ON THE THERMAL CONDUCTIVITIES OF CERTAIN EOCKS. 



145 



De la Eive, ' Ann. Chim. Phys.' (4), 1, 504 (1864) : also ' Bibl. Univ. de Geu6v.' 

 1864. — Conductivity of ice. Plates of glass, ice, iron, fixed in wooden" tube, and 

 interspaces filled with Hg. Outside of glass, H„0 @, 0° C, outside of Fc, cooled 

 turpentine. Thermometer between glass and ice falls, and when it reaches mini- 



K (ice) 



mum flow across glass = flow across ice, hence 



obtained 1-70. K (glass) 



K (glass) 



got by Peclefs method, using water at 0° C. and mercury on opposite sides. Re- 

 sults for glass, -0013, ice, -0023 (c.g.s). Paper then discusses rate of increase of 

 thickness of ice in a lake. (See Forbes, ' P.R.S.E.' 8, 62.) 



Comparative results 



Tyndall, 'Ph. Trans.' 185.3, 217.— Woods and organic bodies, 

 only. Results in ' Heat a mode of motion.' 



Despretz, ' Compt. rend.' 7, 833 (1838). — Passage from one solid to another. Cu 

 and Sn fixed end to end (pressed together). Temperature of junction calculated 

 from each bar : Cu thus about l°-5 hotter. 



Despretz, ib. 35, 540 (1852). — New determinations of K for metals, ifcc. 

 objections raised by Langberg and others to the former results. 



Answer to 



Cast iron 



Iron 



Statuary marble 



Lithographic stone 



Pierre de Tonnerre 



Pine wood 



1 



2-0024 



2017 

 2133 

 2100 

 2-302 

 2-190 



Schumeister, ' Chem. Soc. Jour.' 34, 831 (1878). — Conductivity of cotton, wool, and 

 silk. K, (air = 1) for cotton 37, wool 12, silk 11. 



Littrow, ' Wien. Ber.' 1875, 4, ' Chem. Soc. Jour.' 28, 1150 (1875).— Soils. Thermo- 

 meters bedded in the soils at different distances from the source of heat in an 

 india-rubber cyUnder. Finely divided soil conducts worse than coarser. Organic 

 matter diminishes conductivity. Wet soils conduct better than dry. 



Less, ' Pogg.' Ergiinzb. 8. — Rocks and woods. Plate gripped between mercury-wetted 

 copper bottom of steam vessel and mercury-wetted upper surface of equal-sized 

 blackened Cu jjlate. When stationary state of things reached, thermopile exposed 

 to radiation from Cu plate, and deflections give relative conductivity. 



A Supplementary List of Original Notices and Memoirs on Subjects relating 

 to Conduction of Heat. B>j J. T. Dunn. 



