With the object in view of doing away with the mistakes that were continually being made in the operation of the time─book system, the check system was introduced. This was probably the first attempt at automatic time recording. Under the check system, each man is assigned a number and given a brass check on which his number is stamped. In entering the works the men are required to pass in front of the time─keeper's office and to hand in their checks. The time─keeper has, in his office, a large board with hooks numbered to correspond with the check numbers. As the checks are handed in they are hung in their proper places on this board. The checks on the board show what men are in the works, and from them the necessary entries are made in the time books. When the men pass out at noon their checks are handed to them. Every man must pass out and take his check; otherwise he will not receive credit for the half─day's time. The system does not prove entirely satisfactory for several reasons. It is not exact, for no accurate record of the time a man enters is possible. Usually the time─keeper's window is closed at starting time and opened fifteen minutes later to take care of the late arrivals. Thus the man who is one minute late pays the same penalty in lost time as the man who comes in fifteen minutes after the whistle blows. As a natural result, when a man finds that he cannot reach the works on time he takes the full fifteen minutes. While the handing in of a check furnishes reasonable proof that the man has entered the works, it furnishes no proof that he is at his work. Many a man has turned in his check in the morning, left the works by another exit, returned a few minutes before noon, received his check and full pay for the half day. In some manufacturing plants where the check system is still used, this difficulty has been overcome to a certain extent. The operation of the system is reversed, the men receiving their checks from the time─keeper as they enter the works. In the shops there are check boards on which the men hang their checks. These boards are hinged and provided with locks, the keys being carried by the foremen. Five minutes after starting time the boards are locked, and late arrivals are required to turn in their checks to the foreman who makes records of the time of arrival. Once during each working period, the time─keeper makes the rounds of the shops and takes the time records in his time book. At the quitting hour the boards are unlocked, the men take their checks as they pass out, and turn them in at the time─keeper's office. =9. Time Clocks.= The modern system of time recording makes use of a time clock or mechanical recorder. Instead of trusting to the accuracy of a time─keeper, or depending on the workmen to keep records of their own time, the modern recorder automatically records the time of arrival and departure of every employe.