the Thermal Conductivity of Water. 49 



sheet was, on the average, the same at the divisions between the 

 three parts of the coils as for the rest of their areas. 



It will be convenient to speak in future of the right hand 

 (R.H.) and left hand (L.H.) of the two similar halves of the 

 apparatus, these expressions referring to their positions with 

 regard to the observer when set up. 



The resistances of the two inner coils a 7 when measured in 

 position were 



?•?• { r?\ H2? °\ ms \ * is 0, 



L.H. («Y) 6-191 ohms J 



and the areas in each case 43*73 sq. cm. ; half the space 

 between the areas actually covered by a 7 and 7 8 being 

 allowed to a y. From these data the ratio R/A in equation (1 ) 

 was obtained. 



To connect the two heating-coils so that their central 

 portions only formed the arms of a Wheatstone bridge and 



Phil. Mag. S. 5. Vol. 48. No. 290. July 1899. E 



