497 ENGELMANN-MEAN & EXTREME TEMPERATE IN ST. LOUIS. 
mile west of the river, lies in Lat. 38° 38' 03" and Long. 90° 12' 
i $;'; the low-water mark of the Mississippi is 379 feet above the 
Gulf, and the foot of Market street (City Directrix) is 413 feet 
above the same. 
My observations were made in the first twelve years on the 
south-east corner of Second and Chestnut streets, only two blocks 
from the river and 75 feet above low-water mark of 1863 ; for the 
next 22 years on the south-west corner of Fifth and Elm streets, 
five blocks from the river and no feet above low-water mark ; 
and for the last 13 years on the north-west corner of Thirtieth and 
Locust streets, two miles from the river and 177 feet above low- 
water mark. When 1 was absent from the city Dr. A. Wislize- 
nus and lately Mr. B. D. Kribben have kindly filled the gaps. 
My instruments were at first such as could then be obtained 
here ; soon I imported correct thermometers from Europe, and for 
nearly 40 years I used those made by Jas. Green, then of Balti¬ 
more, and soon afterwards of New York. 
For many years the observations were made at different peri¬ 
ods of the day, and especially at hours when the extremes might 
be expected to occur, viz. at sunrise and at 3 p.m. ; and the maxi- 
mums and minimums were selected from all of them, often eight 
in a day, at whatever hour of the day they were found. Differ¬ 
ential thermometers were observed only since the last 12 years. 
Thus I may not always have noted the absolute extremes of each 
day, and my tables can claim only approximate reliability; I 
give them for what they may be worth, but I can assure my 
readers that they furnish a record elaborated with zeal, conscien¬ 
tiousness, care and assiduity, and for a length of time such as. 
probably few others, if any, exist in this valley. 
The arrangement of the tables explains itself. The first two 
columns represent the means of the 47 minimum and of the 47 
maximum observations made on each day of the year, and the 
third column the mean calculated from the two former. The next 
“Min.” column gives the lowest and the “Max.” column the high¬ 
est temperature ever observed on that day; the column of years 
next to these gives the year in which these extremes did occur. 
The last column represents a supposed—or estimated—true mean 
for the day after eliminating excessive extremes. 
The year has been divided into 73 periods of 5 days each, the 
