Page:Proceedings of the Royal Society of London Vol 4.djvu/236

Rh face acquires by the absorption of the liquid into the pores of the paper. He also explains a method by which the impression thus made, and which is only transient, can be rendered permanent.

This method of observation is then applied to the further exa- mination of various points connected with the distribution of the thermic rays, the transcalescence of particular media, the polari- zation of radiant heat (which is easily rendered sensible by this me- thod), &c. The reality of more or less insulated spots of heat dis- tributed at very nearly equal intervals along the axis of the spec- trum (and of which the origin is prohahly to be sought in the flint glass prism used — but possibly in atmospheric absorption) is esta- blished. Of these spots, two of an oval form, are situated, the one nearly at, and the other some cMstance beyond the extreme red end of the spectrum, and are less distinctly insulated ; two, perfectly round and well-insulated, at greater distances in the same direction; and one, very feeble and less satisfactorily made out, at no less a distance beyond the extreme red than 422 parts of a scale in which the whole extent of the Newtonian coloured spectrum occupies 539.

A paper was also read entitled, " Remarks on the Theory of the Dispersion of Light, as connected with Polarization ; " by the Rev. Baden Powell, M.A., F.R.S., and Savilian Professor of Geometry, Oxford.

Since the publication of a former paper on the subject referred to, the author has been led to review the subject in connexion with the valuable illustrations given by Mr. Lubbock of the views of Fresnel ; and points out, in the present supplement, in what manner the con- clusions in that paper will be affected by these considerations.

A paper was also read, entitled, " Further Particulars of the Fall of theColdBokkeveld Meteorite;" by Thomas Maclear, Esq.. F.R.S., in a letter to Sir John F. W. Herschel, Bart., K.H., V.P.R.S., &c. communicated by Sir John Herschel.

This communication, which is supplementary to the one already made to the Society by Mr. Maclear, contains reports, supported by affidavits, of the circumstances attending the fall of a meteoric mass in a valley near the Cape of Good Hope. The attention of the wit- nesses had been excited by a loud explosion which took place in the air, previous to the descent of the aerolite, and which was at- tended by a blue stream of smoke, extending from north to west. Some of the fragments which had been seen to fall, and which had penetrated into the earth, were picked up by the witnesses. One of them falling on grass caused it to smoke ; and was too hot to ad- mit of being touched. The mass which was sent to England by H.M.S. Scout, weighed, when first picked up, four pounds. The paper is accompanied by a map of the district, showing the course of the aerolite.

A paper was also read, entitled, "An account of the Shooting Stars of 1095 and 1243;" by Sir Francis Palgrave, K.H., F.R.S., &c.