30 
MrcROGRAPHIA. 
Having therefore fhewn the reafon of the motion of any float towards 
the fides, the reafon of the incurfion of any two floating bodies will eafi- 
ly appear: For the rifing of the water againft the fides of either of 
them,isan A ent fufficient,to fhew the preflure of the Air to be there 
Jefs,then it is further from it,where it is not fo much elevated ; and there- 
fore the reafon of the motion of the other toward it, will be the fame as 
towards the fide of the Glafs; only here from the fame reafon , they are 
mutually moved toward each other , whereas the fide of the Glafs in the 
former remains fixt. If alfo you gently fill the Jar fo full with water, 
that the water is protuberant above the fides, the fame piece of Cork that 
before did haften towardsthe fides, does now fly from it as faft towards 
the middle of the Superficies; the reafon of which will be found noo _ 
ther then this, that the preflure of the Airis ftronger againft the fides of 
the SuperficiesG and H, then againft the middle] 5 for fince, asI fhewed 
before, the Principle of congruity would make the terminating Surface 
Spherical , and that the flatting of the Surface in the middle is from the 
dhancthonr of the waters preflure outwards, by the contrary indeavour 
_ Of its gravity 5 it follows that the preflure in the middle mutt be lefs then 
on the fides; and therefore the confecution will be the fame as in the 
former. It is very odd toone that confiders not the reafon of it , tofee 
two floating bodies of wood to approach each other,as though they were 
indued with fome magnetical vigour ; which brings into my mind whatl 
formerly tried with a piece of Cork orfuch like body, which Ifo orders 
ed, that by putting a little {tick into the fame water, one part of the faid 
‘Cork would approach and make toward the ftick, whereas another 
would difcede and fly away,nay it would have a kind of verticity , foas 
.that if the Zquator (as Imay fo {peak ) cf the Cork were placed to- 
| wards the ftick, if let alone, it would inftantly turn its appropriate Pole 
‘toward it,and then run a-tilt atit:and this was done only bytakingadry 
Cork, and wetting one fide of it with one {mall ftroak 5 for by thismeans 
gently putting it upon the water, it would deprefs the fuperficies on eve- 
ry fide of it that was dry , and therefore the greateft preflure of the Air, 
being near thofe fides caufed it either to chafe away,or elfe to fly offfrom 
any other floating body, whereas that fide only, againft which the water _ 
afcended, was thereby able to attract. | peels daidgeae 
Itremains only, that I{hould determine how high the Water or other 
Liquor may by this means be raifed in a {maller Pipe above the Superfi- 
cies of that without it , and at what height it may be fuftained: But to 
determine this, will be exceeding difficult, unlefs I could certainly know _ 
how much of the Airs preflure istaken off by the fmalnef§of fuch and _ 
fuch a Pipe,and whether it may be wholly taken off,that is;whetherthere 
can be whole or pore fo {mall , into which Air could notatall enters; 
though water might with its whole force ; for were there fuch,,.’tis manis 
feft, that the water might rife in it to fome five or {1x and thirty Englifh — 
Foothigh. [know not whether the capillary Pipesin the bodies of fall Z 
Trees, which we call their Aficrofcopical pores,may not be fuch 3and whe= 
ther the congruity of the fides of the Pore may not yet draw the» juyce 
om = even 
