I. Obfervations on the Graduation of Afronomical Infruments ; 
with an 'Explanation of the Method invented by the late Mr. 
Henry Hindley, of York, Clock-maker , to divide, Circles 
into any given Number of Parts . By Mr. John Smeaton, 
F. R. S . ; communicated by Henry Cavendifli, Efq. F. R. S. 
and S. A. 
P ERHAPS no part of the fcience of Mechanics has been 
cultivated by the ingenious with more affiduity, or more 
defervedly fo, than the art of dividing Circles for the purpofe 
of Aftronomy and Navigation. It is faid, that Tycho Brahe 
Yol. LXXVL B and 
