56 U. S. COAST AND GEODETIC SURVEY 



Table 7. — Mean tide level on original tide scale, Boston Navy Yard 



1 Records for year incomplete; see note 1, Table 2, p. 50. 



Mean tide level from entire series is 20.12 feet on original tide scale. 



Above table is derived from the mean high and low water heights given in Table 2. 



Tabi-e 8. — Mean tide level referred to sea-level datum, Boston Navy Yard 



1 Records for year incomplete; see note 1, Table 2, p. 50. 



Mean tide level from entire series is 0.06 feet below sea-level datum. 



Above table is derived by referring the values in Table 7 to the sea-level datum defined on p. 41 



Table 9. — High-water lunitidal interval, Commonwealth Pier No. 5 



