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Table land as a prominent eminence, an important seam is described by Dr. Spencer, which lies many feet higher up in the measures, and which so far as we know does not occur in that part of the Lookout Mountain that extends into Alabama.

The clays described are of several kinds, (1) the kaolin-like clays, (2) the residual clays from the decomposition of limestones and calcareous shales, (3) the clays formed from the disintegration of shales, and (4) the alluvial clays. The first variety occurs in "horses" or in sheets or pockets in the residual earths from the decomposition of the strata of the Knox Dolomite and Fort Payne series. These are often quite pure and white, and have nearly the theoretical composition of kaolin. Although they occur in the residual matters they are not, according to Dr. Spencer, residua of the limestones, but are derived from the rocks of the metamorphic series.

The residual clays produce sometimes fairly good brick, but they are generally too rich in fusible materials to make fine products. Of greatest promise are the clays derived from the disintegration of shales and slates, some of which have given beautiful vitrified brick, such as would probably be well suited to serve as paving brick. The alluvial clays, especially such as belong to the Second Bottom deposits, in Georgia as well as in Alabama and Mississippi, furnish by far the greater part of the material for the manufacture of ordinary building brick, and it is of interest to note that the best quality of building brick along the whole Appalachian region is made from deposits of this character.

In chapters XL and XLI we have a plea for better roads, with numerous illustrations of country roads in Europe and America, which emphasize sufficiently well the contrast between good roads and bad ones. This is a seasonable chapter in view of the great interest now being awakened in the subject of better roads throughout the southern states.

Part III, chapters XLII to XLIV, is devoted to the discussion of the origin and characteristics of the soils derived from the various Paleozoic formations, and the composition of these soils is shown also by a number of chemical analyses.

An appendix containing acknowledgments and an account of the progress of the Survey, a classified table of contents and a full index conclude the volume. The base of the map has been compiled chiefly form the topographic sheets of the U. S. Geological Survey, and in the