802 



SCIENCE. 



[N. S. Vol. VIII. No. 206. 



thirty days. The new water-tube boilers 

 were passed, ia parts, through the hatches 

 and the old boilers were cut in pieces below 

 and passed up in small sections ; thus sav- 

 ing the time, cost and risks of destruction 

 and reconstruction of the decks which 

 would have been necessary had the old types 

 of boiler and ways of doing work been 

 adopted. This necessity had been foreseen 

 and provided for before the war actually 

 began, and a provisional contract with the 

 only firm known to be ready and able to 

 undertake the task had been made. In 

 five hours after the contract was sigued the 

 work had been commenced. The perform- 

 ance of these ships with the new boilers 

 excelled the best work with the old. 



The most tremendous work, in kind and 

 quantitj% was that of fitting out the auxili- 

 ary fleet of more than a hundred ships, of 

 all sizes, kiuds and duties, from tugs and 

 ferryboats to ocean-steamers from the trans- 

 atlantic lines. All were necessarilj' exten- 

 sively altered to adapt them to their new 

 duties, and the provision of stores, already 

 alluded to, proved an essential element of 

 success in securing their services promptly 

 upoQ the outbreak of war. Even floating 

 machine-shops to make repairs in the 

 midst of the fleets were sent out and 

 proved of inestimable value. 



" There was a remarkable absence of cas- 

 ualty in the machinery departments of the 

 vessels of the fighting fleet during the war. 

 Even in action, when forced draught con- 

 ditions were iu operation and the excitable 

 natures of the men most wrought upon by 

 the surroundings, the reports show that the 

 machinery not only worked well generally, 

 but that in no case was it greatly distressed. 

 This is as fine a comment upon the person- 

 nel as upon the machinery." The state- 

 ment does not apply to the torpedo-boats, 

 the condition of which, under circum- 

 stances of operation entirely unintended in 

 their construction, ' can only be described 



as horrible— boilers were burnt, cylinder- 

 covers broken, piston and valves stuck, 

 everything in bad shape.' This was due to 

 absence of expert and professional super- 

 vision and to employment on duty for which 

 these craft are not intended and for which 

 they are unfit. No member of the Naval 

 Engineer Corps could be spared to care for 

 them, and the inexperienced and the inex- 

 pert young officers in charge of the boats 

 could not be expected to succeed in keeping 

 their machinery in order. 



The amount of work performed by this 

 Bureau, in designing new machinery', in re- 

 fitting old, in construction at the navy 

 yards and in repairs of ships, can only be 

 realized on reading in detail the full report. 

 Over four millions of pounds of iron and 

 steel passed under inspection and were 

 shipped to points at which this material 

 was needed. All specifications and methods 

 of inspection and test have been revised ; 

 including physical, chemical and mechan- 

 ical methods and limitations of quality. 

 Nickel- steel has been made an important 

 and useful material for engine-construction ; 

 steel tubes are now made without weld 

 and wonderfully perfect. New methods of 

 shaping and welding parts give hitherto 

 unapproachable security in use. Steel con- 

 taining an unusually high proportion of 

 carbon is now found applicable to even 

 steam-boiler construction. Tenacities ex- 

 ceeding 74,000 pounds per square-inch are 

 attained, with extensions rising above 21 

 per cent., and with elastic limits above 

 40,000 pounds. Such gains allow reduction 

 of sizes and parts and, still more important, 

 in a battle-ship, diminution of weights. 



Water-tube boilers are unqualifiedly ap- 

 proved for naval purposes, and experience 

 with those of the Marietta, while accompa- 

 nying the Oregon on the long 14,000-mile 

 voyage around Cape Horn, proves the reli- 

 ability of such boilers when properly made 

 and handled. The experience confirms the 



