All purchased stock, material, and stores are turned over to the General Storekeeper, whose duty it is to classify them, store them properly, and issue them only on properly authorized requisitions. A large portion of his stock he obtains by making requisitions upon the Purchasing Agent. To account properly for the receipts and issues of this stock so as always to have on hand what is wanted, and at the same time to avoid carrying an unnecessarily large stock of any of the articles in store, he uses a _Stock Ledger Card_ of the form shown in Fig. 22. This gives the name of the article listed, and its dimensions, weight, etc. At the right of this are entered the maximum and the minimum quantities to be kept in stock. Whenever the stock on hand is reduced to near the minimum quantity, the Purchasing Agent is requested to order enough more to bring the quantity up to the maximum. [Illustration: Fig. 22. Stock Ledger Card. Same form is printed also on back of card.] [Illustration: Fig. 23. Form of Requisition. Carbon copies of the entries are made on the Invoice form, Fig. 24.] In making requisitions upon the Purchasing Agent, the Storekeeper must take into consideration the length of time necessary to obtain the article wanted. Wire nails, wood screws, and such articles can usually be obtained in 24 hours, while brass tubing may take three weeks. Iron castings can be had in two days, while steel castings will frequently require six weeks. When articles are _received in stores_, the date and quantity will be entered under the heading _Received_, and other quantities added to these as received. Articles issued will be charged under the heading _Issued_, giving the date and amount. The quantity on hand may be quickly ascertained by adding the quantities received and the quantities issued, and subtracting the sum of the issues from the sum of the receipts. [Illustration: Fig. 24. Form of Invoice. Entries are made by means of carbon paper, duplicating those made on the Requisition form, Fig. 23.] As most articles are purchased in considerable quantities and issued in small lots, there will be few entries of receipts and a large number of entries of issues; therefore the greater portion of the card is devoted to records of issues. The card is printed with the same form on both sides; and when the spaces on the first side are filled, the account is balanced, and the results carried to the opposite side. These cards are kept in filing drawers, where they are located in alphabetical order by the names of the articles they represent.