10 E. Loomis— Contributions to Meteorology. 
120° 5’, and is elevated 7,017 feet above the sea. At these 
stations meteorological observations were made three times a 
day for three years in connection with the Geological ae 
of California under the direction of Prof. Josiah D. Whitney 
The monthly means of the barometer and thermometer were 
published by Prof. Whitney in a volume entitled ‘ Contribu- 
tions to Barometric Hypsometry,” and the original observations 
have been placed in my hands by Prof. Whitney. For the 
purpose of comparing these observations, a table was prepared 
showing for each day of the three years—1l. the height of the 
barometer at Summit according to the mean of the three daily 
observations reduced to 32° F.; 2. the mean of the tempera- 
tures at Summit and Sacramento for each day, according to the 
three daily observations; and 3. the difference between the 
mean barometric heights at Summit and Sacramento for each 
day. ese results were then divided into classes according to 
temperature in such a manner that each class should include a 
range of five degrees, and the middle ts aephagelae should be 
some multiple of five. The observations of each of these 
classes were then compared in respect to Sieompitie pressure 
at Summit, so that all those observations which were made at 
computed from the formula ut Laplace, the latter shear the — 
reduction deduced from the actual observations. 
n examination of this table shows that the reduction of the : 
mula; and tor all earmabisateh above 40° the Sbeeryasice : 
show a decrease in the amount of me heer fully equal to — 
the increase computed from the formula. is result shows — 
that while the formula of Laplace gives the reduction to sea- 
level with tolerable accuracy when the atmosphere is nearly in 
a condition of equilibrium, it gives very erroneous results when 
ery 
the atmosphere is pias disturbed. While the pressure at — 
