The Prince George's enquirer and southern Maryland advertiser. (Upper Marlborough, Md.) 1882-1925, 1902-05-16

A comprehensive report on the clays
and the clay industries of Maryland has
been prepared by the Maryland Geoiog-
ical Survey and is now ready for issue.
Heinrich Ries, the leading expert on clays
in the United States, wrote the report as
the result of 10 lbs of work in the
field, the laboratory, and the office, in
co cooperation with biologists of the State
Survey. In 800 large octave pages it
gives IA comprehensive sketch of the gen
eral clay industry in all its scientific and
industrial aspects, and furnishes Il full
account OF the industry in Maryland and
the developments which are possible here
The general text will thus he of the high
est value to Maryland's practical clay
workers, and its detailed survey of the
States resources with full description of
all its products, will furnish just the data
that outside manufacturers and investors
need.
Maryland possesses an abundance of
valuable clays and shales which are little
known. The present publication aims to
bring them to public attention in form
which will attract the immediate notice of
all who are interested in the industries
dope nding upon them. We already rank
eleventh among the "clay states" and
seventh among the producers of pottery.
The total value of Maryland's annual out
put of clay in bricks, terra Gotta, pottery
and porcelain is $50.
The first half of the new report is
systematic review of information concern
ing clay, of sort not easily to be obtain
ed elsewhere. 1t will answer many ques
tions commonly asked by investors and
those already owing properties. 1t out
lines fully the geological history of clay
formations and explains their present
positions and qualities with reference to
their origin. The impurities in common
clays are noted in great detail and their
effects upon the clay are fully discussed.
Moisture in clay, and the shrinkage due
to it; the Elasticity of clay, its causes, and
the methods of measuring it; the behavior
Of clay under strong heat; its tensile
strength and the measurement of it; and
the classification of clays, are some of the
topics here treated in as popular a way as
possible.
General directions are given for pros
pecting for clay in several regions of
Maryland. Methods of working deposits
are outlined and also methods for testing
the physical and chemical qualities of the
product The distribution of clays over
the entire country is considered in we'll
ordered manner and analyses of many of
them are furnished, for comparison by
local producers with their own products.
The methods and machinery for working
the deposits and grinding the product on
a large scale, and the processes through
which it becomes brick, terra Gotta,
enameled ware, or fine pottery, are all full
ly explained in the text and illustrated by
photographs and drawings. The discus
sion of brick molding and burning is
especially comprehensive.
The section which treats of Maryland
clays commences with general descrip-
ton of the geology of the deposits. This
is amplified by geological maps showing
the several great clay regions, the Cecil
area, the Mount Savage area, the deposits
bordering the upper western shore of the
Chesapeake, the Potomac deposits, ex-
tending up to Baltimore, and the forma-
tions in Southern Maryland. Every for
nation of any note is carefully set down
and complete description of its clay is
given, even to summary Of its physical
properties and its chemical composition
when these could be obtained. The resi-
dual clays of Washington, Frederick,
Carroll, Montgomery, Hartford, Howard
and Baltimore counties are all fully treat.
ed in the same way. Tables showing the
resistance to heat effects exhibited by
some Of the States clays, their physical
tests, and their chemical composition, to-
gether with a directory of Maryland clay
workers, close the volume, which also in
cludes a complete photography of the
works containing references to the clays
of Maryland.