Page:On an inversion of ideas as to the structure of the universe.djvu/43

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Dilatancy
31

experiment, which you see is on a very small scale, was not designed to show to an audience, being the original experiment made for my own satisfaction when the idea of dilatancy first presented itself.

Without knowledge of dilatancy the results thus obtained must appear paradoxical, not to say magical.

Taking a larger apparatus, a bag which holds six pints of sand, the interstices being filled with water, without any air, the glass neck being graduated, so as to measure the water drawn in and the sand and water subjected to such distortion as would cause the grains to be in normal piling.

Then, if the neck be closed so that it cannot draw more water, we come upon the startling fact, that this indiarubber bag, filled with sand and water, cannot have its shape changed without a sufficient distorting pinch, as by these pincers, to cause a vacuum inside the bag.

The pinch is now some 200 lbs., but the bag does not flinch. It cannot change its shape without drawing water into the bag and this is prevented.

To show that there is an effort to expand the bag, while the pinch is on, it is only necessary