Mathematical Proceedings of the Cambridge Philosophical Society


The Instability of a Compressible Fluid heated below

Mr Harold Jeffreysa1

a1 St John's College

The vertical gradient of temperature needed to produce convection currents in a layer of incompressible liquid has already been investigated in several instances. For a compressible fluid instability cannot arise until the gradient exceeds the adiabatic one; it has been assumed usually that what matters is the excess of the actual gradient over the adiabatic. Thus the excess needed in a compressible fluid is to be found by the same formula as gives the gradient needed for instability in an incompressible fluid. It is desirable, however, to investigate the validity of this assumption.

(Received January 07 1930)

(Accepted January 27 1930)