rk).
_Rivers_, see _Index to Reports of the Chief of Engineers_, United
States Army (3 vols., 1900, covering 1866-1900); publications United
States Geological Survey. On _population_: United States Census, 1900.
_Administration_: J. W. Mills' _Annotated Statutes of the State of
Colorado ..._ (2 vols., Denver, 1891; vol. iii. 1896); Helen L.
Sumner, _Equal Suffrage in Colorado_ (New York, 1909,); J. E. Snook,
_Colorado History and Government_ (Denver, 1904), is a reliable school
epitome.

On _history_: F. L. Paxson, "A Preliminary Bibliography of Colorado
History," being vol. iii., No. 3, of _University of Colorado Studies_
(June 1906); H. H. Bancroft, _History of ... Nevada, Colorado and
Wyoming, 1540-1888_ (San Francisco, 1890); on _labour conditions and
troubles_ consult: _Reports_ of the State Bureau of Labour Statistics
(since 1892); _Annual Reports_ of the State Board of Arbitration
(since 1898); publications of United States Bureau of Labour
(bibliographies); also especially Senate Document 122, 58th Congress,
3rd Session, covering the years 1880-1904. See also CRIPPLE CREEK and
LEADVILLE.

FOOTNOTES:

[1] The market value of silver varied in the years 1870-1885 from
$1.32 to $1.065 an ounce; 1886-1893, $0.995 to $0.782; 1894-1904,
$0.630 to $0.5722.

[2] The mineral yield for 1907, according to _The Mineral Resources
of the United States_, 1907, amounted to $71,105,128.

[3] The special census of manufactures of 1905 was concerned only
with the manufacturing establishments of the state conducted under
the so-called factory system. The capital invested in such
establishments was $107,663,500, and the product was valued at
$100,143,999. The corresponding figures for 1900 reduced to the same
standard for purposes of comparison were $58,172,865 and $89,067,879.
Thus during the five years the capital invested in factories
increased 85.1%, and the factory product 12.4%. The increase in
product would undoubtedly have been much greater but for the labour
disturbances (described later in the article), which occurred during
this interval. Of the total product in 1905 more than four-fifths
were represented by the smelting of lead, copper and zinc ores, the
manufacture of iron and steel, the production of coke, and the
refining of petroleum. The value of the flour and grist-mill product
was $5,783,421.