The method of arriving at the machine rate is easily understood, and reduces itself to the item of depreciation on the original cost price of the machine with its shafting, belting, tools, and installation cost figured at, say, 5%, the power to operate machine at an estimated cost per horse─power, ordinary repairs, divided by the number of hours the machine is estimated to be in operation for the same period; this will give the hourly rate of cost to operate. Some mechanical engineers advocate including in the above cost, interest on the investment at 6%, also insurance and taxes; and by others, the value of the floor space occupied by the machine is also included; but in all these latter points referred to, engineers greatly differ in opinion, and it is generally decided by each manufacturer for himself according to his own ideas. On the question of the value of machine rates there is probably more argument by mechanical engineers and accountants than on any question in factory accounting; in fact, engineers themselves are very far apart in their opinions and do not seem to agree among themselves. Accountants generally are inclined to take a somewhat different view of the situation from our mechanical friends. While it is admitted there is good argument for both positions, it is to be remembered that we are considering the question of machine rates as a means of distributing the expense account, and it seems to be the prevailing opinion among accountants that as such it is found wanting. While, theoretically, it is undoubtedly the correct solution of the problem, it is more often found in practice to be a case of a "distribution that does not distribute," and for this reason is not used by the very class of factories and machine works for which it was designed and intended to benefit. Let us consider in detail a few of the objections that may be raised to the machine─rate method: (a) It will be noticed there are other expenses in the shop than that of operating the machines and not covered at all by the machine expense. Machine rates are absolutely worthless for bench labor and the assembling room, for these two must also share in carrying the shop burden. Not to do so would be manifestly unfair. It is therefore necessary that a second distribution must be made entirely different in its calculation, to handle this undistributed expense not covered by the machine rates, which means two different operations for the same shop. This necessitates two different time records to be kept, one card for each machine showing jobs worked on and hours idle, and another time card for the workman. Is is easy to appreciate that this double operation greatly increases the clerical work in the shop, besides two sets of entries by the cost clerks, and more detail for all concerned. If a method can be found which requires but one time record to be kept, this double process can be done away with and the duplication of work avoided.