785 and on the Possibility of Approaching the North Pole. 786 (c.) Many of the most prodigious fields are entirely free from abrupt hummocks from one extremity to the other, and field-ice, as it appears in general, would be easily passable. 66 (d) The degree of interruption from mountainous ice, would depend on the quality of its surface. If, as is most probable, it were smooth, and free from abrupt slopes, it would not prevent the success of the expedition. "2. The direct route would be pointed out, for some part of the way at least, by the magnetic needle; and when its pole should be directed towards the zenith, should that position ever obtain, the sun would be the only guide. Or, the position of the true north being once ascertained, three sledges in a line, at a convenient distance apart, might enable the leading one to keep a direct course. A chronometer would be an indispensable requisite, as the opportunity for lunar observations could not be expected to occur sufficiently often. Were the Pole gained, the bearing of the sun at the time of noon, by a chronometer adjusted to the meridian of north-west Spitzbergen, would afford a line of direction for the return; and, the position, in regard to in regard to longitude, (were the sun visible) could be corrected, at least twice a day, as the latitude decreased. The degrees of longitude being so contracted, any required position would be pointed out by the watch, with the greatest precision. "3. (a.) Among the dangers to be apprehended, the coldness of the air stands prominent. As, however, the cold is not sensibly different, between the latitudes of 70 and 80 degrees with a strong north wind, it may be presumed that at the Pole itself, it would be very little more oppressive than at the borders of the main ice, in the 81st degree of north latitude, under a hard northerly gale: and since this cold is supportable, that of the Pole may be deemed so likewise. 787 Interesting Particulars respecting Stonehenge. 788 in journeying under difficulties which | What could be the mode of conveymay bear a comparison with the un- ance? and, To what purposes the dertaking here alluded to, and occa- structure was appropriated? are quessionally under circumstances the most tions not easily resolved. Every ef unfavourable to success. fect must have an adequate cause-hence the learning employed by antiquarians on the subject. "1st. When treating of ice-bergs, I alluded to the journey of ALEXEI MARKOFF, in which it appears, that he performed near eight hundred miles across a surface of packed ice, in the spring of 1715, in a sledge drawn by dogs; and, consequently, that he might be supposed to have encountered the principal difficulties that could be expected in the proposed scheme, whilst we have the advantage of improving by his experience. "As to the appearance of Stonehenge, seventeen huge stones are now standing, which, with several others lying on the ground, form the outward circle. The inward circle is about eight feet from the outward, having eleven stones standing, and eight fallen. Between these two circles, is a walk about three hundred feet in circumference. The stones are from eighteen to twenty feet in height, from six to seven broad, and about three feet in thickness! The original structure was encompassed by a trench, over which were three entrances. It is most probably the relic of a Druidical temple. In the reign of Henry the Eighth a tin tablet was found here, inscribed with strange characters. This has been lost; had it been retained, and understood, it might have elucidated this venerable monument of anti "2d. Speaking of the south-western tendency of the ice, I have also noticed the loss of several of the Dutch Greenland fleet in 1777, from which we learn, that part of the unfortunate suffering crews, under every privation of provision and clothing, and expoed to the severity of an Arctic winter, accomplished a journey on foot, along the coasts of Old Greenland, from the east side, near Staten Hook, to the Danish settlements on the west, a distance of near an hun-quity. dred leagues. "3d. On contrasting the projected polar journey with the catalogue of marvellous occurrences, and wonderful preservations which are exhibited in the records of maritime disasters, the difficulties of the undertaking in a great measure vanish, and its dangers are eclipsed, by the wonderful results which necessity has, in various instances, accomplished." Dr. Stukely, who, about half a century ago, visited Stonehenge in company with Lord Winchelsea, observed, half a mile north of it, and across the valley, a hippodrome, or horse-course. It is included between two ditches, running parallel east and west 350 feet asunder, and 100,000 long. The Barrows round THIS MONUMENT are numerous and remarkable, being generally bell-fashion, yet there is