xl REPORT OF THE STATE GEOLOGIST. 



on compression by suitable machinery a firm and durable briquette 

 will be produced, perfectly adapted for all uses as fuel, clean, fully as 

 desirable as ordinary coal, and at a lower cost. Instead of asphaltum, 

 other cementing materials, such as starch, or even clay, are sometimes 

 used, but the product is not usually as good. It is altogether prob- 

 able that lignite could be used very profitably in the manufacture of 

 water-gas, and thereby furnish the very cheapest of fuels for manu- 

 facturing purposes. 



Laredo Coal. — While the Laredo Coal Seam belongs to the same 

 series of beds as the lignites of the other parts of the State, local con- 

 ditions have resulted in the formation of a fuel of much greater value 

 than they. The seam outcrops at San Tomas, north of Laredo, and the 

 San Tomas mine is connected with the city by a railroad. The mine 

 opening is in the bank of the Eio Grande, about forty-seven feet above 

 the river. The seam is from 30 to 36 inches in thickness, with a clay 

 parting from 1 to 6 inches thick, which is usually about 12 inches from 

 the top. The roof is of a tough black clay. The coal is massive, 

 black, glossy, with conchoidal fracture, and in some places has a thin 

 stratification similar to bituminous coal. It also resembles Albertite in 

 some measure, though somewhat less glossy. Numerous other outcrops 

 of the same coal are known in the surrounding hills. The coal is 

 being extensively used as a fuel for all purposes and proves very satis- 

 factory. We have no record of its having been successfully coked. 



Gas. — In several places occupied by the outcroppings of the Tertiary 

 strata borings have proven the presence of natural gas in considerable 

 quantities. It is also known through natural openings in the eastern 

 part of the State, and well deserves a special investigation. 



Petroleum has been found in numerous localities in the area covered 

 by the Timber Belt beds. It is, however, to be classed as a lubricant 

 rather than an illuminating oil, and resembles the heavy West Virginia 

 oils. The deposits, from the very nature of their origin, while very 

 widespread, can not be of more than local extent; but at places, 

 such as have been prospected already in Nacogdoches and San Au- 

 gustine counties, these deposits, in spite of this local character, may 

 prove of very considerable value. This is rendered very probable 

 from the fact that they lie near the surface, and on that account the 

 expense of boring wells is very little. In places this petroleum is 

 hardened, by the evaporation of its more volatile parts, into asphaltum, 

 more or less mixed with sand or calcareous matter, and such deposits 



