436 VALUATION, DEPRECIATION AND THE RATE-BASE
Eight years in a twelve-year probable life table is fairly com-
parable with 6.67 years in a ten-year table and with 10 years
in a fifteen-year table.
Remaining value (at 6 per cent):
For age 6.67 years from the ten-year table........... .... . $58.80
For age 10 years from the fifteen-year table................ _62.30
Difference... LLL coll LLL ad tc S12 SO
or approximately 58.80 + 2 X 3.50 = $60.20.
It remains to be noted that when remaining value is to be
determined age may be entirely disregarded when expectancy
can be ascertained by an inspection of the article in question.
The condition of the article and all other circumstances affecting
its serviceability being taken into consideration its probable
remaining term of service or its expectancy is estimated. In this
case it will be more convenient to use Table 33 than Table 31.
Select the subdivision of Table 33, corresponding with the
probable life new of the article, and use only the headings of the
columns at the bottom of the page. For the expectancy noted
in the right-hand column, the remaining value and the accrued
depreciation will be found in their respective columns. Inter-
polation may be resorted to for fractional years if this refinement
be thought desirable.
Because expectancy in the case of individualized articles which
have been long in use can best be determined by inspection and
by a consideration of local circumstances affecting continued
serviceability, it has been thought sufficient to note values in
the long-term subdivisions of Table 31 and for articles long in
service only for every fifth or every tenth year.
To find the current depreciation of any single article in any
year by the use of Table 31 subtract from its remaining value
at the beginning of that year the remaining value at the begin-
ning of the following year.
Example. — What is the current depreciation in the sixth year,
at 6 per cent interest, of an article whose probable life is 15 years?
Remaining value at the beginning of the sixth year........... $76.90
Remaining value at the beginning of the seventh year......... 2.60
Depreciation in the sixth year........ $4.30
