Page:Popular Science Monthly Volume 9.djvu/384

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362
THE POPULAR SCIENCE MONTHLY.

CORRESPONDENCE.



THE WATER-HAMMER.

To the Editor of the Popular Science Monthly.

SIR: The following phenomenon can, perhaps, be explained by yourself or one of your readers: I have a water-hammer, made of a straight tube of glass, about eighteen inches long and three-quarters of an inch in diameter. At the top of the tube there are two bulbs, the upper one about half the size of the lower, with only a narrow passage of about a sixteenth of an inch in width to connect the lower bulb with the tube, and the upper bulb with the lower.

PSM V09 D384 Vacuum effect experiment.jpg

About one-third of the tube contains water. When the tube is inverted, and the water allowed to fill both bulbs, it will not, upon the tube being reversed, run out, but will remain in the bulbs for an indefinite time, until shaken or otherwise disturbed. This may be owing to adhesion simply, or, possibly, to capillary attraction, but it is not to this fact chiefly that I wish to call your attention. The water being in the bulbs, and the tube held with the bulbs upward, if a smart blow with the palm of the had be applied at the bottom of the tube, there arises, under certain conditions which I have been unable to determine, a ringing noise resembling sometimes the singing of a bird, sometimes the noise produced by a thin iron instrument—a fork, for instance—when knocked rapidly against an empty tumbler. During this time, no water escapes from the bulbs, but the water at the mouth of the lower bulb is violently agitated, as if small particles of air were quickly ascending to the height of a quarter of an inch in the bulb. Not a drop of water is displaced, the water remaining at the bottom of the tube not being perceptibly increased while the noise continues. It lasts sometimes from five to ten minutes, and it seems as though, under favorable conditions, it might continue indefinitely. Very frequently, however, the experiment does not succeed, though apparently all the conditions are exactly the same. Here, therefore, are two questions:

1. What is the reason why the water, when caused to enter the bulbs, does not flow out of them when the position of the tube is reversed, but remains stationary as if there was no such thing as gravity, and, in this case, a vacuum besides?

2. What is the reason of the singing noise above described? G. M.

New York, March 23, 1876.
 

 

To the Editor of the Popular Science Monthly.

Will you allow me to state the precise ground of objection to your criticism of my book, "The Sexes throughout Nature?" "What she proposes to do," you affirm, "is nothing less than to reduce the whole organic world, with all its vital and physical characters, into exact and demonstrable quantitative expression."

I only insist that, until science can offer us exact quantitative proof that the total of male characters is in excess of the total of female characters, no scientist should assume to determine, on scientific authority, that woman is inferior to man. I make no attempt to place my hypothesis, that, in each species of being, the sexes are true equivalents, on a "demonstrable quantitative" basis.

Though presented in the form of equations, and defended in a series of carefully argued propositions, the theory waits to be tested experimentally and quantitatively. It assumes to be nothing but a provisional hypothesis, destined to be either confirmed or rejected, as it is found to agree or not to agree with the decisive facts of Nature. I merely offer various evidence in defense of the assumption that, physical powers compared with physical, and psychical powers with psychical, the female is everywhere the equal of the male of its own species.