286 
NATURAL HISTORY 
of an inch for every hundred feet elevation, then the Newton 
barometer, by {landing three-tenths lower than that of Selborne, proves 
that Nezvton-houfe muft be three hundred feet higher than that in 
which I am writing, inftead of two hundred. 
It may not be impertinent to add, that the barometers at 6"^- 
borne ftand three-tentlis of an inch lower than the barometers at 
South Lambeth : whence we may conclude that the former place 
is about three hundred feet higher than the latter ; and with good, 
reafon becaufe the ftreams that rife with us run into the Thames 
at PFeybrido-e, and fo to Londo-n. Of courfe therefore there muft 
be lower ground all the way from Selborne to South Lambeth ; the 
diftance between which, all the windings and indentings of the 
ftreams confidered, cannot be lefs than an hundred miles. 
I am, 8cc. 
L E T E R 
