ADMINISTRATIVE REPORT 
J 5 
REPORT ON CLAY TESTS FOR PAVING BRICK.* 
As a country develops, the demand for information regarding 
the clay products as well as the other natural resources, becomes the 
more insistent. This is particularly true in Florida where the exten¬ 
sive use of brick for road paving has created a large demand for a 
product that is not now being made in the State. At the present 
time all the paving brick used in Florida is imported, and the ques¬ 
tion is constantly being asked whether or not there exists in the 
State a clay suitable for the manufacture of vitrified brick. A source 
of domestic supply, if such can be found, will not only effect a sav¬ 
ing in freight rates, but in addition will bring an important new in¬ 
dustry into the State. In view of these facts the State Geological 
Survey has undertaken to find, if possible, a clay in the State suit¬ 
able for the manufacture of paving brick. Even should no paving 
brick clay be found, the general information regarding clay deposits 
of the State that will be obtained in connection with these investiga¬ 
tions will abundantly justify the undertaking*. 
In this work the State Survey has been particularly fortunate in 
having secured during the past year the assistance of the United 
States Bureau of Standards. This Federal Bureau maintains at 
Pittsburgh, Pennsylvania,' an excellently equipped clay testing lab¬ 
oratory in which, through the generous co-operation of the Director 
of the Bureau, the actual burning tests of the Florida clays have been 
made. For this purpose twenty-five samples were collected by the 
State Geological Survey and submitted to- the Bureau during the 
summer of 1914. Twenty-one counties in Florida are represented 
in these tests. Each sample as shipped consisted of approximately 
250 pounds of clay and was representative, as nearly as could be 
judged, of the clay of the locality from which it was taken. Tbe 
burning tests have been made by experienced ceramists under favor¬ 
able conditions and the results may be accepted with confidence. 
PREPARATION OF SAMPLES. 
After being received at the Pittsburgh laboratory the samples 
were prepared by the ceramists who 1 were making the tests as fol¬ 
lows : 
“Preparation of the Sample .—Each sample as received was 
ground in a Stevenson pan and screened through a 10-mesh sieve. 
*First published as Press Bulletin No. 7, April, 1915. 
