V. 



A Scientific Account of the Inner Harbor of Boston, with a Synopsis of the General Prin- 

 ciples to be observed in the Improvement of Tidal Harbors. 



By CHARLES HENRY DAVIS, A. M., A. A. S., M. A. P. S., etc., 



LIEUTENANT U. S. NAVT. 



{Communicated April 1, 1851.) 



Whilst employed in executing the hydrographic portion of the survey of Boston 

 Harbor, and since that time, I have been occasionally consulted as to certain proposed 

 changes in the upper part of the harbor. These inquiries, my acquaintance with the 

 subject and interest in it as a native Bostonian, have led me to make a particular exam- 

 ination for the purpose of ascertaining what alterations have taken place since the sur- 

 vey of Commodore Wadsworth in 1817. Some changes must necessarily have followed 

 from the great diminution of the water receptacle above the channel, from the construc- 

 tion of wharves and piers, from neglect, and from the constant operation of those laws of 

 tidal deposit which were the subject of a previous communication to the Academy. 



The gradual deterioration of Boston Harbor is now generally admitted, and appre- 

 hensions are felt that the consequences of this deterioration may be, if it is suffered to 

 continue, seriously injurious to the future prosperity of the city. The time seems, there- 

 fore, to have arrived, when it is expedient to inquire into the comparative condition of 

 the harbor, using the most accurate means of investigation attainable ; to state the ac- 

 tive causes of change of which the present condition is the natural result ; and to lay 

 down those principles of hydraulic engineering which must be consulted in order that 

 any future constructions, demanded either by the business of the city or the preservation 

 of the channels, may prove beneficial, and answer the purposes for which they are de- 

 signed. To make such an application of these principles as will form the safe basis of a 



VOL. V. NEW SERIES. 14 



