MOTES. cxliii 



been described by Pingre, viz. those of 1500, 1505, 1506, 1512, 1514, 1516, 

 1518, 1521, 1522, and 1530; as well as the comets of 1531, 1532, 1533, 

 1556, 1558, 1569, 1577, 1580, 1582, 1585, 1590, 1593, and 1596. 



(^) p. 399. This is the "malignant comet" which was supposed to an- 

 nounce (or occasion), in storm and shipwreck, the death of the celebrated 

 Portuguese discoverer, Bartholomew Diaz, when he sailed wi;h Cabral from 

 Brazil to the Cape of Good Hope. Humboldt, Examen crit. de 1'Hist. de la 

 Geogr. T. i. p. 296, and T. v. p. 80 (Sousa, Asia Portug. T. i. P. i. cap. 5, 

 p. 45). 



( W1 ) p. 399. Laugier, in the Connaissance des Temps pour 1'an 1846, 

 p. 99. Compare also Edouard Biot, Recherches sur les Ancieunes Appari- 

 tions Chinoises de la Comete de Halley anterieures a 1'Annee 1378, work 

 before cited, p. 7084. 



( 652 ) p. 399. On the comet discovered by Galle in March 1840, see 

 Schumacher's Astr. Nachr. Bd. 17, S. 188. 



( 653 ) p. 399. See my Vues des Cordilleres (ed. in-folio), PI. Iv. fig. 8, 

 p. 281 282. The Mexicans had also a very correct view of the cause of a 

 solar eclipse. The same Mexican manuscript, executed at least a quarter of a 

 century before the arrival of the Spaniards, represents the Sun as almost 

 covered by the disk of the Moon, and shews the stars visible at the same time, 



( 654 ) p. 400. This origin of the tail from the front part of the head of the 

 comet which engaged so much of Bessel's attention, is in accordance with the 

 view already taken by Newton and by Winthrop. (Compare Newton, Princip. 

 p. 511 ; and Phil. Trans. Vol. Ivii. for the year 1767, p. 140, fig. 5.) Newton 

 thought that the tail was developed in greatest strength and length when 

 near to the Sun, because the celestial air (that which with Encke we call the 

 " resisting medium") is there most dense, and the " particulse candae," being 

 strongly heated, ascend most easily, being upborne by the denser celestial 

 air. Winthrop thought that the principal effect does not take place until a 

 little after the perihelion, because, according to the law established by 

 Newton (Princip. p. 424 and 466), maxima are always in arrear (as iu 

 periodical changes of temperature, as well as in the tides of the sea). 



t 653 ) p. 400. Arago, in the Anuuaire for 1844, p. 395. The observa- 

 tion was made by the younger Amici. 



( 666 ) p. 400. On the comet of 1843, which in the month of March of that 

 year shone out with a lustre unexampled in the North of Europe, and which 

 approached nearer to the Sun than any other observed and calculated comet, 

 see Sir John HerscheFs Outlines of Astronomy, 589 597; and Peirce 



