20 COSMOS. 



tractoria) extends to the earth ; and that this force, similar to 

 that exerted by the magnet on iron, would deprive the earth 

 of its water if the former should cease to attract it. Unfor- 

 tunately this great man was induced ten years afterwards, in 

 1619, probably from deference to Galileo, who ascribed the 

 ebb and flow of the ocean to the rotation of the earth, to re- 

 nounce his correct explanation, and depict the earth in the 

 Harmonice Mundi as a living monster, whose whale-like mode 

 of breathing occasioned the rise and fall of the ocean in re- 

 curring periods of sleeping and waking, dependant on solar 

 time. When we remember the mathematical acumen that 

 pervades one of the works of Kepler, and of which Laplace has 

 already made honourable mention, 33 it is to be lamented that 

 the discoverer of the three great laws of all planetary motion 

 should not have advanced on the path whither he had been led 

 by his views on the attraction of the masses of cosmical bodies. 



Mundi, libri quinque, 1619, lib. iv. cap. 7, p. 162. The same 

 work which presents us with so many admirable views, among 

 others, with the data of the establishment of the third law (that 

 the squares of the periodic times of two planets are as the 

 cubes of their mean distances), is distorted by the wildest 

 flights of fancy on the respiration, nutrition, and heat of the 

 earth-animal, on the soul, memory (memoria animce Terra), 

 and creative imagination (anwice Telluris imaginatio) of this 

 monster. This great man was so wedded to these chimeras, 

 that he warmly contested his right of priority in the views 

 regarding the earth-animal, with the mystic author of the 

 Macrocosmos, Robert Fludd, of Oxford, who is reported to have 

 participated in the invention of the thermometer. (Harm. 

 Mundi, p. 252.) In Kepler's writings, the attraction of masses 

 is often confounded with magnetic attraction. " Corpus solis 

 esse magneticum. Virtutem, quse Planetas movet, residere 

 in corpore solis." Stella Martis, pars iii. cap. 32, 34. To 

 each planet was ascribed a magnetic axis, which constantly 

 pointed to one and the same quarter of the heavens. ( Apelt, 

 Joh. Kepler's astron. Weltansicht, 1849, s. 73. 

 33 Compare Cosmos, p. 710 (and note). 



