DENVER & RIO GRANDE WESTERN ROUTE. 67 
the formations seen in the dome below Swallows are all below water 
level, and the surface of the country is composed of the Pierre 
shale. This shale is soft and does not form steep cliffs, and conse- 
quently the traveler here may see more of the surrounding region 
than he could farther east. Soon after passing milepost 147 he may 
see far on the right, if the atmosphere is clear, the summit of Pikes 
Peak, towering high above the surrounding plateau. The peak is 
frequently obscured by clouds which gather about its summit and 
stream off to the east in long banners of misty white. In the sun- 
shine of a clear day it shows yellow or rosy red, but when the evening 
shadows fall or the mountain is partly obscured in the distance it is 
blue and hazy. The mountain is more than 30 miles from this 
point. 
As the harder rocks disappear from view and the softer Pierre 
shale takes its place, the surface of the country becomes more nearly 
Wikeiticd: level and the hills less prominent. In this shale 
Elevation 5,199 feet, 
Population 2,629. 
Denver 152 miles. 
oil was discovered before Colorado was admitted 
to statehood. Florence is the natural center of 
the oil field, which was developed by sinking a 
great many wells and to-day produces more oil than any other oil 
field’ in the State.24 
Refineries at Florence convert the crude oil into many marketable 
products. As the train approaches the town oil-well derricks and oil 
monly an impure limestone may fur- 
nish all the materials 
tion are used 
heat of a material that has the proper 
chemical composition. First, the raw 
materials must be ground to a fine 
powder, dried, and mi Rarey mixed ; 
secon mixture 
repared 
must be burned at a es intetarace 
until it unites chemically and physi- 
cally into a clinkered mass; and third, 
the clinker must be ground very fine. 
The fine mixture of the raw materials 
is burned in large steel cylinders that 
are slightly tilted and rotated by ma- 
chinery. The fuel generally used i 
powdered coal, which is forced see 
‘mixture is fed 
the cylinder at its lower end. The 
into the cylinder at its 
upper end and in the intense heat of 
e burning coal is fused into a clinker, 
which falls out at the lower end of the 
cylinder. This clinker when 
very fine forms the Portland cement of 
enters Arkansas River a few miles 
east of Canon City. A small still was 
put in operation that year, and the oil 
that flowed from the gravel in the 
stream bank was distilled for local use. 
It is said that this spring is still flow- 
ing at the rate of about 20 gallons 
a day. 
The first deep well was drilled in the 
field in 1876 and struck oil at a depth 
of 1,187 feet. From this beginning the 
field was developed in and around the 
town of Florence. It extends south- 
ward for about 4 miles and westward 
