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75.

        DISCOURS II
    of the measure of spouting waters
    according to ye different heights
    of ye reservatorys.

  It hath been proved that ye quantity of water wch goeth out thrô equal holes made at ye bottom of reservatorys of different heights are one to another in ye subduple proportion of ye heights;  but to confirm that rule by experiments I have made many with great exactness whereof there are the principall.

       Experiment I
     For the expence of spouts of the
       bottom of reservatorys of
          different heights.

  A hole of 6 lines having its center at 39 lines below ye surface of ye water of ye vessel, gave in one minute 8 6/7 pints of those wch weigh 2 pound less by 7 drachms ye water did run horizontaly, as in ye experiment above where ye same hole had its center 7 lines below ye surface of ye water of ye [[strikethrough]] lines [[/strikethrough]] vessel and gave 15 demiseptiers in a minute to compare these 2 experiments according to ye rule we must take a mean proportional number between 7 and 39 wch is 16 1/2 near and to 3 numbers 7, 16 1/2 and 15 find ye 4th proportional, wch is 35 3/7 near 35 3/7 demiseptiers make 8 6/7 pints, and by consequence ye expences of ye water have been according to ye subduple proportion of ye heights of ye reservatorys.

      Experiment II

  A pipe having its height 16 inches gave thrô an hole of 3 lines placed at ye bottom thrô wch ye water did run perpendicularly 25 pints and about 2 spoonfulls in 30 seconds maintaining ye water always at ye height of 16 inches;  there was placed at ye bottom of another pipe ye same plate where ye hole was of 3 lines; that second pipe had ye height of its water at 64 inches wch is a quadruple of ye former of 16 inches, and by consequence it ought to give ye double of 2 pints 1/2 and 2 spoonfulls, keeping ye water always at that height of 64 inches, wch hath been proved by experience;  for there went out of this paper 5 pints and about 4 or 5 spoonfulls of water in ye same time of 30 seconds:  This experiment was made with great care and repeater times.  Moreover we made some other for waters wch spout from below upwards to 5 or 6 feet heigh, and we always found ye same subduple proportion of ye heights of ye reservatorys.  We may therefore take for true ye follow rule.

      Rule
    For ye measure of Spouts.

  Spouts of water wch go out thrô equal holes at ye bottom of different elevations of ye reservatorys, spend their water in respect one of another according to a subduple proportion of ye heights of ye upper surfaces of ye water of ye reservatory.  To find out easily by calculation all ye quantitys of water wch reservatorys give of what height soever they are I made choice of a mean height to wch we might easily refer all ye other;  that height is 13 feet, and I have found by many very exact experiments that a round hole of 3 lines diameter being 13 feet below ye surface of ye water of a large pipe, did give an inch, ie there went out in ye space of one minute 14 pints Paris measure, at those wch weigh 2 pounds and where of 35 make a cubic foot.

  The experiments were made in this manner.  Ye pipe was crooked below, and had a reservatory C wch held about 20 pints ye hole at 3 lines was at ye point G its diameter was such that ye 2 points of a compass whereas ye 

Transcription Notes:
mandc: also hard at work! I think the annotations in her diagrams are a "J" not an "I" as she writes them differently in the text. I also think she uses : as a full stop. It's OK once you get used to her writing! mandc: Re-reviewed. Chnanged 9 to 64. In the Desaguliars translation "repeater times" was transcribed "repeated 3 times." [[p. 166; scan 203.