60 



U. S. COAST AND GEODETIC SURVEY 



Table 18. — Monthly extreme high wafer above sea-level datum, Commonwealth 



Pier No. 5 



1925: 

 Jan. 25, 26..., 

 Feb. 23, 25... 

 Mar. 25, 28... 



Apr. 12 



May 11 



June 9 



Ju]y8 



Aug. 6, 7 , 



Sept. 3 ., 



Oct. 5, 25 



Nov. 16 



Dec. 17 



Highest 



Average 



1926: 



Jan. 15 



Feb. 10 



Mar. 13, 14.... 



Apr. 1 



May 10 



June 26 



July 24, 25, 27. 



Aug. 25 



Sept. 20, 21, 22. 

 Oct. 20 



Height 



Feet 



6.7 

 6.4 

 5.5 

 6.3 

 6.2 

 7.0 

 6.8 

 6.7 

 6.7 

 6.2 

 6.9 

 6.7 



7.0 

 6.51 



1926: 



Nov. 19 



Dec. 11 



Highest 



Average 



Monthly aver- 

 ages for entire 

 series: 



January 



February... 



March 



April 



May 



June 



July.. 



August 



September.. 



October 



November.. 



December. - 



Average 

 for series 



Height 



Feet 

 7.0 

 6.9 



7.8 

 6.73 



6.76 

 7.04 

 6.56 

 6.80 

 6.58 

 6.70 

 6.62 

 6.58 

 6.57 

 6.77 

 7.15 

 6.62 



Highest tide of these observations was 7.8 feet above the sea-level datum and occurred on Nov. 29, 1921 

 and on Feb. 10, 1926. 

 The heights in the above table are referred to the sea-level datum defined on p. 41. 



Table 19. — Monthly extreme low water below sea-level datum, Commonwealth 



Pier No. 5 



Height 



1926: 

 Nov. 20. 

 Dee. 19. 



Heigh I 



Feet 

 6.8 

 6.9 



Lowest tide of these observations was 8.2 feet below the sea-level datum and occurred on Apr. 3, 1923. 

 The heights in the above table are referred to sea-level datum defined on p. 41. 



