Posted by Smokey Stover on July 19, 2005
In Reply to: Jump-off point posted by Norm on July 19, 2005
: "Jump-off point" is obvious enough as a transition point. Would anyone know of an origin. Guesses: passenger trains, hobo lingo, parachuting
In the 19th century "jump-off" was often used, at least in the U.S., the same way Americans use "drop-off," as a precipitous descent, except that in a jump-off one was required to jump. One often uses "drop-off" to characterize a sudden change of level (deep instead of shallow) while wading into the water at the shore of a pond or lake or ocean, although many other locations can have a drop-off, an abrupt change in elevation. A jump-off could be found on, say, a road or path that abruptly ended above a deep hole--or a drop-off.
Jump-off came to be widely used for the start of a military campaign during World War I and subsequently. "The Fifth and Eighth armies have launched the greatest drive in Mediterranean warfare in the jump-off of Allied spring offensives. " It also came to be used to describe an aircraft using vertical take-off, or the act of thus taking-off.
The word jump-off is sometimes used synonymously with "jumping-off." The OED gives an example: "A space station in permanent orbit round the earth could be used as a 'jump off' point for travel to the moon" The OED prefers to use "jumping-off point" for this use of "jump-off point." In the 19th century "jumping-off point" or "jumping-off place" was sometimes used for the farthest reach of civilized land, from whence one jumped off into something else. You could also use some particular place as the "jumping-off point" for, say, expeditions to the Antarctic, or for shipments of aid to foreign destinations, or for military campaigns and raids into enemy territory. This last was a more recent development than just "jump-off" as the start of a campaign. Not surprisingly aircraft have sometimes had a designated "jumping-off place," normally an airfield. (This use seems a bit old-fashioned.)
Jumping-off point (or place) can be used figuratively. One example given by the OED is, "1930 G. B. SHAW Apple Cart I. 37 Today the nation would be equally amazed if a man of his ability thought it worth his while to prefer the woolsack even to the stool of an office boy as a jumping-off place for his ambition."
The transition from "jump" to "jump-off" to "jumping-off" seems very logical, even smooth, although the uses seem to be too diverse to be easily categorized. I haven't encountered any references to parachuting. Parachutists obviously jump off into the air when they jump out of planes, but I haven't heard that they use the phrase. Plainly a railroad passenger can say, for instance, Chicago was my jumping-off place for journeys into the western U.S., but that would not be a special use. Nor have I heard that hobo lingo was ever involved, although a Depression-era hobo might have said, "My jump-off place is the railroad yard just south of the city." SS