From: mike and linda <mikeandlinda_at_shaw.ca> ... > Ded is a shortened form of the word deduced. It is > not spelled with an "a" , > much the same as Led in Led Zeppelin. Etymolology often gives way to phonology or to standard spelling, and thus it's not uncommon for spelling to change when words are combined or divided. (The Led Zepplin example is a move in the opposite direction, an attempt to create a distive non-standard spelling). However: The deduced->ded origin is by no means accepted as definitive by scholars. The Oxford Companion to Ships and the Sea calls this etymology "... improbable; it has too much of a modern ring about it." The spelling of "ded" is not seen in any but a few very recent writings; in the 17th Century it was always "dead reckoning". I suspect the "deduced" theory is a modern folk etymology. The more likely origin is from the other sense of "dead" as in exact, fixed, unmoving- as a machinist would say of an exact alignment, it's "dead nuts on". mike, feeling a bit didactic today ;-) ===== -------------------------- Michael Edelman mje_at_spamcop.net http://foldingkayaks.org http://findascope.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Michael Edelman wrote: > However: The deduced->ded origin is by no means > accepted as definitive by scholars. The Oxford > Companion to Ships and the Sea calls this etymology > "... improbable; it has too much of a modern ring > about it." The spelling of "ded" is not seen in any > but a few very recent writings; in the 17th Century it > was always "dead reckoning". > > I suspect the "deduced" theory is a modern folk > etymology. The more likely origin is from the other > sense of "dead" as in exact, fixed, unmoving- as a > machinist would say of an exact alignment, it's "dead > nuts on". The modern folk etymology notion is persuasive. But isn't the fact of dead reckoning "Here's where I infer--based on current, paddling speed, crosswind, etc--I am" rather the opposite of exact, fixed, and unmoving? > mike, feeling a bit didactic today ;-) Me, too. -- Steve Cramer Athens, GA *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
No. If you review again, the definition of dead reckoning cited in "The American Practical Navigator," Ho. Pub. No. 9 (Defense Mapping Agency Hydrographic/Topographic Center publication) the "Dead" Reckoning is the advanced position based on course, time and speed, without considering the influence of current, wind and other unknowns. In common terminology, if you are in "Dead Water" you are in water which is not moving. Thus, Dead Reckoning is a calculation based on the premise that you are in water which is not moving. Definitino of Dead Reckoning. Determining the position of a vessel by adding to the last fix, the ship's course and speed for a given time. The position so obtained is called a Dead Reckoning Position. Comparison of the dead reckoning position with the fix for the same time indicates the sum of currents, winds, an dother forcdes acting on the vessel during the intervening period. Ho. 9, "The American Practical Navigator" is an addition of Nathaniel Bowditch's work on the thirtheenth (1798) edition of John Hamilton Moore's (1738-1807) book, "The Practical Navigator." In 1868 the newly formed U.S. Navy Hydrographic Office bought the copyright from Bowditch and has continually published the book since that time under the name ^SThe American Practical Navigator.^T (H.O. Pub. No. 9). Ho. Pub. No. 9 has become the oldest book published in the United States, still in current publication. http://www.redlandsfortnightly.org/Taylor01.htm Etymology: http://encyclopedia.thefreedictionary.com/Ded%20reckoning On Wed, 29 Sep 2004 09:47:00 -0400, "Steve Cramer" <cramersec_at_charter.net> said: > Michael Edelman wrote: > > > However: The deduced->ded origin is by no means > > accepted as definitive by scholars. The Oxford > > Companion to Ships and the Sea calls this etymology > > "... improbable; it has too much of a modern ring > > about it." The spelling of "ded" is not seen in any > > but a few very recent writings; in the 17th Century it > > was always "dead reckoning". > > > > I suspect the "deduced" theory is a modern folk > > etymology. The more likely origin is from the other > > sense of "dead" as in exact, fixed, unmoving- as a > > machinist would say of an exact alignment, it's "dead > > nuts on". > > The modern folk etymology notion is persuasive. But isn't the fact of > dead reckoning "Here's where I infer--based on current, paddling speed, > crosswind, etc--I am" rather the opposite of exact, fixed, and unmoving? *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Almost... the GPS only knows the course, not the heading. With dead reckoning, you know the heading, but not the course. On Wed, 29 Sep 2004 12:59:10 -0400, "Steve Cramer" <cramersec_at_charter.net> said: > Robert C Cline wrote: > > > No. If you review again, > > Assumes prior review not in evidence :) > > > the definition of dead reckoning cited in "The > > American Practical Navigator," Ho. Pub. No. 9 (Defense Mapping Agency > > Hydrographic/Topographic Center publication) the "Dead" Reckoning is the > > advanced position based on course, time and speed, without considering > > the influence of current, wind and other unknowns. In common > > terminology, if you are in "Dead Water" you are in water which is not > > moving. Thus, Dead Reckoning is a calculation based on the premise that > > you are in water which is not moving. > > Ah, so the "dead" refers to the water, not the reckoning. No current, no > wind, no unknowns. Sounds like the frictionless slides located in > vacuums in Physics 101. > > So dead reckoning is just geometry and trig, and therefore very precise, > since all you need to know is beginning position, course, and speed, > which of course you know precisely because....it's part of the readout > on your GPS. > > Steve *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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