Verified by so many combinations independent of each other, our arc of France and Spain acquired farther rights to become a fundamental model for measures. An occasion presented itself of making it of still more importance. Since the rebellion of 1745, the English government had perceived the utility of constructing a detailed map of the three kingdoms, which could serve equally to direct the amelioration of the country in time of peace, and its defence in time of war. I may state in passing, that it is the war which, for twenty years back, has given to geodesiacal operations the great extension, and the extreme perfection, which they have acquired in all the states of Europe; and the value of this slight advantage is thus enhanced by its being dearly enough paid for. However this may be, the English triangulation, begun by General Roy, and continued after him by Colonel Mudge, was prolonged from the south of England to the north of Scotland, and presented in that extent many degrees of the terrestrial meridian, measured with excellent instruments. It was extremely desirable that this arc should be joined to the arc of France. But as, from the geographical position of England, she is placed a little to the westward of ours, there was ground to fear lest all the terrestrial meridians, not being exactly alike, the difference of longitude would affect the results which might be obtained from that junction. Nevertheless, there could be no dread of this, so far as concerned the measurements of the pendulum, which are much less disturbed than the degrees by the slight irregularities of the figure of the earth. The Board of Longitude was desirous that the same apparatus which had served for these measurements in France and Spain, should be employed over the whole extent of the English arc. To wish for any thing useful to the sciences, was to have at once the assent of the men of science in England, and the approbation of the government of that enlightened country. Neither the one nor the other was wanting to us. The respectable Sir Joseph Banks, and his worthy friend Sir Charles Blagden, assured us of all imaginable facilities. M. Lainé, the minister of the interior, with whom every thing useful or honourable has only possi

bility for its limit, was able, from the resources of his good will, to furnish means for this enterprise, and the Board of Longitude had the goodness to entrust me with the execution of it. I left Paris at the commencement of the month of May last year, carrying with me the apparatus I had made use of on the other points of the meridian, a repeating circle by M. Fortin, an astronomical clock, and chronometers by M. Breguet; in fine, every thing which was necessary for the observations. Orders from the English government, obtained through the vigilant intervention of Sir Joseph Banks, awaited their arrival at Dover. The whole was sent to me quite entire, and under the seal of the customs, without fees, without inspection, absolutely as if I had not passed from one country to another. Every thing was protected with the same care in the carriage to London, and was at last deposited in the house of Sir Joseph Banks. How can I describe what I felt on seeing for the first time the venerable companion of Cook, rendered illustrious by his long voyages, remarkable for a reach of mind, and an elevation of feeling, which make him equally interested in the progress of all human knowledge

possessing high rank, great fortune, and universal respect-Sir Joseph has made all these advantages the patrimony of the learned of all nations. So simple, so easy in his kindness, it almost seems, to him who experiences it, the effect of a naturally acquired right; and at the same time he is so good, that he leaves us all the pleasure, all the individuality of gratitude. What a noble example of a protection whose sole authority is founded in esteem, respect, and free and voluntary confidence-whose titles consist only in an inexhaustible goodwill, and in the recollection of services rendered, and of which the long and uncontested possession necessarily supposes rare virtues, and an exquisite delicacy-when we reflect, that all this power is formed, maintained, and exercised among equals !

Under these honourable auspices, every thing became easy. Colonel Mudge, who had shown himself most favourably disposed towards our enterprise, seconded it by all the means in his power. We departed from Edinburgh together, and fixed our

first station in the fort of Leith. There I received, equally from him and Colonel Elphinston, commandant of the military engineers, all the assistance which the most eager wish to oblige could grant, or even suggest. I required a situation where the view was free, and which was at the same time sheltered, in order to erect my circle. I was induced to construct upon the terrace of the fort a portable observatory, which being capable of being easily taken to pieces at plea sure, permitted me to make observations on all sides of the horizon. It was necessary that the apparatus of the pendulum should be fixed with solidity; and stones, of the weight of sixty quintals, were fixed in thick walls with iron chains. Every thing that could be useful was lavished upon me; and, if my observations were bad, I had no excuse; it was entirely my own fault. Unfortunately the health of Colonel Mudge, enfeebled by former labours, did not permit him to enjoy with me these preparations so much as both of us could have wish

ed; but in this respect his place was supplied by one of his sons, Captain Richard Mudge, a young officer full of zeal, with whom I completed my labours. The care which I employed in this duty, did not hinder me from stealing an occasional glance at every thing that was fair and good in Scotland, that abode of morality and intelligence. But foreseeing that such objects might cause me to look upon the minute details of weights, lengths, and measures, as somewhat dry, I resolved not to think of them till my return; and, luckily for the experiments, I faithfully kept the word I had pledged to them.

