TIDES AND CURRENTS IN BOSTON HARBOR 57 



Table 10. — Low-water lunitidal interval, Commonwealth Pier No. 5 



Table 11. — Duration of rise of tide, Commonwealth Pier No. 5 



Table 12. — Mean high water on tide staff, Commonwealth Pier No. 5 



The above heights are referred to the tide stafiE installed in September, 1922, the zero of which is 21.45 feet 

 telow bench mark 7. 



