Tables 3 and 4. This is the more valuable, as the returns of seven trials on the measured mile are given with it.

Your Committee are aware that several officers are conducting a series of experiments under various conditions, which it is their intention to report to your Association, through this Committee, on their return home.

The Log-book, compiled by your Committee, is also being filled up by the same officers, with a similar object.

Your Committee have met with great success in their applications to shipowners, engineers, and builders for information respecting the sea performances of merchant vessels. In no case have they met with a refusal to supply all the data in their possession, and your Committee have reason to believe that before long the records kept on the voyages will be amplified, and the data thus obtained be published periodically by shipowners themselves.

The thanks of the Committee are especially due to the Peninsular and Oriental Company, to the London and North-Western Company, to the Pacific Steam Navigation Company, to the City of Dublin Steam Packet Company, to Messrs. Morrison and Co. of Newcastle, to Messrs. Penn and Sons, the Thames Shipbuilding Company, Messrs. R. Napier and Son, Messrs. Fawcett, Preston and Co., and Messrs. J. and W. Dudgeon.

The Peninsular and Oriental Company freely offered their books for inspection, and placed the logs of their vessels Candia,' 'Ceylon,' ' Columbia,' 'Delta,'' Nubia,' and 'Pera,' in the hands of the Committee, to make any extracts they deemed useful.

Copies of voyages from Southampton to Alexandria, and from Aden to Calcutta, and return of those vessels respectively, were taken, and the average performances worked out. They are given in the Table of Merchant Vessels (Appendix, Table 5).

The London and North-Western Railway Company have furnished your Committee with information of especial value, viz., the trial performance and ordinary working performance of one of their vessels, the Cambria,' under two conditions-the first as originally constructed, the second after being lengthened 40 feet. Data of this description are precisely those required to enable the naval architect to judge what are the qualities which constitute a good vessel, and assist him in designing vessels possessed of high speed, great capacity, limited draught of water, economy of power, and all the qualities which constitute good sea-going ships, with much greater certainty than heretofore.

In the same table (No. 5) your Committee have thought fit to repeat a somewhat similar return, given in their last Report, viz., a Table, &c., showing the Trial Performance of the steam vessels Lima' and ' Bogota' when fitted with single-cylinder engines, and after being refitted with doublecylinder engines; also the sea performances of the same vessels under both these conditions of machinery, and on the same sea-service.

These returns, therefore, show the difference of performance of a vessel with the same machinery but lengthened in her hull, and of two vessels with the hull a constant, but with entirely different engines.

A glance at the column showing the consumption of coals in each case will at once demonstrate the importance of the subject in a commercial point of view.

The London and North-Western Company have likewise furnished returns of the speed and consumption of coal of their express and cargo boats, under regulated conditions of time, pressure, and expansion, from January 1 to December 31, 1860 (Appendix, Table 6). Similar returns for 1858 and 1859 are contained in the two former Reports of this Committee, and show the regularity with which the service has been conducted.

1861.

Your Committee would again call the attention of shipowners to the system of trials which has resulted in the combination of perfect regularity and efficiency of service with economy (so far as the vessels and machinery would admit) which this series of returns exhibits.

In the first Report of this Committee, presented to your Association at the Meeting held in Aberdeen, a series of tables are given, showing the method which was adopted for ascertaining the working capabilities of each vessel. The following explanation was furnished by Admiral Moorsom, and illustrates the means by which the proper service to be obtained from a vessel may be estimated*:

"When the four passenger vessels, 'Anglia,' ' Cambria,'' Hibernia,' and 'Scotia,' were first employed in August 1848, the commanders were authorized to drive them as hard as they could, subject only to the injunction not to incur danger."

After some months' trial the qualities of each vessel and her engines were ascertained, and a system was brought into operation which continues to the present time. (Tables 3-14.)

The Returns Nos. 2 and 6 show the results of the hard driving and the commencement of the system periods. The column indicating "Time," "Pressure," and "Expansion," is the key to the columns "Average Time of Passage," "Weight on Safety Valves," and "Proportion of Steam in Cylinder," and, as a sequence, also to the consumption of coal.

