2S 



20* 



10' 



^i'A'CTif J<? DEC. S lO IS 20 2S JO 



WASHlNGTOiM 

 Fig. 41a. — Period of 6.6485 days in Washington, D.C., weather. 



25 NO^. 30 Dec. S 



/a /s 20 



NEW YORK 



Fig. 41b.— Period of 6.6485 days in New York City weather. 

 50 



