British Association(glossary entry)
This term is used in early selenographic works to refer to the British Association for the Advancement of Science or BA (not to be confused with the BAA) which in the mid-1800's established a series of Lunar Committees for various purposes.
- The most famous of the BA Lunar Committees is probably the one appointed in 1864 and tasked with a comprehensive map and catalog of standard nomenclature for the Moon. Neison, 1876 describes their activities starting on page 107.
- The original appointment of this Committee, tasked with preparing forms for registering craters and visible objects, and constructing an outline map at four times the scale of Beer and Mädler is described on page xlviii of the Report of the British Association 1864 Meeting. The members were J. Glaisher (Chairman), Lord Rosse, Rev. T. W. Webb, W. R. Birt (Secretary), Dr. Lee, J. N. Lockyer, W. R. Dawes, Sir J. Herschel, Bart., Professor Phillips, J. Nasmyth, Warren De la Rue and H. S. Ellis.
- The Committee (whose most active participant appears to have been Birt) proposed preparing an outline map at a scale of 200 inches to the lunar diameter, and detailed maps at a half that size (100" diameter). In addition to adopting the four-quadrant system introduced by Beer and Mädler, They further proposed dividing the Moon into regions 5° wide in longitude and latitude. These small map map regions were designated by an odd combination of Roman and Greek letters and numerals, and each observable feature within the smallest zone was assigned what was supposed to be a unique (and permanent) number. Most of the features numbered in this way also appear to have had names, similar in style to the modern ones (primary names with satellite features designated by letters).
- The BA Lunar Committee sub-divided each of Beer and Mädler's four quadrants (indicated by upper case Roman numerals) into 16 sections designated by upper case Roman letters. For Quadrant I, these look as follows:
- Each of these lettered areas is 25° wide in longitude and latitude, with the outermost vertex of the square labeled A touching the Moon's center, and P farthest from it. Since the areas are square in degree measure, their sizes as seen in projection vary. Those at the edges extend beyond 90°, an intentional feature for plotting features seen (at favorable libration) beyond the normal limb. The pattern for Quadrants II-IV are the same, but rotated and inverted (as necessary) so that the magnitude of longitude and latitude increases (in 25° steps) in going from A to P.
- Each 25°x25° Roman-lettered square was further subdivided into 25 5°x5° squares designated, in a similar fashion, by the 25 lower case Greek letters.
- The intent of the project was to publish a map and catalog for each of these 5°x5° squares. The number of map/catalog sheets required would have been 4x16x25 = 1600.
- It is widely reported that only two of the 1600 sections were ever completed, but Neison, 1876 mentions two sections being issued in 1866 and a third in 1868, at which point the BA declined to re-appoint the Committee due to the impracticality of their undertaking. See Whitaker (which includes a reproduction of one of the sections) starting on page 135. According to Whitaker, the BA's main influence on nomenclature was through Birt's outline map of the visible disk, with names.
- According to Neison (1880), the British Association's nomenclature consisted of the 427 names from Beer and Mädler plus 91 additions. In his own book (developed independent of the BA efforts) Neison omitted or rejected 24 of the new names. These are listed in his 1880 paper. As mentioned by Neison, 86 of the BA names are also listed as catalog entries 405-490 in the 1873 3rd Edition of Webb's Celestial Objects for Common Telescopes.
- Later Committees seem to have explored a system of dividing the Moon into polygonal "Districts" around each primary named feature. Each secondary feature within the polygon was expected to follow the name of the primary, after which the District was named. See, for example, the outline diagram of the District of Picard in which both the BA designations and common names of each object is listed in the accompanying catalog. The outlines of the districts around Hyginus are shown here. The work of the BA Lunar Committees may, in this case, be confused with the similar efforts of Committees of the Selenographical Society (of which Birt was Secretary, and Neison editor of the Journal in which these District maps were published).
- Anon. 1872. The British Association and Lunar Work. Astronomical register, vol. 10, pp. 205-207.
- The Reports of the British Association from the relevant years are available on the Internet Archive: