The final reports for the 1939 Census of Manufactures, which were published in pamphlet form (multilithed or printed), have been assembled in three bound volumes, as follows:

Volume I. General Report-Statistics by Sub-
jects.

Volume II. Part 1, Reports by Industries-
Groups 1 to 10.

Part 2, Reports by Industries-
Groups 11 to 20.

Volume III. States and Outlying Areas.

The Census of Manufactures covering the year 1939 was the twenty-third such census taken in the United States. It was also the tenth of a series taken at 2-year intervals, beginning with 1921. The first census of manufactures covered the year 1809, and a census at 10-year intervals in connection with the Decennial Census of Population was taken thereafter up to and including 1899, with the exception of 1829, at which time no census of manufactures was taken. From 1904 through 1919, the census of manufactures was taken at 5-year intervals, after which the biennial series was begun. The 1921 census and all subsequent censuses have been taken under authority contained in section 32 of the Fourteenth Census Act, and later in section 17 of the Fifteenth Census Act. The Sixteenth Decennial Census, of which the 1939 Census of Manufactures is a part, was also taken under the Fifteenth Census Act.

1. Area and period covered. The 1939 Census of Manufactures covered the 48 States and the District of Columbia, and manufacturing activities in Alaska, Hawaii, and Puerto Rico were canvassed with simplified questionnaires. The census of Hawaii and Puerto Rico related to manufacturing operations in the calendar year 1939, and that for Alaska covered the year from October 1, 1938, to September 30, 1939.

2. The canvass.-The canvass for the 1939 Census of Manufactures began on January 2, 1940, and was practically completed by the end of June, although some manufacturers failed to make their returns until some time later. The questionnaires were distributed and the returns collected by field enumerators, of whom approximately 6,400 were employed in the censuses of Manufactures, Business, and Mines and Quarries.

Logging camps and sawmills and manufacturing plants, such as planing mills, operated in conjunction with them, were canvassed in the 12 Western States

and in Alaska by employees of the United States Forest Service, of the Department of Agriculture. Forest Service employees also reviewed the production data collected from the same classes of establishments in eight Eastern States. Through a cooperative agreement with the Agricultural Marketing Service, of the Department of Agriculture, the census returns for establishments producing butter, cheese, condensed and evaporated milk, and ice cream in the State of Wisconsin were collected and reviewed by the Madison office of that Department in conjunction with its annual canvass of dairy products.

All such cooperation by other Federal departments is handled by employees who are also sworn employees of the Bureau of the Census. It is believed that this type of cooperation is of benefit to all the agencies participating, and that it results in greatly enhancing

the value of the statistics.

3. Establishments covered-type.-The censuses are confined, in general, to manufacturing industries proper. Data were collected for a few industries, however, the activities of which are not manufacturing in the sense in which the term is generally understood, the most important example being printing and publishing. The following classes of establishments are not covered by the Census of Manufactures:

(a) Those that were idle throughout the year or that manufactured during the year products which were valued at less than $5,000 (see sec. 4, below).

(b) Those engaged principally in the performance of work for individual customers, such as repair shops, custom tailor shops manufacturing products valued at less than $100,000 within the census year, and dressmaking and millinery shops (but this does not apply to large establishments manufacturing to fill special

(c) Those engaged in the construction industries.

(d) Those engaged in the so-called neighborhood industries and hand trades, in which little or no power machinery is used, such as carpentry, blacksmithing, harnessmaking, tinsmithing, etc.

(e) Cotton ginneries.

(f) Small grain mills (gristmills) engaged exclusively in custom grinding.

(g) Wholesale and retail stores that incidentally manufacture on a small scale.

(h) Educational, eleemosynary, and penal institutions engaged in manufacturing. (Data for the production of binder twine in penal institutions and of brooms in institutions for the blind were, however, collected.)

(i) Establishments engaged in the manufacture of heating, cooking, and illuminating gas, distributed through mains. (j) Electric and steam railroad repair shops.

(k) Electric light and power plants operated as public utilities.

