Page:Graphic methods for presenting facts (1914).djvu/311

 Fig. 217. A Standard 4-inch by 6-inch Filing Case Is Used for the Curve Cards. Cards Twelve Inches Long Can Be Filed Lengthwise in a Drawer without Inconvenience

Guide cards separate the curve cards by departments. If desired, blue prints can be made from each curve card and the blue prints filed by expense-account numbers, as a cross-index of the data on the white cards which are filed by departments

this total card would be filed blue prints showing the employees in each department of the whole plant. Thus, if a total card at the front showed that the employees were increasing, the manager could refer to each one of the department cards filed immediately back of the total card to see in just which departments there had been an increase during the last month, and in which department there had been a decrease. In a similar manner, the blue print showing total expenses would have filed back of it cards showing the detailed expenses by departments or by account numbers. If expenses had increased the manager could refer to the departmental or account-number cards and see just which departments or accounts were responsible for an increase or decrease in the curve giving the total. The cards in a large business would be filed by expense-account numbers, with the total card referring to any expense account for the whole business filed at the front of each group of cards giving the figures for that expense account by departments. Thus, in a manufacturing plant, the card showing the loss