Elger, 1895

Elger: The Moon (1895)

(glossary entry)

Description

Thomas Gwyn Elger's The Moon: A Full Description And Map Of Its Principal Physical Features is one of the little known classics from the golden age of visual lunar observing. Because it is in the public domain, and freely available through the kind services of Project Gutenberg and Steve Ridgway (who transcribed it electronically), Chuck has chosen to use it to add a historical perspective to the descriptions of lunar features on the-Moon Wiki. Elger was a careful observer, and if nothing else it gives a good impression of what can be observed by eye, through a small telescope, from Earth. In recognition of his accomplishments, a 21-km diameter crater on the Moon's nearside is named after him.
 
 

Additional Information

• Two copies of Elger can also be viewed as a searchable on-line "flip-book" or PDF download at the Internet Archive: Copy 1 or Copy 2.

In many cases Elger's terminology differs from that in modern use. In particular, Elger wrote his book in an era when the convention for what should be regarded as east and west on the Moon was the reverse of the IAU directions used today. For the-Moon Wiki, the Easts and Wests in most of the entries from Elger have been converted to the modern IAU usage. So if a passage is marked IAU Directions it will be consistent with E being on the Crisium side of the Moon. A few older entries may be in Elger's original reversed E-W format.

Antiquated Spellings

You will also encounter a number of terms that are not in common use today. For example:

ELGER'S TERM	Modern Term
walled plain or ring plain	crater
cleft	rille

(list to be expanded...)

Also, Elger used what are now antiquated names for a number of the lunar features. Some of these have been replaced by newer names, others have been dropped.

ELGER'S SPELLING	IAU Spelling
ALPS	Montes Alpes
ANAXIMINES	Anaximenes
APENNINES	Montes Apenninus
AZOUT	Auzout
BACON	Baco
BERNOUILLI	Bernoulli
BOND, G.P	G. Bond
BOUVARD	Vallis Bouvard
BURG	Bürg
BUSCHING	Büsching
CAPE AGARUM	Promontorium Agarum
CAROLINE HERSCHEL	C. Herschel
CARPATHIANS	Montes Carpatus
CATHERINA	Catharina
CAUCASUS	Montes Caucasus
CONDAMINE	La Condamine
CRUGER	Crüger
FONTINELLE	Fontenelle
GALILEO	Galilaei
GARTNER	Gärtner
GRUITHUISEN DELTA	Mons Gruithuisen Delta
GRUITHUISEN GAMMA	Mons Gruithuisen Gamma
GUERIKE	Guericke
GUTTEMBERG	Gutenberg
HAEMUS MOUNTAINS	Montes Haemus
HARBINGER MOUNTAINS	Montes Harbinger
HEVEL	Hevelius
ISODORUS	Isidorus
J.F.W. HERSCHEL	J. Herschel
KASTNER	Kästner
LA PEYROUSE	La Pérouse
LACAILLE	La Caille
LAHIRE	Mons La Hire
LANDSBERG	Lansberg
LEGENTIL	Le Gentil
LEVERRIER	Le Verrier
LINNE	Linné
LUBIENIEZKY	Lubiniezky
MACCLURE	McClure
MADLER	Mädler
MOSTING	Mösting
MOUNT ARGAEUS	Mons Argaeus
MOUNT BRADLEY	Mons Bradley
MOUNT HADLEY	Mons Hadley
MOUNT HUYGENS	Mons Huygens
MOUNT WOLF	Mons Wolff
OTTO STRUVE	Struve
OTTO STRUVE A	reference to the crater Eddington?
PICO	Mons Pico
PINGRE	Pingré
PITON	Mons Piton
PONTECOULANT	Pontécoulant
PROMONTORY ACHERUSIA	Promontorium Archerusia
REAUMUR	Réaumur
ROMER	Römer
SCHROTER	Schröter
SOMMERING	Sömmering
STOFLER	Stöfler
TAQUET	Tacquet
TAURUS MOUNTAINS	Montes Taurus
THE ALTAI MOUNTAINS	Rupes Altai
THE HERACLIDES PROMONTORY	Promontorium Heraclides
THE LAPLACE PROMONTORY	Promontorium Laplace
THE STRAIGHT RANGE	Montes Recti
THE STRAIGHT WALL	Rupes Recta
THE TENERIFFE MOUNTAINS	Montes Teneriffe
TOBIAS MAYER	T. Mayer
VASCO DE GAMA	Vasco da Gama
W. HUMBOLDT	Humboldt
W.C. BOND	W. Bond
WALTER	Walther
WILHELM I	Wilhelm
ZUCHIUS	Zucchius

Discontinued Names

Several names Elger used do not match any currently approved name in the IAU Nomenclature. Those features, of course, still exist, they are just no longer named:

D'ALEMBERT MOUNTAINS
DORFEL MOUNTAINS
LEIBNITZ MOUNTAINS
ORIANI
PROM. AENARIUM
THE HERCYNIAN MOUNTAINS
THE HUMBOLDT MOUNTAINS
THE NORTH POLAR RANGE
THE PERCY MOUNTAINS
THE SILBERSCHLAG RANGE
THE SINUS IRIDUM HIGHLANDS
THE STAG'S-HORN MOUNTAINS

Finally, it appears that Elger did not stick strictly to the convention of referring to satellite craters with Roman letters and elevations (peaks) with Greek letters -- a practice that was used by many of his contemporaries. Although he frequently did use Greek letters in this way, his references to something like Fontinelle A may still be to a peak near Fontenelle rather than to the modern lettered crater of that name.

- JimMosher

Description: Wikipedia

wikipedia

LPOD Articles

Elger Reborn? A Quadrant of Elger Who Named that Crater? Ray Systems

Bibliography

• Full Elger text with E-W directions in modern style:
  • media:Elger_17712-converted_to_IAU_directions.txt
    

• Fielder, Gilbert. 1963. Some Lunar Studies by T. G. Elger. Sky and Telescope Vol. 15, No. 4 (May issue), pp. 248-251. article illustrated by drawings made by Elger between 1884 and 1896, with particular emphasis on his depiction of "lineaments"

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