Dead Reckoning (was Charles Nordhoff & HMS Bounty)

[Ray Ott]

The American Practical Navigator by Nathanial Bowditch--which has been the
standard textbook of marine navigation for probably 150 years--gives two
definitions or origins for the term which are said to combine:

"Dead" reckoning, so called because it is based on the velocity of the vessel
as determined by the so-called "Dutchman's" log.  This is a plank of wood
thrown overboard which then remains "dead" in the water, while a length of
string with knots in it plays out over the side of the ship.

"Deduced" reckoning which is "dead" reckoning elaborated by taking into
account the effect winds and currents, etc.

What do you call this, a conflation?

Ray Ott