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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Ded and Dead
From: Frank Reed
Date: 2009 Jan 11, 20:04 -0800
From: Frank Reed
Date: 2009 Jan 11, 20:04 -0800
A couple of months ago, I noted that the etymological story saying that "dead reckoning" should really be "ded reckoning" (derived from 'deduced reckoning') is more common among flying navigators than floating navigators. I've been collecting bits and pieces on this over the past few months, and it does still seem to be true that navigators in aviation repeat this explanation more often than marine navigators. Also, people who work on autonmous navigation/robot navigation also seem to repeat this "etymology." Just a difference in culture... I've tracked down what appears to be the earliest version of this explanation of "dead reckoning". I have found no cases before 1920 (and that also could explain why aviators picked this up since long-distance air navigation had its origins very close to this date). I could not find the original article, but this one appears to quote it verbatim: From "The Rudder" Jan. 1920 "In every ship's log, in all books of instruction, in all works on navigation, and in innumerable other publications, we find a special point made of the "dead reckoning" on board ship. Why dead? It has been for a century or more a stumbling block to investigators, and, as Daniel Defoe would have said, "lexicographers have gone astray in this unknown channel." One after another has attempted to arrive at some reasonable explanation of it, but has had to abandon the task as hopeless, for when they have marshalled all the facts at their disposal it is always found that the operations which the word covers are anything but dead. They are, indeed, very much alive! Henry Harries, acting marine superintendent meteorological office, thus explains the phrase in the London Morning Post: "It was not until nearly the close of the Eighteenth century that printed log books were supplied by the Admiralty. Long before that officers were compelled to keep a journal, the form of which was only gradually developed. Originally it was on loose sheets of small size, and the columns, when introduced, had to be ruled by hand. The log of the Dreadnought, 1679, had twelve very narrow columns on a page. For want of space the column for the latitude, 'deduced from the reckoning,' as Riddle has it, was headed Ded. Latt. "This abbreviation Ded., for 'deduced,' has become corrupted into dead, which has for generations served to exercise in vain the most learned savants on two continents to get at its real and in the result perfectly simple meaning. There is not a mariner who, on reading this explanation, will fail to realize that deduce is the only word which correctly expresses the method of obtaining his so-called dead reckoning. He deduces his position from the account he has kept, just as any tradesman deduces his profit or loss from his account." " There are a couple of problems with HH's theory. First, the spelling "ded" for "dead" was not unusual in the 17th century. English spelling was not yet standardized (or is it standardised?). Second, there are early 18th century nautical dictionaries that say "dead reckoning" and make no mention at all of some earlier spelling or a derivation from "deduced reckoning". That would be very hard to account for considering the few decades that had elapsed since HH's logbook evidence. Also, he mentions the phrase "deduced from the reckoning" which is found in many 19th century navigation manuals. Unfortunately for the theory, this phrase was *never* used as a synonym or a replacement for dead reckoning. It's not relevant to the origins of the phrase. The real etymology is mostly irrelevant today... I can imagine something about calculating as if in "dead water" (without currents). But I suppose the phrase thrived for generations because it's a bit of comedy: when you're "dead", you'll face your "reckoning" (i.e. judgement). Puns have legs. -FER --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---