An attempt has been made, from the accompanying register, to estimate the total quantity of sediment carried down in suspension during the year. Each pair of succeeding entries in the fifth column, viz. "discharge per minute," have been added together, the sum divided by 2, and the quotient multiplied by the number of minutes between the observations. The result is a total of 3564 tons for the year.

The surface of the valley of the Onny is 84 square miles; and the effect of the above result would be (taking the average specific gravity of the Silurian rocks as 2.5) to reduce the level of the whole by 0025, or of an inch. Probably, however, the rate of denudation during the year has been exceptionally low; and, besides, no account is here taken of any but suspended matter.

Report of the Committee on the Chemical Nature of Cast Iron. The Committee consists of F. A. ABEL, F.R.S., D. FORBES, F.R.S., and A. MATTHIESSEN, F.R.S.

We regret to have to report that it has not been in our power during the past year to make any important progress in the investigation of the chemical nature of cast iron, which was intrusted to us.

In the Appendix to the Report which we submitted last year, a process was described by which pure iron could be prepared in considerable quantities; and it was intended to apply this process at once to the preparation of the material necessary for our investigations. The apparatus and arrangements required for this purpose, however, have been unavoidably in a dismantled condition during the greater part of the year, in consequence of the reconstruction of the Laboratories of St. Bartholomew's Hospital. They are now again in working order, and it is hoped that the experiments will be resumed without much further delay.

Numerous experiments have been made with a view to ascertain whether the pure-iron sponge, prepared by the process above referred to, can be converted, by welding, into thoroughly solid masses without detriment to the purity of the metal. Hitherto the results obtained (though instructive in connexion with the physical properties of the pure metal) have not been of a promising nature in the particular direction desired. It is contemplated, however, to continue these experiments with the aid of facilities which, we believe, will be available for this purpose at the Royal Arsenal, Woolwich.

For the foregoing reasons we beg leave to suggest that the reappointment of this Committee be recommended; but we do not consider it necessary to apply for a grant of money on this occasion.

Report on the practicability of establishing "A Close Time" for the protection of indigenous Animals. By a Committee, consisting of Prof. NEWTON, M.A., F.L.S., Rev. H. B. TRISTRAM, F.R.S., J. E. HARTING, F.L.S., F.Z.S., Rev. H. BARNES, and H. E. DRESSER (Reporter).

THE Committee appointed for the purpose of continuing investigations as to the advisability of establishing a close time for the preservation of our indigenous animals beg leave to report as follows:-Having regard to the state of business during the late session of Parliament, your Committee have not thought it expedient to press the object your Committee are directed to obtain on the attention of Members of the Legislature, or the general public. Your Committee have learnt with satisfaction that, in several cases where the provisions of the Sea-birds' Preservation Act have been enforced, very beneficial results have followed, instances of which are added in the appendix. In consequence hereof, your Committee see good reason to hope that an extension of similar protection to other groups of indigenous animals will be attended by similar happy results; and your Committee consider that such extension could not be better commenced than with the group of birds commonly known as "wild fowl," comprising as that does, very many

kinds of birds which, being largely used as food, are of great value to the community, and are generally admitted to be entirely innocuous. At present, very great numbers of Wild Ducks, of many species, Snipes, Woodcocks, Plovers, and other kindred birds are killed during the spring months, even when in the act of breeding. The destruction thus effected cannot fail to continue the ever-increasing diminution of these birds, if indeed it does not promise, at no distant date, to result in their utter extermination. Accordingly, your Committee are unanimously of opinion that protection should be afforded by law, during the breeding-season, to such "wild fowl" as these, in order to prevent that result; while your Committee think that, with protection, these birds may long continue to furnish, at other times of the year, valuable food to the public, notwithstanding the changes which some parts of the country are undergoing through agricultural improvements and increase of the population.

