A PRELIMINARY REPORT ON CLAYS OF FLORIDA 247

the products from western Florida; and on the other hand, the Escambia County producers can best dispose of their wares in West Florida and adjoining portions of Alabama and Mississippi.
 Paving brick, the highest grades of face brick and sewer pipe are not produced in Florida, and, so far as is known at the present time, there are no clays within the State adapted to the manufacture of these products. Face brick of good quality can be produced in many places, but the best grades, suited for certain types of work, cannot be satisfactorily produced. For paving brick, sewer-pipe, and certain grades of face brick, therefore, Florida will be dependent upon outside supplies.
 SUBSTITUTES FOR CLAY PRODUCTS
 Numerous substitutes for clay-building products have been used with varying degrees of success and, without doubt, some of them will continue to be extensively used.
 Reinforced concrete, for example, has proved very satisfactory in Florida as in practically all of the other states, and much of the structural work of the future will be of this material. At present, Portland cement is not produced in Florida, and again Georgia and Alabama products, or those from other states, must be imported with very high freight rates to supply local needs; moreover, clean, sharp sand and gravel for concrete work is difficult to obtain in south Florida, where the greatest construction work is being carried on.
 The lime industry in Florida is an important one and has given rise to the production of sand-lime brick. These are artificial brick, made of sand and quicklime. Florida ranks third in the manufacture of sand-lime brick. These brick have the same dimensions as common brick, and are used in structural work in the same manner. The use of sand-lime brick has proven successful, and will doubtless continue to be a common substitute for brick.
 Florida has no good building stone. Some of the soft limestones in west Florida and the coquina rock as well as the oolitic limestone occurring along the east coast, have been successfully used to some extent for structural materials.
 An artificial building stone, particularly for ornamental work, columns, arches, keystones, sills, etc., is made of crushed Ocala limestone, coquina, or loose shells, with sand and lime. This makes a very