Engineers are prone to endeavor to apply a decimal subject classification in filing trade catalogs, with the result that they fall into many intricate difficulties. However, small offices using only a few trade catalogs on special subjects can file under subjects with other library material if desired. (The organization of an alphabetical subject file for miscellaneous data is described in Chapter VI.) All trade catalogs filed under the names of the firms should be subject card indexed, because it takes less time to make a working index than it does to look through various catalogs to find desired information when there is no index.
Trade catalog index card made under the name of the firm and showing the subject name and trade name under which additional cards have been made.
The method of indexing should be as follows: there should be a card made for the name of each firm issuing the catalog, and the address of the firm may be added to this card in order to use it as a mailing list if desired. The subjects, i. e., specific names of merchandise, which the catalog covers and any well known trade names, should be written on the face of this main card (see illustration) and additional cards made for the subjects and any important trade names, and all of the cards should be filed in a single alphabet. A Cutter number (which is explained in detail in the chapter on cataloging) may be put on each index card and trade catalog, in order to facilitate the alphabetizing and quick location of individual trade catalogs. The subject index in Thomas' Register of American Manufacturers, an invaluable tool to purchasing departments, is a great aid in selecting subject names to be used in the trade catalog index.
Photographs
Photographs are important sources of information for any business firm, as they visualize printed or written descriptions and make an accurate and unchangeable record which does not permit of any misunderstanding, as is sometimes the case in reading a printed account. Every industry should have a photograph file illustrating the various aspects of its products or the installations and construction for which it is responsible and which may be supplemented by any photographs which can be obtained on similar work done by firms other than its own.
Banks and investment houses should have photographs of all tangible properties on which they issue securities, as they have been found to be of great aid in making a stock and bond offering concrete in the mind of possible customers.
Photographs are best filed by mounting singly or in groups on a standard size photo-mount board 11 by 14 inches and put into architectural size vertical file drawers. A dry mount process by the use of gum tissue and a hot iron is much to be preferred to the ordinary method of mounting, as photographs expand when wet and shrink in drying, thus subjecting the mounting board to more or less warping unless heavy pressure is used.
A photo-mount board 11 by 14 inches in size. The title of the photograph with date when taken is lettered across the top and the classification number is shown in the upper left hand corner.