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Re: Coverage of lunars in Bowditch
From: Dan Allen
Date: 2001 Jul 22, 11:44 AM
From: Dan Allen
Date: 2001 Jul 22, 11:44 AM
In the book entitled "History and Bibliography of The New American Practical Navigator and The American Coast Pilot" by John F. Campbell (Peabody Museum, Salem, MA: 1964), it says in part on page 119: Bowditch continued to be published without any major revisions until 1887, when it again underwent revision. Although seach succeeding printing resulted in minor changes, Bowditch did not have its next major revision until 1907. This revision almost saw the lunar distance problem eliminated from the work, but it was decided, in view of its archaic principles, to relegate it to the appendix. In 1914, Bowditch was again revised and improved. In charge of this revision was Lieutenant G. W. Logan, USN. A sign of the changing times is noted in this revision, as the chapter on lunar observations was finally excluded. It had been a part of the work since it was first printed in 1799. So there you have it. Editions printed up until 1913 had lunars, and the best material was probably pre-1907. I just got an 1888 version which has excellent coverage of lunars. Dan -----Original Message----- From Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Herbert Prinz Sent: Sunday, July 22, 2001 10:21 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Coverage of lunars in Bowditch The last edition of Bowditch to fully describe the method of lunar distances was that of 1914. I quoted from the 1909 edition merely for the reason that this is one that I happen to have handy. Appendix V in the edition of 1909 describes the method, contains all necessary auxiliary (!) tables and a worked example using the distances shown in an extract from the Nautical Almanac 1855. Without having checked, I would therefore assume that any edition since 1855 would not differ too much in the way the subject is treated and would be surprised if it had changed in the last 5 years before discontinuation. Note that the necessary lunar distances themselves were tabulated in the Nautical Almanac only until 1906. An explanation on how to compute them from R.A. and Dec. was substituted for the tabulation until 1919. In the American Nautical Almanac I find such an explanation even in my 1930 edition. This, by the way, as an afterthought, provides another answer to Nigel Gardner's question, whether in the absence of tabulated LD's, it is possible to establish longitude by means of currently available ephemeris (Nautical or Astronomical Almanacs) log. tables and a sextant, without the use of calculators or computers: Yes, it is. See American Nautical Almanac 1930 (or thereabouts) p.102. Herbert Prinz (from 1368950/-4603950/4182550 ECEF) Glendon (Lee Martin) wrote: Hi,I'm trying to find out which edition of Bowditch was the last to cover lunars, and/or which was the last to have a reasonably comprehensive coverage. I am looking to buy an early edition of Bowditch ( 1938 is currently my earliest), and want one that covers lunars. In the recent thread on lunars, one member (cant recall who, without checking) said his 1909 edition covered lunars, and wondered/surmised whether that was the last edition to do so. Any other thoughts??