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directed aether wind (vent relatif de l’éther) of same absolute amount

$v=2\pi \cdot N\cdot r\,$

1)

of relative aether velocity.

The imagined rotation of the system shall happen counter-clockwise ($L*$)

thus the relative aether circulates clockwise ($R*$) in relation to the system imagined as being at rest.

Of the two light rays denoted by $R$ and $L$, which are circulating clockwise and counter-clockwise, one (namely ray $R$) at first travels faster away from $O$, then in the same measure faster around the whole circle, and also faster back to point $O$; the other one, $L$, is held back in the same way. –

When any wave is transmitted faster or held back by a relative stream $v$ of the wave-carrying medium, then it's known that (in first approximation), the time $\Delta T$ of earliness or delay is defined – with respect to normal time $T$ employed at standard velocity $c$ – by

${\frac {\Delta T}{T}}={\frac {v}{c}}$,

in case the directions of $v$ and $c$ coincide or are precisely opposite; instead of time $\Delta T$ one can also introduce the (apparent) path-contraction or -elongations $\Delta U$, then $\Delta U$ is defined – with respect to the normal path ("real" path) – by

${\frac {\Delta U}{U}}={\frac {v}{c}}$