CONTENTS. 



PART I. 



Page 



I. An Account of Observations made in Scotland on the Distri- 

 bution of the Magnetic Intensity. By JAMES DUNLOP, 

 Esq. Communicated by Sir T. M. BRISBANE, K. C. B. 1 



II. Notice concerning an Autograph Manuscript by Sir ISAAC 

 NEWTON, containing some Notes upon the Third Book of 

 the Principia, and found among the Papers of Dr DAVID 

 GREGORY, formerly Savilian Professor of Astronomy in 

 the University of Oxford. By JAMES CRAUFURD GRE- 

 GORY, M.D., F.R.S. Ed., Fellow of the Royal College of 

 Physicians of Edinburgh, - 64 



III. An Inquiry into the Geometrical Character of the Hour-Lines 

 upon the Antique Sun-Dials. By T. S. DAVIES, Esq. 

 F.R.S.Ed., F.R.A.S. 77 



IV. On a New Analysis of Solar Light, indicating three Primary 

 Colours, forming Coincident Spsctra of equal length. By 

 DAVID BREWSTER, LL. D., F. R.SS. Lend. & Ed. - 123 



V. Notice regarding some Experiments on the Vibration of 



Heated Metals. By ARTHUR TREVELYAN, Esq. - 137 



