96 
CONCRETE SILOS 
Puffer- 
Hubbard 
Manufactur- 
ing Co. 
The St. Jacob Lumber & Hardware Co., of St. Jacob, Illinois, are 
manufacturers of silos, building block pillars and other poured or cast 
concrete work. In the last two years a number of successful 
Lumber and ^Sive been built near St. Jacob and other parts of Illinois, 
Hardware Co. ^his company, using the Blummer Perfect Silo Form, owned 
by them. 
The Puffer-Hubbard Manufacturing Co., of Minneapolis, Minn., has 
recently put out what are called Duplex Forms, for building concrete silos. 
This company claims that the special advantage of these forms is 
their use in placing monolithic concrete foundations, such as are 
required for all types of silos, whether concrete or other material. 
This company does not manufacture hoisting machinery, nor do 
they furnish complete silo equipment, but these forms can 
undoubtedly be handled successfully by following the directions as to 
bracing, etc., given on page 56. 
The diameters of silos which can be built with these forms are of dif- 
ferent sizes, varying from ten to twenty feet. The inner form consists of 
eight segments held together by two 2-inch by 6-inch by 2-foot cleats, 
cut to the same circle. These hold the segments to a true circle. Three- 
foot lengths of 1-inch boards are nailed to the curved edge of the ribs, 
the latter being placed 2 feet center to center. These boards are then 
covered with 28-gauge galvanized sheet steel. 
Eighteen-gauge galvanized sheet steel is used for the outer forms 
fitted with proper attachments for clamping the sections together, and 
raising them to their new position, as the work progresses. 
W. H. Warford of Geneva, Illinois, a successful concrete silo contrac- 
tor, has perfected and patented a roof form. Mr. Warford uses the Polk 
System of reinforced concrete construction for the building of silos, but the 
roof form is of his own 
W. H. 
Warford 
manufacture. A detail 
of these roof forms is 
shown on this page. These roof 
forms have been in successful 
operation and the inventor claims 
that concrete roofs can be put 
on silos with this form very easily 
and at a comparatively low cost, 
all factors considered. The form 
weighs about 1200 pounds com- 
plete. It is light in weight, self- 
centering, has twenty-four rein- 
forced ribs and allows for a 6-inch 
ventilator on top. All sections 
are identical except the one with 
the manhole. The form is also 
suggested for use in building roofs 
of combination milk rooms, water 
towers, small grain bins, grain 
storage and cattle tanks. 
Detail of Roof Forms (patented) of W. H. Warford, 
Geneva, Illinois, a successful silo contractor who has 
built a number of good concrete roofs on concrete silos 
with this form. 
