420 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [50] 



[From October 24, 1887, to July 1, 1888, by Passed Assistant Engineer C. R. 



Roelker, U. S. Navy.] 



The main engines and boilers have worked generally satisfactorily, 

 and, with tfie exception of some slight repairs to a leaky bottom blow- 

 pipe at Montevideo, Uruguay, all the incidental repairs and adjustments 

 were made by the engineer force of the vessel and have caused no de- 

 lay in her movements until her arrival at San Francisco, California. 

 There the machinery, both main and auxiliary, was thoroughly over- 

 hauled and placed in an efficient condition, the shops of the Union Iron 

 Works being utilized for such work as could not be done to advantage 

 by the engineers' force of the vessel. 



Only one boiler has been in use at a time, and during the greater por- 

 tion of our steaming the grate surface of the boilers was reduced to 49£ 

 and 45 square feet in order to steam more economically with a limited 

 consumption of fuel. Leaks have continued to develop in the bottom 

 of the boilers, the most active cause for this being undoubtedly the low 

 temperature of the feed- water. The donkey- boiler has been used in 

 port for lighting, heating, and ventilating the vessel and for running 

 the steam-pumps whenever the fires could be hauled in the main boilers 

 with due regard to safety and economy. 



With the exception of a small quantity of anthracite coal remaining 

 in the bunkers from the supply received at Norfolk, Virginia, and a few 

 tons of Seattle and Wellington coals received at San Francisco, the fuel 

 used has been Cardiff and Chilian coal. About 170 tons of the latter 

 were obtained from the Alberto mine at Lota, Chili. The bulk of this 

 coal is about 11 per cent, greater than that of Cardiff coal. It ignites 

 easily and burns rapidly with a large flame ; it does not cake, but breaks 

 up into small particles, which run through the grate, but should be put 

 back into the furnace. It forms large clinkers, which often cover the 

 entire grate and are the principal part of the refuse. The quantity of 

 refuse produced amounted to 7J per cent, of the quantity of coal con- 

 sumed. Its evaporative power was about 75 per cent, of that of good 

 Welsh coal. For economical reasons the consumption of coal was lim- 

 ited to 10J tons per day. With this consumption the vessel maintained 

 a speed of 8J knots per hour in smooth water under steam alone, and 

 attained a speed of 9 knots per hour on several occasions. 



At Panama, March 21, the vessel was beached for the purpose of 

 scraping and painting her bottom, which was quite foul, but unfortu- 

 nately the slight rise and fall of the tide on that day left the greater 

 part of the bottom inaccessible. During the latter part of June, how- 

 ever, she was placed on the hydraulic lifting dock of the Union Iron 

 Works, at San Francisco, where her bottom was thoroughly cleaned 

 and painted. 



Temporary repairs were made to the leaky steam-piston of the Sigs- 

 bee Sounding Machine at Montevideo, whereby the working of the mar 



