( 74° ) 
in England ', Holland, the maritime Provinces of France, 
ana in general all thofe Countries which border upon 
the Sea, the Mercury Hands higheft, that the higher 
you remove from the Sea into the midland Countries 
the lower the Mercury will defcend, becaufe the Air 
alfo becomes more rarefied and lighter, and that upon 
the Tops of the higheft Mountains it falls loweft, and 
thefe Heights of the Mercury in different Places are 
reciprocally, as the Expanfions of the Air. From thefe 
Principles, fupported by a competent Number of Ob- 
lervations, it hath been attempted by feveral learned 
Men, to derive proper T ables, whereby the Height of 
any Place may be determined, if the Height of the 
Barometer be given, or the Height of the Barometer 
determined from the given Altitude of the Place, and 
like wife the Expanfions of the Air fettled, as they an- 
fwer to every Inch, or Part of an Inch, in the Baro- 
meter. 
I pafs over the firft Experiment of this Kind, which 
was made in the Year 1648 (but a few Years after the 
Invention of the Torricellian Tube was made publick 
in France by Father Merfenne) by Monfieur Eerier 
according to the Directions of the celebrated Monfieur 
Eafcal, his Brother-in-Law, upon the high Mountain 
Tuy de Homme, near Clermont in Auvergne, the 
Height whereof was thereby determined to yoo French 
rotfes, or 3000 Ear is Feet. (See the Appendix to 
M. Eafcali Trait e de /’ Equi libre des Liqueurs * ) 
Nor will my prefeut Purpofe admit a particular Enu- 
meration of thofe made fometime after, in 1661 166 c 
and 1 666, by George Sinclair, ProfefTor of Philofo- 
phy in the Univerlity of Glafgow,. upon the Cathe- 
* PMSi 1665 , 8 vo. pag. 177 , 
dral 
