midnight
`` Then we tested it the other way , they sending the same guinea pig to us , and in moments it flashed into being in our receiving chamber . Of course the step-down force in the receiving chamber had to be in operation , since had it not been at that moment the radio-vibrations of the animal would have simply flashed on endlessly in endless space . And the same would happen to any of us were we flashed forth and no receiving chamber turned on to receive us . `` We signalled the Martians that all tests were satisfactory , and told them that on the next night at exactly midnight by our time we would flash out ourselves on our first visit to them . They have promised to have their receiving chamber operating to receive us at that moment , of course , and it is my plan to stay there twenty-four hours , gathering ample proofs of our visit , and then flash back to earth . `` Nelson must stay here , not only to flash us forth to-night , but above all to have the receiving chamber operating to receive us at the destined moment twenty-four hours later . The force required to operate it is too great to use for more than a few minutes at a time , so it is necessary above all that that force be turned on and the receiving chamber ready for us at the moment we flash back .