852 Recent Literature. [ August, 
beds with their included slate and bony layers, and the thickness 
and character of the rocks between the respective beds, drawn on 
the following scales : coal-bed sections 10 ft. = I in., coal-measure 
sections 40 ft. — 1 in., conglomerate (mill-stone grit) sections 100 
ft. — I in.; one topographical sheet, showing the surface features 
of the same area covered by the mine sheets, scale 1 .=I 
in.; and one sheet showing the development of the surface of 
the highly-flexured Mammoth bed into a horizontal plane. In 
addition to these sheets relating to the Panther Creek basin there 
is one sheet giving a general map of the entire coalfields, with a 
list of the working collieries, with their production in 1881, and 
the thickness of the coal beds and coal measures in the different 
districts, and also one sheet showing the annual production of the 
region since 1820 to 1881 inclusive. 
r. Ashburner’s report of progress descriptive of these sheets 
is now going through the press; his more technical discus- 
sion of the geology of the Panther Creek basin will not appear 
until his final report is published, after the completion of the en- 
tire survey. 
The special. methods which Mr. Ashburner has devised, and 
which have been approved by J. P. Lesley, State geologist, de- 
serve particular notice, since they have, without doubt, applied 
the science of geology more directly to the art of mining than 
has ever before been done by any of the State surveys on te 
American continent. When this survey was ordered the strong- 
est prejudice existed among the mining men in the coal basins 
against the possibility of the State corps accomplishing any m 
sults which would be of utility in the exploitation of the coal 
ds. Without the support and coöperation of the mining com- 
panies, by which the facts in their possession could be obtained, 
it would have been useless to have attempted any wo k. 2 
information was secured by adopting a plan of work v hich sought 
to clearly indicate the precise position of each coal be and the 
amount of workable coal contained. The practical questions E 
be answered were: How much coal is there? Where !s it? = 
what depth? With how steep a dip? In what direction ? Wi 
what basins, and saddles of what length, breadth, depth, an 
height? In what direction would level drifts run? Where wou 
i ? 
water courses or other features on the surface of the ste 
and the like. It is easily conceivable that it would be imp 
d satisfac 
sible to give indications of that kind so fully an ie 
torily with a whole volume of words as with properly ae 
structed maps and sections on scales large enough for reta e 
measurements to be taken directly from them. As tar ortieth 
Panther Creek basin is concerned, which is about one-forti 
