No. XXI.
How to raise water constantly with two buckets only, day and night, without any other force than its own motion, using not so much as any force, wheel, or sucker, nor more pullies than one, on which the cord or chain rolleth, with a bucket at each end. This, I confess, I have seen and learned of the great mathematician Clavius's Studies at Rome, he having made a present thereof unto a cardinal; and I desire not to own any other man's inventions; but if I set down any, to nominate likewise the inventor.
NOTE.
The construction of an hydraulic engine with powers nearly similar to this, may be thus described: two buckets of unequal size must be first suspended by a flexible chain turning on a double roller or pulley; so that one bucket will be elevated to the required height, while the other reaches the level of the water to be raised; a small stream of water must then be made to communicate with the largest bucket, which will speedily be depressed and descend to the lower level, while the opposite bucket will discharge its contents into a cistern or reservoir at the top of the machine: the larger bucket being likewise emptied by striking against a projecting beam placed there for that purpose.
Mr. Sarjeant has described a very simple and powerful machine for raising water, nearly similar in point of principle to the above. An engraving of Mr. S.'s engine, together with an account of its construction, is inserted in the Trans. of the Soc. of Arts, vol. xix. p. 255.