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found where the amount of sands and clay at the surface are in almost any desired proportion for use.

LIME AND CEMENT MATERIAL.—There are several beds of limestone in the Lower Cretaceous formation that will produce good quick lime. Of these the indurated chalk near the upper limit of the Caprina bed, in which occurs the horizon of black flints, is most excellent, as is attested by the extensive White Lime Works located at Austin and other places.

Specimens have been taken from every horizon of the chalk, chalk marl, and clay of the Upper Cretaceous in Williamson county, and it is reasonably certain that when a thorough study has been made of them materials will be found which will give the proportions of lime and clay suited to the manufacture of cements.

The soil of the Upper Cretaceous limestone, chalk marl and Ponderosa marl is known as the black waxy land, because of its color and adhesive power when wet. During the rainy season the roads in this region often become almost impassable for loaded wagons. An enormous amount of labor to both man and beast is wasted because of the character of the roads, and it has been a long standing problem how to improve these roads at nominal cost.

It is the province of the Geological Survey to investigate this matter and to locate and point out the best and cheapest road making material.

The field work of the season of 1891 has developed the fact that in recent geological times almost the entire area occupied by the black waxy land in Williamson county has been submerged and overflowed by rapid and strong currents of water from the northwest, which have laid down a deposit of sand, gravel and boulders of limestone and flint, which in some places attain a thickness of strata twenty to thirty feet in depth. These flint and lime fragments are in sizes varying from that of a man's head to fine grains of sand. Over this material there has since been formed a residual soil very closely resembling that derived from the marl which underlies the drift. On hillsides, in ditches, and in ravines, the erosion which has given the region its present contour has brought the pebbly drift, flint, etc., to the surface at many places, and the flint fragments are scattered far and wide over the surface where it has withstood destruction by the atmospheric agencies which formed the soils.

Here nature has selected and assorted and deposited the best possible material for this use, and in quantities sufficient to macadamize every road in the district.

In the area west of the black waxy land there are limestones or sands close at hand to make the best of roads.