Plate XVIII. 
Trans. Wis. Acad., Vol. XI. 
Depth. April. 
May. 
15 ° 16 ° 
Aug. 
25 ° 
Oct. Depth. 
15 ° 
April. May. June. July. Aug. Sept. Oct. 
Fig. 4.—Summer temperatures, 1896. See p. 296. 
