(a) The inability to fix a standard for the efficiency of the labor lays the man─hour rate open to criticism. Could this be done, this method would in many cases prove a very equitable way of distributing expense. It will, however, be seen at once that as it is, a skilled workman carries no more expense than an apprentice boy, and if both work on a productive job a full week, the expense in either case is the same regardless of the wages paid. This is hardly a fair proposition. Either the apprentice's time must be accepted as standard and the skilled workman considered twice as efficient in work─hours, or _vice versâ_. To do this would lead to endless complications, yet the quantity and quality of the output between these two classes of labor should be considered and adjusted in some way so that the injustice done the manufacturing cost may be corrected. But this is not an easy matter to regulate, and means extra work on the part of the cost clerks in recording the time spent on job work and adjusting these inequalities in the labor. (b) The man─hour rate requires that the hours worked be carefully recorded and totaled, as well as the cost. Many concerns with heavy pay─rolls to be apportioned over a large number of job orders, ignore the footing of the long columns of hours and fractions, and use only the totals of labor cost, which are of course necessary for entry in the commercial books. It is obvious that in doing this an immense amount of clerical labor is saved. The man─hour method requires that both hours and labor cost should be recorded and totaled──a double operation and duplication of work, which, unless it can be simplified, should be avoided, as it means time and unnecessary expense. =9. Machine─Hour Rate Method.= This machine─rate plan of distributing expense was designed to meet the needs of a shop where the product is largely the result of a machine or tool operation, rather than the labor of the mechanic himself. It somewhat resembles the man─hour plan in that the rate of distributing expense is reduced to an hourly rate for the time the machine is working on the job instead of the time of the operator. Each machine is intended to have its own rate.