TABLES I 
TABLE 30. THE PROBABLE USEFUL LIFE OF VARIOUS 
ARTICLES (Continued) 
Description. Erpect Residual" 4 thority. Remarks. 
Years - - 
Condensers (continued) 
old equipment. ........... 20 S.J. L. &. P. Co. Cal R. R. Com. rate hear’gs. 
25 Trac. Val. Com. Chi. Union Trac. Co. Case. 
Conduis......0.... el all 50 Wis. R. R. Com Milwaukee 3¢ Fare Case. 
50 St. L. P. S.C. Union Elec. L. &P. Co., Case. 
100 Floy 3rd Ave. Case N. Y. City. 
mains... 0. 30 15% Parsons Jour. Inst. E. E., 1907. 
ucts. vais lr SE Hammond Jour. Inst. E. E., 1907. 
“solid ” system...........I 30 Hammond Jour. Inst. E. E., 1907. 
* ducts ” system..........| 30 Hammond Jour. Inst. E. E., 1907. 
““solid ”’ sys. in wood... . . .. 40 12% Preece Report Bristol Corp., 1906. 
clay in concrete. .......... 50 0% Chi. Tel. Com. Chicago Telephone Com. 
fibre in concrete. .......... 20 0% Chi. Tel. Com. Chicago Telephone Com. 
subsidiary............ ...0 20 0% Chi. Tel. Com. Chicago Telephone Com. 
main-vitrified clay. ....... 50 0% Tel.“ Data” Quoted by H. A. Foster. 
main-concrete. ............ 53 0% Tel. “ Data” Quoted by H. A. Foster. 
main-fibre................ 20 0% Tel. * Data” Quoted by H. A. Foster, 
main-iron................ 20 0% Tel. “ Data” Quoted by H. A. Foster. 
main-creosoted wood. .. ... 20 0% Tel. “ Data” Quoted by H. A. Foster. 
subsidiary... .......000 I5 0% Tel. *“ Data Quoted by H. A. Foster. 
vitrified tile..............} 50 P.G.&E. Co. S.F. rate hearings, 1913-14. 
vitrified tile and fibre. . ... 40 P. G. & E. Co. S. F. rate hearings, 1913-14. 
fibre duct..............:: EE P.G.&E.Co. S.F.rate hearings, 1913-14. 
wrought iron pipe. ........ 20 P. G. &E. Co. S. F. rate hearings, 1913-14. 
Edison tube and fittings...: 20 15% P.G.&E.Co. S.F.rate hearings, 1913-14. 
paperconduit............) 25 P. G. & E. Co. S. F. rate hearings, 1913-14. 
wood conduit. ............ 25 P. G.&E. Co. S. F. rate hearings, 1913-14. 
w. i. lateral pipes.......... 15 P.G.&E. Co. S. F. rate hearings, 1913-14. 
conduit under tracks. . . ... 40 P. G.&E. Co. S. F. rate hearings, 1913-14. 
manholes and paving. ..... 40 P. G. & E. Co. S. F. rate hearings, 1913-14. 
service holes and paving. . 40 P. G.&E. Co. S. F. rate hearings, 1913-14. 
Converters 
static transformers. ....... 15 Hammond Jour. Inst. E. E., 1907. 
cs MNCRVRMIRG I feb loll 20 Hammond Jour. Inst. E. E., 1907. 
CONDENS. oo is cilia su is 10 Hammond Jour. Inst. E. E., 1907. 
Cranes... ivi ih rh 15 Chi. U. T. Co. Chi. Union Trac. Co. Case. 
20 Stone & Webs. Chi. Union Trac. Co. Case. 
50 Wis. R. R Com Milwaukee 3¢ Fare Case. 
50 Arnold 4 Chicago Appraisals. 
Woolen, .... tu. dey 15 P. G.& E. Co. S. F. rate hearings, 1913-14. 
SUEEL..... 0s iii suv iiv same 
as bldg P. G. & E. Co. S. F. rate hearings, 1913-14. 
Culverts 
CRSEIION. oa vu. coun vss DR 16 Cal. R. R. Com Stockton Term.& East Case. 
log and timber. ........... 163 Gillette Gt. Nor. & N. P. R. R. Ap 
praisal. 
Dams 
arth... ie. i iris oR T00 Cal. R. R. Com Cuyumaca Water Co. Case. 
earth and loose rock.......i so S.J. L. & P. Co. Cal. R. R. Com. rate hear’gs. 
COMOTEEE. ars en 50 S.J. L. & P. Co. Cal. R. R. Com. rate hear'gs. 
concrete diverting........ | 100 Cal. R. R. Com. Cuyumaca Water Co. Case. 
fer dan 
A323;