In Britain silver mines were worked before the invasion of the island by the Romans, and gold must also have been well known to the inhabitants before the arrival of Cæsar, since coins of that metal were then in circulation. Cæsar and Strabo both state that the Britons obtained their copper from foreign countries, and we may hence infer that the art of refining this metal was either unknown, or little cultivated by our forefathers at that remote period. Iron is described by Cæsar as being so rare, that pieces of it were sometimes used as a medium of exchange, and almost as highly valued as gold; but a century afterwards it had become very common, as in Strabo's time, it was an article of exportation.* Tin was anciently the most celebrated product of Britain, and appears even at that time to have been extracted in considerable abundance, since it was the desire of obtaining possession of these mines, and becoming thereby independent of the Phoenician monopoly, which first induced the Romans to visit the island. Before the conquest of their country the Ancient Britons extracted this metal from its ores by methods which they had themselves discovered, and which were probably improved on by their conquerors. The smelting process would seem to have been very simply conducted. The broken ore was placed in a hole in the ground, the sides of which were lined with pieces of wood, which, on being ignited, reduced the lead and tin, which were separated from the slags by being run off through a narrow channel into another receptacle. Many of these rude furnaces have been found in various parts of Cornwall and elsewhere, in which not only charcoal and slags have been discovered, but also portions of the reduced metal, which, in many instances, had, from long exposure to oxidising influences, again become partially converted into tin ore. This very rude method must have been attended with considerable success, as the slags resulting from it have proved on examination to contain but a small amount of metal. § From these and many other relics which have been met with in different parts of the world, we may infer, that although the arts of working the metals were carried on formerly on a much smaller scale than at the present day, the operations of the early metallurgists were tolerably successful, and that in spite of the rude apparatus which they employed, the results obtained by them were generally of a satisfactory nature. That a great degree of attention was at a very early period bestowed on the manufacture of alloys destined for particular purposes, is proved by the uniform composition of the several cutting instruments examined; although it is evident that but little care was taken to obtain a correct standard for the early brass money, as many pieces of nearly the same date, and of similar value, differ materially * Strabo, IV., 305. Jews' house tin. † Strabo, I. On this sub in the amounts of the metals of which they consist. ject 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. 1 5 No. 1. Sword-blade, found under Chertsey Bridge, Thames. 2. A broken sword-blade, from Ireland. 8 دو 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. |