270 COSMOS. 



not the place to discuss the probability or improbability 39 of 

 such an hypothesis. Praise is, however, due to the eminently 

 active director of the Observatory at Dorpat, for having by 

 his diligent labours determined the positions and proper 

 motions of more than 800 stars, and at the same time excited 

 investigations which, if they do not lead to the satisfactory 

 solution of the great problem itself, are nevertheless calcu- 

 lated to throw light on kindred questions of physical as- 

 tronomy. 



sun in 8' 18"-2, would in that case take 500 years to pass 

 from Alcyone to the earth. The fancy of the Greeks delighted 

 itself in wild visions of the height of falls. In Hesiod's 

 Theogonia, v. 722-725, it is said, speaking of the fall of the 

 Titans into Tartarus : " If a brazen anvil were to fall from 

 heaven nine days and nine nights long, it would reach the earth 

 on the tenth." This descent of the anvil in 777600 seconds 

 of time gives an equivalent in distance of 309424 geographical 

 miles, (allowance being made, according to Galle's calcula- 

 tion, for the considerable diminution in the force of attrac- 

 tion at planetary distances,) therefore 1J times the distance 

 of the moon from the earth. But, according to the Iliad, i. 

 v. 592, Hephaestus fell down to Lemnos in one day, " when 

 but a little breath was still in him." The length of the chain 

 hanging down from Olympus to the earth, by which all the 

 gods were challenged to try and pull down Jupiter (Iliad, viii. 

 v. 18), is not given. The image is not intended to convey 

 an idea of the height of heaven, but of Jupiter's strength and 

 omnipotence. 



39 Compare the doubts of Peters, in Schum. Astr. Nachr., 

 1849, s. 661, and Sir John Herschel, in the Outl. of Astr., 

 p. 589 : " In the present defective state of our know- 

 ledge respecting the proper motion of the smaller stars, we 

 cannot but regard all attempts of the kind as to a certain ex- 

 tent premature, though by no means to be discouraged as 

 forerunners of something more decisive." 



