Editorial Coiiinicnt. iii 
and glaciation ; (3) volcanoes and volcanic activity; (4) con- 
cretionary structures in crystalline and fragmental rocks (see 
pi. XII ), and (5) faults, folds and other phenomena produced 
by purely dynamic agencies. In addition to these there is a 
systematic series of rocks and fossils from the various geolog- 
ical horizons of America. 
Some of the more striking of the exhibits in this division 
are shown in the accompanying illustrations. The collections 
in this section now occupy a floor space of but 50 by 90 feet. 
At the time Dr. Hawes entered upon his duties as curator, 
he also assumed charge of that branch of the tenth census re- 
lating to the quarry industry of the United States. To this 
work he gave almost his entire attention, and although his la- 
bors were unfortunately cut short when little more than a be- 
ginning had been made, yet the carrying out of the work as 
planned resulted in the accumulation of several thousand sam- 
ples of building and ornamental stones, and the large mass of 
information relating thereto which appeared in volume X of 
the reports of the tenth census. Out of the materials thus col- 
lected upwards of 3,000 specimens were dressed in the form of 
four inch cubes for exhibition purposes. These have been de- 
scribed by the present head (then assistant) curator in a hand- 
book of some 370 pages, published in connection with the an- 
nual report for 1886. Another important collection is a series 
of metallic ores and non-metallic minerals arranged on a geo- 
graphic basis, i. e., by states, and a large series of economic 
materials arranged on one of the recently completed galleries 
in the southwest court, a section of which is shown in plate i. 
This last collection alone comprises upwards of 4,000 speci- 
mens, the non-metallic portion of which has been described in 
the report of the National Museum for 1899, just issued. 
Space has also been devoted to collections illustrating the 
methods of treatment of ores, and reference should be made to 
an important series illustrating the extraction of gold, silver, 
lead, copper, zinc, iron and the manufacture of steel. This 
series, together with a descriptive catalogue of the systematic 
^collections in economic geology, was described in Bulletin No. 
42 of the National Museum, published in 1891. These series 
are very complete and illustrate all stages of the process from 
the crude ores to the linishcd product, with also the fuel, fluxes 
