NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Burdwood's Tables
From: Chuck Taylor
Date: 2007 Oct 9, 21:12 -0700
I have a pair of azimuth tables
H.O. No. 71 Azimuths of the Sun and Other Celestial Bodies of Declination 0 to 23
[Fifteenth Edition] United States Navy Department Hydrographic Office
1934
H.O. No. 120 Azimuths of Celestial Bodies Whose declinations range from 24 to 70 degrees
for latitudes extending to 70 degrees from the equator
[SEVENTH EDITION] United States Navy Department Hydrographic Office
1940
What is the relationship between these two sets of tables and Burdwood's Tables? They appear to contain essentially the same data, except that in H.O. No. 71 the azimuths are given in degrees and minutes (vice degrees and tenths) for every 10 minutes of time (vice every 2 minutes of time). Another obvious difference is that Burdwood's tables are British, and these are American.
There is no mention of Burdwood in either of these publications.
Here is an excerpt from the preface of H.O. No. 120:
"This work was prepared by the Hydrographic Office in 1902 on account of the value of star observations in determining azimuths, and the growing necessity of frequent observations for position in high-speed ships.
"Taken together with the solar azimuth tables of the Hydrographic Office, which give the true bearings of the sun and other celestial bodies within ecliptic limits, the present tables supply the navigator with ready means for finding the azimuths of the great majority of bodies appearing in the firmament and for applying, over a vastly increased extent, the other useful objects of azimuth tables, such as finding the true course in great-circle sailing and laying down the Sumner line of position."
Best regards,
Chuck Taylor
48d N
122d W
Check out the hottest 2008 models today at Yahoo! Autos.
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To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
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From: Chuck Taylor
Date: 2007 Oct 9, 21:12 -0700
Here's a page from Burdwood's Tables. The latitude limit is 64 degs in the second edition. Commander John Burdwood RN was was in the Admiralty Hydrographic Department. The second edition 1940 was revised by Percy Davis FRAS of HM Nautical Almanac Office.
H.O. No. 71 Azimuths of the Sun and Other Celestial Bodies of Declination 0 to 23
[Fifteenth Edition] United States Navy Department Hydrographic Office
1934
H.O. No. 120 Azimuths of Celestial Bodies Whose declinations range from 24 to 70 degrees
for latitudes extending to 70 degrees from the equator
[SEVENTH EDITION] United States Navy Department Hydrographic Office
1940
What is the relationship between these two sets of tables and Burdwood's Tables? They appear to contain essentially the same data, except that in H.O. No. 71 the azimuths are given in degrees and minutes (vice degrees and tenths) for every 10 minutes of time (vice every 2 minutes of time). Another obvious difference is that Burdwood's tables are British, and these are American.
There is no mention of Burdwood in either of these publications.
Here is an excerpt from the preface of H.O. No. 120:
"This work was prepared by the Hydrographic Office in 1902 on account of the value of star observations in determining azimuths, and the growing necessity of frequent observations for position in high-speed ships.
"Taken together with the solar azimuth tables of the Hydrographic Office, which give the true bearings of the sun and other celestial bodies within ecliptic limits, the present tables supply the navigator with ready means for finding the azimuths of the great majority of bodies appearing in the firmament and for applying, over a vastly increased extent, the other useful objects of azimuth tables, such as finding the true course in great-circle sailing and laying down the Sumner line of position."
Best regards,
Chuck Taylor
48d N
122d W
Check out the hottest 2008 models today at Yahoo! Autos.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
