522 TRANS. ST. LOUIS ACAD. SCIENCE. 



south of Worms. As, however, the 13 lay not 6° but 5 east of 

 the sun, it is evident that the obscuration of the sun must have 

 been smaller in Worms, probably total in Strasburg. The cor- 

 rection of the time (-|-46m.) and the parallax alter this result a 

 little. According to Pingre, the central shadow of the moon de- 

 scribed the following curve : 43 , 45 , 49°_37°. 



No. 13. English and Holland chroniclers (Calvisius's Opus 

 Chr.) narrate that a.d. 1133, Aug. 2d, about noon, a total eclipse 

 of the sun happened both in London and Bruegge. Hansen's 

 Tables state that the central line of the shadow traversed Nor- 

 thumberland, because the longitude of the 13 (S° E. of the sun) 

 was too great. Pingre's curve is 55 , 50 , 13 . Since the 13, 

 however, lay about 36' nearer to the sun (p. 429), its total obscu- 

 ration was nearer Bruegge by many miles. In recalculating this 

 eclipse, the correction of the place of the apogee (-5') is to be 

 taken into account. 



Nos. 14, 15, and 16, finally, refer to certain days of a.d. 1433, 

 1598, and 1652 ; and the magnitudes of these solar eclipses, com- 

 puted by Hind, remain nearly the same. For my approximate 

 corrections of the secular accelerations of the moon, her Nodes 

 and Apsides, are not very important for epochs of such modern 

 dates. Besides, the localities of the related solar eclipses, some- 

 times copied in the chronicles of that time, are not always accu- 

 rate and reliable. 



Summarily, the objection that the present theory of the moon, 

 especially Hansen's Tables, has been confirmed by Hind's 

 Ancient Eclipses, misses the mark ; for, in the first place, the ma- 

 jority of the computed eclipses are irreconcilable with history, 

 fixed by mathematical facts. Prof. Airy, moreover, being at pres- 

 ent about to establish, as he himself says, another theory of the 

 moon's motions, I do not doubt that Prof. Hind is now equally 

 convinced that the usual theory concerning the accelerations of 

 the moon, her Nodes and Apsides, deduced from the eclipses in 

 the Almagest, is no longer tenable in face of the really observed 

 eclipses of the Greeks and Romans ; otherwise, Prof. Hind would 

 certainly have disavowed, either publicly or privately, the con- 

 tents of my missive of Feb. 11, 1S73 ; for, amicus Plato, tnagis 

 arnica Veritas. 



5. The most important objection is, no doubt, the following : — 



