-The 6.6456-day periodicity in VVasliinglon, D. C, temperature. 



Lower curve, the daily departures from normal temperature, Jan. . to Apr. i., 194O (see Weather liureau ^'^j'" J"^"). Tj^e (-.6456^da^^ 

 Upper curves, average temperature departures for 55 repetitions of the periodicity each year, iy40-i948. and the mean 01 tnun lor j jea . 



is indicated by short, thick, vertical lines. 



