Blagg and Müller

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Blagg and Müller : Named Lunar Formations (1935)

(glossary entry)


This catalog and map published by Mary Blagg and Karl Müller was the first official version of the IAU nomenclature for lunar features. The work is an outgrowth of Blagg's Collated List (1913), in which she compared how each prominent lunar formation had been named on the classic maps of Neison, Schmidt and Beer & Mädler. In the present work, one of the names was adopted, and additional names were added for some features that had not been named by the three "authorities". Blagg and Müller's list remained the authoritative IAU list for about 30 years until, between 1963 and 1966, it was supplanted by the quadrant maps and catalog of the System of Lunar Craters.

Additional Information

  • The following information is gleaned from Whitaker (pp. 160-164): - Jim Mosher
    • The publication consists of a Catalogue (Volume 1) and a set of Maps (Volume 2).
    • Over 6100 formations are listed, each with its number in Blagg's Collated List, coordinates, diameter (in thousands of the lunar radius), serial number in the control networks of Franz or Saunder, and earlier names.
    • Satellite craters are indicated by capital Roman letters, elevations by lower case Greek letters, and rilles by Roman numbers (such as Triesnecker IIIr).
    • Because names are given to both the very small craters used by Franz and Saunder as well as to the large historically named features, there is an odd mid-range of unnamed features.
    • The maps were drawn in 14 sections at an original scale of 50 inches to the lunar diameter, but reduced to 36.5 inches in the publication. The center 4 sections had been drawn earlier by W. H. Wesley. The remaining 10 were added, much more sketchily, by Blagg.

  • Work on the book that ultimately resulted extended over more than 20 years. The rules Blagg used for resolving cases in which the previous authorities assigned different names to a given formation can be found in IAU Transactions II (1925). The maps had reportedly been completed by that time, but the catalog of names to be assigned to the features was still in progress.

  • From the Introduction by F. W. Dyson: "As Chairman of the Commission, I have supported M. Lamech's suggestion that the names of Blagg and Müller should be given to two lunar formations and over-ruled the objections made by Miss Blagg and Dr. Müller. I am confident that the Commission will approve of my actions." This is thus two more cases of names being given to living people, and seems to initiate the arrogant habit of members of the various IAU lunar nomenclature commissions naming craters after each other. Blagg spent decades making valuable contributions to selenography and fully deserves a crater named in her honor; but why not wait until her death as the rules required? - tychocrater Aug 9, 2007

  • In some library listings, Samuel Saunder and Julius Franz are listed as co-authors (see Bibliography below).
    • CA Wood: There is an error in the reference below. I have the catalog in my hands - only Blagg and Müller are listed as authors!
    • The reason for the additional authors seems to be that "Vol. II" (the map) has the annotation "Map of the moon, by W.H. Wesley and Mary A. Blagg, based on the fiducial measures of S.A. Saunder and J. Franz" (see Library of Congress catalog record).

  • Additional information from the introductory material:
    • Each feature in the list was assigned a catalog number, either the same as in the Collated List or interpolated by adding lower-case letters. Not all features in the Collated List were included.
    • In addition to the three authorities consulted for the Collated List (Mädler, Neison and Schmidt), Named Lunar Formations includes names found in the maps and publications of Lohrmann, Gaudibert, Elger, Fauth, Pickering, Franz, Goodacre, Krieger (as edited by König), Debes, Wilkins, Andel, Lamèch and others. Each entry indicates the first person in this list (in the order given), to use that particular name (although not necessarily for the same formation?). The authority is also sometimes listed as Riccioli, Schröter, Birt, the IAU Commission, the Collated List, Blagg, Müller, or a unique authority. For example, the name Da Vinci is attributed to Peucker. Sometimes a conflicting or un-approved name used by one the main authorities is mentioned. For example, they note that Franz used the name Olblatt for Hansen B (#13).
    • Unlike the modern IAU system, the names in Blagg and Müller, although internationally approved, were not themselves always intended to be international. For example the names of mountain ranges (and certain other features) are given in English, and it was the stated intention of the authors (p. VIII) that each astronomer would translate an English name like “Alps” into the equivalent in his or her native tongue. The catalog also includes a number of lettered craters with double letters like AA, AB, etc. for features close to one called “A”. It even encouraged astronomers to add additional designations of this sort, but with the second letter in lower-case to indicate it was an unofficial name.
    • The catalog includes the projected positions of the listed features (to the nearest one-thousandth of the lunar radius) and their diameter. The nature of the feature is also identified using the following categories:
      • Valleys
      • Rills
      • Single hills and peaks
      • Ridges, chains and plateaus
      • Maria
      • Overlapping twin craters
      • Irregular and indistinct walled plains
      • Bays, gulfs and features not fully enclosed
      • Normal walled craters
    • Letter designations were used for minor features from a variety of the classes listed above, including impact craters, "walled plains", minor "valleys" and "confluent craters". The symbol accompanying the listing has to be consulted to be sure what the letter is meant to represent.
    • Named Lunar Features included a number of lettered craters named after non-crater primary features, such as mare. The authors of the later System of Lunar Craters seem to have disapproved of this practice and re-assigned most of these to nearby craters. For example, Named Lunar Features’s Mare Crisium E was renamed to Yerkes E.

  • In addition to the resources mentioned above, something similar to the Blagg and Müller list can be viewed on-line as the index to the Lunar Topographic Maps on the LPI website. Unfortunately the names used on that map do not appear to adhere to the original nomenclature as reliably as the Index list would imply (see Bullialdus and Henry Frères). - Jim Mosher

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