A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Andrés Ruiz
Date: 2009 Dec 18, 09:11 +0100
HM Nautical Almanac Office: History
This page provides a focus for historical information on HM Nautical Almanac Office. Work is in progess on a history of The Nautical Almanac, HM Nautical Almanac Office and its Superintendents covering the period 1767 to the post-war era.
The personal memoirs of Dr. D.H. Sadler, former Superintendent of HMNAO from 1936 to 1971, are now available. HMNAO wishes to thank Dr. George Wilkins for making these memoirs available to us and editing the original manuscripts.
A Personal History of The Royal Greenwich Observatory at Herstmonceux Castle, 1948-1990 by Dr. G.A. Wilkins, former Superintendent of HMNAO from 1971 to 1989, is now available via a link to the RGO Archives Collection at the
Enviado el: viernes, 18 de diciembre de 2009 8:34
Asunto: [NavList 11236] Re: Almanac status and history
Nautical Almanac history is a big topic...
The year 2008 was the fiftieth anniversary of the modern Nautical Almanac, and we cut a cake in its honor at the Mystic Navigation Weekend in June of 2008. Geoffrey Kolbe had the "honor" of blowing out the candle as his "Longitude Prize" for having travelled the greatest distance to attend. But our modern "Nautical Almanac" descends in a rather round-about fashion from the others published in the preceding two centuries. It's more complicated than you might think.
"What is the source and status of modern Spanish, Dutch, Chinese, etc. almanacs?"
Almost no one has bothered calculating an independent almanac in decades, except if you count some online projects. The modern Nautical Almanac, standardized in 1958, has been offered since 1958 or 1960 to other navigational authorities to be localized in their own languages. So if you find a Norwegian Nautical Almanac, for example, from 1970, it look just like the standard British/US N.A. from that year but with the explanatory text and column headings translated. More recently, this data has been offered at a price, so the "Commercial Nautical Almanac" publishers pay a little something to license that data. Most other countries have simply stopped publishing since the demand for a localized version is very low. The French "Ephemerides Nautiques" ultimately based on the "Connaissance des Temps" and the German "Nautisches Jahrbuch" maintain an independent tradition and in many ways, their nautical almanacs are very different, but of course at this late date, there is no independent calculation of astronomical positions because they are known quantities. You don't calculate the position of Jupiter in 2010, working orbital elements, iterating for eccentric anomaly from mean anomaly, and all that; you just look up the results of the standard numerical integrations in a table and insert where needed.
One thing to know as you get into the history of the nautical almanacs: for much of their history, the books with the titles "Nautical Almanac" were not nautical at all. They started out that way, but they quickly evolved into astronomers' almanacs, and in the late 19th and early 20th centuries, most almanac authorities split their publications in two, and perhaps strangely, the books for the astronomers kept the nautical title. If you picked up a copy of the "Nautical Almanac" in 1950, you would readily recognize it as an ancestor of the modern "Astronomical Almanac" --a book that belongs in an observatory library and definitely not for use at sea. The most important actual nautical almanacs before 1958/60 were the slimmer volumes published as "The American Nautical Almanac" (which most closely resembles the modern Nautical Almanac) and "The Abridged Nautical Almanac" in Britain (the content was identical in 1958 while the titles were merged in 1960). These were the almanacs used by mariners. Other important nautical almanacs included the commercial almanacs "Reed's Nautical Almanac" (no relation) and "Brown's Nautical Almanac" (also no relation ;->).
And be aware: the history of the nautical almanacs is NOT the history of celestial navigation. Just as an example, the presence of lunar distance tables in a nautical almanac in 1905 does not mean that anyone at all was using them. If you want to study real history, then go dig up logbooks and notebooks and find out what they were actually doing. There is a relationship between almanacs and navigational practice, but it is not exactly one-to-one...
more? Here's my long-ish history of the nautical almanacs which formed the
basis of my presentation in Mystic in 2008:
Chronology of the nautical almanacs
1682: First volume of the French almanac published in 1679 with data for 1682: "Connaissance des Temps" (variously spelled, e.g. "Connoissance des Tems"). Its relevance to celestial navigation at sea was limited until later in the 18th century. 
1767: The origin of the British "Nautical Almanac and Astronomical Ephemeris", the first almanac widely used by mariners at sea. It was known almost universally as "The Nautical Almanac". It is hereafter refered to as the NA&AE to distinguish it from the modern Nautical Almanac. The first volume contained ephemeris data for the year 1767 (calculated during most of 1766 and published in January, 1767. later volumes three to four years in advance). The almanac was published by the Board of Longitude under the personal direction of Nevil Maskelyne. It was primarily for lunars. All times in apparent time. The "Tables Requisite..." were published to accompany the NA&AE containing data which did not change from year to year. [2,3]
1771: Appendix to NA&AE by Campbell: Tables for...finding the latitude of a ship at sea by double altitudes [based on Douwes method]. 
1772: Appendix to NA&AE by Maskelyne: A correct and easy method of clearing the lunar distance. Appendix by Lyons and Dunthorne: Problems in navigation. 
1774: Appendix to NA&AE by Maskelyne: elements of the lunar tables. 
1774-1778: Following the success of the NA&AE, the French almanac "Connaissance des Temps" publishes British lunar distance tables without modification. First use of the meridian of Greenwich in France (tables give the lunar distances for 0h9m16s, 3h9m16s, etc., simply adding the longitude difference between Greenwich and Paris to the hours of the tables in the British NA&AE. Until at least 1796, French lunar distance tables and other almanac data were only published about one year in advance rendering the French almanac less relevant to long ocean voyages.  [3, for 1776]
1776: First issue of the German Nautical Almanac, "Nautisches Jahrbuch". From first publication, this volume was separate from the German astronomers' almanac, so, unlike the British, American, and Spanish almanacs, there was no need to spin off a separate mariners' almanac in later decades. 
1781: Second Edition of the "Tables Requisite..." with significant changes and revisions. [2,3]
1792: First issue of the Spanish Nautical Almanac, "Almanaque Nautico y Efemerides Astronomicas". 
1794: Appendix to NA&AE by Brinkley: Tables to improve...the method of finding the latitude [by double altitudes]. 
1798: Appendix to NA&AE by Brinkley: ditto (corrected and improved). 
1800-1807: French lunar distance tables again copied (in part?) from British NA&AE. [4,9]
1802: First American commercial reprints of the British NA&AE. Blunt, Garnett, Megarey, Patten re-published the Nautical Almanac through the early 1850s with occasional (apparently minor) editorial corrections and additions. Blunt's edition began in 1811 and continued at least as late as 1856.
1808: Significant improvement in the calculation of the lunar ephemeris and the lunar distance tables in the NA&AE using Buerg's tables (possibly a year or two earlier). 
1818: Appendix to NA&AE by Brinkley: Two practical rules for reducing lunar distances. [2,3]
1822: Appendix to NA&AE by Brinkley: A practical method of computing the latitude. 
Appendix to NA&AE by Lax: An easy method of finding the latitude and time
at sea (using the altitude observations from a lunar distance observation).
[2,3] The altitudes yield latitude and local time while the lunar distance
itself yields Greenwich Time so the entire observation yields a complete fix.
Precursor of Sumner's method.
1831: Appendix to NA&AE by Lax: An easy method of correcting the lunar distance (for the oblateness of the Earth). [2,3]
1833: Appendix to NA&AE by Schumacher: [predicted geocentric] lunar distances of Venus, Mars, Jupiter, and Saturn. [2, but probably not correct 3] Appendix by Lax on correcting a lunar for oblateness of the Earth. 
1833: French almanac "Connaissance des Temps" begins publishing lunar distances of Venus, Mars, Jupiter, and Saturn. 
1834: Major revision of NA&AE. The Nautical Almanac Office of the Admiralty is now the publisher (Board of Longitude having been disbanded in 1828). All ephemerides in mean time instead of apparent time, except the noon position of the Sun which is listed both for mean time and apparent time. Planet distances and "PL difference" added to lunars tables. Substantially larger book. Many tables of interest to astronomers rather than seagoing navigators from this date. [2,3]
1855: Spanish Nautical Almanac name simplified to "Almanaque Nautico". 
1855: First year of "The American Ephemeris & Nautical Almanac", hereafter AmE&NA. Publication began at Cambridge, Massachusetts in 1852 with data for 1855. Appendix by Chauvenet this year: Chauvenet's tables for correcting lunar distances.  American commercial editions of the NA&AE cease soon after.
