This appears to be the first experiment in signalling on a subaqueous wire.
She appeared before Lydia in the dining-room and gave her a signalling grimace.
But she did not answer, for Anne was at the window, signalling.
Their signalling devices were inadequate even to reach Earth.
And to whom could Wilks be signalling across this Lunar desolation?
The Active is coming in slowly, and has been signalling us all the morning.
And Marjory's busy brain at once began to devise methods of signalling.
It was standing and signalling to him with its finger, as though inviting him.
"We ought to have some way of signalling," he had said as they went out of doors.
They are not using their searchlight, and we have no way of signalling to them.