Your Committee respectfully suggest the reappointment of this Committee. Extract of a letter from H. L. Stevenson of Norwich." The beachmen at Salthouse (Norfolk) are delighted with the new Act, as, through summer shooters, their means of earning a few shillings were going fast. Only three or four pairs of Lesser Terns nested there this year; and, as the men reminded me, ten years ago they had forty or fifty pairs at least. I am sure the marshmen on the Broads would be equally glad of a close time there, as they complain to me of gentlemen shooting Snipe into May."

Extract of a letter from the Rev. H. F. Barnes of Bridlington.- -"With regard to our Sea-bird Act, I am happy to tell you that here it has been very effective. *** It renders the birds, however, remarkably tame. They sit on the cliffs only a few feet below the observer, and nod and bow in the most amiable manner, as if all that breathed must needs be kin. Then, again, they swim about the shore, on a calm day, like ducks in a pond. this may safely be set down to the degree of immunity they have enjoyed. One noticeable and very valuable fact is, that they have bred (in small numbers) this year at Flamborough, which they have not done for the last twenty years."

All

Captain Hadfield, of Ventnor, in a communication to the Zoologist' (June 1870, p. 2184), has remarked on the "increase of the sea-fowl breeding on the freshwater cliffs" since the passing of the Act.

Report of the Committee on Standards of Electrical Resistance. The Committee consists of Prof. WILLIAMSON, F.R.S., Prof. Sir CHARLES WHEATSTONE, F.R.S., Prof. Sir W. THOMSON, F.R.S., Prof. W. A. MILLER, F.R.S., Dr. A. MATTHIESSEN, F.R.S., Sir CHARLES BRIGHT, C.E., F.R.G.S., J. CLERK MAXWELL, F.R.S., C. W. SIEMENS, F.R.S., BALFOUR STEWART, F.R.S., Dr. JOULE, F.R.S., C. F. VARLEY, Prof. G. C. FOSTER, F.R.S., C. HOCKIN, M.D., and Prof. FLEEMING JENKIN, F.R.S. (Secretary).

THE Committee are unable to report any material progress during the last year in the work which remains to be done, and beg leave to suggest that this work may probably be more effectually expedited by the appointment of several small Committees than by retaining the large but somewhat cum

brous organization by which their work was commenced. When the Committee was first appointed, no coherent system of units for the measurement of electrical resistance, currents, quantity, capacity, or electromotive force had met with general acceptance. The so-called absolute system existed indeed on paper, but in far too intangible a form to be either understood or used by practical men. At the same time, proposals for the adoption of isolated units, variously determined, had been carried out, with more or less success, so as to meet in some degree the immediate requirements of telegraphy. Many competing units of this nature were in the field. The Committee chose a system based on the absolute measure, and so, at least as far as electrical resistance was concerned, made this measurement a tangible and practical operation; and their choice has been ratified by men of science over a great portion of the globe. Copies of the unit of resistance adopted by the Committee in 1864 were deposited at the Kew Observatory; and others exist in the hands of electricians in various parts of the world. Comparisons of several of the copies, which were published in the Report of the Committee for 1867, showed that, with one or two exceptions, the ratio of their resistances remained unchanged. It is, however, desirable that additional comparisons should be made from time to time. Incidentally many researches of considerable value were carried out by the Members of the Committee; and the yearly reports have been so generally in request that it may be advisable to reprint the entire series.

No second unit, however, has been issued by the Committee, although apparatus for the determination of the units of capacity, quantity, potential, and intensity of current have been constructed, both with the funds of the Association and from the private means of its members. The great numbers of the Committee render meetings of rare occurrence; and the Subcommittees appointed to undertake the work have been lately remiss in its execution; the Committee, believing that direct responsibility to the Association and greater freedom of action will act as a stimulus to individual members, beg to suggest that the Electrical-Standards Committee be not reappointed, but that three new Committees of smaller numbers be chosen, to determine and issue:-1st, a condenser representing the unit of capacity; 2nd, a gauge for showing the unit difference of potential; 3rd, an electrodynamometer adapted to measure the intensity of currents in a decimal multiple of the absolute measure.