After they were finished, it behoved us to go and repeat them in the Orkneys, the uttermost limit of the English arc. But Colonel Mudge, always reflecting upon what might render his operations more complete, perceived, that it was possible to connect the Orkneys with the Shetland Isles, by triangles, whose apices should rest upon the Isles, or rather, upon the intermediate rocks of Faira and Foula. This plan extended the new arc two degrees to the north; and this was sufficient to decide him. But relatively to the general system of the operations of England and France, it had still another advantage of very

different importance. This consisted in carrying the English line of operations two degrees towards the east, almost upon the meridian of Formentera, our last southern station in the Mediterranean. By this happy change, the English operation became the prolongation of ours, and the two together form an arc almost equal to the fourth part of the distance from the pole to the equator. If one might hope that the different nations of Europe would agree to chuse the base of a common system of measures, in nature, is there not here an element the most beautiful and the most sure which they could adopt? And this great arc, which, leaving the Balearic Isles, traverses Spain, France, England, and Scotland, and stops at the rocks of the ancient Thule, being taken in combination with the flattening of the earth, which is deduced from the measurement of the pendulum, or from the theory of the moon, will it not give for fundamental unity, or the "METRE,” a measure the most complete, and, I dare to say it, the most European which can ever be hoped for.

As soon as the possibility of this great project was recognised, it absorbed all our thoughts; the delicate health of Colonel Mudge did not permit him to realise it in person, and he entrusted the execution of it to one of the officers who served under his orders. He left me his son, whose assistance had been so useful, and which became still more so. My apparatus, the portable observatory, the large stones, and the iron chains, were all embarked with the instruments of the English operation, in the Investigator brig of war, commanded by Captain George Thomas, whose activity and skill do not certainly stand in need of any praise of mine, but whose inexhaustible politeness demands all my gratitude. This officer was so good as take me on board his ship to Aberdeen, where, during a short day, I experienced the most distinguished hospitality. On the 9th of July we set sail for the Shetland Islands. We remained a long time at sea, detained by calms or contrary winds, regretting with all our hearts the loss of so many beautiful nights, which we could have so well employed in making our observations. On the 6th day we left the Orkneys, with their mountains, of a reddish colour, on our left, which

even Roman enterprise had not passed; we discovered the Isle of Faira, which saw the vessel of the Admiral of the Invincible Armada broken to pieces upon her rocks. At last the peaks of Shetland appeared to us in their clouds, and on the 18th July we made the land, not far from the southern point of these Isles, where the tides of the Atlantic, clashing with those proceeding from the sea of Norway, cause a continual swell, and an everlasting storm. The desolate aspect of the soil did not bely these approaches to it. It was no longer those fortunate isles of Spainthose smiling countries-Valentia, that garden where the orange and lemon trees, in flower, shed their perfumes around the tomb of a Scipio, or over the majestic ruins of the ancient Saguntum. Here, on landing upon rocks mutilitated by the waves, the eye sees nothing but a soil wet, desert, and covered with stones and moss, and craggy mountains, scarred by the inclemency of the heavens; not a tree, not a bush, to soften the savage aspect; here and there some scattered huts, whose roofs, covered with grass, allowed the thick smoke with which they are filled to escape into the fog. Reflecting on the sadness of this abode, where we were about to remain in exile during many months, we took a direction, not without trouble, across pathless plains and hills, towards the small assemblage of stone houses, forming the capital called Lerwick. There we began to feel that the social virtues of a country are not to be measured by its appearance of poverty or riches. It is impossible to conceive hospitality more free, more cordial, than that with which we were received. People who, but a moment before were ignorant of our names, were eager to conduct us every where. When informed of the object of our voyage, they gave us of themselves all the information which might be useful; they collected and delivered it to us, with the same interest as if they had been acting in a matter in which they were personally concerned. Above all, we received much essential counsel from Dr Edmonston, a wellinformed physician, who has published a very good description of the Shetland Islands, and who recollects with pleasure having attended, when at Paris, the lectures of our colleague M. Dumeril. He gave us a letter to his bro

