them for a future and more complete report.

The writer avoided entering upon any general considerations, reserving

Third Report of the Committee on Steam-ship Performance.

Report.

CONTENTS.

Appendix, Table 1.-Table showing the results of the performance of H.M. vessels, furnished by the Admiralty.

Table 2.-Table showing the results of the performance of six of H.M. vessels under various circumstances.

Table 3.-Table showing the results of the performance of H.M.S. 'Victor Emmanuel,' when at sea.

Table 4.-Return of seven trials on the measured mile in Stokes Bay of H.M.S.' Victor Emmanuel.'

Table 5.-Table showing the results of the performance of a number of vessels in the Merchant Service under various circumstances.

Table 6.-Quarterly returns of the speed and consumption of coal of the London and North-Western Company's express and cargo boats, under regulated conditions of time, pressure, and expansion; from January 1st to December 31, 1860.

Table 7.-Quarterly verifications of consumption of coal of the above vessels, from January 1 to December 31, 1860.

Table 8.-Return from the City of Dublin Steam Packet Company of the average time of passage and consumption of coal of the Mail Steamers for six months ending June 30, 1860.

Table 9.-Return from the City of Dublin Steam Packet Company of the average time of passage and consumption of coal of the Mail Steamers for three months ending September 30, 1860.

Table 10.-Return of the results of performance of 50 vessels in the service of the Messageries Impériales, 1859.

Table 11.-Return of the results of performance of 50 vessels in the service of the Messageries Impériales, 1860.

Table 12.-Return of average passages of Mail Packets and consumption of coal for six months ending March 31, 1861.

Table 13.-Log of Steam-ship Ulster,' April 6, 1861.

Table 14.-Log of Steam-ship Leinster,' on trial from Holyhead to Kingstown, April 4, 1861.

Circular as issued from the Committee on Steam-ship Performance.

Form as issued from the Committee on Steam-ship Performance.

REPORT.

Ar the meeting of the British Association held at Oxford in June 1860, the Committee was re-appointed in the following terms :—

"That the Committee on Steam-ship Performance be re-appointed, to report proceedings to the next meeting.

"That the attention of the Committee be also directed to the obtaining of information respecting the performance of vessels under sail, with a view to comparing the results of the two powers of wind and steam, in order to their most effective and economical combination.

"That the sum of £150 be placed at the disposal of the Committee." The following noblemen and gentlemen were nominated to serve on the Committee:

Vice-Admiral Moorsom.

The Duke of Sutherland

(formerly Marquis of Stafford). The Earl of Caithness.

The Lord Dufferin.

William Fairbairn, F.R.S.

J. Scott Russell, F.R.S.

Admiral Paris, C.B.

The Hon. Capt. Egerton, R.N.
William Smith, C.E.

J. E. McConnell, C.E.

Professor Rankine, LL.D.

J. R. Napier, C.E.

R. Roberts, C.E.

Henry Wright

(Honorary Secretary).

With power to add to their number.

The following gentlemen also assisted your Committee as corresponding members :

Lord C. Paget, M.P., C.B.
Lord Alfred Paget, M.P.
Lord John Hay, M.P.
The Earl of Gifford, M.P.

The Marquis of Hartington, M.P.
Viscount Hill.

The Hon. Leopold Agar Ellis, M.P.
Captain Ryder, R.N.

Captain Hope, R.N.
Captain Mangles.
T. R. Tufnell.
William Froude.
John Elder.
David Rowan.

J. McFarlane Gray.

Your Committee re-elected Admiral Moorsom to be their Chairman, and at his decease the Duke of Sutherland succeeded him.

Your Committee having held monthly meetings, and intermediate meetings of a sub-Committee, presided over by the Chairman, beg leave to present the following Reports:

At the last meeting of the British Association, after the Committee's Report had been presented, Admiral Moorsom read a paper before the Mechanical Section on the Performance of Steam Vessels, and a discussion ensued which demonstrated the great want that is felt by men of science, both in England and in other countries, of definite knowledge based on actual experiment respecting the resistance offered by vessels of various sizes and types, to being drawn through the water. As the means of trying such experiments could only be satisfactorily obtained from a Government having every description of vessel in its service, your Committee determined urgently to renew their applications to the British Admiralty, that that body should, for the benefit of science generally, conduct a series of experiments; and to state that the Committee were even prepared to advise upon or conduct such experiments, if the Admiralty so desired.

