Springs and Dews, and accounc ior the Cafpian Seas being al- 
ways at a ftand, neither wafting nor overflowing; as like- 
wife for the Current faid tofet always in, at the Streighrsof 
Gihra(ter, tho thofe Mediterranean Seas receive fo many and 
fo Gonfiderable Rivers. 
To eftimate the quantity ofWater arifing in Vapour out ot 
theSea^ I think I ought to confider it only for the time the 
Sun is up, for that the Dews return in the Night, as much if 
not rnore. Vapours than are then emitted; and in Summer the 
Days being longer than twelve hours, this excefs is balian- 
ced by the weaker Aftion of the Sun, efpecially when rifing, 
before the Water be warmed : fo that if I allow ro of an inch 
of the Surface of the Sea to be raifed per diem in Vapours, it 
may not be an improbable Conjcfture. 
Upon this Suppoficion, every lofquare Inches of the Sur- 
face of the Water yields in Vapour per diem 2i Cube inch of 
Water 5 and^each fquarcfoot half a Wincrpint ; every fpace of 
4 foot fquare, a Gallon ; a milefquare, 69 14 Tons; a fquare 
Degree, fuppofed of 69 ^wg///^ .miles, vvill <?vaporatc 33 Mil- 
lions of Tons : and if the Mcditerrarie,an be eliimated at 40 
Degrees long and 4;broad, Allowances being rhade for the 
Places where it is broader by thofe where it is narrower, (and I 
am fure I ghefs at the leaft,) there will be 160 fquare Degrees 
of Sea 5 and confequently, the whole Mediterranean nluft lofe 
in Vapour, ina Summers-day, at Icaft 5280 Millions of.Tons. 
And this quantity of Vapour, tho very gire^j, is as little as 
can be concluded from the Experiment produced: And yet 
there remains another Caufe, which cannot be reduced to 
Rule, I mean the Winds, vvhereby the Surface of the Wat^r 
is lick'd up fometimes fafter than it exhales by the heat of the 
Sun ; as is well known to thoTe that have confidered thofe dry^ 
jng Winds which blow fometimes. 
To eftimate the quantity of Whter the Mediterranean Sea 
receives from the Rivers that fall into it, is a very hard task, 
unlefs one had the opportunity to meafure their Channels and 
Velocity ;^ and therefore we can only do it by allowing more 
than 
