136 REPORT OF NATIONAL MUSEUM, 1914, 
the surface conditions at the mine, its most significant feature is the 
clear comprehension it imparts of the system of coal mining in com- 
mon vogue in this country, known as the room and pillar system. In 
this respect it is an excellent companion piece to the one previously 
mentioned, whose dominating exhibition feature is its depiction of 
surface operations. The model covers a floor space of 8 by 12 feet. 
A relief panel illustrating processes involved in the manufacture 
of illuminating gas, tar, ammonia, and other coal products in what 
is known as the by-products coke industry, and designed to set forth 
these complicated processes in the most readily comprehensible man- 
ner. For a most admirable solution of this problem the Museum is 
indebted to Mr. C. G. Atwater, of the American Coal Products Co., 
of New York, and Mr. C. H. Ramsburg, of the H. Koppers Co., of 
Chicago, in accordance with whose plans the exhibit was constructed 
in the division workshop. . 
Seven pictorial enlargements, 34 by 6 feet in size, showing typical 
underground operations incidental to coal mining, the gift of the 
Jeffry Manufacturing Co., of Columbus, Ohio, are remarkable ex- 
amples of photographic art, in view of the extreme difficulty of the 
subject, and add greatly to the educational value of the coal series 
now being developed. 
A series of native gypsum and gypsum products, presented by the 
United States Gypsum Co., of Chicago, Il., which has given gen- 
erous cooperation in connection with the entire subject, forms part 
of an industrial exhibit designed to cover the occurrence, mining, 
treatment, and industrial adaptability of this mineral. 
A collection illustrating crude mica and its industrial products, 
constituting part of an exhibit in which the occurrence, technology, 
and uses of mica will be summarized, contributed by the Westing- 
house Electric Manufacturing Co., of East Pittsburgh. A most 
remarkable 45-pound specimen of pure mica in its natural condition 
was the gift of the Ridgeway Mica Co. 
The materials pertaining to mineral technology, which had been 
accumulating previous to the organization of the division, were 
found packed in more or less inaccurately or incompletely labeled 
boxes, stored in various places. During last year all of these boxes 
except such as contained only ornamental terra cotta were opened 
and suitable disposition made of their contents. The greater por- 
tion of the specimens proved to be wholly unsuitable for use along 
the accepted lines of development of the division, and were either 
returned to the donors or destroyed. Of the remainder, a part was 
listed and filed away, to be drawn upon as required, and the balance 
at once prepared for exhibition, which demanded extensive repairs 
and cleaning, and in some cases even rebuilding. The principal 
exhibits so attended to were the large working model of the Con- 
solidation Coal Co.’s colliery at Fairmont, W. Va.; the colliery 