"Time a minimum" shows the hard driving. "Time a constant" shows the system. The relations of "pressure" and "expansion " show how, under hard driving, the highest pressure and the full cylinder produced the highest speed the wind and tide admitted, or how, the time being a constant, those two elements were varied at the discretion of the commander, within prescribed limits, to meet the conditions of wind and tide.

The result of the system on the coal is a decreasing consumption.

The Return No. 1 shows the results of certain trials under favourable conditions, but in the performance of the daily passage by four of the vessels, which results are used as the standard tests with which the results of each quarter's returns are compared.

For example, the 'Scotia' at 15.9 statute miles an hour consumes 6840 lbs. of coal as a standard. (See Table 4.)

In the Return No. 3, at the speed of 12.96 miles she consumed 5226 lbs. ; the first at the rate of 430 lbs. per mile (see Table 5), and the second at about 403.

Again, in the succeeding quarter, the Scotia' consumed 7528 lbs. at 14.65 miles an hour, or more than 513 lbs. per mile.

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Here was a case for inquiry and explanation. It will be observed that in Return No. 1 the consumption of the Scotia' at ordinary work at sea is 5820 lbs. per hour, and it is only when the consumption exceeds 6840 lbs. that it becomes a subject of question, the difference between those figures being allowed for contingencies.

No. 4 (see Tables 12, 13) is a Return which shows the difference between the issues of coal each half year, and the aggregate of the returns of consumption, the object of which needs no elucidation.

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No. 5 (see Table 14) shows the duration of the boilers, with particulars the work done. The saving in money under the return system, as compared with hard driving, was of course very considerable, and the latter was only justifiable as a necessary means of learning the qualities of each vessel, to be afterwards redeemed by the economy of the system.

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The Hibernia,' it will be seen, was unequal to the service; and I may * See Volume of Transactions of the Aberdeen Meeting, 1859, page 276.

here observe that experience has shown me that in machinery, as in animal power, it is essential that it should be considerably above its ordinary work. The want of this extra power was a defect of the early locomotive engines, whose cost of working per mile was very considerably higher than that of the engines now in use.

This defect, which is that of boiler-power, prevails largely in steam-vessels, and especially in the Queen's ships.

It would be easy to show how system must tend to economy; and the saving of coal is apparent from the returns, and of course all the engine stores are commensurate.

But the repairs-the wear and tear-involve a much more important element of economy than even a reduced consumption of coal.

The Return for 1860 is accompanied by a check account of the consumption of coal. (Appendix, Table 7.)

The City of Dublin Steam Packet Company have obligingly furnished returns of the consumption of coal and average time of passages of their mail boats Prince Arthur,' Llewellyn,' Eblana,' and 'St. Columba,' from January 1st to December 30th, 1860, the last quarter embracing the fast vessels 'Leinster' and 'Ulster.' (Appendix, Tables 8 and 9.)

Your Committee were invited to attend a trial of the latter vessels between Holyhead and Kingstown, and a deputation, consisting of Admiral Moorsom, the Duke of Sutherland, Lord Alfred Paget, Mr. Wm. Smith, C.E., Mr. J. E. McConnell, and Mr. H. Wright, attended. They were kindly assisted by Mr. Watson, the Managing Director of the Company, in obtaining information connected with these vessels and their performances. The particulars of these trials will be found in Appendix, Table 5.

A deputation from your Committee, consisting of Mr. W. Smith and Mr. Wright, also at the invitation of the London and North-Western Railway Company, attended the trial of the 'Admiral Moorsom,' a new cargo boat built expressly for the conveyance of live stock. The particulars are given in Appendix, Table 5, to which your Committee would direct attention, as the speed obtained, and the steadiness exhibited by the vessel in a very heavy sea, excited considerable surprise. They have received numerous invitations from other companies and shipowners to attend the trials of their vessels. Your Committee have been in correspondence with the Imperial naval authorities of France and of the United States.

The latter have already published various trials conducted with admirable skill and precision, and embracing most of the particulars asked for by the Committee.

