752 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1796. 



Prop, 1. The angles of inflection and deflection are equal, at equal incidences. Prop. 2. The 

 sine of inflection is to that of incidence in a given ratio, which is determined in the paper. Prop. 3. 

 The sun's light consists of parts which ditFer in degree of inflexibility and deflexibility, those which 

 are most refrangible being least flexible. Prop. 4. The flexibilities of the rays are inversely as their 

 refrangibilities ; and the spectrum by flexion is divided by the harmonical ratio, like the spectrum by 

 refraction. Prop. 5. The angle of reflection is not equal to that of incidence, except in particular, 

 tliough common, combinations of circumstances, and in the mean rays of the spectrum. Prop. 6. 

 Tlie rays which are most refi-angible are least reflexible, or make the least angle of reflection. 

 Prop. 7. The reflexibilities of the difl^erent rays are inversely as their refrangibilities, and the spec- 

 trum by reflection is divided in the harmonical ratio, like that by refraction. Prop. 8. The sines of 

 reflection of the different rays are in given ratios to those of incidence, which are determined in 

 tlie paper. Prop. <). The ratio of the sizes of the different parts of light are found. Prop. 10. 

 The colours of natural bodies are found to depend on the diflerent reflexibilities of the rays, and 

 sometimes on their flexibilities. Prop. 11. The rays of light are reflected, refracted, inflected, and 

 deflected, by one and the same power, variously exerted in different circumstances. 



Meteorological Journal, kept at the ydpartmeiits of the R. S.,for the Year 1795. 

 By order of the Presideiit and Council, p. 279. 



Thermometer 

 within. 



ai .... 

 :t3 be 



49 

 55 

 59 

 61.5 



68 

 66 

 68 

 73 

 73 

 66 

 61 

 62 





36 



42 



47 



53 



57 



56 



39 



64 



63.5 



59 



49 



54 



« -a, 



oj bo 



43.4 

 47.9 



52.7 

 57-5 

 61.1 

 61.1 

 62.S 

 67.4 

 67-8 

 62.6 

 55.4 

 57.5 



58.1 



Barometer.* 



o- 





c *i 



V bO 



Inc. Inc 

 30.47^29.16 



30.68; 29.04 



30.35 29.02 

 30.22' 29.34 

 30.49 29.73 

 30.14 29.50! 

 30.26,29.54! 

 30.31 [29.62 

 30.46 29.64 

 30.18 29.16 



30.58 

 30.39 



28.94 

 29.42 



Inc. 

 30.01 

 29.60 

 29-80 

 29-79 

 30.17 

 29.S6 

 29..<;7 

 29-97 

 30,08 

 29.6(1 

 29.87 

 29-97 



29-90 



* The quicksilver in the basin of tlie barometer is 81 feet above the level of low-water spring 

 tides at Somerset- house. — Orig. 



END OF THE SEVENTEENTH VOLUME, 



C.and K. Baldwin, Printers, 

 New Bridge-street, London. 



