a Inclusive of value of squares (10 by 10 feet) of roofing asphalt as follows: 1922, 588,636 squares, $870,200; 1923, 783,028 squares, $1,124,491. Corresponding exports not separately shown prior to 1922.

Asphalt exported from the United States in 1923, by countries

North America:

Canada.
Central America-

Costa Rica.
Guatemala..
Honduras.
Panama

Salvador
Mexico.
Newfoundland and Labrador
West Indies-
British-

Bermuda
Jamaica..

Other
Cuba.
Dominican Republic.
Dutch
French.

Haiti.
South America:

Argentina. Bolivia. Brazil.. Chile. Colombia Ecuador Guiana

British

Dutch. Peru. Uruguay

Venezuela.
Europe:

Belgium
Denmark
Finland.
France.
Germany
Greece.
Italy
Netherlands.
Norway
Portugal
Spain.
Sweden
Turkey.
United Kingdom-

England.
Ireland

Scotland.
» Less than 1 ton

10, 573

110 7, 432 20, 990

336 5,321

546
191
10

21, 721

16 22, 809 6,831

619

Asphalt exported from the United States in 1925, by countries—Continued

Asia:

China.
East Indies
British

India.
Straits Settlements.

Other..
Dutch..

French Indo-China.
Hongkong
Japan..
Java and Madura.
Kwangtung, leased territory
Palestine and Syria.
Philippine Islands.

Siam.
Africa:
British

East.

South.
Canary Islands.
Egypt.
French-

Algeria and Tunis.

Other.
Morocco.

Portuguese East.
Oceania:
British

Australia.
New Zealand.

753
11

14, 193

345

• Less than 1 ton.

1

PRODUCERS
The following operators reported to the United States Geological
Survey that they produced asphaltic material from crude petroleum
in the United States in 1923:

Atlantic Refining Co., 260 South Broad Street, Philadelphia, Pa.
Byerlyte Co., 2484 West Fourth Street, Cleveland, Ohio.
Craig Oil Co., Toledo, Ohio.
Freeport Gas Co., Freeport, Tex.
Gulf Refining Co. Frick Building Annex, Pittsburgh, Pa.
Harbor Refining Co., 2475 East Ninth Street, Los Angeles, Calif.
Indian Refining Co., Lawrenceville, Ill.
King Refining Co., 255 Holbrook Building, San Francisco, Calif.
Magnolia Petroleum Co., Box 1667, Dallas, Tex.
Mexican Petroleum Corporation, 120 Broadway, New York, N. Y.
Paraffine Companies (Inc.), 475 Brennan Street, San Francisco, Calif.
Pioneer Asphalt Co., Lawrenceville, Ill.
Pioneer Paper Co., 247 South Los Angeles Street, Los Angeles, Calif.
Producers Refining Co., Bakersfield, Calif.
Seaside Oil Co., Summerland, Calif.
Sinclair Refining Co. of Louisiana, 45 Nassau Street, New York, N. Y.
Standard Oil Co. of California, 200 Bush Street, San Francisco, Calif.
Standard Oil Co. of Indiana, 910 South Michigan Avenue, Chicago, Ill.

(plants in Illinois, Indiana, and Missouri).
Standard Oil Co. of Louisiana, Baton Rouge, La.
Standard Oil Co. of New Jersey, 26 Broadway, New York, N. Y.
Sun Co., Finance Building, Philadelphia, Pa.
Texas Co., Houston, Tex.
Union Oil Co. of California, A. G. Bartlett Building, Los Angeles, Calif.
United States Asphalt Refining Co., 90 West Street, New York, N. Y.
Warner Quinlan Asphalt Co., 79 Wall Street, New York, N. Y.

