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June 1. ISS^ to May 13. 1835. Communicated by Dr ?♦!. Gairdnsr. 



Dew-point is ascertained by means of an instrument on the principle ot Pouillet's, but using 

 a thin transparent glass capsule, which, upon trial, 1 have found more delicate than a po- 

 lished metallic surface. 



Fort Vancouver is about 60 feet above the level of the sea. 



