Note 44 — Chapter XII · THE EQUATIONS OF ELECTROMAGNETICS AND LORENTZ’S THEORY
Reading edition
The classical or Galilean transformations were , , , , where was the velocity of the frame with respect to a frame at rest in the ether, hence with respect to the ether itself; this velocity being directed along the axis and the two frames being assumed to have coincided at the initial instant . Under the same conditions the Lorentz transformations were , , ; where being the velocity of light. It is easy to see that when is small compared to , the difference between the two types of transformations becomes negligible.