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> On Sunday, January 18, 2004, Frank Reed wrote:

> When did the New take over decisively from the
> Old?

I have the impression from my reading that the sight
reduction method of choice as late as WW II was the
Cosine-Haversine method.  Hosmer (1926) mentions the
use of tables, but only as an afterthought.  Dutton's
(1942) describes H.O. 208 (Dreisonstok), H.O. 211
(Ageton), and H.O. 214, but in less detail and only
after presenting the Cosine-Haversine method.  The
implied message as I read it is, "Here are some new
methods that may be worthy of your attention some
day."  As Dan Allen has pointed out, the 1943 Bowditch
took a similar stance.

When I was a Midshipman in the late 1960's, the U.S.
Navy was definitely teaching tabular methods and only
tabular methods.  At what point tabular methods became
more widely used than the Cosine-Haversine method is
an interesting question.  My conjecture is that the
change took place after WW II.

Still, I agree that most of the features of "The New
Navigation" (as described by Frank Reed) with the sole
exception of the use of tabular methods (point number
5), had long since become common practice by the time
of WW II.

Does anyone have any evidence to the contrary?  If so,
I would like to hear it.

Chuck Taylor
 47? 55.2' N
122? 11.2' W

Begin quote:
===========
Features of the New Navigation:
1) All altitude sights are treated as equivalent.
There are no separate sights for latitude and
longitude.
2) For every sight, a distance away and azimuth are
calculated from an assumed position (possibly the DR
position).
3) Position is determined by intercept plotted on a
chart as a "Line of Position". Crossing two or more
LOPs determines the vessel's position on the chart.
4) Star sights are common and encouraged.
5) Simple tabular methods are common. Navigators using
tables in practice rarely encounter the mathematical
terminology underlying their calculations.
==========
End quote


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