Scientific amusements . strument,which we can easily describe, is a most interesting objectof study. The Harmonograph belongs to mechanics inprinciple, and to the science of acoustics in will first examine the apparatus itself. It is composedof two pendulums, A and B {see page 164), fixed tosuspensions. Pendulum B supports a circular plate, P, onwhich we may place a small sheet of paper, as shown inthe illustration. This paper is fixed by means of smallbrass clips. Pendulum A supports a horizontal bar, atthe extremity of which is a glass tube, T, terminating atits lower extremit
Scientific amusements . strument,which we can easily describe, is a most interesting objectof study. The Harmonograph belongs to mechanics inprinciple, and to the science of acoustics in will first examine the apparatus itself. It is composedof two pendulums, A and B {see page 164), fixed tosuspensions. Pendulum B supports a circular plate, P, onwhich we may place a small sheet of paper, as shown inthe illustration. This paper is fixed by means of smallbrass clips. Pendulum A supports a horizontal bar, atthe extremity of which is a glass tube, T, terminating atits lower extremity with a capillary opening ; this tubeis filled with aniline ink, and just rests on the sheet ofpaper; the support and the tube are balanced by a 164 SOUND. counterpoise on the right. The two pendulums, A and B,are weighted with round pieces of lead, which can bemoved at pleasure, so that various oscillations may beobtained. The ratio between the oscillations of the twopendulums may be exactly regulated by means of pen-. M. Tiblcy s Harmonograpli. dulum A carrying a small additional weight, the heightsmall wmdiass. If we give to pendulum A a slight move-iTne on ^r ° * P°^ ^t.^ ^ traces a straight B the n P^ P-^^^ ? ^ ? ^t ^f-- -°ve pendulumB, the paper also is displaced, and the point of tube T w^trace curves, the shape of which varies with the nature of CURVES. t6s the movement of pendulum B, the relation between theoscillations of the two pendulums, etc. If the pendulumsoscillate without any friction the curve will be clear, andthe point will pass indefinitely over the same track, butwhen the oscillations diminish, the curve also diminishesin size, still preserving its form, and tending to a pointcorresponding with the position of repose of the twopendulums. The result is therefore that the curves traced
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Keywords: ., bookcentury1800, bookdecade189, booksubjectscientificrecreations
