First Proposed (for canal) --------------------------- 1819
 Chartered -------------------------------------------- 1848
 Commenced -------------------------------------------- 1851
 Headings met ---------------------------- November 27, 1873
 Completed -------------------------------------------- 1875
 Total Length in feet ------------------------------- 25,081
 East End to Central Shaft, feet -------------------- 12,837
 Central Shaft to West Shaft, feet ------------------- 9,694
 West Shaft to West End, feet ------------------------ 2,500
 Depth central Shaft, feet --------------------------- 1,028
 Depth West Shaft, feet -------------------------------- 318
 Size Central Shaft, feet ---------------------------- 15x27
 Size West shaft, feet ------------------------------- 10x14
 Height Eastern Summit, feet ------------------------- 1,429
 Height Western Summit, feet ------------------------- 1,718
 Error in line at point of meeting ---------------- 9/16 In.
 Rock ----------------------- Mica Slate with Quartz Nodules
 Water pumped from Central Shaft gallons per minute ---- 214
 Rock excavated in tons -------------------------- 1,900,000
 Height in feet ----------------------------------------- 20
 Width in feet ------------------------------------------ 34
 Water discharged East End ------------- 100 gal. per minute
 Water discharged West End ------------- 600 gal. per minute
 Men employed ----------------------------------- 800 to 900
 Miles from Boston ------------------------------------- 136
 First Train through ---------------------- February 9, 1875
 First Freight ------------------------------- April 5, 1875
 First Passenger ----------------------------- Oct. 13, 1875
 Above Tide at East Portal, feet ----------------------- 766
 Total Length of brick arching, feet ----------------- 7,573
 Number of bricks used in arching --------------- 20,000,000
 Cost ------------------------------------------ $14,000,000
 Live Lost --------------------------------------------- 195
 Contractors, F. & W. Shanley, Montreal.
 Chief Civil Engineer, Benjamin D. Frost.

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