REPORT OF COMMISSIONER OF FISH AND FISHERIES. XIX 



From among many bids for the building of the same, that of Messrs. 

 Pusey & Jones, of Wilmington, for $44,000, was accepted and the vessel, 

 to be known as the Fish-Hawk, pat under contract. 



After the close of the cruise of the Speedwell in the autumn of the 

 year, Captain Tanner was detached and placed in charge of the Fish- 

 Hawk, visiting it at short intervals to inspect the progress of the work. 

 In the course of the year considerable advance in its construction was 

 made, and it is hoped that the vessel will be available for Use in the 

 spring of 1880. A detailed account of this vessel will probably appear 

 in the next report of the Commissioner. 



7. — ABSTRACT OF RESEARCHES PROSECUTED UNDER DIRECTION OF 



THE COMMISSION. 



Among the collateral subjects of attention by the Fish Commission 

 has been an investigation into the chemical composition of fish under 

 the varying circumstances of age, sex, and the condition of the repro- 

 ductive apparatus. This has a very important bearing both upon the 

 availability of fish for food and also as furnishing material for the making 

 of oils and fertilizers. A large number of analyses have been made by 

 Professor Atwater which already supply the means of important deduc- 

 tions, especially as to the comparative nutritive power of the same quan- 

 tity of flesh in different species. 



A fuller statement of the general results of this inquiry will be found 

 in the next report of the United States Fish Commission. 



Among the more important researches made at Proviucetown during 

 the summer was that by Dr. Kidder, U. S. 1ST., surgeon of the party, in 

 regard to the temperature of fishes. For a long time it had been sup- 

 posed that the temperature of fishes was always the same as that of the 

 water in which they happened to be placed, but the experiments of Dr. 

 John Davy indicated that, in some cases at least, especially where 

 mackerel and tunny were the species in question, the actual temperature 

 of the fish was a few degrees higher than that of the water. Dr. Kidder 

 utilized such opportunities as were presented to him in determining this 

 question and obtained some exceedingly interesting results, which have 

 been published by the Fish Commission. 



Among the special problems connected with the interests of the fish- 

 eries are economical methods for the production of cold, to be used in 

 the preservation of fish for a certain length of time, either directly by 

 reducing the temperature of the storage space, or indirectly by making 

 ice to be employed for a similar purpose. In ordinary seasons, after an 

 abundant ice crop, the ruling prices of $1 to $3 a ton is by no means 

 exorbitant; when, however, as is not infrequently the case, the cost is 

 from $10 upwards, the tax becomes very serious. 



Among those who have devoted themselves to the solution of this 

 question is Professor Gamgee, and to his pen am I indebted for an able 

 article published in the last United States Fish Commission report. 



