No. 8. — (Letter No. 4.) To Carlile P. Patterson, Superin- 

 tendent United States Coast and Geodetic Survey, Washington, 

 ■D. C, from Alexander Agassiz, on the Dredging Operations 

 carried on during part of June and July, 1880, hy the United 

 States Coast Survey Steamer " Blake,'' Commander J. R. B artlett, 

 USK 



I JOINED the " Blake," at Newport, late in June. According to your 

 instructions, we proceeded to the northeastern edge of George's Shoal, 

 where we ran our first line of dredgings from the 100-fathoni line to a 

 depth of nearly 1250 fathoms. Our second line was run to the south- 

 east, off Montauk Point. This was interrupted by bad weather. We 

 were compelled to put into Newport, and completed the line on our 

 return from the South. This line extended to nearly 1400 fathoms. 



On leaving Newport for the second time we steamed directly for 

 Charleston, S. C. A line of dredgings was run from the 100-fathom 

 line normal to the coast directly across the Gulf Stream to a distance of 

 about 120 miles to the eastward of Charleston. Finding that our depth 

 did not increase at that distance, — our greatest depth not being much 

 more than 350 fathoms, — Commander Bartlett thought it prudent to 

 return towards shore, to the so-called axis of the Gulf Stream, and to 

 run a line in a northeastern direction parallel to the coast in the trough 

 of the Gulf Stream. To our great astonishment the depth did not in- 

 crease. We carried from 250 to less than 300 fathoms until we nearly 

 reached the latitude of Cape Hatteras, when in a short distance there 

 was a very rapid drop from 352 fathoms to 1,386 fathoms. A fifth line 

 was run normal to this northern slope of the Gulf Stream plateau, to a 

 depth of 1,632 fathoms. A sixth line was run to the northward of Cape 

 Hatteras, to a depth of 1,047 fathoms. A seventh hue was run east ofi' 

 Cape May, from the 100-fathom line to nearly 1200 fathoms. 



We were greatly disappointed in the richness of the fauna on the 

 lines off" Charleston and in the Gulf Stream, owing partly to the very 

 gradual slope of the continent towards deep water, and the strong cur- 

 rent of the Gulf Stream, which sweeps everything off the bottom along 

 its course. , There is but little food for the deep-water animals, and it 

 was only along the edges of the Gulf Stream where mud and silt accu- 



VOL. VI. — NO. 8. 