1857: Appendix to AmE&NA by Chauvenet: Chauvenet's tables for correcting lunar distances (same as 1855). Appendix by Chauvenet: Improved method of finding the error and rate of a chronometer by equal altitudes.
1858: (possibly 1855 but probably this date) Part One of the AmE&NA, the nautical section, published separately as the soft-bound "Almanac for the Use of Navigators" or sometimes "Astronomical Ephemeris for the Use of Navigators" known generally as the "American Nautical Almanac" and renamed as such in 1882, hereafter AmNA. Until 1916, the AmNA is merely an extract of the AmE&NA. 
1874: Appendix to AmE&NA by Coffin: Tables for finding the latitude of a place by altitudes of Polaris. 
1877: First edition of Brown's Nautical Almanac & Tide Tables. Included lunar distance tables for Sun-Moon lunars only. Failed to include Moon HP required to make these tables useful. (Dunraven mentioned these tables c.1907 in his navigation treatise).
1882: The title of the American "Almanac for the Use of Navigators" is changed to the "American Nautical Almanac", AmNA. The content is still simply an extract of the AmE&NA.
1889: Beginning of publication of the French "Ephemerides Nautiques" [possibly without this title], designed for mariners, alongside the astronomically-oriented "Connaissance des Temps". 
1896: First part of the British "Nautical Almanac" (NA&AE) published separately for mariners. At first its title was simply the "Nautical Almanac & Astronomical Ephemeris, Part I" (see 1914). The remainder of the NA&AE is primarily of interest to astronomers.
1905: Lunar distance tables no longer published in the French almanac "Connaissance des Temps".
Lunar distance tables no longer included in the British NA&AE. An appendix
explained how to calculate predicted lunar distances and clear them using a
variant of Airy's method until 1919 (and through
1911: Beginning of close international cooperation among the almanac offices of the US, Britain, France, Germany, and Spain. 
1912: Separate publication of the Spanish "Extracto del Almanaque Nautico" for mariners. Like its counterparts in Britain and the US, the main publication, the "Almanaque Nautico", included data of interest primarily to astronomers. 
1912: Major re-design of the AmE&NA (not 1916 as reported elsewhere). Lunar distance tables no longer included in the AmE&NA (and the AmNA extract as well). An appendix in the AmNA, updated annually, explained how to calculate geocentric lunar distances, if desired, until 1933 (same appendix in AmE&NA was printed up to and including the volume for 1935, also updated annually). Unlike the appendix in the British almanacs, this appendix offered no advice on clearing a distance. 
1914: Mariners' extract of British "Nautical Almanac & Astronomical Ephemeris" renamed "The Nautical Almanac Abridged for the Use of Seamen" and known generally as the 'Abridged Nautical Almanac' (this was the title on the book's spine), hereafter AbNA.
1916: From this date, following the earlier revision of the AmE&NA in 1912, the AmNA is no longer simply an extract from the AmE&NA but a separately prepared volume. A list of 55 numbered navigational stars, the "selected stars", appears for the first time and is maintained with little modification until 1950. The star numbers are not considered permanent and stars shift on the list due to additions and also precession.
1920: (or 1924? definitely before 1926 ) Lunar distances dropped from the German nautical almanac "Nautisches Jahrbuch".
1925: From January 1, 1925, the "astronomical day" is dropped from the American and British almanacs (apparently the French made this switch about 1918). Days in the almanacs are now civil days. Appendix on calculating and reducing lunar distances finally deleted from AbNA. [ ,3]
1929: Major revision of the British AbNA (the mariners' almanac).
1931: Major revision of the British NA&AE (the astronomers' almanac). For this year there is a large explanatory section detailing the astronomical calculations, similar in many ways to the later 'Explanatory Supplement'. [2,3]
1932: GHA tables for the Moon included in AmNA.
1934: Significant revision of the AmNA. GHA now included in parallel with RA for all objects (not just the Moon as in previous two years). This change followed the experimental publication of the "Air Almanac" with extensive GHA tables a year earlier. The appendix on calculating lunar distances is no longer included.
1936: Revision of the AmE&NA. Appendix on calculating geocentric lunar distances is finally dropped (two years after AmNA).
1941: Beginning of regular publication of US "Air Almanac". Other countries began publishing almanacs for use by aviators in the late 1930s.
