MicROGRAPHIAY 
of their (walnefs, 3. The difficulty of finding the defired point, and of 
placing it fos.as to reflect the light conveniently for the Inquiry; Laftly, 
‘ones being able to view it but with ove eye‘at once, they will appear‘no 
{mall obftrutfiows, nor atethey eafily remov'd: without many contridan- 
ces. Butto proceed, I could:not find that water, or fome deeply ting’d 
liquors would: in {mall ones rife fo high as one would expects’ andothe 
higheft U have found it-yet rife in any of the pipes I have try'd, 'was'to 
a1 inches above the level of the water inthe vefiel: for though I found 
thatin the\{mall pipes it would wmbly enter at firft, and run about 6 or 
7 inches upwards; yet Ifoundit then to move upwards fo fow, that l 
have not yet had the patience to obferve it above that height of 21in- 
ches (and that.was in a pretty /arge Pipe, in comparifon of thofedT for- 
merly mentionéd; for I.could obierye the progre/s.of a very deep ting'd - 
liquor in it with my waked eye, without much trouble; whereas many of 
the other pipes were fo very fall, that unlels in a convenient poftureto the 
light, I could not perceive them :) But ‘tis very probable; that a greater 
patience and. affiduity may difcover the liquors torde, ‘at leaft to.remain 
fifpended, at, heights that I fhould be loath now evento gheft at; if at 
leaft there be any proportion kept between the height of the afcending 
liquor, and the bigne/s of the holes of the pipes. 
An Attempt for the Explication of this Experiment. ws 
Tg “NCA Ae TORY 
My Conjecture, That the unequal height of the furfaces of the water, 
proceeded from the greater preffure made upon the water by the Air 
without the Pipes A BC, then by that within them:, 1 thall endeavour to 
confirm fromthe truth of the two following Propofitions : | 
The firft of which is, That ax unequal prefure of the incumbent Air, 
mill caufe au unequal height in the water's Surfaces. bert 
And the fecond is, That in this experiment there is fuch an.nnequal 
refure. to Shaw 
? sae the firftis true, the following Experiment will evince. | Forif 
you take any Veflel fo contrived, as that you can at pleafure either zn- 
creafe or diminifh the prefure of the Air upon this or that part of the Sx- 
perficies of the water, the equality of the height of thofe parts will pre- 
fently be /of#; and that part of the Superficies that fultains the greater pref 
fare, will be zxferior to that which undergoes the /es.. A fit Veflebfor 
this purpofe, will be an inverted Glafs Syphon, fuch an one as is defcri- 
bed in the Sixth Figure. For if into it you put Water enough to fillitas- 
high as.4B, and gently blow in at D, youtfhall depre/s the Superficies By 
and thereby raifethe oppofite Superficies.4 to a confiderable height, and 
by gently jocking you may produce clean contrary ethedts. : 
Next, That there isfuch an umequal prefure, 1 thall prove from this, 
That there is a much greater incongruity of Air to Glafs and fome other Bodies, 
then there is of Water to the fame, | AEE ttgt 
rt’ 
PE ae 
