TIDES AND CURRENTS IN BOSTON HARBOR 47 



Bench mark 10 (established in 1922) is a Coast and Geodetic Survev standard 

 •disk, stamped "10/1922" set in water table about 2 inches above sidewalk on 

 F Street side of No. 423 West Broadway, 45.6 feet from front of building. In 

 1922 building was occupied by F. W. Woolworth Co. store. Elevation, 44.675 

 feet above sea-level datum; 49.55 feet above Boston low-water datum. 



Bench mark "481 West Broadway" (established by Boston city engineers) is 

 a Boston city bench mark, on the right buttress of the stone stairway at No. 481 

 West Broadway. The right outer corner of the buttress, facing the building. 

 Elevation, 59.15 feet above sea-level datum; 64.02 feet above Boston low-water 

 datum. 



Bench mark "82 G Street" (established by Boston city engineers) is a Boston 

 city bench mark on the right buttress, facing the building, at the side of the 

 stairway at No. 82 G Street. The lower outer corner of the buttress. Elevation, 

 104.183 feet above sea-level datum; 109.05 feet above Boston low-water datum. 



Bench mark 11 (estabhshed in 1922) is a Coast and Geodetic Survey standard 

 disk, stamped "11/1922," set in north end of fifth marble step inside iron gate 

 and back of north gatepost at entrance to Washington Monument in Thomas 

 Park, Dorchester Heights, South Boston. Elevation, 143.884 feet above sea- 

 level datum; 148.75 feet above Boston low-water datum. 



Bench mark 12 (established in 1922) is a Coast and Geodetic Survey standard 

 disk, stamped " 12/1922," set in top of step at right of doorway on entering build- 

 ing at north entrance to South Boston High School. Elevation, 111.578 feet 

 above sea-level datum; 116.45 feet above Boston low-water datum. 



CAMBRIDGE 



The following bench marks are referred directly to the Boston 

 standard datums by spirit-leveling connections : 



Bench mark E2, at East Cambridge, Middlesex County, about 600 feet north 

 of the Boston & Maine Railroad depot, in the top of the footing at the east end 

 the north abutment of the bridge carrying the Southern Division over the Fitch- 

 burg Division, 4 feet east of the east rail and 2 feet above the Fitchburg Division 

 track level. A brass disk. Elevation, 9.16 feet above sea-level datum; 14.03 

 feet above Boston low-water datum. 



Bench mark "Massachusetts Institute of Technology" is in the basement of 

 the Massachusetts Institute of Technology, in the floor in front of the door to room 

 3-019, in the concrete cap on a pile driven into the ground and covered by an 

 iron plate in the floor. A brass plug in the concrete cap. Elevation, 5.203 feet 

 above sea-level datum; 10.07 feet above Boston low-water datum. 



Bench mark " Cambridge City" is in the top at the west end of the north abut- 

 ment of Harvard Bridge carrying Massachusetts Avenue over the Charles River, 

 at the street level and on the Charles River Road, 2 feet from the railings on the 

 bridge. A brass plug. Elevation, 14.951 feet above sea-level datum; 19.82 

 feet above Boston low-water datum. • 



BROOKLINE 



The following bench marks are referred directly to the Boston 

 standard datums by spirit-leveling connections: 



Bench mark Q2 is about 300 feet west of the west end of the Boston and Albany 

 Railroad depot at Brookhne, 5 feet south of the south rail, in the center of the 

 south abutment of the Boston & Albany Railroad bridge No. 1.56, 3 feet above 

 the ground. A brass disk. Elevation, 17.743 feet above sea-level datum; 22.61 

 feet above Boston low-water datum. 



Bench mark "Van Orden St. Marys Street" is at the east end of the north 

 abutment of St. Marys Street Bridge over the Boston & Albany Railroad tracks, 

 in the top of the second stone. A chiseled square. Elevation, 11.706 feet above 

 sea-level datum; 16.58 feet above Boston low- water datum. 



NEPONSET RIVER RAILROAD BRIDGE 



The following bench marks are referred to the Boston standard 

 datums through the primary tide station at Commonwealth Pier No. 



