618 PROCEEDINGS OF THE AMERICAN ACADEMY. 



differences between them. An excess of temperature when the moon 

 was south was indicated by a plus sign, and a deficiency by a minus sign. 

 Dividing the year into thirteen lunations, averages of these differences 

 were obtained for each lunation with the following results : — 



These figures indicate that, when the sun is moving from south to north 

 declination, January to June, the air averages colder when the moon is 

 south than when north of the equator ; on the other hand, when the sun 

 is moving from north to south declination, July to December, the air 

 averages warmer when the moon is south. The greatest average differ- 

 ences are about o° F., and occur near the first of May and November 

 respectively, about six weeks after the equinoxes. There are other 

 periods in the reversals of phase, but to recount the numerous methods 

 by which I have tried to isolate them and to determine their length 

 would be tedious and unnecessary, as the results are as yet unde- 

 veloped. 



