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STATE GEOLOGIST. 173 
the entire length of the posts, doubling over at the top and bottom as 
shown in the accompanying illustration, figure 111. Wire is wrapped 
around one of these straps and looped out sufficiently beyond the surface 
of the cement to form attaching loops, either for barbed or net wire 
fencing, or for common fence boards. A special machine is used for 
compressing the concrete into the forms. 
Corner posts are made 81% feet long, 8 inches square at the base, 
and 6 inches square at the top, and weigh about 500 pounds. Such 
posts cost from 30 to 35 cents a piece. The line posts are much lighter, 
being 74% feet long, 3%4 inches square at the bottom, 2%4 inches at the 
top and weighing about 60 pounds. These posts cost from 8 to 12 cents 
each. 
PILES. 
Several kinds of concrete piles have been employed in construction. 
One of the earliest uses of steel concrete piles was in the form of a steel 
tubular casing or wrought iron pipe sunk through yielding ground or 
sand to good bearing and then filled with concrete. This form was 
especially adapted for small highway-or railway bridges, and has been 
quite extensively used. 
Cushing’s pile foundation, which consisted in driving a group of 
woden piles, encasing them within an iron casing extending below low 
water line, and then filling in all the space within the casing and around 
the piles with concrete, has long been used for bridge pier foundations. 
Raymond Pile——The Raymond pile consists of a steel shell 20 feet 
or more in length, 18 inches in diameter at the butt and 6 inches near the 
point, which is driven with a collapsable core. When the pile is driven, 
an extra blow given to one portion of the core drives in this portion 
collapsing the core so it can be drawn, leaving the shell in place. The 
casing is then filled with concrete. The cost is estimated at 50 cents per 
foot of pile, or $1.00 per foot in place. 
~The new Carnegie library building, Aurora, IIl., is being built upon 
a foundation supported by the Raymond pile reaching to bed rock. These 
piles are encased in No. 20 sheet iron filled with Portland cement concrete 
of the proportions 1 cement, 2 sand and 4 crushed stone. Figures 112 
and 113 illustrate the Raymond pile. 
Hennebique Armored’ Piles. —The Hennebique armored pile consists 
of four round iron rods spaced 9 or Io inches apart in a square, and tied 
together about every three feet with iron bars. These pieces are set in 
forms and concrete cast about them to form a post 14 inches square and 
of any desirable length. At the bottom they are shod with steel shoes as 
shown in the accompanying illustration. These have been used in Eng- 
land and upon the continent. They are especially valuable along the salt 
water harbors, as they can not be injured by the teredo. Such piles are 