Native asphalt and related bitumens were produced commercially in this country in 1923 by the following operators:

Alabama Rock Asphalt Co., Florence, Ala.
American Asphalt Association, 918 Wainwright Building, St. Louis, Mo.
City Street Improvement

Co., 400 California Street, San Francisco, Calif.
Continental Rock Asphalt Co., Dwight Building, Kansas City, Mo.
Crown Rock Asphalt Co., 911 Neave Building, Cincinnati, Ohio.
Ferron, Fred, Duchesne, Utah.
Gilson Asphaltum Co., 1900 Land Title Building, Philadelphia, Pa.
Glafcke, Ludlow B., Dooly Block, Salt Lake City, Utah.
Kentucky Rock Asphalt Co., 712 Paul Jones Building, Louisville, Ky.
Natural Rock Asphalt Corporation, Owensboro, Ky.
Ohio Valley Rock Asphalt Co., 1403 Starks Building, Louisville, Ky.
Sattler & Stevens, Carpinteria, Calif.
Texas Rock Asphalt Co., San Antonio, Tex.
Utah Gilsonite Co., Watson, Utah.
Uvalde Rock Asphalt Co., San Antonio, Tex.

By B. H. STODDARD

PRODUCTION

The domestic mica industry in 1923 showed substantial increases over 1922 in quantity and value of both sheet and scrap mica sold by producers during the year, the total quantity of sheet mica sold being 2,063,179 pounds (1,032 short tons), valued at $311,180, and of scrap mica (which includes some derived from mica schist) 8,054 short tons, valued at $129,695. The total quantity and value of all mica sold represents increases of 27 and 43 per cent, respectively. Sales of sheet mica showed increases of 91 per cent in quantity and 60 per cent in value. Scrap mica, the quantity of which was the largest ever recorded, showed increases over 1922 of 21 per cent in quantity and 14 per cent in value. The average value of sheet mica was 15 cents a pound, against 18 cents in 1922, and the average value of scrap mica was $16 a short ton, against $17 in 1922. North Carolina and New Hampshire reported 95 per cent of the total quantity of sheet mica and 76.per cent of the scrap mica sold in 1923.

The figures for sheet mica shown in the following table represent uncut sheet mica and punch mica. A very small quantity of splittings

A is also included as uncut sheet.

Mica sold by producers in the United States, 1919–1923

• The figures for sheet mica in 1920-1923 are not strictly comparable with those for earlier years, as they represent uncut sheet mica exclusively: Prior to 1920 some cut sheet mica was included.

Includes mica derived from mica schist.

The sales were made by producers in 11 States-North Carolina, New Hampshire, New Mexico, Virginia, South Dakota, Wyoming, Georgia, Colorado, Connecticut, South Carolina, and New York, named in order of total quantity of mica sold.

Domestic mica sold by producers in certain States, 1919–1923

Sales in New Mexico greatly exceeded those in 1922, being 30,300 pounds of sheet mica, valued at $8,489, and 898 short tons of scrap mica, valued at $16,417. In 1923 South Dakota sold 324 short tons of scrap mica, valued at $6,480. Sales in the other States—Colorado, Connecticut, New York, South Carolina, and Wyoming—were comparatively small.

CLASSIFICATION OF MICA Mica is valuable in sheet form and as scrap suitable for grinding into a powder. For commercial sheet mica the individual pieces must be large enough to contain a rectangular area measuring at least 142 by 2 inches, which must split easily and evenly and be nearly free from "cracks," "rulings,

- rulings," "markings,

"markings,” and all fracture lines and reasonably free from inclusions or specks of foreign mineral matter. The size stated is the smallest rectangular size that is salable in the form of uncut sheet; the irregularly bounded roughtrimmed mica sheet must be nearly twice as large to yield this size in other words, a sheet that would yield a suitable rectangle 142 by 2 inches and would be classed as “12 by 2 inches” would have to measure nearly 3 by 4 inches.

Splittings are the thin films or flakes of mica that are split from the smaller sheet or waste material. They are about one-thousandth of an inch thick and are irregular in shape.

Material suitable as scrap mica for grinding must be free from all foreign matter, especially gritty material such as quartz and feldspar.

The system of classification of mica, by sizes, is different in the United States, Canada, and India. The United States classification is as follows (figures represent inches): Punch, circle, 192 by 2, 2 by 2, 2 by 3, 3 by 4, 3 by 5, 4 by 6, 6 by 6, 6 by 8, 8 by 10, and larger.