﻿Convective Cooling in Fluids. 



Table I. 



Details of the Wires used. 



929 



Diam. 

 d. 



1 



Uncompensated 

 gd\ length. 



/. 



a. 



Bo. 



cm. 



•0083 



0155 



cms. 

 5-02x10-* 5-95 



366 X10- 4 6-5 



•00183 

 •00385 



ohms. 

 2-127 



•355 



instead. It was 10 cm. high with a base 16x6 cm. It was 

 used quite full and with the wires 5 cm. below the surface 

 of the liquid. In all cases the vessel stood upon an insulated 

 levelling table on a concrete slab on the floor, and no ripples 

 were observable on the liquid surface. It was completely 

 covered in by a draught-proof enclosure of cotton-wool over 

 a cardboard frame, for draughts might by local cooling set 

 up convection currents in the liquid, and might also cause 

 evaporation of the more volatile liquids. A thermometer 

 with 1/1 0°C. divisions checked the temperature of the fluid. 

 Table II. is a summary of the physical constants of the 

 liquids used. It was complied from published data in books 



Table II. t 

 Physical Constants of the Liquids used. 



Liquid. 



10 4 *. 



10%. p. 



s. 



V T . 



cv/Jc. 



ac*/k* 



^T + 2o/^T- 



Toluene 



3-42 



2-66 

 4-1 



10-9 ! 0866 



! 



11-8 1-582 

 8 5 i 1-023 



0-40 



0-198 

 0514 

 0-47 



0-58 



00062 



0-0108 

 0-055 

 117 

 9-3 



724 



8-03 

 693 

 1402 

 7940 



1118 



1630 

 1390 



842 

 611 



•728 

 •465 

 •363 

 '42* 



Carbon tetra- 

 chloride 



Aniline 



Olive oil 



1 



3-92 70 0-9 Ifi 



Glycerine 



6-8 



5-3 1-26 



specific heat. ?; = viscosity. p = density. c=sp. 



V = 7}/p. 



of physical constants, and since pure liquids were used it is 

 sufficiently exact for present purposes where (as will be seen 

 later) we are concerned mainly with a small fractional 



t The majority of these values were obtained from ' Physical and 

 Chemical Constants, etc.,' by G. W. C. Kaye and T. H. Lab)\ 



