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27.

air that that how for it remounted at ye height of 29 feet because of ye spring of ye air of bubles wch were seperated from ye water and mounted to ye top of ye [[strikethrough]] ye [[/strikethrough]] pipe.  Two days after there was put into it water wch had been boiled a little before to seperate ye aerine matter; ye experiment was made after ye same manner, and ye water after some vibrations stopped at 29 feet and about 4 [[?]] inches, it is seen to mount higher by little and little and to stop at 30 feet 2 inches, ye other Barometers not being changed.  I attributed ye cause to this that ye water wch had been put in was mixed a little with Dirt, and by consequence weighed heavier than clean water; but that dust descended in a little time to ye bottom of ye small vessel; and by that means ye water becoming higher it ought to rise somewhat higher. two days after ye observed that ye common Barometer being at 27 inches 9 lines, ye water of ye great pipes was risen to 30 feet 8 inches, it would have mounted a little higher if there had not been elevated some bubles of air wch might keep it down; ye common Barometer returns below 28 inches, whence I knew that ye Barometers of water have their changes proportional to those [[strikethrough]] that [[/strikethrough]] of Mercury and that one may take 32 feet of water for ye greatest hight (or near it) of these Barometers when ye water where with they are filled if ye less weighty and that ye aerine matter is thence separated.

For ye ease of calculation let us suppose [[?y^[[t]]]] ye weight of ye atmosphere makes precisely an equilibrium with 32 feet of water, and [[?y^[[t]]]] ye mercury weighs 14 times more precisely.  

The weight of ye air may be moreover known by an experiment sufficiently curious: take a glass botle A B in wch make a hole of 2 or 3 lines as in C; put in ye neck G a pipe of glass D E about 2 lines diameter and sodder it was a mixture or wax and turpitine or with pitch so that ye air cannot pass between them; then fill ye bottle with water thrô ye overture C in its lying down and also ye pipe E B keeping stopped ye end D, and when ye bottle is put in its perpendicular

[[image: drawing of a tall, small-necked bottle containing water and a narrow pipe inserted in the top of the bottle down into the water.  The shoulders of the bottle are labeled A and H. The opening is labeled G.  Three-fourths of the way down the side of the bottle is a small opening labeled C. There are two levels of water in the bottle designated by two dotted lines: N and O; P and Q.  The top of the pipe sticking out above the opening of the bottle is labeled H and the bottom I. About a tenth of the way from the bottom of the pipe is a circle labeled E; and another tenth above it is another circle labeled L.  The circle E is opposite the opening in the bottle C.]]

situation ye water wch is in ye pipe descends unto E and goeth out by ye hole C if ye extremity of ye pipe is of ye same hight with ye middle of ye overture C; but if ye pipe is extended below ye overture as unto I ye water will cease to run ye pipe being empty unto E and ye bottle shall remain full of water unto ye sodder towards G; but if ye end of ye pipe is higher than ye top of ye overture C as in L, and that is 2 or 3 lines large then ye air shall be seen to go out thrô ye open end and remount to top of ye bottle and ye water shall go out at ye same time thrô overture C until that is is not much above ye point C, these effects are explained in the following manner

The weight of ye exterior air makes an effort towards ye overture C to push back ye water which makes an effort by its weight to go out and if air wch is above ye pipe E D makes also an effort and acts by its weight upon ye water wch is there contained; and being joyned to ye weight of ye water it ought to force ye weight of ye air wch acts towards C wch makes ye water of ye pipe descend unto E and then ye air makes an effort from one side in E and from ye other in C and conicyntly sustain ye water of ye bottle from E unto A H; and it would keep up that place through ye hight C H should be 30 feet ye end of ye pipe being below ye bottom of hole C; but when ye pipe descends but to L then ye water from L unto E joyned to ye weight of ye air wch weighs upon L forceth ye air in C and ye water runs thrô C while ye air descending from D to L and inters drop by drop in ye water by ye open end L; and is elevated

Transcription Notes:
Reviewed mandc: aerine matter is translated Aerial Matter in the Desaguliers translation. "y with a t above it" may be abbreviation for "that?" "overture" must mean aperture; "ouverture" is French for aperture. The diagram on this page can be found on page 119 of the Desaguliers translation, Fig. 14: http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=%2Fpermanent%2Flibrary%2FQERNH1MN%2Fpageimg&start=11&viewMode=images&mode=imagepath&pn=119&ww=0.1019&wh=0.2761&wx=0.4702&wy=0.0483