CAPILLAR Y A TTRA CTION. 23 



tension is positive, are placed in contact and 

 left to themselves undisturbed by gravity (in our 

 favourite laboratory at the centre of the earth 

 suppose), after performing vibrations subsiding in 

 virtue of viscosity, the compound mass will come 

 to rest, in a configuration consisting of two 

 intersecting segments of spherical surfaces con- 

 stituting the outer boundary of the two portions 

 of liquid, and a third segment of spherical 

 surface through their intersection constituting 

 the interface between the two liquids. These 

 three spherical surfaces meet at the same angles 

 as three balancing forces in a plane, whose 

 magnitudes are respectively the surface tensions 

 of the outer surfaces of the two liquids and the 

 tension of their interface. Figs. 2 to 5 (see pages 

 24, 25) illustrate these configurations in the case 

 of bisulphide of carbon and water for several 

 different proportions of the volumes of the two 

 liquids. [In the figures the dark shading re- 

 presents water (or sulphate of zinc) in each case.] 

 When the volume of each liquid is given, and 

 the angles of meeting of the three surfaces are 