great variety in their diameters, and their manner of com INTERESTING PARTICULARS RESPECT- position. These were single sepul ING STONEHENGE. THE following observations on this stupendous monument of Druidical superstition, is copied from the preface to Dr. Richards's Cambro-British Biography. "We now posted forwards, (July, 1799,) to Salisbury 'plains, those immense downs, where the stranger, without a guide, would be bewildered. We drove to the spot where stands Stonehenge, the most singular curiosity in the kingdom. Here, quitting the carriage, we gazed at THE PILE with astonishment! Whence these vast stones were brought hither? chres, as it appeared from many that were opened. On the west side of one was an entire segment, made from centre to circumference. It was good earth quite through, except a coat of chalk, of about two feet thick, covering it quite over under the turf. Hence appears the manner of making these Barrows, which was to dig up the turf for a great way round till the Barrow was brought to its intended bulk, then, with the chalk dug out of the surrounding ditch, they powdered it all over! At the centre was found a skeleton perfect, of a reasonable size, with the head lying northward. On open 789 Interesting Particulars respecting Stonehenge. 790 ing a double Barrow, the composition | Moan'd in his lifted locks; thou, NIGHT, was thus: after the turf was taken off, there appeared a layer of chalk, and then fine garden mould. About three feet below the surface, was a layer of flints humouring the convexity of the Barrows. This, being a foot thick, rested on a layer of soft mould, in which was inclosed an urn full of bones! The urn was of unbaked clay of a dark reddish colour, and crumbled into pieces. It had been rudely wrought with small mouldings round the verge, and other circular channels on the outside. The bones had been burnt, though the collar bone and one side of the under jaw were entire. There was a large quantity of female ornaments mixed with the bones, as beads of divers colours, many of them amber, with holes to string them, and many of the button sort were covered with metal. 66 Stonehenge has lately undergone an alteration, part of it having about three years ago fallen to the earth. We saw and conversed with some shepherd boys, who were loitering around the pile, and from whom we learned, that the fall occasioned a concussion of the ground! This must have been expected, and it excited among persons in its vicinity no small astonishment. The following sonnet hath interwoven the sentiments of the learned on the subject, written at Stonehenge : Thou noblest monument of ALBION's isle, Whether by Merlin's aid from Scythia's shore, gore, T'entomb his Britons, slain by Hengist's guile; Studious to trace thy wondrous origin, WARTON. These ruins are in their appearance peculiarly solemn, and their isolated situation in the midst of an immense plain heightens the sensations with are contemplated. which they Was it a spirit on YON SHAPELESS PILE? the while, pours Dost listen to his sad harp's wild complaint, Breathe on the weary air; and now more loud O'er the wild plain the hurrying tempest flies, And 'mid the storm unheard, the song of sorrow dies! LOVELL. "The architectural phenomenon of Stonehenge is confessedly the most interesting relic of antiquity by which Britain stands distinguished." Dr. E. D. Clarke, in his truly classical Travels through various countries of Europe, Asia, and Africa, has this paragraph still further explanatory of the subject. Speaking of Russia, (vol. I. octavo edition, page 276) this distinguished traveller says, "Throughout the whole of the country are seen, dispersed over IMMENSE PLAINS, mounds of earth, covered with a fine turf, the sepulchres of the world common to almost every habitable country! If there exist any thing of former times, which may afford monuments of primeval manners, it is this mode of burial. They seem to mark the progress of mankind, in the first ages after the dispersions, rising wherever the posterity of Noah came. "Whether under the form of a Mound, in Scandinavia, in Russia, or in North America; a Barrow, in England; a Cairn, in Wales, in Scotland, and in Ireland; or of those heaps which the modern Greeks and Turks call Tepe; or, lastly, in the more artificial shape of Pyramid, in Egypt; they had universally the same origin. They present the simplest and sublimest monuments that any generation of men could raise over the bodies of their forefathers, being calculated for almost endless duration, and speaking a language more impressive than the most studied beheld in a distant evening horizon, epitaph upon Parian marble. When skirted by the rays of the setting sun, and, as it were, touching the clouds that hover over them,-ima gination represents the spirits of DEPARTED HEROES as descending