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80.

IE that if ye small one gave half a pint paris measure ye great one gave 8 1/2 pints or 8 3/5, we measured exactly again ye two holes and found that that of 12 lines was [[strikethrough]] two holes [[/strikethrough]] a little stronger in proportion than that of 4 lines, at least we were assured that it was not weaker, and by consequence that ye [[?deted]] of ye quantity of water it ought to give, did not proceed from that cause.  In ye experiments wch were made seperately with different holes ye great hole gave ordinarily more in proportion than ye small there are three causes wch may contribute to this effect.

  The first that their is more rubbing in proportion in ye small holes than in ye great:  for ye circumferences of different holes are one to ye other in proportion of their diameters, whereas ye water they give is in a double proportion of ye same diameters; now if we suppose ye water by its viscosity sticks a little to ye sides of ye holes, it will necessarily diminish for that reason a small part of ye largeness of ye diameters.  For example at a hole of 3 lines it may diminish 1/20 of a line therefore at a hole of 6 lines althô ye square of 6 ye quadruple ye square of 3 and that ye round holes are one to another as ye squares, whose sides are equal to ye diameters of ye circles, yet ye circumference of ye hole of 6 lines diameter, shall be only double to that wch is 3 lines;  and therefore it will diminish but 1/5]] or 2/10 for that hinderance where we see that ye spouts of ye great holes are that so retarded and hindred as ye small, and give more water in proportion of their diameters:

The second cause is that a small stream of water finds more resistance in ye air as it goeth out than a gross spout, as it happens to small balls of lead wch go not so far as large ones, althô they go out of ye same musket in ye same time.

  The third cause is ye greater shoc of ye water wch is poured to maintain ye running thrô great holes.  For to keep ye reservatory full where there water go's out but at 4 lines, (1) is sufficient to pour ye water gently with a small vessel;  but when ye spout is 12 lines large, ye water must be poured with a full pail, and with great swiftness wch giveth an impression to ye water that makes it go swifter than if it had only its own weight to push it;  we made an experiment placing horizontally an hole of an inch height and 4 inches long for it gave in 36 1/2 seconds a quantity wch it ought not to give but in 1/4 of 154 seconds, viz in 38 1/2 wch did proceed from hence that ye water was poured with great force to maintain that wch went out, and also when we did not maintain ye reservatorys full ye water descends swifter thrô a pipe of 3 or 4 inches large when ye spout is gross than when it is small;  wch necessarily augments ye swiftness of its going out.  These 3 causes joyned together are oftentimes a little stronger than the difficulty of ye running along and sometimes but equall, when ye experiments are made seperately thrô different holes.

  Here are some experiments I have made with a hole of 3 lines and one of 6 lines.

        Experiment I

  The hole of 3 lines having its reservatory 5 1/2 foot heigh gave 14 pints, of 2 pound weight in 93 seconds, and ye hole of 6 lines gave them in 23 seconds instead of 23 1/4

      Experiment II

 A reservatory being of 24 foot and a little more gave thrô a hole of 3 lines 14 pints in 44 seconds and 1/2 and thrô 6 lines in 11 seconds maintaining ye height of ye water in ye reservatory.

      Experiment III

  From ye height of 12 1/3 feet ye hole of 3 lines 14 mean pints in 61 seconds 1/2 keeping it full, and thrô a hole of 6 lines it was given in 15 1/2.

      Experiment IV

  There was put a mark in ye reservatory wch was at ye top of ye pipe heigher than that wch marked ye 12 feet 4 inches, and another lower an an equall distance, that permitting ye water to run from ye upper mark to ye lower it might provide ye same effect as if it was always kept full at 12 feet 4 inches;  there was 13 1/2 pints in ye reservatory from ye inferior mark to superior, these were run out thrô 3 lines in 58 seconds, and through 6 in 15 instead of 14 1/2

Transcription Notes:
mandc: Reviewed. "IE" id est, in other words.