Examples from the Web for vortex ring
Historical Examples of vortex ring
Through a vortex-ring or tube, the fluid circulates in closed lines of flow, each one of which is laced through the tube.Lord Kelvin
A vortex-ring produced in the air behaves in the most surprising manner.
Such a vortex-ring is made by the smoker who purses his lips into a round hole and sends out a puff of smoke.
Now this is just what a vortex-ring would do in an incompressible frictionless fluid.
It is certainly possible roughly to conceive how such a structure as a vortex-ring in the ether might be formed.