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"A mountain and spring, showing how the principle of the syphon operates to produce the effect described. Suppose there is a crevice, or hollow in the rock from a to b, and a narrow fissure leading from it, in the form of the syphon, b c. The water from the rill fe, filling the hollow, up to the line a d, it will then discharge itself through the syphon, and continue to run until the water is exhausted down to the l g of the syphon b, when it will cease. Then the water from the rills continuing to run until the hollow is again filled up to the same line, the syphon again begins to act, and again discharges the contents of the reservoir as before, and thus the spring p, at one moment flows with great violence and the next moment ceases entirely." —Comstock, 1850

Intermitting Spring

"A mountain and spring, showing how the principle of the syphon operates to produce the effect described.…