CLAYS STUDIED WHICH ARE SUITABLE FOR USE IN THE MANUFACTURE OF PAVING BRICK.
The clays especially studied for the purposes of this report are listed below. They are, with few exceptions, now being used in the manu facture of pavers of proved excellence.
While the writer believes that most counties in the State contain days from which high grade pavers could be made, if the materials were properly handled, there are only eight localities where this is actually done. This is probably due to the facts, that there is no very large demand for pavers; that both Indiana and Iowa have large plants near the borders of this State; that commercial considerations which are in no way influenced by the qualities of the clays favor these plants; and also to a large extent because no systematic survey of our clays has been made and so their qualities are not known. • In order to give the reader a clearer idea of the qualities a paving brick clay should possess, it was decided, because the Illinois factories are so fetv, to include a number of those which are making first class pavers in the neighboring states of Ohio, Indiana, Iowa, Missouri and Kansas. All the Illinois clays now used for pavers are from the coal measures, and many people have an idea that shales from this horizon furnish the only material suitable for the manufacture of such wares. The clays used in these other states are from various horizons, and, as will be seen by a comparison of the tables below, they possess qualities in every way equal to the coal measure shales used in Illinois.
Preliminary tests were made on a considerable number of samples covering a large part of the State. These tests were made on small samples taken usually from more or less weathered outcroppings. Such tests are always unsatisfactory because the samples are not large enough to permit studies which will give decisive results, and also because the changes which occur in weathering usually tend to destroy those qual ities of a clay, which make it desirable for the manufacture of pavers. While the tests made indicated that a considerable percentage of the clays tested, some 30 or 40 in all, were suited to the manufacture of pavers, thy limitations under which the work was conducted made it impossible to carry out complete studies on any large number of samples.
H16—II23 are examples of such clays.
11. Sandstone 10 12. Sandy shale 25 13. Shale 200 Building brick are manufactured from No. 2 as a whole. The lower half of No. 2 is used for pavers. Nos. 12 and 13 are reached by shaft.
F 1—The Danville Brick and Tile Co., manufacturers pavers from No. 12 of the section shown under K 14. This deposit outcrops near their plant.
H 16—Is a blue coal measure shale from the pit of Mr. Carter at East Peoria.
H 17—This clay was obtained from the bank of the LaSalle Pressed Brick Co., near LaSalle, Ill. It is not now used for the manufacture of pavers.
Feet 1. Stripping .. 12 2. Sidewalk clay v 2 10 3. Green clay v 1 7 4. Clay with much pyrites 5 5. Red burning clay H 17 14 The indications are that v 1 and 2 and H 17, if mixed, could be used in making pavers of good quality.
H 18—From a weathered outcrop probably 40 feet thick situated one mile east of the station of the C. & N. W. R. R. at Sterling, Ill. It belongs to the Cincinnati (Maquoketa) series of the Lower Silurian (Ordovician). The indications are that it would probably make good pavers.
H 20—Cincinnati shale from the farm of Dupiers & Son, near Savannah, Ill. It is a weathered sample and unless the unweathered portion should make a better showing, is worthless as material for pavers.
H 23—Is from the bank of the Argillo Works at Carbon Cliff, Ill. Would probably make good pavers.
H 21—This sample of Cincinnati shale came from the west end of the tunnel of the Great Western R. R. near Rodden, Ill. Aside from its fine ness of grain the material seemed to be well adapted to the manufacture of pavers. As the sample was from a weathered outcrop it is possible, perhaps probable, that the unweathered material could be so treated as to overcome this difficulty.