Wheel Barometer

is a Contrivance for the applying an Index to the common Barometer, which Index shews the Variation of the Altitude of the Mercurial Cylinder, which at most does not exceed 3 Inches, which nevertheless may be made as distinguishable as if it were 3 Foot or 3 Yards, or as much more as is desired; the Form of it is as here described.

Definition taken from The Universal Etymological English Dictionary, edited by Nathan Bailey (1736)

Baroˊmeter * Beam