"Agreed; if you will induce a stream of water to run up hill, a fountain to rise above its head, I will believe any statement you may henceforth make."
"Be ready, then," he replied, "and procure the materials named." So saying he picked up his hat and abruptly departed.
These substances I purchased the next day, procuring the silver sand from Gordon's pharmacy, corner of Eighth and Western Row, and promptly at the specified time we met in my room.
He came, provided with a cylindrical glass jar about eighteen inches high and two inches in diameter (such as I have since learned is called a hydrometer jar), and a long, slender drawn glass tube, the internal diameter of which was about one-sixteenth of an inch.
"You have deceived me," I said; "I know well enough that capillary attraction will draw a liquid above its surface. You demonstrated that quite recently to my entire satisfaction."
"True, and yet not true of this experiment," he said. "I propose to force water through and out of this tube; capillary attraction will not expel a liquid from a tube if its mouth be above the surface of the supply."
He dipped the tip of a capillary tube into a tumbler of water; the water rose inside the tube about an inch above the surface of the water in the tumbler.
"Capillary attraction can do no more," he said. "Break the tube one-eighth of an inch above the water (far below the present capillary surface), and it will not overflow. The exit of the tube must be lower than the surface of the liquid if circulation ensues."
He broke off a fragment, and the result was as predicted.
Then he poured water into the glass jar to the depth of about six inches, and selecting a piece of very thin muslin, about an inch square, turned it over the end of the glass tube, tied it in position, and dropped that end of the tube into the cylinder.