J. P. Kimball—Grahamite in the Huasteca, Mexico. 288 
common in the surrounding portions of eastern Mexico, as 
That portion of the overflow which originally appeared at the 
base of the river bank, has now been worked out, 210 tons 
having been quarried and shipped. So far as can now be ascer- 
tained, the overflow was altogether west of the fissure, which 
sides, and shrinkage partings, or joints, parallel to its sides. It 
has thus far proved remarkably homogeneous in structure, and 
adam to a depth of ten feet, and, at the same place, measured 
feet deep, sunk from the top of the river bank or terrace, 196 
feet from the edge. From the bottom two levels have been run 
out at right angles, one 194 feet long toward the river (east), 
and the other 274 feet long toward the north. These work- 
ings are in that portion of the deposit which for convenience I 
1 the overflow. Its greatest thickness is iene in the 
15 inches, and a dip of 20° to the northeast. In the shaft the 
thickness of the deposit falls from 34 inches at the southeast 
corner, to 154 inches at the opposite N. W. corner, to 20 inches 
at the S. E. corner, and to 15 inches at the N, E. corner. | It 
therefore appears that the overflow of the vein has a limited 
to its ed : is of entle 
Eygts ges. The fissure occupies the axis 0 ag 
oe with a dip of 14° W. on the W. side, and of 4° E. on 
Ne opposite side. As the overflow conforms to the steeper dip, 
