Remarks on Ancient Eclipses. 1 9 



cap. 3, who produces four observations from Timocharis at cer- 

 tain years of the first Calippic period. In this period are rec- 

 koned nine hundred and forty lunations, equal to seventy-eight 

 lunar years, and four lunar months. 



These accounts of the cycles and periods of the ancients mani- 

 festly show their persevering attempts to establish a lunar theory 

 on a perpetud principle; each theory correcting the foregoing 

 by additions and subductions established on corresponding ob- 

 servations and eclipses, as indeed the experience of every suc- 

 ceeding age bas proved in the same attempt. 



Witli respect to the justness of the Chaldean tlieory, and how 

 far the same is, or is not supported bv modern observations, I 

 shall not presume to enlarge, but refer the reader to Mr. Fergu- 

 son's explanations on the subject, chap, xviii. art. o2(), and 

 especially to a Dissertation on Eclipses quoted by this author, on 

 the returns of eclipses according to the saros, wherein, among 

 the rest, the great eclipse of the sun expected to happen in the 

 month of September of this current year, is computed from four 

 Chaldean periods, concerning which eclipse, and for the satisfac- 

 tion of such as have not at hand Mr. Ferguson's book, I shall 

 take the following extract, p. 252. "In 1820, August 26th 

 (?. e. old style, or September 7, N. S.) betwixt one and two, 

 there will be another great eclipse at London, about ten digits ; 

 but happening so near the equinox, the centre will leave every 

 part of Britain to the west, and enter Germany at Embden, 

 passing by Venice, Naples, Grand Cairo, and set in the Gulf of 

 Bassora near that city. It will be no more visible again till 

 1S74, when five digits will be oI)scured, the centre being uow 

 about to leave the earth on September 2Sth. 



*' In LS92 the sun will go down eclipsed at London; and again, 

 in 192s, the passage of the centre will be in the expansion, 

 though there will be two digits eclipsed at London in October 

 the 31st of that year ; and al)out the year 2090, the whole pe- 

 numbra will be worn off; whence no more returns of this eclipse 

 can happen till after a revolution often thousand years." 



But to return : the cycle of nineteen years was found by ex- 

 perience to surpass every other in utility, and most convenient 

 for its adaptation with the .lulian calendar, insomuch that it was 

 early adopted in tbe Christian church, and its characters marked 

 in gold to show its distinguished importance in the regulation of 

 the festival of Easter, and has ever since retained the name of 

 the Golden Number. The ecclesiastical full moons were thought 

 unalterably fixed by this cycle until the council of Nice, A.D.325, 

 discovered and corrected the errors of the sun's and moon's place 

 in the calendar, and restored the equinoxes to their true seasons. 



The solar reckoning being however imperfect, and the ([uan- 

 C 2 tity 



