Height of Mountains, as determined by thefe early 
Writers, doth not fo very much deviate from Truth, as 
one would be apt to fufped from the infmt State o t 
Arts and Sciences in thofe Times. Particularly the iy 
Stadia of Cleomedes y which make out 9375" Roman , 
or \o y 'i\\ c Paris Feet, will be found by the following 
Obfervations to come very near the Height of the Moun- 
tains of Swifter land which, although the higheft of 
Europe^ do not rife above 10,000 *Paris Feet above 
the Level of the Sea ; and it may feem furprizing, 
that fubfequent Writers, even fuch as were otherwise 
deeply skill’d in mathematical Learning, have run them 
up to an extravagant, and altogether unnatural Height. 
At firfl, it is not improbable, they went only upon 
bare Conjectures ; but afterwards, when Geometry 
came to be more and more improved, Quadrants, Semi- 
circles, and other Geometrical Inflruments were call'd 
in Ufe, by the Means of which, and by a Trigonome- 
trical Calculation, the Heights of Places could be de- 
termined in a more fatisfadory Manner. And yet, 
however true the Principles be, upon which this Me- 
thod is founded, however nice the Inflruments, and 
however curious the Obferver, the Method itfelf muft 
be owned, and hath been found by undoubted Experi- 
ments, to fall far fhort of that Accuracy, which it 
feems to promife and the more confiderable the Heights 
are, the more uncertain it will beA For in the firlf 
Place, as the State of the Air is very different in dif- 
ferent Seafons and different Weather, its RefraCtion alfo 
becomes thereby greatly altered, which occafions the 
Tops of Mountains to appear higher at fome Times 
than they do at others, and at all Times higher than 
they adually are. But befides, there is another In- 
x conveniency. 
