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Re: Early lunars
From: John Huth
Date: 2010 Mar 20, 11:05 -0400
From: John Huth
Date: 2010 Mar 20, 11:05 -0400
Gerard of Cremona is quoted in Wright as:
"Luna existente in medio coeli si oequaveris eam per tabulas alicuius regionis: scies longitudinem inter regiones per differentiam locorum lunae: et no oportebit te expectare eclipsim."
Something like " When the moon is on the meridian, if you compare her position with that given in the lunar tables for some other locality, you may determine the difference in longitude between the place where you are and that for which the lunar tables were constructed by noting by noting the differences in the position of the moon as actually observed and recorded in the tables. It will not be necessary to wait for an eclipse."
But this is a quotation of Gerard in a text from 1478. Wright's translation, not mine.
On Sat, Mar 20, 2010 at 10:47 AM, Wolfgang Köberer <koeberer@navigationsgeschichte.de> wrote:
According to Maddison ("Medieval scientific instruments and the development
of navigational instruments in the XVth and XVIth centuries", 30) the
nocturnal was first described by Ramón Llull by the end of the XIIIth
century, but this is based on an edition of 1721 and I would not place too
much faith in it.
Hester Higton ("Sundials at Greenwich", 387) also states that nocturnals
were in use "by at least the tenth century"; she does not give any
reference, though.
Finally Günther Oestmann has written an article in the SIS-Bulletin (No. 69,
5 - 9) on the history of the nocturnal and says that there must have been
forerunners of the instrument that early and that - in contrast to the
astrolabe - manuscripts on this type of instrument are rare; only 18
manuscripts describing the use and manufacture from the 15th and 16th
century are known to him.
Wolfgang