in the amounts of the metals of which they consist. On this subject I shall offer no observations, as the object of the present paper is rather to shew the composition and proportions of the ancient alloys, than to enter into a discussion on the coins of antiquity, and I therefore leave this matter for the consideration of the numismatist and antiquarian, whose labours in that direction may possibly be, in some measure, aided by the facts elicited from the foregoing analyses.

No. 1. Sword-blade, found under Chertsey Bridge, Thames.

2. A broken sword-blade, from Ireland.

4. A broken spear-head, from Ireland, presenting the only specimen of unalloyed copper examined.

5. A celt, with a socket for the introduction of a wooden handle and an eye, probably for the purpose of attaching a string.

Nos. 6 and 7. Celts, composed of a harder alloy, and without sockets.

No. 8. A celt, with socket and loop, found in Ireland, and made of a hard alloy. This specimen appears to have been sharpened by grinding.

Account of Observations on the Solar Eclipse of July 28, 1851, made at Sebastople. By EDWARD SANG, Esq., F.R.S.S.A., Professor of Civil and Mechanical Engineering, Constantinople. Communicated by the Royal Scottish Society of Arts.*

While engaged in preparing to observe the eclipse of the sun from Constantinople, I received a copy of a letter, of date June 5th, addressed by the Astronomer Royal to Mr Waddington, proposing a trip across the Black Sea, and accompanied by copies of the Suggestions to Astronomers, prepared by the Committee of the British Association, which was forwarded to me by His Excellency Sir Stratford Canning. Subsequently, I have learned that this was at the instance of the Secretary of the Royal Scottish Society of Arts, and, accordingly, to that Society I make my report.

The idea of a journey into Russia had previously crossed my thoughts, and, for various reasons, had been dropped; but on learning that my observation of the phenomena of the total eclipse might be of the least service, and that no one had been deputed from England to this quarter of the world, I laid aside all my preparations here, and resolved on a journey to the region of total shadow.

Unfortunately, His Excellency's note of date July 12th only reached me on the 15th, and the very next was the sailing day of the Odessa steamer; it was utterly impossible to complete my arrangements in time; there would be no other opportunity by steam until the 26th, and thus our only chance of reaching the Crimea previously to the eclipse, was by a sailing vessel; this chance, too, with the prevailing north winds, and the high state of the barometer, was a very small one. So long, however, as a possibility of success remained, I was determined not to abandon the enterprise. With a change of wind we might still reach Kertche or Theodosia, and make the observations from the quarantine grounds. I

*Read before the Society, 24th November 1851.

therefore proceeded at once to make the necessary preparations, and obtained a readily granted leave of absence from His Highness Ahmet Fethi Pasha.

On learning the state of matters, His Excellency the Baron Titoff shewed all the anxiety to assist us which could have been hoped from the most enthusiastic astronomer. After weighing in his own mind the almost impossibility of our reaching in time by help of a merchant vessel, M. Titoff made me the unexpected and most welcome offer of a passage on board the brig of war Perseus, which was about to return to Sebastople, and whose departure he proposed to accelerate. Since, even this with aid, our only hope lay in a change of weather, it is needless to say how gratefully I accepted so liberal an offer.

His Excellency M. Titoff having furnished me with letters which every where procured for me the most courteous assistance, we left the Bay of Buyukderé, under the command of Prince Chickmakoff, early on the morning of the 21st. Notwithstanding the most strenuous exertions, and the help of the steamer Molnia, it was not until noon of the next day that we succeeded in stemming the current and fairly launching into the Black Sea.

The anxiety attending such hasty preparations being now over, we had leisure to concoct our plans and to discuss the nature of the instruments which we had collected. The tedium of our voyage may be well relieved by an account of both.