1937: For this year only, there is a table of Moon-Sun lunar distances for every 12 hours of Greenwich Time in the AmE&NA.
1950: Major revisions to the AmNA. The AmNA now resembles the modern almanac in tabular format and other features (cardboard orange cover, previous year had tan paper cover). A list of 57 numbered navigational stars is included on the daily pages (the names are tabulated on the inside cover but only the numbers are displayed in the daily pages). The two new navigational stars added to the former list of 55 are El Nath and Alkaid. [6,3]
1951: The Spanish almanac "extracto" becomes the "Almanaque Nautico para uso de los navegantes". 
1952: The British "Nautical Almanac Abridged for the Use of Seamen" (AbNA) was revised and renamed "The Abridged Nautical Almanac", the name by which it had been known colloquially for decades. The AbNA now tabulates GHA instead of Right Ascenion, a change which had been made some eighteen years earlier in the AmNA. [7,3]
1953: The list of 57 navigational stars in the AmNA and the AbNA (the list of "selected stars") reaches its final modern form. The earlier list included a half-dozen different stars. Polaris and Dschubba, for example, previously on the AmNA list are replaced by Menkar and Zubenelgenubi. A few other star names have been added to replace stars previously given by Bayer designations only (Epsilon Argus becomes Avior). And a small number of star names have been changed to match British prefered usage (Deneb Kaitos becomes Diphda). The star numbers are now considered permanent and will not be renumbered as precession changes their order by right ascension. [8,9,3]
1958: "The Abridged Nautical Almanac" is unified with "The American Nautical Almanac". Content is identical starting with the volume for 1958 though the titles are distinct for two more years. The style, layout, and content of the almanacs are essentially unchanged from 1958 onward. The majority of the features of the new unified almanac are derived from the American almanac. The British almanac continues with different bindings and covers and also includes advertisements.
1960: The title of the jointly published American and British nautical almanacs is changed to "The Nautical Almanac" (joint publication of identical content beginning with the volume for the year 1958, first volume with the common title for 1960). AbNA+AmNA-->NA. Meanwhile, on the astronomical side of the fence, the British NA&AE is at last renamed "The Astronomical Ephemeris" which is now identical in content to the AmE&NA. [6,7,3]
1961: The Spanish "Almanaque Nautico" which had evolved into a publication primarily used by astronomers was renamed the "Efemerides Astronomicas" paralleling changes in the American and British publications. A year later, the Spanish "Almanaque Nautico para uso de los navegantes" recovers the more sensible and shorter name "Almanaque Nautico" paralleling the American/British "Nautical Almanac". 
1967: Bicentennial edition of "The Nautical Almanac". The British printing, but not the otherwise identical American printing, included a brief history of the almanac, extracted later in "Man Is Not Lost". [7,3]
1981: The titles of the AmE&NA and the British "Astronomical Ephemeris", already identical in content, are changed to "The Astronomical Almanac". [6,3]
1983: "The Nautical Almanac: Yachtsman's Edition" is licensed for sale by independent publishers: Paradise Cay Yacht Sales (at least from this year, possibly earlier). Identical in primary content to the NA but with occasional brief articles and additional tables and sight reduction forms. Like the official British printing of the Nautical Almanac (and unlike the American printing), this privately published edition has a blue paperback binding and includes advertisements. 
1989: Sight reduction tables added to "The Nautical Almanac". [6,3]
1993: "The Nautical Almanac: Yachtsman's Edition" is renamed "The Nautical Almanac: Commercial Edition", licensed for sale by Paradise Cay Publications.
minor revision, irrelevant to practical navigation, is made to the refraction
tables of the NA which had been fixed and unchanging for nearly fifty years.
 The Explanatory Supplement.
 Confirmed by me, Frank Reed, by direct inspection.
 Marguet, "Histoire Generale de la Navigation", 1931.
 "Man Is Not Lost" by D.H. Sadler.
 Hydrographic Office, "American Practical Navigator" (Bowditch), 1962.
 Confirmed by Herbert Prinz by direct inspection.
 Simon Newcomb, "Side-lights of Astronomy" 1879.
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To unsubscribe, email NavListemail@example.com --
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To unsubscribe, email NavListfirstname.lastname@example.org