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I think they probably chose 1900 for the star declinations because stellar 
coordinates are usually published for "even" dates, like 1900, 1950, 2000 
etc. These are termed "epochs" and if you need a exact star position at a 
specific time you calculate the position based on the published epochal 
position.


Mitch
 -----Original Message-----
From:   Royer, Doug [mailto:doug.royer@REMEC.COM]
Sent:   Friday, September 26, 2003 4:02 PM
To:     NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Subject:             "Latitude"questions

I am reading my copy of the book "Latitude" and have some questions on 2
subjects I ran across.
On pages 61 thru 64 a method for the "telegraphing of correcting longitude"
useing a telegram is explained.All well and good.For those who don't have
the book here is a short explaination of the method.Each station used to
relay the time was equiped with a chrono,telegraph key,telescope that would
rotate 180* on it's verticle axis and a cylendrical record.At every 2 sec.
of time the chrono would cause a tick to be recorded on the record as would
every minute be recorded as a double tick.The observer would then use the
special telescope and observe a celestial body's movement  in the reticle.As
the body crossed a series of lines in the reticle the observer would depress
a telegraph key which would also record a tick on the record.Then the
observer would then reverse the scope 180* on the verticle plane and repeat
the proceedure to cancel certain errors and allow corrections to be computed
for others.I cannot visualize this scope.Can anyone help?
On pages 84 and 85 it states that in 1896 the rules governing the
nomemclature of variable stars were inconsistant at the time.The locations
of the stars were expressed by R.A. and Declination.All well and good so
far.Here's where I get lost:"in Seth Chandler's system the designation of a
variable star was obtained by dividing by ten the number of secounds in its
R.A. during the year 1900".
As like Forrest Gump I can say "I am not a smart man" but this statement has
me totally baffled! Can someone in the list please explain what is being
conveyed as I don't understand what 1900 has in common with 1896.
Thanks for any insights you can give me.

   

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