[ O 6 ] 
IX. Experiments upon the Refijiance of the Air. By Richard 
Lovell Edgworth, EJq, F. R. S. In a Fetter to Sir Jofeph 
Banks, Bart. P . R. S. 
4 \ j 1 
Read January 1 6, 1782. 
DEAR SIR Edgeworth’s Town, Ireland,.. 
’ May z, 1782. 
T HE laft time I had the pleafure of feeing you, the con- 
verfation turned upon the refinance of the air, and 
upon a lingular experiment related by Mr. robins in his Trea- 
dle upon Gunnery. I have lince repeated his experiment, and 
tried fome others, which I beg you to lay before the Royal 
Society, if you think them worthy their attention. 
I have the honour to be, &c. 
MANY experiments have been tried to afeertain the force 
and velocity of the wind, with a view to the conftru&ion and 
management of different engines, and more particularly for 
the purpofes of navigation. Several machines, which have 
been employed in thefe enquiries, are deferibed in the Tranlac- 
tions of the Royal Society, and in the Memoirs of Foreign 
Academies ; but the mod; accurate which I have feen was in- 
vented by the late Sir Charles knowles ; and from a number 
of experiments made with it, he had conftru&ed tables, {hew- 
ing at one view the force of the wind upon each fail of a {hip 
at every degree of velocity from one to ninety miles an hour. 
But 
