ADMINISTRATIVE REPORT 
porosity at temperatures ranging from 850 to 1320 degrees C. 
(1562° to 2408° F). 
RESULTS. 
Although, as will be seen in the report which follows, the tests 
thus far made are negative, so far as paving brick are concerned, yet 
the results obtained are such as to justify the continuation of the 
investigation. 
With regard to the tests as a whole it is of interest to find that 
a fair number of the Florida clays of which samples were submitted 
show satisfactory molding, drying and other working properties, 
and may be used in making building brick, some being suitable also 
for tile and face brick. 
It is apparent that the progress of the investigation of Florida 
clays would be much facilitated if the State Survey could have its 
own testing plant. This applies not only to tests of clays for paving- 
brick but to the general study of clays for building and face brick 
and tile, and of kaolins for pottery purposes. At present space in 
which to install clay testing machinery is not available and the State 
Survey can not make its own clay tests until adequate office and lab¬ 
oratory space is provided. For the tests that are here reported the 
Survey is indebted, as already stated, to the co-operation of the 
United States Bureau of Standards. 
REPORT ON SAMPLES. 
The following report on individual samples will serve to illus¬ 
trate the properties of the clays that have been tested. In reading 
these returns it is well to remember that the tests were made pri¬ 
marily to determine whether or not the clays would vitrify at tem¬ 
peratures practicable in commercial kilns. It is doubtless true that 
more favorable results may be obtained in many cases by the mixing 
of various clays; this, however, remains to be tested. 
Sample No. 1, Jackson County. The clay works with some difficulty in the 
stiff mud condition; water of plasticity in per cent of dry weight, 40.80%; 
warped and cracked during the drying treatment; linear drying shrinkage in 
terms of wet length, 9.95% ; linear burning shrinkage in terms of dry length, at 
850 degrees C., 0.77% at 1010 G, 4.59% ; at 1,130 G, 6.60% ; at 1250 C, 7.55% ; 
color after burning, light red at lower temperature, changing to dark red at 
higher; per cent porosity, at 850 degrees C, 36.75%> ; at 950 C, 40.55%; at 980 
C., 34-30%; at 1010 C, 30.30% ; at 1040 C, 24.20%; at 1070 C, 24.00%; at 1100 
C, 26.10%; at 1130 C, 25.15%; at 1160 G, 23.65%; at 1190 G, 23.60%; at 1220 
C., 23.85% ; at 1250 G, 20.70%. A somewhat plastic and sticky clay of high dry- 
