Hocus Pocus; or The Whole Art of Legerdemain, in Perfection. / By which the meanest capacity may perform the whole without the help of a teacher. Together with the Use of all the Instruments belonging thereto.

How to make the fountain of command.

Take a vessel A. B. which has two bottoms, this is close on all sides like a drum; through the middle of it run a long pipe, C. D. sodered to the lower bottom at F, with its two ends open, C. D. the first of which C. must not quite touch the uppermost bottom, but leave passage for the water; when one has a mind to fill the vessel A. B. which is done by turning up the vessel A. B. with its pipe C. D. so that the hole D. will then be the uppermost, and pouring in the water at D. this done, stop up the pipe C. D. with another, and a very little smaller pipe E. D. that can just enter it, and is fixed in the bottom of a case or cistern that is a little longer than one of the two bottoms of the vessel A. B. the two pipes C. D. ought to have at an equal height, two appertures or holes I. I. and the smallest D. E. ought to be movable within the greater, C. D. that so you may turn the smaller with its case G. H. when you will, fill the two holes I. I. meet farther the vessel A. B. ought to have several little holes in its lower bottom, as K. L. for giving egress to the water, and the case or receptacle G. H. ought likewise to have smaller vent, M. N. for the water to run out. Now the vessel A. B. being filled with water as we directed but now, and the pipe C. D. being stopt by the pipe D. E. which is supposed so thin, that it could just fill it without any necessity of the extremity E. it reaching to the end C. provided the other two ends D. D. do but fit: is it done, I say, turning the vessel again to its first position, in which it will stand as in the figure, the case G. H. being its base, and being turned together with its pipe E. till the two vents I. I. meet and make but one orafice, for then the water contained in the vessel A. B. will run out at the vents K. L. as long as the air can pass through the apperture I. to supply the room of the water that runs A. B. into the case G. H. but when the water in the receptacle G. H. rises above the vent I. which will infallibly happen, since more water runs at the vents K. L. than at M. N. the former being supposed to be larger than the latter, the air not finding access at I. the water in the vessel A. B. will give over running through the vents K. L. but the water in the receptacle G. H. will continue to run at the vents M. N. so that this water will grow lower by degrees, till the vent I. is uncovered again, and then the air having access at I. will renew the flux of the water thro’ K. L. which in a small time will raise the water in the case G. H. so as to recover the vent I. again, upon which the stream A. B. will stop, and so on alternately, till there is no water in the vessel A. B.

This is called the fountain of command, because it runs at a word, when the water is near the renewal of its flux, thro’ the vents K. L. which is easily known; for when the vent I. begins to get clear of water in G. A. the air struggling for access at the vent makes a little noise, and so gives notice that the fountain is about to run. This is a merry device.