Not the least interesting feature of the records are the data 

 concerning temperatures during the winter niontlis when vege- 

 tation is supposed!}' in a resting condition. The first genei-al 

 drop occurs earlv in Sei)tember when the temperature is h)w- 

 ered 5° to G° C. '(0° to 10° F. ). A month later a second gen- 

 eral downward movement was noticeable, in October, whicli 

 reached the freezing point on October 22. After a few days 



^ 





a\rik^:\uunnnw 



Fkj. 3. — Tnicings of tlicniio^'rapliic curves of tlie aii', ami of the soil 

 at a depth of 30 centiineters (1 foot), Juno 3()-August 4, li)02. The maxi- 

 mum temperatures of the year are iucluded. Centigrade scale. The 

 temperature of the air is sliown liy the uppermost of each pair of tracings. 



fluctuation about this point a decrease began which reached 

 the annual minimum of — i^° 0. (2(5.4:° F.) on December 10. 

 A heavy snowfall was followed b}' a steady rise which carried 

 the temperature above the freezing point on December 15. 

 The total jDeriod during which temi^eratures below the freez- 



