EXPERIMENTS WHICH SERVE TO SHOW TIIK ANALOGY 5

kiln chamber; until an equilibrium is established between its
inflow and its outflow. When this equilibrium is established, the
lower surface of the layer of colored kerosene assumes a permanent
level.

It can be seen in Fig. 2 that only the upper portion of the

FIG. 2.
kiln, above its mid-height, is filled with hot gitBen, and that the*
space between the lower surface of the layer of kerosene and the
hearth of the kiln contains none at alL Thin space, therefore, will
only be heated by such eddy currents as form, and theĢe are due
entirely to the differences in density which exist between the