Photographic Reduction of Drawings Photographs of drawings, made on a reduced scale, are useful for superintendents of erection or others engaged on extensive works, for storing in safe-deposit vaults, or for any other purposes where the information on the cumbersome original is required to be preserved in compact form. In making tracings that may have to be so copied, the usual rules for preparing drawings for photographic reproduction should be followed; that is to say, details must be bold and open, lines well separated one from another, and, above all, lettering and descriptive symbols must be readily legible. The "Photo-print" process now in use, by which tracings, blueprints, paper drawings, etc., may be photographed on sensitized paper and delivered in a few minutes time and at a reasonable cost, presents increased opportunities to the use of photo-reductions of drawings. BILLS OF MATERIAL Bills of material may range in importance from a table on the drawing used merely to amplify the information thereon given, to a combined List of Material Required for 1 Carrier. bill, production-order, and routing chart to which the drawing is only an explanatory attachment. An example of a very usual type of bill of material written on the drawing itself is given in Fig. 215; while an example of the more complete type mentioned is shown by Fig. 216, being a form used by a modern general-manufacturing shop. SEC. IV. CATALOGUE FILING AND INDEXING A collection of the catalogues of the various manufacturing and supply companies may very well form a library hardly less valuable than that of the usual engineering text books. This fact is recognized by all the large engineering firms, and the libraries of these companies provide for the filing and indexing of trade catalogues in the same manner as for books, periodicals, reports, etc. Smaller concerns, however, very frequently do not get as much good out of their collection of catalogues as they might under a suitable system of filing and indexing. Several systems are outlined below, each adapted to different requirements and points of view. The filing and indexing of trade literature presents certain peculiar difficulties. There are no standards of size, arrangement, or methods of binding this material. A large and heavy volume and a two-leaf pamphlet may refer to exactly the same class of material and would logically be placed side by side on the shelves. One concern may issue separate booklets for each line of material manufactured, and another may catalogue thousands of widely varying articles under one cover. Also, one firm may issue one well-bound book at long intervals, and another may send along pamphlets every few weeks to be bound in a loose-leaf binder provided with the first few leaflets. In each instance, most probably, the exigencies of the business render each method the best for the conditions. Any system of filing and indexing must take due note of these circumstances, in addition to providing for the present and future requirements of consultants. A CATALOGUE FILING SYSTEM FOR A SMALL PURCHASING AGENT'S OFFICE The name used above ("small purchasing agent's office") merely refers to one of a class having similar requirements. The purchasing agent usually has an intimate knowledge of the names of manufacturing and supply concerns, and the class of goods they handle. He requires a system that will locate at once the Blank Mfg. Co's. catalogue listing steel wheel-barrows for example: he does not care, particularly, to find out who supplies steel wheel-barrows, for he has other and better means of obtaining this information, nor is he concerned about the design of them as the draftsman might be. His system must be simple, it must keep the large catalogues and the pamphlets in separate files so that the latter will not get crushed and lost behind the former, and it must provide for the removal and rearrangement of any manufacturers' catalogue. The following system has been in use for several years in a purchasing agent's office and has been found to answer the above requirements. The catalogues are arranged on the shelves according to their size or binding; thus, all the large, heavily bound ones are placed together, the medium-sized ones are together, the small "pocket-size" ones are grouped on shelves of less height, and finally, pamphlets and leaflets are placed in stout envelopes or ledger files and are filed vertically on the shelves. A letter mark is given to each of the above classifications; "A," "B," "C," "D," etc.-eight or ten are usually enough-and this letter is used as a prefix to a number for each catalogue on that shelf. Thus, the catalogues will be numbered A1, A2, B1, B2, etc., the numbering starting at "1" for each letter; the catalogues being filed, of course, according to their number. The mark should be written on a small gummed label and pasted on the upper left-hand corner of the cover. For indexing, a card index is used, cards 3 in. × 5 in.; a sample card is shown in Fig. 217. The cards are filed alphabetically, with a set of tabs of a suitable number of divisions to aid in quick location of a card. The user looks up in the card index the name of the manufacturer and is shown at once the number of the catalogue. As there is no necessity for filing all the catalogues of one concern side by side, or of getting all catalogues on one class of article together, the system is capable of unlimited extension. Care must be taken, FIG. 217.-Sample card, 3 in. × 5 in. for catalogue index. of course, to fix up the card index whenever a catalogue is permanently removed or replaced by a new edition differently arranged. A cross index may be compiled if desired, based on the article manufactured and referring to the manufacturer, but its utility is doubtful in a small office. A CATALOGUE FILING SYSTEM FOR A SMALL ENGINEERING OFFICE The draftsman or engineer who wishes to consult a catalogue library knows little, as a rule, concerning the names of the manufacturers. What he wants is to get together, with a minimum of effort, as many catalogues as possible illustrating and describing, say, high-speed fourvalve engines. It is necessary, therefore, that all catalogues on one subject be grouped together on the shelves, so that all may be withdrawn at one motion. At the same time a system of indexing must be used that will enable the ready location of the catalogues of any given manufacturer. Furthermore, inasmuch as many engine builders for example, will list a great variety of engines in one catalogue (and will often include boilers, tube-cleaners, and what not), it is necessary that there be an index refer |