CONTENTS. xxvS 



VIIL Experiments and Obfervations on the Inflexion, Reflexion, and Colours 

 of Light, By Henry Brougham, jim. Efq. — — P-55t 



Piopofitlons refpeftinj^ the means by which light is made to alter its direftion. Expcrimcnisand ob- 

 .fervations. The lealt refrangible rays are fiich as deviate mod by inflexion — and alfo by deflexion. 

 Flexion, refraftion and reflexion are performed by a force aSing at a definite diftance. Coloured 

 fpeilrum by reflexion — Order of the colours. They are not produced by any new modification, 

 but by the ordinary decompofition of light. The colour-making rays thus feparated are homo- 

 geneous and unchangeable. The leafl; refrangible rays are the moft reflexible, or rebound nearcft 

 the perpendicular. Spef^rum by reflexion is divided in the fame proportions as the Newtonian 

 fpefltum by refraftion. Meafurement of the colours. On the phyfical caufe of reflexibility. 



IX. An Account of the Manner in which Heat is propagated in Fluids, and its 

 general Confeqnences in the Economy of the Univerfe. By Benjamin Count 

 ofRumford. (Concluded from p. 348) — — P- 5^3 



Experiments of the fufion of ice by water fufFered to repofe upon it. Precautions. Rjcfults with 

 boiling hot water, exhibiting the quantities of ice melted in a given time. Experiments with cold 

 water at 41 degrees, by which a greater quantity of ice was melted than by boiling water. Ge- 

 neral con fcquences applied, at length, to the dittribution of heat over the furface of the globe, by 

 rirtue of the internal motions of water, and currents which take place in the feas, fimilar to the 

 trade winds in the atmofphere. 



X. Ufeful Notices refpeding various Objefts. — Welding of Caft-Steel — Flexure 

 of Compound Metallic Bars by Change of Temperature — p. 375 



Sir Thomas Frankland's method of welding caft-Scel to iron. Experiments to determine the pro- 

 portion between the thicknefs of compound metallic bars and their flexure by heat. 



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