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23. Perpetual Motion

Mercurial displacement in a cistern of water

A cistern full of water 4 feet deep. Let B be a wheel; freely suspended within it, let there be four glass tubes 40 inches long, c, c, c, c, having large bulbs, holding, say, a pint, blown at the closed end. Fill these tubes with mercury, fix on an India-rubber bladder, that will hold a pint, to each of them at the open end, and let them be attached round the wheel, as in the figure.

As the pressure of 40 inches of mercury will exceed the atmospheric pressure, and also that of the four-feet column of water, when the India-rubber bottle is lowest, and the tube erect, as at D, the mercury will fill it, leaving a vacuum in the glass bulb above. On the opposite side the mercury will fill the glass bulb, and the India-rubber bottle will be pressed flat, as will also be the case in the two horizontal tubes. Now, it is evident that the two horizontal tubes exactly balance each other; but the tube, D, with its bulb swelled out, displaces a pint of water more than its opposite tube, and hence will attempt to rise with the force of about one pound, and each tube, when it arrives at the same position, must produce the same result; the wheel must have a continual rower, equal to about one pound, with a radius of two feet.

(Subsection 956, from p.383)

From: Gardner D. Hiscox, M.E., Mechanical Appliances and Novelties of Construction (1927), Norman W. Henley Publ. Co.

Nature bears long with those who wrong her. She is patient under abuse. But when abuse has gone too far, when the time of reckoning finally comes, she is equally slow to be appeased and to turn away her wrath. (1882) -- Nathaniel Egleston, who was writing then about deforestation, but speaks equally well about the danger of climate change today.
Carl Sagan: In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) ...(more by Sagan)

Albert Einstein: I used to wonder how it comes about that the electron is negative. Negative-positive—these are perfectly symmetric in physics. There is no reason whatever to prefer one to the other. Then why is the electron negative? I thought about this for a long time and at last all I could think was “It won the fight!” ...(more by Einstein)

Richard Feynman: It is the facts that matter, not the proofs. Physics can progress without the proofs, but we can't go on without the facts ... if the facts are right, then the proofs are a matter of playing around with the algebra correctly. ...(more by Feynman)

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by Ian Ellis