48 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



At station 266, in 268 fatlioms, the island of Oahu being then in 

 sight, the specimen cnp brought up about a pint of clean foraminifera, 

 no mud or sand being present. The shells were globigeriua and orbu- 

 lina. From this station to the harbor of Honolulu the specimens exam- 

 ined consisted of line sand, broken shells, small pieces of coral, and 

 sponge spicules. 



Eeturuing over a line south of the other, the results were about the 

 same. 



We found no evideiice of the red clay supposed to form the bottom 

 of the ocean in the vicinity of the Hawaiian Islands. 



REPORT ON THE MACHINERY, 



[By A. M. Hunt, Assistant Engineer, U. S. N.] 



(Abstract.) 



Main engines. — During the year, the engiues have been in operation 

 2,831 hours while the ship was on her course in free route. The time 

 occupied in sounding and dredging at sea, when the engines were 

 worked to signals, was 600 hours. The engines have been stopped for 

 sounding and dredging, from full speed abead, 640 times during the 

 year, in addition to the number of stops incidental to her regular cruis- 

 ing. The ship has steamed 24,991 knots by log, an average of 8,85 knots 

 per hour. The engines have made 10,592,556 revolutions, an average 

 of 62.5 per minute. The maximum speed recorded during the year is 

 11.45 knots, and the highest average for six hours is 11.15 knots. 



The run from San Francisco to Unalaska, in July, 1891, was made at 

 high speed, and the wear on the crank-pin brasses was very excessive 

 and abnormal. Babbitting the brasses, and changing the oiling gear, 

 has reduced this wear to a minimum. 



Such repairs have been made from time to time as to enable the ship 

 to continue her work, but the engiiies are now in need of a thorough 

 overhauling. The propeller shafts have worn down very much in the 

 outboard bracket-bearings. The shafts are out of line and the star- 

 board one shows signs of being sprung. Many parts are so worn as to 

 require renewal, and much of the piping will have to be renewed. These 

 repairs are fast becoming imperative. 



Boilers. — Fires have be^n lit under the forward boiler, 5,128 hours; 

 under the after one, 4,223 hours; under the donkey boiler, 471 hours. 

 They have given a great deal of trouble during the year. The cast- 

 iron check-valve chambers gave out in the second quarter, and have 

 all been replaced by composition ones. Two hundred and lorty-five 

 new tubes were put in the boilers in June, 1891. Quite a number of 

 these have pitted through, probably owing to imperfections in tubes. 

 During the last two quarters, much trouble has been experienced from 

 the tubes leaking at the back ends. This has become so aggravated 

 during the last quarter that the tubes and connections become choked 