The ingress of Mercury on the 8th November 1848 was beautifully seen here. I had the good fortune to study it with an excellent 4 inch aperture refractor, by Plössel, belonging to Ohanes Dadian, Esq. Having had every reason to be satisfied with the performance of this instrument, and being desirous of leaving my own telescope for the use of my family, I applied to Mr Dadian, who at once most kindly conceded to me the use of the Plösselsche. We constructed a light octahedral frame of slender fir rods to fit upon the eye-piece of the instrument, and to carry a card on which a graduated circle was traced. The intention was to receive the sun's image on this card, under a tent, and to watch there

the progress of the phenomenon, so as to avoid fatiguing the eyes; the graduated circle would enable us to refer any appearance to the proper place on the sun's disc. With the lowest power, the sun's image on this screen is about 7 inches in diameter; the spots with their surrounding umbrae, the variegation of the sun's surface, and its gradual diminution in apparent brilliancy towards the edge are beautifully distinct. In this way we had examined the ingress of Mercury; the progress of the planet was distinctly followed without any appearance of that distortion which is mentioned in the Committee's suggestions. Hence I expected that this instrument would afford conclusive evidence concerning the nature of the beads.

The owner of this refractor procured from the same maker a splendid equatorial of 14 inches aperture, completely mounted, for the Ottoman Government; this magnificent instrument has not yet been set up.

For the purpose of determining our geographical position, we had an 8 inch portable astronomical circle, by Adie of Edinburgh, the performance of which has long given me the greatest satisfaction. It is read to 10" with three verniers, both in altitude and in azimuth, and is fitted with all the adjustments which an instrument of that size can require. This was accompanied by a chronometer, whose rate had, for several years, been found sufficiently steady, with a slight over-compensation, that is, a tendency to go faster in summer. Its winter rate had been Os. 9 losing, and its summer rate was Os. 24 losing. For comparison we had also a pocketwatch, whose rate was as close as that of the chronometer. A mountain-barometer for correcting the refraction, a pair of Nicol's eye-pieces, darkening glasses, boxes of tincture of litmus of various thicknesses, stearine candles for comparing shadows, and other odds and ends completed the apparatus.

Encountering only light winds and calms, we saw our prospects of reaching Kertche gradually wane; computations for Theodosia were made, and instructions were drawn up for a nearly tangential phase. Latterly we had been hoping against conviction, when, on sighting the south point of the Crimea, our hopes were revived by a fresh breeze.

With the sunset of the 27th, however, the wind again fell, and the morning of the 28th dawned upon us with the impossibility of reaching even Theodosia. There was still a small probability of making Sebastople, the only other place at which we could set foot on shore: so after a short consultation the vessel was put about.

Computations were now made for our new haven of hope, and corresponding instructions were drawn up. The rate of the log and our distance from the lighthouse of Kherson were anxiously compared; the light breeze gradually stiffened; the chronometer was coming up to the computed time of commencement, and our race against the moon promised to be a very close affair. We rounded the point of Kherson, and just as the quarantine bay was opened up, the index pointed to the time of look-out. Meantime, in anticipation of our anxiety, our commander had caused the boat to be lowered and the instruments to be handed down; and almost simultaneously with the first appearance of the moon's edge came the intimation "boat ready."

A very smart pull brought us to the quarantine while the vessel continued on her way. To choose our stations, open the boxes, set up the instruments, and compose ourselves for observation, occupied some time and gave occasion for anxiety; but within forty minutes from the beginning of the eclipse we were all settled to our duties.

The party consisted of the first lieutenant, Mr Gregory Jelesnoff, who had engaged to measure the distance between the cusps, accompanied by Lieutenant Andreowsky, with a chronometer; of Mr Zazebin the first sailing master, who had undertaken to measure the breadth of the illuminated part, accompanied by Mr Daïn, the second master, with another chronometer; and of myself and son who were occupied with observations on the appearance of the beads.

As our computation had given 38" for the least breadth of the illuminated part, there was no other physical phenomenon likely to come under our notice; so, excepting a glance at the aspect of the surrounding scenery, and an attentive examination of the cusps in search of any appearance of the moon's limb beyond the sun's disc, of which there was no