652 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [48] 



ing is entirely of brass, ami is provided with proper valves, tap-cocks, 

 and safety-valve, which may be regulated in the laboratory. The 

 pump and piping were erected by the men in this department. 



Cost of the aquarium pump $'M. 5G 



Cost of piping 48.23 



Cost of valves, cocks, ami fittings 11. 89 



Total 150.68 



STEAM CUTTERS. 



These two boats continue to do good service, and are always ready 

 for use when required. The nature of the service of this ship, which 

 gives us semi-annual opportunities to overhaul these two boats, and the 

 hearty co-operation of the commanding officer in all matters pertaining 

 to their efficiency, are two important elements in the great success of 

 these Herreshoff boats. During the year the following repairs were 

 made to the larger boat, at the Washington yard : A sheet-brass cover 

 was put on the separator, new wrist-pins were put in the cross-heads, 

 and the cross-head gibs were rebabbitted; the lower half of the cas- 

 ing of the boiler has been renewed; new pins were made for the ec- 

 centric-rods; new pins were made for the link blocks; the plunger and 

 valve of the hand bilge-pump were refitted ; a new steering-wheel and 

 drum were made. In November a set of grate-bars were made. Re- 

 pairs, such as straightening the screw-blades, which had been bent, re- 

 making joints, &c, have been made by our own men. The cost of re- 

 pairs to this boat at the Washington navy-yard amounted to $54.GG. 

 During the year we have bought from the builders of the boat a new 

 slide-valve for the high-pressure cylinder, at a cost of $5.50. The wear 

 of these slide-valves, which are made of brass, is all on one side. 



The smaller boat (the gig) broke her high-pressure piston ring and 

 spring and bent the rod and follower on the 7th of March. The brass 

 follower was screwed to the cast-iron piston by a fiue thread ; this be- 

 came loose and unscrewed. We repaired it temporarily by casting a 

 solid Babbitt-metal ring, in place, and straightening the rod and fol- 

 lower ; we replaced the piston, later in the year, by one of wrought iron. 

 Later in the year we lost the low-pressure piston in the same way, and 

 replaced it in like manner. The slide-valve of the high-pressure engine, 

 which was worn to a knife-edge on one side, has been replaced with a 

 new one. 



The smoke-pipe was rolled out of the gig on the night of the 5th of 

 March, in 3J fathoms of water ; it was recovered by a native diver. 

 The top of the boiler was so badly torn by the accident, and the lower 

 casing so badly corroded and burned out by the end of the summer 

 cruise, that we were obliged to put on an entirely new casing. As the 

 fine boiler-shop at the Washington navy-yard had been discontinued, as 

 such, we were obliged to employ a journeyman boiler-maker and build 



