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correction of their chains. This is marked by monuments in the Texas Base Line.

That portion of the work which was finished appears with the report of Prof Streeruwitz on the geology of his district

CENTRAL MINERAL REGION.

The topographic work in Dr. Comstock's district was carried on by Mr. J. C. Nagle, and is intended to furnish, in connection with the work of the United States Geological Survey, the accurate topography of the entire area of the rocks older than the Coal Measures in Central Texas, as a basis for mapping the complicated geology of this region. The work was carried as far as possible in the time allowed by the present field season, and the map as far as completed accompanies this Report

In September Mr. Nagle was elected Assistant Professor of Engineering at the Agricultural and Mechanical College of Texas, and the completion of the plotting of the map has been done by him without cost to the Survey.

MAP OF TEXAS.

The map of Texas used in the First Annual Report was printed from the plates belonging to the United States Geological Survey, by permission of Major Powell. As it was necessary for us to have maps of the State on several different scales, we began early in the year to collect materials for getting as correct data as possible for use in construction.

Maps of each county were sent to the respective county surveyors and all required alterations noted. These were compiled on a post route map of the State corrected to late date, and the copy from which engraving is to be made was drawn from this corrected base.

This has been engraved on the following scales for the use of the Survey and the Department of Agriculture:

• 1/267200, or 20 miles to one inch.
• 1/2534400, or 40 miles to one inch.
• 1/6336000, or 100 miles to one inch.

GEOLOGY.

EAST TEXAS.

On March 28th Mr. W. Kennedy was sent into East Texas to continue the work of mapping the iron ores of Cass, Harrison, and other