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Re: Lunar eclipse report
From: Alexandre Eremenko
Date: 2004 Nov 1, 09:45 -0500
From: Alexandre Eremenko
Date: 2004 Nov 1, 09:45 -0500
Dear Herbert, Thank you for your interesting information. If Ptolemy and Brahe did not use water clock, then what did they use for the timing? > Ptolemy, on the use of water clocks in antiquity > (Almagest, V 14, > Translation by Toomer, p. 252): "Of the various methods used to solve > the latter [i.e. the timing] problem, > we have rejected those claiming to > measure the luminaries by measuring [the flow of] water [...], > since > such methods cannot provide an accurate result > for the matter in hand." > Tycho Brahe picked up the idea, replacing the water by mercury. > (Progymnasmatum Prima Pars, > Opera Omnia, Tomus II, ed. Dreyer, pp157ff). > He makes no quantitative statements about accuracy. > Nothing must have > come of it, otherwise we would find a description of such > a clock in his > Astronomiae instauratae mechanica. If you want to blame me of an > argumentum ex silentio, I shall take it in stride. Alex.