HYDROGRAPHY. 3 1 7 



has completed the physical examination of the Gulf of Mex- 

 ico, with the Yucatan and Florida channels. The contour of 

 the bottom has been thoroughly determined, and serial tem- 

 peratures have everywhere been taken. Large quantities of 

 bottom specimens and dredgings have been collected, and 

 are now being examined under direction of Professor A. 

 Agassiz, who is this season, for the second time, supervising 

 the dredging operations on board the Blake, now under com- 

 mand of Commander Bartlett, U.S.N., who succeeded Lieut. - 

 Commander Sigsbee in the command of the vessel and the 

 charge of the physical and hydrographic work. This sea- 

 son's work will consist of a similar examination of the ap- 

 proaches to the Gulf Stream in the San Antonio and Bahama 

 channels. 



A chart of the Gulf of Mexico, embodying the results of 

 Lieut.-Commander Sigsbee's work, has been published. 



On the coast of Maine a great deal of sounding has been 

 done, both inshore and offshore. 



Changes in the bar at the mouth of the Merrimac River 

 have necessitated a re-survey of Newburyport harbor, which 

 has been completed. An examination has been made of the 

 shoal ground near Block Island, and the southwest shoal be- 

 tween Block Island and Montauk Point has been re-surveyed. 



In Delaware Bay and River, valuable observations on tides 

 and currents have been made. 



Lieutenant Moser, U.S.N., in the schooner Endeavor, be- 

 sides a valuable series of soundings off the coasts of North 

 and South Carolina, has made a survey of an excellent an- 

 chorage recently formed by the extension of the shoal off 

 Cape Lookout. 



The parties at work on the northern coast during the sum- 

 mer are transferred to southern waters for the winter, and 

 have accomplished valuable results in and near the St. John's 

 and Indian rivers, and off the east and west coasts of Florida, 

 a new shoal having been discovered and located off Cape 

 Canaveral. 



A photo-lithographed chart, in 13 sheets, of the Mississippi 

 River, from Fort Jackson to about twenty miles above New 

 Orleans, has been completed and published. 



On the coast of Southern California, in San Pablo and Sui- 

 sun bays and San Diego harbor, as well as on the coast of 



