As fast as the checks are received at the cashier's desk they are checked. If one of the clerks should sell goods to a friend, and send one slip to the packer, but destroy the cashier's copy, the fraud would be detected, as the next slip which would be sent in would show by the number that the previous one was missing. The matter could be investigated immediately. The auditing departments of different stores handle the detail of the work in various ways—which, however, are about the same. Some stores, after they prove that there are no slips missing by checking the slips by the serial numbers, add them up on adding machines. As some stores do not care for a list of the slips, they use a non-listing machine, such as the comptometer. Other stores add the sales of each clerk separately, and add the totals of all the clerks to secure the total sales. The total sales of each clerk are then entered on a statistical sheet which shows a comparison of the total daily sales of each clerk for the month, as shown in Table II. The slips are then sorted according to departments, then added again, and similar information written on statistical sheets with the department numbers at the top, instead of the clerk numbers. The grand totals must agree to prove the work. The slips are then sorted according to customers. If Mrs. J. B. Jackson has bought goods in three different departments, the auditing department will pin the three slips together and mark the total of the slips to be charged to her account on the back of the under slip. If there are twelve bill clerks and twelve billing machines, all the slips will then be assorted into twelve lots, each lot representing the number of accounts taken care of by each bill clerk. TABLE II COMPARISON OF DAILY SALES OF CLERKS ══════╤═════════╤═════╤═════╤═════╤═════╤═════╤═════╤═════╤═════ │Clerk No.│ 1 │ 2 │ 3 │ 4 │ 5 │ 6 │ 7 │ 8 ──────┼─────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼───── Total │ Days │ │ │ │ │ │ │ │ 335 38│ 1 │30 50│55 45│47 70│35 35│56 78│34 25│40 56│34 79 492 53│ 2 │56 74│87 55│9 76 │87 23│54 09│19 89│86 75│90 52 etc. │ etc. │etc. │etc. │etc. │etc. │etc. │etc. │etc. │etc. ──────┼─────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼───── │ │ │ │ │ │ │ │ │ ──────┴─────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴───── Each bill clerk receives the slips in alphabetical order. The monthly folded bills are arranged in the same order. These are held in binders—a special kind, such as the Tengwall, being used—from which the bills can be easily and quickly removed. Some firms prefer to file daily in vertical files the current monthly bills, upon which the charges are being made.