Since August 1921 the U. S. Coast and Geodetic Survey has had an automatic tide gauge in operation in Boston Harbor. Periodically the elevation of the tide staff, to which the observations are referred, has been checked by leveling it to a number of bench marks. These observations now cover a little over 22 years and furnish definite data for use in the study of the vertical stability of the coast.
Marmer, H. A.. 1944. "The vertical stability of the coast at Boston in the light of recent tide observations." Journal of Marine Research 5, (3). https://elischolar.library.yale.edu/journal_of_marine_research/619