26

easterly, are large beds of feldspar, from two to four feet thick.

Extensive beds of the same variety of feldspar (orthoclase) are near the Anderson Copper Mine, in the Chinati mountains, in the southeastern part of Presidio county. There the beds are from 20 to 50 feet thick, inclined at an angle of about forty-five degrees, and of a yellowish white color.

These feldspars can be utilized in the manufacture of the finer porcelain.

Porcelain clays, suitable for making common wares, prevail in Concho and Tom Green counties, and westward to the Rio Grande.

SLATE-ROOFING.

Near the base of Packsaddle mountain, on the banks of Honey creek, are large beds of bluish black slates, of a jointed and thinly stratified structure, in beds inclined at high angles. These slates resemble the surface slates of New Hampshire and Vermont, which lead lower down to quarries of good roofing slates.

It may be that those of Llano county, when quarried to the depth of a few feet, may afford a good material for roofing. Mr. Williams, who has recently been locating lands in Presidio county for the Central Railroad, assures me that extensive beds of good roofing slate are in the Chinati mountains of that county.

These slates are on section 3d of the Central Railroad survey. Strata about one hundred feet thick and dip southward.

GYPSUM

We saw disseminated in the shales and clays bordering the Rio Grande, -between Fort Quitman and the Hot springs. We were told by the United States officers and. others that gypsum abounds in the eastern part of El Paso county, the northern portion of Presidio county, and also in the northern part of Bexar Territory. These deposits, with those in the Pan Handle, on the waters of the sources of the Red River, show that Texas has enough of this valuable mineral for fertilizing and other purposes.

Besides its well known use as a fertilizer, it is used for stucco work, for casts, etc. Under the name of plaster of