



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



[28] 



Note in 1870. — Wheu the table of reductions for temperature above 

 given was constructed, the investigations relative to the same subject 

 made by Thorpe and Eiicker (Eoyal Society's Proceedings, January, 187G> 

 were not known. The following comparison of the results of the experi- 

 ments on the thermal dilation of sea-water, as taken from Professor Hub- 

 bard's tables, and as derived from the results of Thorpe and Eiicker, 

 shows the differences within the range of temperature covered by our 

 table of corrections: 



DEPARTURE OF THE VESSEL FROM WILMINGTON. 



At 4 p. m. July 29, 1880, the Fish Hawk left the builder's yard for 

 [Newport, E. L, the headquarters of the Commission for the season. 



The hatching machinery was not entirely comf)lete, but the dredging* 

 apparatus was in place, and it was considered advisable to leave at once^ 

 returning for the remainder of her hatching outfit after completing her 

 work of deep-sea exploration for the season. 



The weather was clear and pleasant, with a gentle breeze from NW. 

 The vessel attained a speed of 7 to 8 knots during the night, the engines 

 working smoothly. Passed Cape Henlopen ot 11.20 p. m., Absecon at 

 4.30, and Barnegat at 8.35 a. m. July 30. The position at noon was 

 latitude 40° OG' N., longitude 73° 09' W., 177 miles from Wilmington^ 

 giving an average sx)eed of 8.55 miles per hour. 



At 5 p. m. passed Fire Island light-house, and between 5 and ob- 

 served azimuths of the sun on such courses as we would require during 

 the trip for the purpose of ascertaining the deviation of our compasses, 

 July 31, at 12.25 a. m., passed Montauk Point, at 3.30 Point Judith, at 

 4.15 Beaver Tail, and at 4.40 a. m. anchored in Dutch Island Harbor for 

 the purpose of cleaning and painting ship. 



Monday, August 2, got under way and steamed to Newport, the head- 

 quarters of Commission, and reported for duty in connection with deep- 

 sea exploration. 



The weather was unsettled and rainy during the 3d, 4th, and 5th, 

 clearing during the night of the latter date, and on Friday, the Cth, we 

 left the wharf at 8.35 a. m., with the naturalists on board, for our first 

 Iredging expedition of the season. It was an exi^erimental trip for the 



