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CLIMATOLOGY. 103 
CLIMATOLOGY. 
By GEORGE ENGELMANN, M.D. 
The climate of a country is the result of its geographical posi- 
tion and its topographical configuration. Missouri, in the center 
of that part of the great North American Continent that extends 
from the Rocky Mountains eastward to the Atlantic Ocean, ina 
great plain, so to say, unprotected by mountain ranges, unmodified 
by the proximity of oceans and their currents : largely partakes of 
and typically exemplifies the ‘‘ continental climate,’’ i. e., a cli- 
mate of extremes, extremes in heat and cold, moisture and drought. 
Missouri is a great undulating plain extending from the 36th to 
the 41st degree of north latitude, and between the r2th and roth 
degree of longitude west of Washington, rising from its eastern 
border, on the winding course of the Mississippi River, toward the 
west and northwest, from less than 300 feet to 12 or 1,400 feet 
above the ocean; open towards the Gulf of Mexico, 500 miles dis- 
tant ; open toward the northern country at the sources of the Mis- 
sissippi and the Arctic regions, open eastward through the Ohio 
Valley to the Alleghany Ranges, and open westward through the 
Missouri Valley toward the Rocky Mountains ; well watered by the 
Mississippi and Missouri Rivers and their affluents. 
The altitude above the sea on the Mississippi River rises from 
only about 275 feet near the southeast corner of the State, to 
445 feet on its northeast corner the Missouri River, it rises 
from near 400 feet at its mouth to over 1,000 feet at the northwest 
corner of the State. The inland portion on these points lies from 
50 to 200 feet higher than the low water-mark of the rivers, and on 
the water-sheds of their affluents it is from 400 to 600 feet higher 
yet, while the elevation of the Ozark Hills, in the southeastern 
and southern parts of the State, amounts to several hundred feet 
more, just enough to influence the climate locally, but not suffi- 
cient to bear on that of the whole State. 
The principal elements of the climate of 2 country are its tem- 
perature and its moisture. hey influence and condition the 
existence and prosperity of organized life and the well-being of the 
human family. But these elements are to be considered not only 
in their averages, but even more so in their extremes; for the 
extremes establish the socouaaaea limits of many productions. 
Unfortunately, we have precise observations only of St. Louis, 
where my observations extend through nearly 4o years. Of other 
parts of the State we must judge from the scanty observations 
made in neighboring States, or from analogy. My records give 
the mean temperature of the city of St. Louis 55°5 F., with a 
variation in different years from 53°4 to 58°o, and with a range 
between extremes from — 22°5 to + 104°o. Comparative observa- 
tions prove that these temperatures are peculiar to the built-up, 
paved, and almost vegetation-less city, and that in the country, 
even in the immediate neighborhood, the temperature is on an 
average 2 degrees lower, while in certain localities and under cer- 
tain influences of wind and moisture, it may differ occasionally as 
much as 8 or ro degrees. We are therefore justified in assuming 
for the country near St. Louis a mean temperature of 53 degrees. 
The mean temperature of the seasons varies even more than 
that of the whole year. Our winters may be estimated at 
32°o (in the city 33°6) with the extremes of 25° and 40°; and the 
summers at 75°o (in the city 76°8) with the extremes of 70° and 
80°. The following table gives the exact datas for the city: 
Winter. |Spri g-| Summer Autumn. | Whole Year. 
Sovcedeste saseseconeens iss 55°4 76°83 59°93 55°6 
Mean Temperature 1074 fara "le Zee se 
save secesnsenese saneeess axdevend 72°o 51°3 3°4 
R ma ps highest temperature... rs iSseoo7* id 82°@ 102 93°@r104° 
Hates of the cies temperature...... —22 o> | 0°(@)28143°@ 57°) — fork —27°@+10° 
The two last lines, novel in such tables, but practically quite 
important, require some explanation. They indicate that the 
lowest temperature in our St. Louis winters may rot fall below + 4° 
or it may fall as low as —22°; it ranges between + 4° and —22° 
thus in the same season we reach always a temperature of at least 
49°, but it may rise to 81°. Then our summer heat sometimes 
does not exceed 93°, but may rise to 104°, while it never falls 
below 43°, but sometimes not below 57°. The extreme daily 
es of temperature amount, in winter and spring, sometimes to 
56°, while in summer and fall they do not exceed 40 
The last frosts in spring occur between March 13th and May ad, 
on an average about April 5th; and the earliest autumnal frosts set 
in between October 4th and November 26th, on an average about 
In the southeast part of the State these limits of the freezing point 
will, of course, be much wider apart: and in the northwest, rar- 
rowed down considerably. Our spring opens in March, though in 
some favored seasons vegetation breaks through its wintry bounds 
already in the latter part of February, while in a few very late years 
it can hardly be said to have fairly commenced before the middle 
of April. The progress of vegetable development can best be 
appreciated by the observation of common and well-known wild or 
cultivated trees and shrubs. Thus we find that the first in bloom 
is the alder and the hazel, next—not rarely retarded by intervening 
cold spells—the soft or silverleaf maple ; and a few days after this, 
our common white elm blooms, between February 24th and April 
15th, on an average March rgth. During the next following days 
roses, syringas, gooseberries, and many other bushes, and the 
weeping willows show their young leaves. About two weeks after 
the elms—between March 18th and April 25th, on an average about 
April 2d—the peach trees open their first blossoms, and are one 
week later in full bloom. Plum and pear trees, and sweet cherries 
blossom about the same time, or a few days later, and then the 
sour cherries and the glory of our rich woods, the buds. 
Between March 21st and May 1st (mean April 14th), the early 
apple trees begin to bloom; and between March 28th and May 
toth (mean April 2oth) may be said to be in full bloom. Syringas 
everywhere about farms and in towns, begins to bloom between 
April 11th and May 23d, on an average May rst, and six to ten 
the catalpa, a very irregular bloomer, comes in full “ee dipaivase 
generally between two and three weeks after the acacia 
The maturity and harvest of the winter wheat paling suc- 
ceeds the sie: between ar toth and July 1st, usually about 
June 2ot 
The two seasons of 1842 and 1843 well represented the extremes, 
the former having exhibited the earliest and the latter about the 
latest vegetable development, within the last 40 years, in this 
neighborhood, the difference embracing a period of five to seven 
wee 
The average temperature of a State of the extent of Missouri 
must necessarily vary considerably from that of the country about 
St. Louis; it recedes as we approach the more elevated plains of 
the West and of the North; the mean summer temperature prob- 
ably varies but little in going due West, while the winter tempera- 
ture falls considerably, as the isothermal lines of the map 
approximately indicate. e mean temperature of the northern 
part of the State is about 3 degrees lower than that of the country 
about St. Louis, and that of the low southeastern corner near 5 
h 
degrees higher. 
