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Subject: HO 211 / Bayless
From: Paul Hirose (71202.2014@XXX.XXX)
Date: Mon Sep 06 1999 - 17:27:52 EDT
Russell and the group -
For use at home I prefer the Ageton Method table in Bowditch over
Bayless. The Bayless book is a paperback so it flips shut when you
take your hand off it. Another annoyance is that leading digits are
omitted when they are the same for several entries in a row. Compare
Bayless to Bowditch:
Bayless Bowditch
50042 50042
004 50004
49966 49966
928 49928
890 49890
I find the Bowditch format can be read with more speed and certainty.
The Bayless rules for negative Hc are incorrect.
Finally, the table in Bowditch always has the A value in the left-hand
column and B on the right. In addition, all numbers in the A column
are boldface. The consistent layout lowers my mental workload
noticeably, and is the biggest advantage of the older table. I need
all the help I can get!
Bayless chose to take advantage of symmetry (A of 10 deg. = B of 80
deg.) by making each column do double duty. This clever trick cut the
table size in half, but also made it unavoidable that the A and B
columns would periodically swap positions.
There are pluses to the Bayless table. The book measures only 9" x 6"
x 1/8". I find the table pleasantly clean in appearance, without all
the unnecessary dividing lines seen in Bowditch. Bayless includes
D.H. Sadler's method for reducing sights with full accuracy when LHA
is in the Ageton "danger zone" near 90 or 270. Also included is
Elliot Laidlaw's graph for determining your proximity to the danger
zone (it's a function of t and dec). Neither of these is available in
Bowditch.
If I were doing celestial at sea instead of at a desk, I'd probably
prefer Bayless for its cheapness, compactness, and robustness (the
paper is heavier than that in Bowditch). Original HO 211s are
practically a collector's item nowadays. If I owned one I'd be
reluctant risk getting it wet.
My comparison may be a bunch of moot points. I'm not sure if the
current Bowditch has Ageton's table.
Another variant on Ageton's method is Mike Pepperday's S-Table. I
think Celestaire still sells it. Pepperday has an improvement over
both Ageton and Bayless: the table goes all the way to 360 degrees.
That means you enter it directly with LHA, instead of having to
compute t. The extended range is accomplished with additional column
headings; the table is no larger than Bayless. (Of course you can
annotate your Ageton table with a pencil to extend its range - that's
what I'm doing.) I don't know if Pepperday includes the Sadler and
Laidlaw info.
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