As a cost accountant for San Francisco Cannery, you have been approached by Phil Perriman, canning room supervisor, about the 2017 costs charged to his department. In particular, he is concerned about the line item "depreciation." Perriman is very proud of the excellent condition of his canning room equipment. He has always been vigilant about keeping all equipment serviced and well oiled. He is sure that the massive charge to depreciation is a mistake; it does not reflect the cost of minimal wear and tear that the machines have experienced over the last year. He believes that the charge should be considerably lower. The machines being depreciated are six automatic canning machines. All were put into use on January 1, 2017. Each cost $625,000, having a salvage value of $55,000 and a useful life of 12 years. San Francisco depreciates this and similar assets using double-declining-balance depreciation. Perriman has also pointed out that if you used straight-line depreciation, the charge to his department would not be so great. Write a memo to Phil Perriman to clear up his misunderstanding of the term "depreciation." Also, calculate year-1 depreciation on all machines using both methods. Explain the theoretical justification for double-declining-balance and why, in the long run, the aggregate charge to depreciation will be the same under both methods. Note: This memo need not be formal.