INTRODUCTORY LETTER. 
To His Excellency, 
Tuomas Say, 
Governor of Alabama: 
Str :—I have the honor to transmit herewith, a report on 
the Cahaba Coal Field, by Joseph Squire. In his letter of 
transmittal, Mr. Squire has given a short account of the man- 
ner in which the map was first begun, and has come finally 
to be published by the Survey. From this sketch it will be 
seen that the map and report are the result of more than 
thirty years work on the part of Mr. Squire, and, at the very 
low estimate of $1,500 a year, for the compensation of the 
geologist and for the making of the tests of the seams, they 
represent an expenditure of at least $45,000 ; the cost of the 
Survey has been only about one seventh of that sum; the 
difference has been given to the State by Mr. Squire and 
those for whom he made the explorations. I think we 
should not lose sight of these facts. To make the map 
more complete as to the parts not occupied by the Cahaba 
Field, I have added the colors showing the distribution of 
the Geological Formations in the adjacent valley regions, 
and have appended to Mr. Squire’s report, by way of expla- 
nation of these colors, a short account of the lithological 
and other characters of these different geological formations, 
together with such other matter as seemed necessary to ac- 
count for the present attitude and positions of the strata of 
these formations in the valleys. In 1875, 1876, and later in 
1882, I have published maps and descriptions showing ina 
general way, the structure of these valleys, but in the pres- 
ent work, on so much larger scale than any of the previous 
ones, there was the necessity for much greater detail, and 
this needed amount of detail concerning the distribution of 
the various formations, their limits towards each other, and 
the geological structure, has come chiefly from the notes of 
