“You railroad only when it comes time to railroad”
The Door into Summer“You railroad only when it comes time to railroad” is Dan Davis’s rule for acting within time rather than mastering it. The phrase turns the practical limits of time travel into an image of historical readiness: a traveler may move through time, but cannot make an event or a return route available before its conditions exist.
Meaning and Origin
Dan invokes the saying while reflecting on reports of other time travelers. He mentions cases collected by Fort, accounts associated with Ambrose Bierce, and two women in the gardens of the Trianon; he also suspects that Doc Twitchell may have operated his device more often than he admitted. Yet such journeys rarely produce much, Dan concludes, because a traveler’s capacity to intervene is bounded. His use of the railroad image makes the point in terms of timing: action is possible, but only when the historical moment permits it.
The Risk of Going Too Far
The phrase returns in Dan’s consideration of commercial time travel. He imagines short jumps, machinery prepared to enable a return, and components carried along for the journey. But one jump too many could leave a traveler unable to establish the means of getting back, simply because the time is not right. Even a mundane obstacle such as a special alloy might defeat the plan; a traveler might arrive at the court of Henry VIII with materials intended for the twenty-fifth century, unable to proceed as intended.
That danger gives the proverb a practical edge. Time travel is not a dependable route that can be extended indefinitely by equipment or ambition. Dan’s conclusion is that a device should not be marketed until its bugs are worked out: technical preparation matters, but it cannot abolish the temporal conditions on which a successful journey depends.
Narrative and Thematic Significance
The saying links individual agency to the novel’s account of a single, self-consistent world. Dan does not treat time travel as a license to create arbitrary contradictions; he understands action as taking place within a larger network of rules and consequences. The railroad metaphor captures that balance: people can act, but some actions become possible only when their time has come. Thus the phrase is both a warning against overconfidence and a concise statement of the limits within which time travel operates.
