block-signal

“The passage of a law requiring the adoption of a block-signal system has been proposed to the Congress.”

State of the Union Address (1790-2001)

“Give this boy and girl of yours a few good books and you're starting them on the double-track, block-signal line to happiness.”

Parnassus On Wheels

“Why should he battle with the intricacies of a block-signal system when everybody else round the place has a separate bell?”

Europe Revised

“A goggle-eyed toad stared impudently at him from a long tangle of rubbish that had been a train -- stalled there forever by the final block-signal of death.”

Darkness and Dawn

“a block-signal system has been proposed to the Congress.”

State of the Union Address