In France, the Company of the Messageries Impériales have for some time given annual averages of the results of the navigation of the vessels in their service, for private use only; but on the application of your Committee to be supplied with such returns, copies were at once forwarded, with a letter from the President stating that, although it was not the usual custom of private companies to make public the information requested, and although the Report transmitted to them (the Committee's 2nd Report) contained no analogous comparison of the state of the great English companies who perform similar service, nevertheless they have not hesitated to accede to the Committee's wish, by contributing as much as lay in their power,-thus proving their cordial sympathy with the useful object the British Association have in view. The Tables of Results of their vessels, 50 in number, for the years 1859 and 1860, are given in Appendix, Tables 10 and 11, constituting, with the one given in the last Report, a valuable series extending over three consecutive years.

Your Committee take this opportunity of expressing their satisfaction in being able to report, that since the commencement of their labours in 1857, the interest that has been taken in Steamship Performance, and the desire to assist the Association in eliciting information on the subject, not only by officers of the Royal Navy, but also of the merchant service, fully bear out the opinion expressed at the meeting of the Association in Dublin, that this subject. was second to none in importance, and that its steady pursuit would tend very materially to the advancement of the science of shipbuilding and marine engineering.

The following is a general summary of the results of the Committee's labours during the past season. They have obtained

1. The particulars of the machinery and hulls of seventeen of H.M.'s vessels, and the details of 58 trials made during the years 1857, 1858, and 1859, supplied by the Admiralty. The Committee are in possession of copies of the diagrams taken during the trials in 1859, with notes of observed facts by the officers conducting the trials. The names of the vessels are the James Watt,' 'Virago,' 'Hydra,' 'Centaur,' 'Industry,' 'Diadem,' Mersey,' Algerine,' 'Leven,' Lee,' Slaney,' Flying Fish, Marlborough,' Orlando,' Bullfinch,' Doris,' and Renown.' (Appendix, Table 1.)

2. Returns of seven of H.M.'s vessels when at sea, under various circumstances, viz., under steam alone, under sail alone, and under sail and steam combined. The names of these are the Colossus,' 'Chesapeake,' 'Flying Fish,' St. George,' 'Clio,' 'Sphinx,' and 'Victor Emmanuel.'

3. Return of the London and North-Western Railway Company's steamboat Cambria's' trials and ordinary performances as originally built, and after being lengthened; also of the Pacific Steam Navigation Company's vessels 'Lima' and 'Bogota,' when fitted with original and other machinery; also of the new cargo boat, the 'Admiral Moorsom.'

4. Returns of the Peninsular and Oriental Company's boats Colombo,' 'Candia,' Ceylon,' 'Delta,' Nubia,' and 'Pera,' when on voyages between Southampton and Alexandria, and between Suez and Bombay respectively, together with particulars of their machinery and hulls furnished by the builders and engineers.

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5. Returns of the Pacific Steam Navigation Company's vessels 'Guayaquil' and 'Valparaiso,' with particulars of trials and sea voyages during 1860. 6. Returns of the trials of the vessels Leonidas,'' Mavrocordato,' Penelope,' furnished by Messrs. Morrison and Co., and the Thunder' and 'Midge,' by Messrs. J. and W. Dudgeon.

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7. Tables showing the Results of the Navigation of the steamboats in the service of the Messageries Impériales, during the years 1859 and 1860.

8. Returns of the London and North-Western Company's steamboats 'Anglia,'' Cambria,' Scotia,' 'Telegraph,' Hibernia,' 'Hercules,' 'Ocean,'" and 'Sea Nymph,' under regulated conditions of time, pressure, and expansion, from January 1 to December 31, 1860. Half-yearly verification of the consumption of coals for the same period.

9. Return of the average time of passage and consumption of coal of the City of Dublin Steam Packet Company's mail steamers Prince Arthur,''Llewellyn,' 'Elbana,' and St. Columba,' for six months ending June 30th, 1860. 10. Ditto ditto, with the addition of the fast steamers Leinster' and 'Ulster,' for three months ending September 30th, 1860.

11. Return of the average passages of the mail packets 'Leinster,' 'Ulster,' Munster,' and Connaught,' for six months ending March 31st, 1860. (Appendix, Tables 12, 13, and 14.)

12. Return of the trial of the 'Leinster' and Ulster' between Holyhead and Kingstown. (Table 5.)