’ And we saw that the ‘stroke’ went up from the earth as well as down from the sky; that the flash took place at the meeting, and was simply due to the necessary transference in attaining equilibrium.

A good deal of the success of the experiment was due to the size of the jar, the quantity of electricity it accumulated being proportionate to the extent of the coated surface; while the intensity depended on the thickness of the glass. Ours was a fair-sized jar, but its strength was nothing like that of Cuthbertson’s famous battery, which he built for the Tylerian Society at Haarlem, which consisted of a hundred jars each of five and a half square feet, so that the total amount of coated surface was five hundred and fifty square feet, sufficient to magnetise large steel bars, rend four-inch blocks of boxwood in pieces, melt into red-hot globules iron wires twenty-five feet long, and dissipate eight-inch tin wires in a cloud of smoke. Of course with an ordinary battery we could have done as well, but even with frictional electricity distance is of little importance. Did not Bishop Watson, of Llandaff, send a discharge from a Leyden jar through 2,800 feet of wire and the same distance of earth? Did he not, at Shooter’s Hill, send a discharge through 10,600 feet of wire supported on insulators of baked wood? Did not Franklin, in 1748, send a Leyden jar discharge across the Schuylkill? and did not De Luc discharge a jar across the whole width of the Lake of Geneva? We may not be Watsons, Franklins, or De Lucs, and have their wealth of apparatus and dexterity of manipulation, but the poorest and clumsiest lad amongst us is quite capable of arranging the necessary device for securing ‘a storm in a teacup.’