The periods and deflections were taken in the first four hours after midnight, then, after a few hours' sleep, and far too soon for the temperature to have quieted down, I took the period with the counterweight, but was only able to give ten minutes, as I had to catch a train in order to be able to give my midday lecture at South Kensington. It is not surprising that under such conditions a difference of 1 part in 600 should arise. There is a difference of about the same order of magnitude between the earlier experiments and the favourable four. There is one point about the figures that I should like to mention. No results were calculated till long after the completion of the last experiment. Had I known how the figures were coming out, it would have been impossible to have been biassed in taking the periods and deflections. Even the calculating boys would not have been quick enough to discover whether the observed elongations were such as would give a definite point of rest. I made my observations, and the figures were copied at once in ink into the books, where afterwards they left my hands and were ground out by the calculating machine. The agreement, such as it is, between my results is therefore in no way the effect of bias, for I had no notion till last May what they would be.

My conclusion is that the force with which two spheres weighing a gramme each, with their centres 1 centimeter apart, attract one another, is 6.6576 × 10-3 dynes, and that the mean density of the earth is 5.5270 times that of water. I do not think the fourth significant figure can be more than one or, at the outside, two parts in error.

It is evident, from what I have already said, that this work is of more than one-man power. Of necessity I am under obligations in many quarters. In the first place, the Department of Science and Art have made it possible for me to carry out the experiment by enabling me to make use of apparatus of my own design. This belongs to the Science Museum, where I hope in time to set it up so that visitors who are interested may observe for themselves the gravitational attraction between small masses. Prof. Clifton, as I have already stated, has given me undisturbed possession of his best observing room, his only good underground room, for the last four years. The late Prof. Pritchard lent me an astronomical clock. Prof. Viriamu Jones enabled me to calibrate the small glass scale on his Whitworth measuring machine; and Mr. Chaney did the same for my weights. I would specially refer to the pains that were taken by Mr. Pye, of the Cambridge Scientific Instrument Company, to carry out every detail as I wished it, and to the highly skilled work of Mr. Colebrook, to which I have already referred. Finally, I am under great obligations to Mr. Starling, of the Royal College of Science, who performed the necessarily tedious calculations.

In conclusion, I have only to say that while I have during the last five years steadily and persistently pursued this one object with the fixed determination to carry it through at any cost, in spite of any

opposition of circumstance, knowing that by my discovery of the value of the quartz fibre, and my development of the design of this apparatus, I had, for the first time, made it possible to obtain the value of Newton's Constant with a degree of accuracy as great as that with which electrical and magnetic units are known; though I have up to the present succeeded to an extent which is greater, I believe, than was expected of me, I am not yet entirely satisfied. I hope to make one more effort this autumn, but the conditions under which I have to work are too difficult; I cannot make the prolonged series of experiments in a spot remote from railways or human disturbance; I cannot escape from that perpetual command to come back to my work in London; so after this I must leave it, feeling sure that the next step can only be made by my methods, but by some one more blest in this world than myself.

[C. V. B.]

GENERAL MONTHLY MEETING,

Monday, July 2, 1894.

SIR JAMES CRICHTON-BROWNE, M.D. LL.D. F.R.S. Treasurer and Vice-President, in the Chair.

George W. Field, Esq. F.R.G.S.
Mrs. Henriette Kellgren,

were elected Members of the Royal Institution.

The Special Thanks of the Members were returned for the following donation to the Fund for the Promotion of Experimental Research at Low Temperatures:—

Sir Douglas Galton

£25

The Chairman reported that Mr. Ludwig Mond, F.R.S. had made a proposal to the Managers of the Royal Institution of Great Britain, to convey to the Members of that Institution the freehold of No. 20 Albemarle Street, to be held by them for the purpose of a laboratory to be named "The Davy-Faraday Research Laboratory of the Royal Institution," and for the purpose of providing increased accommodation for the Institution, and that the Managers, at their Meeting held this day, had most cordially and gratefully accepted this munificent gift made in the communication from Mr. Mond, of which the following is an extract :—

"In the year 1843 a proposal was made to establish at the Royal Institution a School of Practical Chemistry, which was not only to give practical and systematic instruction to students, but was also to provide a place where original researches could be conducted by individuals skilled in manipulation, and where the professors could work out their problems by the aid of many qualified hands.

This proposal was submitted by the Managers of the Royal Institution to Professors Faraday and Brande, who expressed their strong approval of the end proposed, and their desire that it might be carried out at the Royal Institution, if it could be done well.' But, on a closer examination of the limited space within the walls of the Institution, it appeared impracticable to afford accommodation for carrying out the proposed scheme.

"In 1846 the Royal College of Chemistry was founded, and since that time numerous schools for the teaching of practical chemistry have been established all over the country. These, however, only cope with the first part of the scheme recommended in 1843, while as to the second part, viz. founding a laboratory for the carrying out of independent researches, no adequate provision exists in England up to this date, although the need for it was so strongly felt so many years ago, and its importance for the advancement of science so forcibly dwelt upon by the promoters of the scheme and by such men as Faraday and Brande.

"I have felt that the need for such a laboratory has become greater and greater since the work of the scientific investigator has become more and more subtle and exact, and, in consequence, requires instruments of precision and a variety of facilities which a private laboratory can only very rarely command; and surely this need exists nowhere to a greater extent than in England, and

nowhere can such a laboratory be expected to bear more abundant fruit than in this country, which possesses such an unrivalled record of great scientific researches, which have emanated from private laboratories not connected with teaching institutions, and amongst which the laboratory of the Royal Institution stands foremost, and has kept up its reputation for nearly a hundred years.