The Chairman accordingly communicated with the First Lord of the Admiralty, repeating the various arguments hitherto advanced, with concise statements of the general nature of the detailed experiments deemed necessary, and which are briefly as follows:

1. The specific resistance of certain ships selected as types, and of the following displacements, viz.,—about 1000, 2000, 3000, 4000, 5000, 6000, 7000 tons, and upwards. Such resistance under traction being measured by dynamometer, and under the three following conditions:

(1.) Of the hull when launched.

(2.) Ditto with machinery on board.
(3.) Ditto when ready for sea.

2. The thrust of the screw, measured by dynamometer, when propelled by steam under the two last of the above three conditions, and under similar circumstances of smooth water and calm.

3. Full particulars of the dimensions and form of the ships, of the boilers and furnaces, of the engines, and of the propeller.

4. Detailed particulars of the performances of the same or similar ships in snooth water at the measured mile, with the particulars and conditions set forth in a Form of Return which accompanied the memorandum, or any other, more comprehensive or effectual, that might be given.

5. The actual performance of the same or similar vessels at sea, with the particulars and conditions set forth as aforesaid.

Your Committee would remark in passing, that from the date of their first appointment, they have not ceased, on every available occasion, to press this subject upon the attention of the authorities; but, up to the present time, your Committee are not aware that any experiments of the kind have been undertaken.

In the Report presented to your Association at Oxford, it is stated that a

table of certain of Her Majesty's vessels, seventeen in number, had been constructed, containing the results of the best trials as conducted by the Government officers, and that it had been forwarded to the Admiralty with the request that the additional particulars of the hull and machinery might be filled in. The table, however, did not arrive in time to be inserted in their Report. Your Committee have great pleasure in being now enabled to lay it before your Association in the state it has been received from the Admiralty. (Appendix, Table 1.) They would remark in connexion with this return, that it appears that the authorities have not been in the habit of recording either the quantity of coals consumed or the evaporation of water, and they have made application to the Admiralty that in future these desiderata may be obtained.

In compliance with the terms of the resolution appointing the Committee, viz., "That the attention of the Committee be also directed to obtaining information respecting the performance of vessels under sail, with a view to comparing the results of the two powers of wind and steam," your Committee have to state that hitherto they have been unable to obtain such comparisons in the case of merchant vessels, but in the Table given in Appendix, Table 2, particulars of one of H.M. vessels are recorded under three conditions, viz., under steam alone, under sail alone, and under steam and sail combined, and of two under the two latter conditions only.

These are especially useful, as they show the effects produced by powers brought to bear upon the hulls of vessels under the same conditions as to draft and trim, but differently applied.

In endeavouring to collect this information from officers in H.M.'s service, the Committee were desirous that the application should be made with the concurrence of the Admiralty, and a circular was accordingly issued to a selected number of officers, accompanied by a form, which they were requested to fill up and return. At the request of the Admiralty, copies of these documents were submitted for their inspection.

The circular stated that the Committee had apprized the Admiralty of the Committee's proposal to communicate with such captains and engineers of H.M.'s vessels as might be disposed to assist the British Association in obtaining facts for scientific calculations relating to the performance of ships at sea. The form proposed was as simple as was consistent with the object of obtaining data necessary for calculation, and the Committee conceived that the time required to fill up such forms would not interfere with the duties of the respective officers. It also stated that the Committee invited the co-operation of officers for the benefit of science alone, and that one of the fundamental rules laid down by the Association in directing their labours was as follows:"The object of the Committee is to make public recorded facts, through the medium of the Association, which, being accessible to the public in that manner, will bring the greatest amount of science to the solution of the difficulties now existing to the improvement of the forms of vessels and the qualities of marine engines. They will especially endeavour to guard against information so furnished to them being used in any other way."

Your Committee issued the Circular and Form of Return (see Appendix, p. 198) to upwards of 200 of H.M.'s captains in commission, and to their chief engineers through the captains.

Numerous replies have been received promising returns; but the distance at which most of the vessels are stationed, namely, China, the East Indies, and America, has precluded our receiving such particulars in time for this Report. Returns, however, of seven vessels have been received, six of which are given in Appendix, Table 2; and the seventh vessel, the Victor Emmanuel,' being returned in a different form, is given separately in Appendix,