62 FLORIDA GEOLOGICAL SURVEY-I5T ANNUAL REPORT

which should be given thorough'consideration by a prospective manufactu rer.
 The aimn of this report is to guide the manufacturer to deposits worthy of his notice and to furnish owners of such clay deposits knowledge of their occurrence, properties, and usefulness and it is hoped that this work will he of some assistance in furthering the development of the clay industries of Florida.
 The general geology, classification, mnineralogy, chemical and physical properties, and uses of clays are briefly discussed in this report. Much has already been -published on these topics and the discussion which follows is by no means exhaustive. It summarizes the more important facts that have been brought out by previous investigators. This is done to answer numerous inquiries continuously being received by the Survey regarding the common properties of clays, and also to enable those people who have neither time nor facilities to consult the other publications to have the benefit of this knowledge which may facilitate their use of the data bearing on the Florida clays. Adequate footnote references are made to other writers so that readers may consult the principal papers previously published dealing with clays.
 A discussion of the methods of manufacture of clay products, descriptions of the individual brick plants and numerous other sections have been omitted in order to conserve space. Numerous photographs, however, have been used to show the types of machinery employed, types of kilns in operation, methods of clay mining, and general plan and arrangements of plants.
 Fuller's earth, a clay with special properties but little or no plasticity, has been discussed at considerable length in previous reports of the Survey, particularly the Second and Sixth Annual Reports, and the time and funds available did not permit a further treatment of it in the present paper.
 FIELD WORK

 The field work was carried on during the season of 1922. At this time all accessible clay deposits of which the State Geological Survey had any knowledge were visited. Inquiries made in each locality during the progress of the work brought many additional deposits to notice. In each case the deposit was examined as thoroughly as time permitted and if the clay seemed promising at all a representative sample was