766 



which acts, not by its mass (by attraction), but 

 as a calorifying orb. If the solar rays, in mo- 

 difying the temperature, produce periodical 

 changes in the atmosphere, it remains to be ex- 

 plained why the two barometric minima nearly 

 coincide with the hottest and coldest periods of 

 the day and night. 



from the mean of the quadratures. Toaldo thought he had 

 found by the mean of 40 years, and by employing a method 

 little exact, that the barometer in Italy is higher in the qua- 

 dratures than in the syzygies, in the apogee than in the pe- 

 rigee. (De la Inji. degli astri, 1781, p. 122. Lambert, Act. 

 Helv., Tom. iv, p. 123. Jaum, de Pky$., 1199, June, jx 

 270,) 



