CONTENTS 



Page 



Introduction 1 



Tide observations, Boston Navy Yard 2 



Tide observations, Commonwealth Pier No. 5 14 



Tide observations, miscellaneous series 18 



Current observations, 18-47 and 1848 18 



Current observations, 1860, 1861, and 1863 19 



Current observations, 1902 21 



Current observations, 1926 ' 21 



Current observations, Boston Light Vessel 24 



Summary of surface currents 25 



Temperature and density observations 28 



Tidal datums 41 



Bench marks 42 



Tables 49 



Appendix. — General characteristics of tides and tidal currents 98 



List of publications relating to tides and currents by the Coast and Geodetic 



Survev - 113 



Index..: 115 



ILLUSTRATIONS 



1. Boston Harbor in 1775 1 



2. Tide stations, Boston Harbor 2 



3. Annual variation in high water. Commonwealth Pier No. 5 16 



4. Annual variation in low water. Commonwealth Pier No. 5 16 



5. Annual variation in range of tide. Commonwealth Pier No. 5 16 



6. Annual variation in mean tide level and sea level. Commonwealth Pier 



No. 5 16 



7. Current stations, approaches to Boston Harbor and Nantasket 



Roads 19 



8. Current stations, Broad Sound 20 



9. Current stations. President Roads and Main Ship Channel 20 



10. Current stations, Dorchester and Quincy Bays 20 



11. Current stations, Hingham Bav 20 



12. Tvpical current curves for stations D46, W13, and "W16 26 



13. Typical current curves for stations D47, Wll, W20, and W16 27 



14. Currents at time of low water at Commonwealth Pier No. 5 29 



15. Currents one hour after low water 30 



16. Currents two hours after low water 31 



17. Currents three hours after low water 32 



18. Currents four hours after low water 33 



19. Currents five hours after low water 34 



20. Currents at time of high water at Commonwealth Pier No. 5 35 



21. Currents one hour after high water 36 



22. Currents two hours after high water 37 



23. Currents three hours after high water 38 



24. Currents four hours after high water 39 



25. Currents five hours after high water 40 



III 



