having a notch cut out in them. E F (fig. 3) is a long lever moving on a centre G, having a small weight M suspended from the longer end, which is gradually raised during eleven and a half hours by a pin resting on the snail H. When raised to its limit it falls from the snail about two minutes before one, and is retained in its position by the prolonged end F being caught on the catch I F attached to other levers K and L, fastened on a collar moving on a stud I. From the angle given to the face of the catch F, the weight exerts a slight force in an upward direction on the levers K and L, the one K coming first into action on the minute-hand disk, and being prevented from rising until the notch has moved forward to relieve the point of the lever, which it does about ten seconds before one o'clock. The upper lever L now comes against its disk on the second's wheel, which prevents its being forced up until the notch has come round to relieve it, exactly as the second's hand falls on the sixtieth second.

The levers K and L being now free to rise, allow the catch to relieve the long lever E F, and immediately the small weight M to fall, while the levers K and L, by their own gravity, drop out of action, and give freedom for the circles. on the minute and second's hands to revolve. Such is the duty of the clock, first to raise the small weight M, weighing about four ounces, and suddenly, exactly at one o'clock, to allow its dropping.

The gun-trigger consists of a heavy weight W, suspended on an arm R, and acting directly by a metal chain over the pulley S on the friction fuse of the gun. About two minutes before one o'clock, the gun being already loaded, the arm R with the weight W is raised by the gunner pulling the chain until it is caught by the trigger P, which moves on the stud O. The chain is now attached to the tongue of the friction fuse, a considerable amount of slack being allowed to give momentum to the weight before the pull is given. The trigger Pis then knocked out by the long arm N O being struck by the fall of the small weight M. These several actions are so very instantaneous as to be inappreciable, and of course are quite uniform every day.

Address by the President, ALEXANDER BRYSON, F.R.S.E., F.S.A. SCOT., P.R.P.S., concluding the Session of 1860-61, at the Meeting 11th November 1861.

GENTLEMEN,-It is usual and proper, before adverting to the progress we have made as a Society during the last session, to remember those fellows who, by death, have fallen from its ranks, and who, while in life, promoted its prosperity. The roll, though not a long one, includes highly distinguished names. Among these was the late Earl of Aberdeen; he did not contribute to our transactions, but he gave us his countenance and patronage,—and that was no mean gift. He was born at Edinburgh on the 28th January 1784, and died at Argyll House, London, on the 14th December 1860. This is not the place where politics dare enter, and to the public eye his life seemed only that of a politician; but he was more a scientific man than the public knew, and he did not seem to wish that they should know of his knowledge, yet there was scarcely a better botanist in Britain than the late Earl of Aberdeen; every, even the tiniest plant that grew in this country he could name, and assign it its place in the systems of Linnæus or Jussieu. In early life he was one of the most distinguished and successful agriculturists of our country, and had the felicity which falls to the lot of few, to see the saplings he had planted grow into goodly trees ere he died. Lord Aberdeen's name will be ever associated with the progress of agriculture, the history of the Church of Scotland, and the Crimean war. Of his conduct at the breaking out of the Russian war various opinions are held, but now that the trumpet has ceased to sound, and the battle's roar is hushed, and the millions who cried for war now rejoice in peace, let us say of him who was the last man in Britain to say that the war was inevitable," Blessed are the peace-makers."

Sir William Keith Murray, Baronet, of Ochtertyre, another of our deceased fellows, claims a large share of our regret. Honoured as I was by his friendship, perhaps I may be partial, but I cannot help expressing my feelings, when I say that we have lost in him almost an Admirable Crichton.

Sir

William was among the most accomplished men of his time; he was an artist, an antiquary, a practical mechanic, an astronomer, and, above all, a gentleman. All who knew him loved him, and those who knew him best loved him most. We have also to regret the loss of Professor Schank More, who always took a deep interest in this Society, and formerly occupied this chair; also Mr John Girdwood, agricultural engineer of London, who, when resident here, was always present at our meetings, and was a member of our Council; Mr William Miller, stockbroker, and Mr James Dickson, merchant, completes the list of our deceased members.

Allow me now to allude to the present condition of the Society, as regards its statistics, kindly furnished to me by our excellent secretary, Mr Beatson Bell. It appears that at the 1st of November 1860, the ordinary fellows amounted in number to 423. During last session we had a considerable addition to our numbers, fifty-six new members having been added to the Society. But I am sorry to say that thirty-four gentlemen have resigned, which, added to the six deceased members, leaves us only eighteen of an increase upon the session. I would urge, therefore, every member of this Society who values its privileges, who knows its aims, and what it has done, to enlist every man in its cause who believes in the ameliorating influence of science and art.

