TRANSACTIONS OF THE SECTIONS. 23 



tte recoi-d ; and it is admitted that even 12" would be too great for these l-equire-" 

 inents, unless the motion of the node were altered also. This, eclipse ought •.there- 

 fore, the author maintained, to be put out of the account. Whatever weiglit it 

 had was, he said, on his side of the balance. It was the same vsdth the eclipse of 

 Thales ( — 584, May 28). Of this there were two records, real or supposed. There 

 is one preserved by Theon, which certainly applied to it ; and this is consistent 

 vriith, if it do not render necessaiy, the supposition that the acceleration is overrated 

 by Hansen. The other is the statement of Herodotus, that the eclipse which 

 terminated the Lydian war was that which was predicted by Thales ; in which case 

 the eclipse must have been total iu the eastern part of Asia Minor ; and this it could 

 not be if the acceleration were only 9". The author objected to this second record, 

 and charged the Astronomer Royal with arguing in a vicioas circle in respect to 

 it. He inferred that the acceleration was so great as he makes it, because this is 

 necessary to make the eclipse satisfy the statements of Herodotus ; while in defiance 

 of authentic chronology he makes the Lydian war to have terminated in 585 B.C., 

 because the limar tables, assuming the acceleration to be thus great, give a track 

 of the shadow which would satisfy the condition of the eclipse which terminated 

 the war. Dr. Hincks, on the contraiy, maintained that if the acceleration were only 

 about 9", either the eclipse of 610 B.C. or that of 603 B.C. might be made to satisfy 

 the requirements of the eclipse which terminated the Lydian war ; the motion of 

 the node being suitably altered to a very moderate extent. The record of Theon 

 respecting the eclipse of 585 B.C. is that Thales predicted that an eclipse of the 

 sun would take place, and that accordingly there was an eclipse at the Hellespont. 

 The author inferred from this that the eclipse was not visible ia Greece, or at 

 Miletus or Sardis ; but that the shadow entered the north- western parts of Asia 

 Minor a little before simset, and left the earth before it reached the middle of the 

 peninsula. This would be in accordance with his views as to the quantity of the 

 acceleration. The third of the Astronomer Royal's eclipses is the so-called eclipse 

 of Larissa ( — 556, May 19). He assumes that a cloud which was said to have 

 obscured the sun when this city was taken by the Persians, was in fact the moon 

 eclipsing him. The date of the transaction is not mentioned, nor the name of the 

 king of Persia who took the city. The Astronomer Royal has put together a 

 number of arbitrary hypotheses, all of which are required to be true ia order that 

 his conclusion should stand. The oiAyfact to which he appeals is that if Hansen's 

 tables were perfectly correct, the centre of the moon's shadow, which was very 

 fiarrow, would in that eclipse pass over Laiissa. If, however, the tables were 

 perfectly coiTect, as he admits himself, the eclipse of Agathocles would not have 

 (jeen total in any possible position of his fleet. He is therefore obliged to 

 suppose that the tables required to be corrected both as to the acceleration, which 

 must be increased 0"-8, and as to the motion of the node ; and that in the eclipse 

 of Larissa these two corrections exactly neutralized one another ! The author of 

 the paper considered this to be almost infinitely improbable, the breadth of the 

 shadow being so small as it was. The remaining eclipse of the Astronomer Royal 

 was the so-called eclipse of Stiklastad. On the 31st of August, 1030, being Monday^ 

 there was a total eclipse of the sun in Norway ; and Professor Hansteen pretends 

 that this eclipse caused the darkness which is said to have been observed when 

 the saint-king Olaf was killed in the battle of Stiklastad. But the chronicler 

 expressly states that this battle took place on Wednesday, the 29th of July, thirty- 

 three days before the eclipse. The week-day is particularly noticed, as well as the 

 month-date; and moreover it appears from the same chronicle that the eclipse 

 in the Orkney Islands, which took place on the 6th of August, 1263, was after the 

 day observed as St. Olaf's day, which was the day of the battle in which he was 

 killed. From this it is quite manifest that this eclipse is a figment of the Danish 

 Professor, and that no weight whatever should be allowed to any evidence that it 

 is supposed to furnish. 



Having disposed of these four solar eclipses, not one of which, as the author 

 contended, offers any reliable evidence that the moon's acceleration exceeded 9", 

 he proceeded to consider some lunar eclipses, observed at Babylon, the records of 

 which were preserved by Ptolemy. The Astronomer Royal had not taken these 

 into account ; but the author maintained that the true quantity of the acceleration 

 could be computed from them vtdth much greater accuracy than from the records 



