than enough; that is, by affuming thefe Rivers greater than 
in all probability they be, and then comparing the quantity 
of Water voided by the Thames, with that of thofe Rivers 
whofe Water we defire to compute. 
The Mediterranean receives thefe confiderable Rivers; the 
Iherm, the Rhone y the Tiber^ the ?o, the Danube^ the Neijler, 
the Boryjhenesy the Tanais^ and the Nile, all the reft being of 
no great note, and their quantity of Water inconfiderable. 
Thefe nine Rivers, we will fuppofe each of them to bring down 
ten times as much Water as the River Thames -, not that any 
of them is fo great in reality, but to comprehend with them 
all the fmall Rivulets that fall into the Sea, which othervvife I 
know not how to allow for. 
. To calculate the W^ater of the Thames^ l afTume that at 
KhgHoyi Bridge, where the Flood never reaches, and the Wa- 
ter always runs down, the breadth of the Channel is lOO 
i Yards, and its depth 3, it being reduced to an equality ; (in 
I both which Suppofitions I am fure I take with the moft ) Hence 
I the Profil of the Water in this Place is 300 fquare Yards : this 
I multiplied by 48 miles, (which i allow the Water to run in 
a4hours,at 2 miles an hour) or 8448oYards,gives 25'3440oo 
! Cubick Yards of Water to be evacuated every day; that is^ 
il 20300000 Tons per dleyn ; and I doubt not but in the exeefs of. 
■| my meafures of the Channel of the River, I have made more 
t| than fufficient allowance for the Waters of the Brent, the Wan-- 
\\ del, the Lea^ and Darwent^ which are all worth notice, that 
fall into the Thames belo w Kmg^^0H. 
Now if each of the aforefaid 9 Rivers yield 10 times a?' 
much Water ^s the Thames doth, 'twill follow that each of 
them yields but 203 millions of Tons /^r and the 
whole 9 but 1827 millions of Tons in a day ; which is but 
little more f of what is proved to be raifed in Vapour 
out of the Mediterranean in 12 hours rime. Now what be- 
comes of this Vapour when raifed, and how it comes to paf^ 
that the Current always fets in at the mouth of the Streights 
oiGibr alter, is intended ^ with leave, for a farther Enter- 
ratnmene . 
