BOOK II. j APHORrSMR. 469 



Mars is coiisldered the warmest after the Sun, then Jupiter, then 

 Venus. The Moon and, above all, Saturn, are considered to be 

 cold. Among the fixed stars Sirius is thought the warmest, then 

 Cor Leonis or E-egulus, then the lesser Dog-star. 



16. The sun gives out more heat as it approaches towards the 

 perpendicular or zenith, which may be supposed to be the case 

 with the other planets, according to their degree of heat ; for 

 instance, that Jupiter gives out more heat when situated be- 

 neath Cancer or Leo than when he is beneath Capricorn and 

 Aquarius. 



17. It is to be supposed that the sun and other planets give 

 more heat in perigee, from their approximation to the earth, 

 than when in apogee. But if in any country the sun should be 

 both in its perigee and nearer to the perpendicular at the same 

 time, it must necessarily give out more heat than in a country 

 where it is also in perigee, but situated more obliquely; so that 

 the comparative altitude of the planets should be observed, and 

 their approach to or declination from the perpendicular in diffe- 

 rent countries. 



18. The sun and other planets are thought also to give out 

 more heat in proportion as they are nearer to the larger fixed 

 stars, as when the sun is in Leolie is nearer Cor Leonis, Cauda 

 Leonis, Spica Virginis, Sirius. and the lesser Dog-star, than 

 when he is in Cancer, where, however, he approaches nearer to 

 the perpendicular. It is probable, also, that the quarters of the 

 heavens produce a greater heat (though not perceptibly), in pro- 

 portion as they are adorned with a greater number of stars, par- 

 ticularly those of the first magnitude. 



19. On the whole, the heat of the licavenly bodies is aug- 

 mented in three ways; 1. The approacli^to the perpendicular; 

 2. Proximity or their perigee; 3. The conjunction or union of 

 stnrs. 



20. There is a very considerable difierence between the degree 

 of heat in animals, and even in the rays of the heavenly bodies 

 (as they reach us), and the heat of tiie most gentle llame, and 

 even of all ignited substances, nay liquids, or the air itself when 

 unusually heated by fire. For the flame of spirit of wine, 

 though diffused and uncollected, is yet able to set straw, linen, 

 or paper on fire, which animal heat, or that of the sun, will 

 never accomplish without a burning-glass. 



21. Tliere are, however, many degrees of strength and weak- 

 ness in flame and ignited bodies : but no diligent inquiry has 

 been made in this respect, and we must, therefore, pass it hastily 

 over. Of all flames, that of spirits of wine appears to be the 

 most gentle, except, perhaps, the Ignis Fafiius, or the flashoa 

 from the perspiration of animals. After this we should be 

 inclined to place the flanae of light and porous vegetables, Bucb 



