APPENDIX I
SIMPLE DERIVATION OF THE LORENTZ TRANSFORMATION [SUPPLEMENTARY TO SECTION XI]
FOR the relative orientation of the co-ordinate systems indicated in Fig. 2, the
-axes of both systems permanently coincide. In the present case we can divide the problem into parts by considering first only events which are localised on the
-axis. Any such event is represented with respect to the co-ordinate system
by the abscissa
and the time