The American Boy's Handy Book/Chapter 40
A jovial-looking commercial traveller once won a wager from the landlord of a certain Detroit hotel by making over a hundred rings with one mouthful of smoke. The writer was sitting in the hotel office at the time, and becoming interested in the conversation, watched to see how the trick was done. Taking some cards from his card-case, the young man proceeded to bend up the edges in such a manner that the centre part of each formed a perfect square. Six cards he folded in this manner; then, after fishing in his pockets for some time, he produced a dime and a lead-pencil. Placing the ten-cent piece upon the centre of one card, he made a ring with the lead-pencil by following the edges of the coin. Opening a pocketknife at the file blade, with the point he cut a round hole in the card, following the circle made by the pencil. He then put the cards together, in the form of a light but strong box (Figs. 232, 233, 234, and 235), and taking a long pull at a cigar which was between his lips, he filled his cheeks, and blew the smoke into the paper box. By this time all the idlers in the office had Image missingHow to make a Card-box. collected around the smoker, who, with a triumphant smile upon his face, commenced to tap the sides of the box with his lead-pencil. At each tap a tiny but perfect and beautiful ring of smoke shot into the air—one hundred and ten were counted before the smoke was exhausted. Fig. 236 shows how similar rings can be made with a lamp-chimney in which a card disk with a hole in it has been placed; a piece of paper or membrane fastened over the other end serves for a vibrating surface, which, when struck with the thumb, forces out the little rings of smoke.
The reader must not for a moment suppose that it is necessary to use tobacco smoke to perform this beautiful experiment; any other smoke will answer just as well to make the "vortex rings," as they are scientifically called. If after dipping a paint-brush into india ink, or any water-color paint, you gently insert the tip of the brush into a glass of clear water, you will see the pigment fall from the end of the brush, and, gradually sinking to the bottom, form rings exactly similar to the circles of smoke described.
The rings made by skipping a flat stone over the water are but another example of the vortex, and the jolly commercial traveller, when he was exhibiting the little paper box and smoke-rings to the laughing crowd of fellow-travellers in the hotel office, was standing upon the threshold of a mighty mystery, experimenting with laws, and showing the action of the Image missingFig. 236.Lamp-Chimney Smoke-Box same forces that are supposed to have produced the wonderful rings around Saturn! Indeed, it is asserted that the broad, misty band of light which we see at night stretched across the heavens, and known to every boy as the milky-way, is nothing more nor less than a gigantic vortex ring, composed of millions of heavenly atoms. Some very learned men think that the secret of the whole universe, the origin of gravitation and electricity, are all locked up in the mystery which controls the formation and motion of a simple smoke-ring.
As Adrien Guebhard wisely remarks, in an interesting article upon this same subject, "Nothing is vulgar to one who knows how to see, and nothing indifferent to one who knows how to observe."