NOVUM ORGANUM 139 



14. The heat of the heavenly bodies, even in the warmest 

 climates and seasons, never reaches such a pitch as to light 

 or burn the driest wood or straw, or even tinder without 

 the aid of burning-glasses. It can, however, raise vapor 

 from moist substances. 



15. Astronomers tell us that some stars are hotter than 

 others. Mars is considered the warmest after the Sun, then 

 Jupiter, then Yenus. The Moon and, above all, Saturn, 

 are considered to be cold. Among the fixed stars Sirius 

 is thought the warmest, then Cor Leonis or Regulus, then 

 the lesser Dog-star. 



16. The sun gives out more heat as it approaches toward 

 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 beneath 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 different 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 Leo he 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, 



