200 TUNNELING 



Length of all sections, ft 109,570 



Total excavation of earth, cu. yds 1,700,228 



Earth to be tilled back, " 773,093 



Rock excavated, " 921,128 



Rock tunneled, " 368,606 



Steel used in structure, tons 65,044 



Cast iron used, " 7,901 



Concrete, cu. yds 489,122 



Brick, " 18,519 



Waterproofing, sq. yds 775,795 



Vault lights, " 6,640 



Local stations, number 43 



Express stations, " 6 



Station elevators, " 10 



Track total, lin. ft 305,380 



" underground, lin. ft 245,514 



" elevated, " 59,766 



In addition to the construction of the railway itself, it will 

 oe necessary to construct or reconstruct certain sewers, and to 

 adjust, readjust, and maintain street railway lines, water pipes, 

 .subways, and other surface and subsurface structures, and to 

 relay street pavements. 



The total cost of the work, according to the contract signed 

 by Mr. McDonald, will be $35,000,000. Dividing this amount 

 by the total length of the road, which is 109,570 lineal feet, 

 we have the unit cost a lineal foot $315, or a little less than 

 unit of cost of the Boston subway, which was $342 per 

 lineal foot. 



The road belongs to the city. The contractor acts as an 

 agent for the city in carrying out the work, and he is the leaser 

 of the road for fifty years. The work is paid for as soon as 

 the various parts of the road are completed, and the money is 

 obtained from an issue of city bonds. During the fifty years' 

 lease the contractor will pay the interest plus 1 % of the face 

 value of the bonds. This 1 / goes to the sinking-fund, which 

 -within the fifty years at compound interest forms the total sum 

 required for the redemption of bonds. 



