  To provide insights into the challenging problem of turbulent convection,
Jack Herring used a greatly truncated version of the complete Boussinesq
equations containing only one horizontal wavenumber. In light of later
observations of a robust large scale circulation sweeping through convecting
enclosures at high Rayleigh numbers, it is perhaps not an implausible point of
view from which to reexamine high-Rayleigh-number data. Here we compare past
experimental data on convective heat transport at high Rayleigh numbers with
predictions from Herring's model and, in fact, find excellent agreement. The
model has only one unknown parameter compared to the two free parameters
present in the lowest order least-squares power-law fit. We discuss why the
underlying simplistic physical picture, meant to work at Rayleigh numbers
slightly past the critical value of a few thousands, is consistent with the
data, when the single free parameter in it is revised, over some eleven decades
of the Rayleigh number -- stretching from about a million to about $10^{17}$.
