BCKEL. I 
ILLINOIS. 
339 
is low, so that cemeni barrels of the usual size will contain only about 
HO pounds of Howard cement. Most of the product is. however, 
narketed in bags containing 80 pounds each. It is said not to stain 
nasonry and to resist well the action of salt air and spray. Its final 
gardening is slow relative to the Louisville cements, and for this rea- 
son it does not show up well in short-time comparative tests for ten- 
ale strength, though at periods longer than a month it gives excellent 
esults. 
The Howard cement is high in both lime and magnesia, compared 
nth the Louisville cements. • Two analyses are given below, the first 
(noted in Cummings's American Cements and the second by W. M. 
iowron. To these have been added the average of five analyses of 
ypical Louisville cements. 
Analyse* of natural cements. 
Howard cement. 
Average 
Louisville 
cement. 
Silica (Si0 2 ) 
Bumina (A1 2 3 ) .. 
ron oxide (Fe 2 3 ) 
,ime (CaO) 
lagnesia ( MgO ) . . 
11.60 
22.58 19.60 
7.23 
3. 35 
48. 18 48. 86 
15.00 18.14 
23. 72 
8. 51 
43. 57 
9.26 
NATURAL-CEMENT RESOURCES OF ILLINOIS. 
I Three natural-cement plants, operated by two companies, are now 
working in Illinois, near Utica, La Salle County. The rock used is a 
imestone belonging to the so-called u Lower Magnesian" group of 
arly western geologists. It is of Ordovician age and underlies the 
t. Peters sandstone. 
The section exposed in the neighborhood of the Utica cement plants 
S as follows, from the top downward: 
Section of cement rock heels exposed at Utica, III. 
Feet. 
Jement rock 7 
iimestone 16-22 
] jJement rock 6 
' sandstone 2-4 
penient rock 5 
Of the three cement rock beds shown in this section, the uppermost 
Ued gives a very quick-setting cement while the two lower beds fur- 
iiish products of much slower set. 
