THE CLIMATE OF PEORIA. 
. 
READ BEFORE THE PEORIA SCIENTIFIC ASSOCIATION, SEPTEMBER 24th, 1886,. 
BY FRED. BRENDEL, M.D., EX-PRESIDENT. 

This abstract of meteorological observations is taken from three daily nota- 
tions during 380 years from December Ist, 1855, to November 30th, 1885. The 
observations were made at 7 A.M., 2 P.M. and 9 P.M, with a Green’s cistern bar- 
ometer and a number of centrigrade thermometers made entirely of glass and 
suspended free in a shady place. It is the temperature of the atmosphere that 
should be measured, and not that of a wall, which being colder or hotter than 
the free air, influences the stand of the mercury by radiation. The maximum 
and minimum was noted every day, and the daily mean is calculated after the 
method adopted by the signal office from the sum of the three observations, 
that of 9 p.m. doubled and the whole divided by four. That gives about the 
true mean in the three winter months, when the minimum does occur at the 
time of the first and the maximum at the time of the second observation, but 
not in the other nine months, particularly in summer, when the minimum 
right before sunrise is left out of the calculation. It would be better to take 
the maximum and minimum and two hours of equal distance, 7. e., 9 A.M. and 
9p.M. The degrees are converted into the old-fashioned Fahrenheit, to which 
the English conservatism is clinging so pertinaciously in spite of the better 
centesimal system, adopted by the rest of the civilized world, based on the 
freezing point of water, a body that does play the most important part in the 
economy of nature. 
The rain and melted snow was measured by a rain-gauge, consisting of a 
funnel and a corresponding graduated glass cylinder, each degree answering 
the hundredth part of an inch. The force of wind was not measured but 
estimated, and so cloudiness. The humidity of the atmosphere and the pres- 
sure of vapor is taken from the difference of the dry and wet bulb thermome- 
ter after the tables of Guyot. The place of observations changed during the 
30 years several times but only within a thousand feet of horizontal distance 
and thirty feet of elevation. 
TEMPERATURE. 
The mean temperature of the year is 52 degrees of Fahrenheit. It is higher 
than on other stations of Illinois of the same latitude, which is readily ex- 
plained by the lower elevation above the sea-level, being only 490 feet at the 
present place of observation, and in the midst of a large city. Even the little 
difference in elevation of the scarcely more than a hundred feet higher bluffs 
would show a several degrees lower temperature, as that part of the city is more 
exposed to the winds, particularly the northwest and west, which are the 
coldest. ‘ge 
The range between maximum and minimum is great, and the change of 