"It has been my desire for many years to found a public laboratory which is to give to the devotees of pure science, anxious and willing to follow in the footsteps of the illustrious men who have built up the proud edifice of modern science, the facilities necessary for research in chemistry, and more particularly in that branch of the science called physical chemistry.

"I have come to the same conclusion as the promoters of the scheme of 1843, viz. that such laboratory would still have the greatest prospect of success under the ægis of the Royal Institution, that in fact it would be the consummation of the work which this great Institution has been fostering in its own laboratory, with such remarkable results, by the aid of the eminent men whose services it has always been fortunate enough to procure.

66

"As only want of space prevented the Royal Institution undertaking this task fifty years ago, I took the opportunity which offered itself last year of acquiring the premises, No. 20 Albemarle Street, adjoining the Institution. This property I found very suitable for the purposes of such a laboratory, and large enough to afford, besides, facilities to the Royal Institution for a much needed enlargement of its present laboratory and its libraries and reception rooms, which I should with great pleasure put at the disposal of the Institution. Being convinced that the Managers of the Royal Institution will give all the encouragement and aid in their power in the foundation and working of such a research laboratory, I hereby offer to convey to the Royal Institution the freehold of No. 20 Albemarle Street, and also the lease I hold from the Institution of premises contiguous thereto, to be held by them for the purpose of a laboratory, to be named "The Davy-Faraday Research Laboratory of the Royal Institution,' and also for the purpose of providing increased accommodation for the general purposes of the Royal Institution, as far as the available space will allow, after providing for the requirements of the research laboratory.

"I also offer to make, at my own expense, all structural alterations necessary to fit the premises for these purposes, and to equip the Davy-Faraday Research Laboratory with the necessary apparatus, appliances, &c., and to make such further adequate provision as will hold the Royal Institution free from all expense in connection with the premises and the working of the said laboratory..

"I am aware that my offer will not provide for the third object of the scheme of 1843, viz. to enable the professors to work out their problems by the aid of many qualified hands; but I trust that if the laboratory which I offer to found proves successful, others will come forward who will supply the means for attaining this end, by the foundation of scholarships and bursaries to qualified persons willing to devote themselves to scientific work and not in a position to do so without assistance."

The PRESENTS received since the last Meeting were laid on the table, and the thanks of the Members returned for same, viz. :—

FROM

The French Government-Documents Inédits sur l'Histoire de France: Recueil des Chartes de l'Abbaye de Cluny, Tome V. 4to. 1894.

The Lords of the Admiralty-Report of Astronomer Royal. 8vo. 1894.

Report of H.M. Astronomer at the Cape of Good Hope, 1879-86. 4to. 1894. The British Museum (Natural History)—A Monograph of Lichens found in Britain, Part 1. 8vo. 1894.

Catalogue of the Mesozoic Plants in the British Museum: The Fossil Plants of the Wealden, Part 1. 8vo. 1894.

Catalogue of Birds, Vol. XXIII. 8vo. 1894.

Accademia dei Lincei, Reale, Roma-Classe di Scienze fisiche, matematiche e naturali. Atti, Serie Quinta: Rendiconti. 1o Semestre, Vol. III. Fasc. 9-11. 8vo. 1894.

Classe di Scienze morali, etc.: Rendiconti, Serie Quinta, Vol. III. Fasc. 3, 4. 8vo. 1894.

American Academy of Arts and Sciences-Proceedings, New Series, Vol. XX. 8vo. 1893.

American Philosophical Society-Proceedings, No. 144. 8vo. 1894.

Asiatic Society, Royal (Bombay Branch)-Journal, Vol. XVIII. No. 50. 8vo. 1894.

Prof. Peterson's Report on the search for Sanskrit MSS. (Vol. XVIII. No. 49 A). 8vo. 1894.

Asiatic Society of Bengal-Proceedings, 1893, No. 10; 1894, No. 1. 8vo. 1894. Journal, Vol. LXII. Part I. No. 4; Part 2, No. 4. 8vo. 1893.

Annual Address by Sir C. A. Elliott. 8vo. 1894.

Astronomical Society, Royal-Monthly Notices, Vol. LIV. No. 7. 8vo. 1894. Bankers, Institute of Journal, Vol. XV. Part 6. 8vo. 1894.

Basel, Naturforschenden Gesellschaft-Verhandlungen, Band IX. Heft 3. 8vo.

1893.

British Architects, Royal Institute of-Journal, 3rd Series, Vol. I. Nos. 14-16. 4to.

British Association for the Advancement of Science-Report of the 63rd Meeting at Nottingham. 8vo. 1894.

British Astronomical Association-Memoirs, Vol. II. Part 3; Vol. III. Part 2. 8vo. 1894.

California, University of-Report of Work of the Agricultural Experiment Stations, 1891-2. 8vo. 1893.

Addresses, March 23, 1893. 8vo.

Annual Report, 1893. 8vo.

Department of Geology: Bulletin, Vol. I. Nos. 3, 4. 8vo. 1893.

Camera Club-Journal for June, 1894.

8vo.

Canada Meteorological Office-Report for 1889. 8vo. 1893.

Chemical Industry, Society of-Journal, Vol. XIII. No. 5. 8vo. 1894.

Chemical Society-Journal for June, 1894. 8vo.

Cooper Union Trustees, U.S.A.-35th Annual Report. 8vo. 1894.

Cornwall Polytechnic Society, Royal-Annual Report for 1893. 8vo. 1894.
Cracovie, l'Académie des Sciences-Bulletin, 1894, No. 5. 8vo.

Editors-American Journal of Science for June, 1894. 8vo.