ther, who resides in the Isle of Unst, the most northerly of the Archipelago; for although, on leaving Scotland, we had thought that we should establish ourselves at Lerwick; and although Fort Charlotte, which protects that town, offered for our apparatus a very favourable situation, nevertheless we were attracted by this little Isle of Unst, which offered us a station more northerly than Lerwick by about half a degree, and also a little more easterly, consequently nearer to the meridian of Formentera. It is true, that it did not promise us a very convenient abode; but it may be conceived, that in going we did not reckon on the enjoyment of luxury ; in short, we made the choice which best suited our operations. Our new friends at Lerwick pointed out to us the most experienced pilot of the Isles, and we departed on the evening of the 20th of July for our final destination. The science of our guide was not useless to us. A thick fog enveloped us ; the wind, always favourable, freshened, and our vessel, plunged in profound darkness, flew with the rapidity of an arrow between rocks so numerous, and through straits so narrow, that, without being conducted in this labyrinth by management so correct and quick, that it had become, one might almost say, a sense, it must have foundered a thousand times. Arrived at Unst, we eagerly ran over the isle. It presented nothing but fishermen's huts, and here and there some gentlemen's houses, too small to receive the great English instruments. We at first thought of pitching them upon the highest and most northerly mountains of the isle ; but the difficulty of transporting thither the great instruments, which must necessarily have been done by men alone, made us give up the project.

We preferred a small island called Balta, situated at the entrance of the principal bay of Unst, (which, closing it in, as it were, on the side of the sea, rendered it an excellent harbour, where the brig could cast anchor in perfect safety), and disembarked our instruments. At first I acceded to this choice. But on more nearly examining the new station, and considering how much it was exposed to gusts of wind, the extreme moisture which prevailed, the remoteness from every habitation, and the manifold difficul

ties which presented themselves to the formation of an establishment sufficiently solid, which the experiments of the pendulum demanded, I dread ed lest, in persisting in it, I should compromise the success of my operations. In consequence of this, Captain Mudge and I decided to return to the Isle of Unst, and to ask a reception for ourselves and our apparatus in the only house which was in sight. Happily it was that of the brother of Mr Edmonston, who received us so well at Lerwick. We experienced here the same kindness. A large sheep-fold, which was empty on account of its being summer, and whose thick walls were capable of resisting every storm, received the apparatus of the pendu lum. The portable observatory, together with the repeating circle, were established in the garden of Mr Edmonston. It was not without much labour that we succeeded in landing the large stones, and dragging them to the place of their destination. It required all the efforts of the brig's crew, animated by the obliging perseverance of the officers. At last, on the 2d of August, we were in a condition to commence our astronomical observations, and on the 10th, we made the first experiment with the pendulum. On the 17th, we had eight of these experiments, and 270 observations of the latitude. I was now certain of the success of the operation; nothing but time and perseverance were required. Unfortunately, Capt. Mudge began to feel, in a disagreeable way, the influence of this residence. Although he carefully concealed what he felt, and his zeal was in no respect diminished, I myself perceived the alteration of his health; and the winds having brought to our isle a whale ship, which was intended for Spitzbergen, I determined him to avail himself of it to return to a more genial climate. He departed with regret, leaving me, on behalf of his father, all the powers, and even all the assistance of which I could stand in need. It was then, that left alone, I could feel how lucky it was that I had taken up my residence with Mr Edmonston. The kindness of that excellent man seemed to increase with the difficulty of my situation. When alone, I could not make observations on the repeating circle, the working of which requires two persons, one to follow the star,

and the other to mark the indications of the level. Mr Edmonston, who took as great an interest in my labours as myself, suggested to me the idea of employing, for this latter part of the observation, a young carpenter, who had already given proofs of his intelligence and address in setting up our observatory, and who, besides, like all the peasants of Scotland, and even of these isles, could read, write, and cipher extremely well. I followed this advice; and having rendered the task of my new assistant as simple as possible, I began to give him some lessons a few days before the departure of Captain Mudge. He made a very rapid progress, and perhaps acquitted himself better than a more learned assistant; for he observed and marked my level with all the fidelity of a mechanic; and on no account whatever, not even to satisfy my impatience to observe, would he have admitted my results to be good, before they were strictly within the condition which I had prescribed to him; that is to say, before the bubble of the level was in a state of perfect immobility. Nevertheless, as it is very necessary to reserve to one's self some means of verification, when one resolves to make an astronomer of a carpenter, I had, among the numbers which he wrote, certain relations which he did not suspect, and which would have shown me his errors, if he had committed them. This happened sometimes at the commencement; and he was always very much surprised at my being able to detect and correct a mistake, which he himself had not perceived when making it, and which I had not seen made. But at the end of three days, there was no occasion for my occult science any longer to display itself. With this useful and sure assistance, I succeeded in the course of two months in collecting 38 series of the pendulum, each of five or six hours, 1400 observations of the latitude in 55 series, made equally on the south and north of the zenith, and about 1200 observations of the absolute heights of the sun and the stars, to regulate the going of my clock. After this, it may be conceived that I hardly did any thing else than observe, and, in fact, I did not calculate in this place more than three or four observations, at great intervals from each other, in order to assure myself of their general rate, and