They would also suggest that it be an instruction to each Committee that it shall carry out the system adopted by the Electrical-Standards Committee, and that these new Committees shall have the use of all instruments hitherto constructed with the funds of the Association, a list of which is appended (in account book).

Considering that the principal instruments have already been constructed, the Committee believe that a small grant of, say, £20 to each Committee, will be sufficient to meet the expenses of the next year.

In conclusion, should this suggestion be adopted, they beg to recommend that a volume, containing the complete series of reports, be issued by the Association, and sold to the public, feeling assured, from the demand for isolated copies, that such an issue would involve no expense to the Association.

Sixth Report of the Committee for Exploring Kent's Cavern, Devonshire, the Committee consisting of Sir CHARLES LYELL, Bart., F.R.S., Professor PHILLIPS, F.R.S., Sir JOHN LUBBOCK, Bart., F.R.S., JOHN EVANS, F.R.S., EDWARD VIVIAN, GEORGE BUSK, F.R.S., WILLIAM BOYD DAWKINS, F.R.S., WILLIAM AYSHFORD SANFORD, F.G.S., and WILLIAM PENGELLY, F.R.S. (Reporter). DURING the year which has elapsed since the Association met at Exeter, the Committee have continued their researches without intermission, and have in all respects adhered to the method of exploration adopted at the commencement and described in detail in their First Report (Birmingham, 1865). The Superintendents have continued to visit the Cavern daily, and to send Monthly Reports of progress to Sir Charles Lyell, the Chairman of the Committee; the daily results have been regularly journalized; the workmen, George Smerdon and John Farr, have continued to give the most entire satisfaction; and the great interest felt in the investigations by visitors and residents in Torquay has undergone no abatement.

At the close of the last Meeting of the Association, a large number of the Members and Associates visited the Cavern, where they were received by one of the Superintendents, who conducted them through it and explained the most striking phenomena connected with it. In addition to this large party, the Cavern has, from time to time during the year, been inspected, under the guidance of the Superintendents, by Professor Stokes (President, British Association), the Duke of Somerset, Lord Talbot de Malahide, Lord H. Thynne, Sir H. Verney, Sir J. Kay Shuttleworth, Sir A. Malet, General Cotton, General Lefroy, General Tremenhere, Rev. Dr. Robinson, Rev. Prof. Maurice, Rev. O. Fisher, Rev. H. H. Winwood, and Messrs. W. R. A. Boyle, J. Dundas, A. Macmillan, E. B. Tawney, R. Valpy, W. Vicary, and A. R. Wallace, and many others.

The Committee have again the pleasure of reporting that they have been enabled to render assistance to those engaged in similar researches elsewhere. Sir J. Kay Shuttleworth, Chairman of the Committee who have recently undertaken to explore the caves in the Mountain-Limestone near Settle, in Yorkshire, opened a correspondence with the Superintendents of the work in Kent's Cavern, which eventuated in an arrangement that Mr. Jackson, Superintendent of the Yorkshire investigations, should visit Devonshire for the purpose of making himself fully acquainted with the mode of operation carried out there. Accordingly, on March 1, 1870, he reached Torquay, where every facility was given him by the Superintendents and the workmen for familiarizing himself with the work in all its details.

It has been stated in previous Reports :-that Kent's Cavern consists of an Eastern and a Western Division, each composed of a series of chambers and galleries; that it has two Entrances, which are about 50 feet apart, 200 feet above the mean sea-level, from 60 to 70 feet above the bottom of the valley in the same vertical plane, situated in one and the same low vertical cliff in the eastern side of the hill, and which open at once into different branches of the Eastern Division; and that the labours of the Committee have been restricted to the Eastern Division, the different branches of which were known as the North-east Gallery, the Vestibule or Sloping Chamber, the Gallery, the Lecture Hall, the South-west Chamber, the Water Gallery, and the North and South Sally-ports. In their Fifth Report (Exeter, 1869) the Committee stated that, with the exception of the last two, the exploration of the entire series had been completed to the depth of 4 feet below the stalagmitic floor,