— 
—— 
ai 
Sst 
Sy 
LA a 1s PMA pt 
j Pa Ae 
a ‘ i NV ae KE 
i [ / iS 7 2 ee Z 
a ] as = a 45 
— : 35 
Fic, 3.—The upper curves are the records of pressure in a white birch t1e™ in diameter; the continuous line covers the period 
April eas, inclusive, 1906; and the dotted lines A, B, C, D are partial records for April 14, 23, 28, 30 respectively; after April 18 
the pressure was somewhat lower than it would otherwise have been, owing to a continuous slight flow of sap from the tree; the lower 
curves are temperatures in the sun; M, midnight; N, noon. 
gtr 
ALLAZVID TYOINVLOG 
aaawaoad] 
