ON STEAM-SHIP PERFORMANCE. 195 



wade through the masses of logs, together with the fact of the Association 

 meeting this year near]}- three months earlier than usual, rendered it imprac- 

 ticable for more than a limited amount of work to be got through. It was 

 therefore determined to make a selection of certain vessels, and to endeavour, 

 as far as possible, to render complete the record of a few. 



Your Committee at the same time communicated with the Admiralty, with 

 a view of instituting a similar comparison between the trial trips and ordinary 

 performances of Her Majesty's vessels at sea. 



They much regret that they have not been able to obtain the latter. The 

 Lords Commissioners, however, very courteously entrusted the Committee 

 with the original returns of Her Majesty's vessels during the years 1857, 

 1858, and 1859, as furnished by the officers who conducted such trials, with 

 permission to copy and make any use they thought fit of the information 

 they contained. Diagrams of the engines taken on the trials during the year 

 1859 were also furnished. 



Your Committee must remark with regard to these trial performances, that 

 they do not appear to be instituted with any other view than as a trial of the 

 working of the engines, excepting in a few instances, when experiments have 

 been made to test the merits of certain screws. In very numerous cases, the 

 officer distinctly reports that the boiler power is insufficient. The speed 

 may or may not be taken at the convenience of the officers, but in no case 

 is any note taken of the economical efficiency of the engines with regard to 

 fuel. 



As your Committee are restricted to a record of facts, it is out of place 

 here to suggest changes in the mode of conducting the trials of Her Majesty's 

 ships. The Committee would, however, fail in their duty if they did not avail 

 themselves of this occasion to repeat their conviction, as expressed in their 

 last Report, — " That it would tend to the advancement of science, the im- 

 provement of both vessels and engines, and to the great advantage of Her 

 Majesty's service, if the trials of the Queen's ships were conducted on a more 

 comprehensive plan, directed to definite objects of practical utility on a 

 scientific basis, and recorded in a uniform manner." 



In addition to the vessels of the British Royal and Mercantile Navies, your 

 Committee have great pleasure in being enabled to lay before the British 

 Association a return of forty-nine vessels in the service of the Messageries 

 Imperiales of France, obligingly furnished by a member of the Committee, 

 Admiral Paris, and recorded in the form used by that Company; also, of 

 two vessels belonging to the United States Navy, the particulars of which 

 have been extracted from the second volume of Mr. Isherwood's recent 

 publication, entitled " Engineering Precedents." They have been introduced 

 into the Tables (see Appendix, Table I.). 



While this Report was preparing, the Committee were gratified by receiv- 

 ing from Mr. Archbold, Engineer-in-Chief, United States Navy, two sets of 

 tabulated returns of performance of the United States steam sloop of war 

 1 Wyoming,' under steam alone, and under steam and sail. 



These returns are of peculiar value, as comprising particulars in a form 

 which the Committee believe has never yet been published. Along with the 

 data afforded by Mr. Isherwood's book, they give the area of sail spread and 

 the force of wind by notation, together with other particulars, useful for 

 calculations of results and for comparisons. 



These Tables are contained in the Appendix, with Mr. Archbold's letter, 

 and a description of the hull, engines, and boilers of the ' Wyoming.' 



The returns furnished by the British Admiralty embrace 216 vessels and 

 353 trials, with about 900 diagrams. For the same reason as above stated, in 



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