Now Jim and I had had many a long talk together about what we should do in case we wanted to signal to each other very pressing.

We thought the time might come some day when we might be near enough to sign, but not to speak.

So we hit upon one or two things a little out of the common.
The first idea was, in case of one wanting to give the other the office that he was to look out his very brightest for danger, and not to trust to what appeared to be the state of affairs, the sign was to hold up your hat or cap straight over your head.

If the danger threatened on the left, to shift to that side.

If it was very pressing and on the jump, as it were, quite unexpected, and as bad as bad could be, the signalman was to get up on the saddle with his knees and turn half round.
We could do this easy enough and a lot of circus tricks besides.