62 AN ERROR IN BURGH'S LUNAR TABLES 



writings of the philosophers and historians of Greece and 

 Rome, contain evidence of a much more accurate and perfect 

 observation of natural phsenomena than had before been sus- 

 pected. It has been found that many of the objects and ope- 

 rations of nature have been described by the ancients, in such 

 a manner, that the resources of modern science may be aug- 

 mented, from the materials they have furnished, however 

 mingled with inconclusive explanation, or encumbered with 

 unfounded theory. 



An interesting example of these facts, in which even the 

 necessity of introducing a correction into the computations of 

 modern astronomy, was shown by reference to the statements 

 of two ancient historians, was communicated some years since 

 to the Royal Society. Mr. Francis Baily, one of the most 

 accomplished astronomers of the present day, whose talents, 

 time, and fortune, are entirely devoted to the advancement of 

 his favourite science, had entered into an investigation of the 

 history of the Solar Eclipse, stated by Herodotus to have been 

 predicted by Thales. In the course of this inquiry some curious 

 facts were brought to light respecting another eclipse of the 

 sun, which is recorded by Diodorus Siculus. 



It is related by Diodorus, that Agathocles, king of Sy- 

 racuse, when besieged in that city by the Carthaginian gene- 

 ral Hamilcar, undertook the bold design of invading the 

 Carthaginian territories in Africa, and thereby removing the 

 seat of war from Sicily to that continent. He accordingly em- 

 barked a numerous army, and set sail for the African coast. 

 The day after he left Syracuse, the historian relates, the fleet 

 was terrified at an eclipse of the sun ; which was so great, that, 

 in the words of Diodorus, " it seemed exactly like night, the 

 stars every where appearing." Such a degree of darkness as this 

 is never produced either by a partial or by an annular eclipse. 

 This, therefore, was evidently a total eclipse in the place 

 where it was seen by the fleet of Agathocles. Mr. Baily as- 

 certained by computation, that it happened on August 15th, 

 in the year 310 B. c. ; and he also computed its elements, or 

 the quantities necessary to be known, before its extent in diffe- 

 rent parts of the earth, and other phaenomena, could be deter- 

 mined. He found, from these elements, by a trigonometrical 

 calculation, the place where the sun rose centrally eclipsed, and 

 the path over the earth, of the centre of the moon's shadow, 

 from that spot, to the place where the sun became centrally 

 eclipsed on the meridian. By comparing the results thus ob- 

 tained, with the fact, as related by Diodorus, he found that 

 Agathocles would not, in any part of his course, (and much less 

 at the commencement of it, as stated by the historian,) come within 



