The CONTENTS. 



The Quadrature of a Portion of the Epycloid. By 

 Mr. Cafwell. 175 

 A General Proportion, Jhewing the Dimenfion of 

 the Areas in all thofe kinds of Curves which 

 are defcritfdby the Equable Revolution of a 

 Circle upon any Bafis, either a Rectilineal or 

 a Circular one. By Edm. Halley. 177 

 A Method of Raifmg an infinite Multinomial to 

 any given Tower , or Extracting any given Root 

 of the fame. By Mr. A- De Moivre. 183 

 A Method of Extracting the Root of an Infinite 

 Equation. By A. De Moivre, F.R.S. 191 

 An Experiment of the Refraction of the Air 7 

 made at the Command of the Royal Society^ 

 March 28. 1699. By J.Lowthorp, A.M.196 

 A Dijcourfe concerning a Method of Dif covering 

 the True Moment of the Surfs Ingrefs into the 

 Tropical Sines. By E. Halley. 202* 

 A Scale $f the Degrees of Heat. 2 1 1 



The Properties of the Catenaria. By David 

 Gregory, M. D. Savilian Profejfor of Afiro-* 

 nomy y and F. R. S. 219 

 Of the Quadratures of Geometrically irrational 

 Figure^. By J. Craig. 251 

 Concerning the Apparent Magnitude of the Sun 

 and Moon, or the apparent diftance of two 

 Stars when nigh the Horizon, and when high- 

 er elevated. 263 

 The Sentiments of the Reverend and Learned Dr. 

 John WalHs R. S. Soc. upon the aforefaid 

 Appearance, communicated in a Letter to the 

 Publijher. 27 $ 



A Demonftration of an Error committed by com- 

 mon Surveyors in comparing of Surveys, fallen at 

 long Intervals of Time, arifmg from the Vari- 

 ation of the Magnetic!^ Needle^ by William 

 * ' ■ T " " - Moly- 



