163 



detach itself from the horizon. This limb was 

 not visible till 4* 56' 56". The disk of the sun, 

 much flattened, was well defined ; during the 

 ascent, there was neither double image nor 

 lengthening of the lower part. The duration * 

 of the sun's rising being triple that which we 

 might have expected in this latitude, we must 

 suppose, that a fog bank, very uniformly ex- 

 tended, concealed the true horizon, and followed 

 the sun in it's ascent. Notwithstanding the li- 

 bration of the stars f which we had observed 

 toward the east, we could not attribute the 

 slowness of the rising to an extraordinary re- 

 fraction of the rays occasioned by the horizon of 

 the sea ; for it is precisely at the rising of the 

 sun, as Le Gentil daily observed at Pondicherry, 

 and as I have several times remarked at Cu- 

 mana, that the horizon sinks, on account of 



* The apparent duration was 8' Y instead of 2' 4F. 

 Though my journals contain near eighty observations of the 

 rising and setting of the sun, made either during the voy- 

 age, or on the coasts, I have never perceived any sensible 

 retardation. 



+ A celebrated astronomer, Baron Zach, (Mon. Corves- 

 1800, p. 396) has compared this phenomenon of an apparent 

 libration of the stars to that described in the Georgics (lib. i, 

 v. 365). But this passage relates only to the falling stars, 

 which the ancients, as well as our mariners, considered as a 

 prognostic of wind. The Latin poet appears to have imitated 

 the verses of Aratus. (Diosem. v. 926, edit. Buhle, i, p. 206. 

 Lucret. ii, v. 143.) 



M 2 