4. Establishments covered-minimum size limit.At the biennial censuses, with certain exceptions explained in the following paragraph, data have been collected only from establishments reporting products to the value of $5,000 or more.

This

In order to reduce the cost of the work and to facilitate the preparation of the statistics, no data (except in regard to wage earners and products, for 1921, and in regard to products only for certain industries, for 1923 and 1925) were collected from establishments with products valued at less than $5,000. At the quinquennial censuses, however, data on all subjects covered by the census were obtained from all establishments with products valued at $500 or more. change in the minimum value-of-products limit, which resulted in a 21.6 percent reduction in the number of establishments in regard to which general and detailed statistics were compiled at the census for 1921, did not otherwise materially impair the comparableness of the biennial and quinquennial figures, since 99.4 percent of the total wage earners and 99.7 percent of the total value of products reported at that census were contributed by the establishments reporting products to the value of $5,000 or more.

5. Definition of establishment.-As a rule, the term "establishment" signifies a single plant or factory. Occasionally, however, separate returns are obtained for different lines of activity, assigned to different industry classifications, carried on in the same plant, in which case a single plant is counted as two or more establishments. In censuses prior to that for 1937 one return was usually counted as representing one establishment, although it might cover two or more plants operated under the same management and located in the same city, or in the same county but in different municipalities or unincorporated places having fewer than 10,000 inhabitants. For 1937 and 1939, however, the number of establishments represented by a return was determined by the respondent's answer to the question "How many plants does this report cover?" The total number of establishments was increased approximately 2,000 by this change in practice, but the change did not materially affect the number of establishments in any specific industry.

6. Classification of industries. Although there are thousands of more or less distinct lines of manufacturing activity, for practical purposes, not only to bring the number of industries within reasonable compass but also in order to group together related processes and products, it has been necessary to establish a definite number of industry classifications. For the 1937 census, 351 separate classifications were recognized; for 1939, the number was increased to 446. The expansion was based on prevailing conditions in the actual organization of industry, and the new classifications were developed in collaboration with the Committee on Stand

ard Industrial Classification established by the Division of Statistical Standards, of the Bureau of the Budget (formerly the Central Statistical Board).

7. Industry groups. To facilitate the comparison of one broad class of manufacturing industries with another, the industries as constituted for census purposes are distributed into groups each embracing those industries that are related, in most cases by the character of the principal materials used, although several of the groups are constituted on the basis of the purpose or use of the chief products, and one, "Chemicals and allied products," on that of the character of the manufacturing processes employed. It is necessary, of course, in some cases to include in a particular group certain industries that use considerable quantities of materials or manufacture considerable quantities of products other than those treated as basic for the group. For example, the "Furniture and finished lumber products" group, in which wood is the basic material, includes industries that use considerable quantities of metal in the manufacture of furniture, shelving, etc.

At the censuses for 1921 and prior years, the classification comprised 14 groups. At the census for 1923 the industries were rearranged into 16 groups, which were retained until the census for 1939, when a further rearrangement into 20 groups was made, as follows:

Group No.

1. Food and kindred products.

2. Tobacco manufactures.

3. Textile-mill products and other fiber manufactures. 4. Apparel and other finished products made from fabrics and similar materials.

5. Lumber and timber basic products.

6. Furniture and finished lumber products.

7. Paper and allied products.

8. Printing, publishing, and allied industries.

9. Chemicals and allied products.

10. Products of petroleum and coal. 11. Rubber products.

12. Leather and leather products. 13. Stone, clay, and glass products.

14. Iron and steel and their products, except machinery. 15. Nonferrous metals and their products.

16. Electrical machinery.

17. Machinery (except electrical).

18. Automobiles and automobile equipment.

19. Transportation equipment except automobiles.
20. Miscellaneous industries.

8. Classification of establishments.-Each establishment as a whole (a single plant being counted as two or more establishments in certain cases, as explained in sec. 5), is assigned, on the basis of its product or group of products of chief value, to some one industry classification.

The statistics as to cost of materials, value of products, and value added by manufacture for any particular industry relate not only to the primary products normally belonging to that industry but also to certain secondary products which normally belong to other