During the past session we have been favoured with many papers of great practical value. The first which deserves our attention is Mr Sang's communication "On the Determination of the Form of a Ship's Hull by Means of an Analytic Expression." Had Mr Sang put us in possession of the formula by which he formed the beautiful model which illustrated his paper, I feel confident that your committee would have awarded him the highest honour they could bestow-the Keith Medal; but I have no doubt that Mr Sang had good reasons for withholding this information, and I honour his patriotism which dictated the resolution. To Professor Smyth and Mr Frederick Ritchie we are indebted for their communication on the "Means Adopted for Securing Accuracy in the Time-Gun Signal," and for which your committee have justly awarded to Mr Ritchie the highest prize of the session. The time-gun is no longer a

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signal failure, as every day it punctually reminds us that tempus fugit, and is now the Jupiter Tonans of our city.

It must, I am sure, be a source of pleasure to all of our fellows, to know that we have now obtained a hall which we can call our own. After many meetings and consultations of the Ways and Means Committee, it was at last arranged to accept the offer made by Mr Smith of 117 George Street, to build a hall slightly larger than the one we are now met in, with a committee room and a gallery, where we can display our models, so long hidden. And as we have this evening to discuss the question of adding to our rooms, may I beg that the members may remain after the public business, to favour the Council with their opinions on so important a subject.

It has been suggested that this Society should affiliate with the Society for the Encouragement of Arts, Manufactures, and Commerce, of London. By this union many advantages would be obtained by the members of this Society; and in future the President should be proposed as a member of the sister Society. Nearly three hundred literary and scientific associations have taken advantage of the privileges which the Society, with great liberality, offer to those in union, and these privileges are neither few nor small. By means of this arrangement, a member of one institution in union with the central Society, when visiting a town in which any other is situated, will be enabled to enjoy, for the time being, all the advantages of membership. Any person wishing to avail himself of this privilege needs only to present his card of membership, it being understood that he will abide by the bye-laws of the particular institution he may visit, as well as in regard to the time to which the privilege may be extended. By a subscription of two guineas per annum, our future presidents will enjoy, when visiting the metropolis, all the privileges of a member of the Society of Arts; and all our members will be entitled to visit its reading-rooms during their residence in London. But another advantage would accrue to us, and on which I put great stress, our proceedings here would be published immediately and in extenso. I have long thought that we have never taken that prominent place which we ought to have done among the institutions of our country;

and the best remedy I can suggest is, that our papers, discussions, and proceedings, should at once appear in the "Journal of the Society of Arts of London," as well as in our own "Transactions," at the close of the session.

When in Manchester at the late meeting of the British Association, I had another example of the evil arising from the tardiness of publishing our papers. It may be in the memory of some now present, that in the address which I delivered on taking this chair, I alluded to the share that our late Vice-President, Professor Swan, had taken in the spectrum analysis discoveries. Had these remarks been made public, I am sure that my friend, Professor Miller, of University College, London, would not have omitted Professor Swan's name among all those who were so honourably associated in those most important investigations, when he de livered his lecture on spectrum analysis, in the chemical section. My friend, Dr Macadam, who was present, will bear witness that I did not let this omission pass without notice; and further, that in the evening, when the Professor repeated the lecture, ample justice was done to Professor Swan.

It may interest you to know, that by means of the spectrum apparatus I obtained on two occasions evidence that the line. D of Fraunhofer was the most prominent in the spectrum of the late comet. The line D is the ray of mean refrangibility; it is yellow and non-actinic. By these observations I was enabled to determine that sodium was a chief constituent of the comet; it also proved that it was self-luminous, but not incandescent. Dr Herschell, besides the sodium line, detected traces of the presence of barium. It is often asked, Where does the salt of the sea come from? Now, if these erratic bodies are picking up the stray atoms in space, and are yet designed to become the abodes of sentient beings, it seems proved by these observations that the sodium was present at their genesis.

At the opening of the session I alluded to the importance of a thorough system of drainage; and through the energy and enlightened philanthropy of Provost Lindsay of Leith, a scheme, devised by Messrs Stevenson and Macpherson, which seems a large and comprehensive one, has been submitted to the Town Councils of Edinburgh and Leith. I sincerely