George Sutherland, United Rys Electric Company of Baltimore v…
“ Depreciation is a reserve to equalize retirements and not a reserve to equalize replacements. A rate of depreciation based upon original cost, even, is little more than an intelligent guess; but based upon reproduction costs is the blindest kind of speculation. With the known original cost of a unit and an engineer's estimate of its service life and salvage value, * * * some semblance of accuracy might be reached. To guess its service life and salvage value is bad enough but who would venture to guess what it would cost to reproduce it ten or twenty years thereafter. ”
