Box 17, Folder 9: Meteorology (Milwaukee) 1859-1871

[Weather Data and Graph].

Milwaukee Aug 7. 1857

My brother in law [lamestone?] arrived from New York to dry and brought me a barometer No 378 by J. Green, with the following note from him.

"Barometer No 378 agrees exact with the Smithsonian Standard-capillary action is allowed for in the final adjustment-no correction is wanted but for temperature in reducing to 32 deg. New York July 10. 1831 J. Green."

Mr Stone brought also a siphow barometer No 400 for measuring altitudes. They are furnished me by Smith'n Institute.

Observations to Compare the two barometers.

[Data Table].

Mean temperature of August 1866 is 63.93 which is only 2 hundreths of a degree above the lowest (1856) known here for 23 years; and [65] 4.18 lower than the mean Rain 3.95 which is 1/3 more than the average of the past 24 years; during which times the quantity was exceeded only 3 times (1848, 1850, & 1865) Max (1850) 9.03 min (1859) 0.27 Evaporation 4.20/31 Mean evap of 5 years being .0214 more than in 1866 [calculations].

[1865 Milwaukee calculations].

7(2) June 1866

[Weather data].

Taking 9 days when the air was most damp-the difference of night & day temperature was 18 deg-Rel Hum .900

Taking 9 days, when the are was most dry-the difference was 29 deg.-Rel. Hum. .560

Showing that agneous vapor prevents the radiation of heat in the night, keeps off frost &c &c.