A radially symmetric progressive acoustic beam has been set up in a closed, gas‐filled tube to cause streams driven by the Eckart, volume, source of verticity. A careful determination of the acoustic pressure at all points of a cross section of the beam has been used successfully to predict the stream velocities at this cross section, for argon. The work with argon and the results of further experiments with dry nitrogen and moist air indicate that: (1) the Navier‐Stokes equation, the equation of continuity, and the acoustic “equation of state”p1 = ρ1c02+Rρ̇1, provide a valid basis for second‐order studies of streaming; (2) thermal conduction effects may be introduced into the Eckart streaming equations in the same manner as they appear in the attenuation formulas; (3) the macroscopic quantity, bulk viscosity, is made up of contributions from the intramolecular processes of vibrational and rotational relaxation.