to irradiate a warrior's grave!" The Rev. Mr. Davies, the erudite author of Celtic Researches, and also of the Mythology of the British Druids, is of opinion, that Stonehenge and Silbury Hill are two of the three works alluded to in a Welsh Triad, constituting the greatest labours of the island of Britain, viz. "Lifting the stone of Ketti; Building the work of Emrys; and Piling the Mount of the Assemblies!" That Stonehenge is a Druidical structure, this elaborate inquirer entertains no doubt. "This is evident," says he, from the language in which it was described, and the great veneration in which it was held by the primitive bards, those immediate descendants and avowed disciples of the British Druids. As the great sanctuary of the dominion, or metropolitan temple, of our heathen ancestors, so complete in its plan, and constructed upon such a multitude of astronomical calculations, we find it was not exclusively devoted to the sun, the moon, Saturn, or any individual object of superstition; but it was a kind of Pantheon, in which all the Arkite and Sabian divinities of British theology were supposed to have been present; for we perceive Noe and Hu, the deified patriarch; Elphin and Rheiddin, the Sun; Eseye, Isis; Ked Ceres, with the cell of her sacred fire; Llyvy, Proserpine; Gwydien, Hermes; Budd, Victory; and several others." ESSAY IV.-ON CALORIC. | bodies, as from the tendency of caloric to exist every where in what has been termed an equality of tension or repulsion." This assumption, however, appears to be gratuitous. We have as much reason for supposing that bodies containing a smaller quantity of caloric attract it from bodies which contain larger quan tity, as we have for supposing that there exists in caloric a tendency to an equality of tension or repulsion. Brass Some bodies conduct caloric more quickly than others. If a rod of iron and a piece of glass of the same dimensions be held in the hand, and the extremity of each put into the fire, it will be found that the caloric will be quickly conducted along the iron rod, rendering it unfit to be handled; whilst the glass may be held for any length of time. It may be laid down as a general rule, that the conducting power of bodies is in the direct ratio of their densities. Count Rumford has observed, that the same substance, in different states of ag gregation, differ as it regards their conducting power. An iron bar, or an iron plate, is a better conductor than iron filings, and wood is a better conductor than saw-dust. Rickman made some experiments in order to determine the relative conducting power of different metals. and copper appeared to have the greatest power of retaining caloric, and were equal to each other; next to these was iron; then tin; and, lastly, lead. Ingenhouz found silver to be the best conductor; gold held the second place; tin and copper were next, being about equal; next to these come platina, steel, iron, and lead, which differed but little; lead, however, was found to be the worst conductor. Count Rumford, with the view of discovering the relative warmth of different articles of clothing, made If a several experiments upon the substances from which they are manufac tured. Of the substances operated upon, the best conductor was raw silk; then followed wool, cotton, fine lint, beaver fur, hare fur, and lastly eider down. It is conceived, that "the imperfect conducting power of these substances will be proportioned to their sponginess, or the quantity of air they can contain in their interstices, and the force of attraction with which the air is retained." By preventing (Continued from col. 730.) 3.-The Laws by which Caloric is regulated. HAVING Considered the effects of Caloric, we intend to take notice of the laws by which it is regulated. In the first place, we shall treat of the communication and diffusion of caloric. We have before observed, that caloric has a tendency to promote equilibrium of temperature. body be heated, it is impossible to preserve it in that state when removed from the source of caloric; it invariably emits its heat to surrounding bodies until a balance of temperature is produced. This tendency of caloric is supposed to arise from its repulsive power. "Thus, when a hot body is placed among others that are colder, the excess of caloric in the former, leaves it, not so much from any attraction exerted to it by other the air, in some measure, from coming in contact with a heated body, they preserve its caloric. It is supposed also, that the imperfect conducting power of snow depends upon this cause, and in consequence of it, vegetables are preserved from the prejudicial effects of intense cold. It is upon this principle, also, that ice-houses are constructed. When we wish to produce any high temperatures, we make use of furnaces which are coated with clay and sand, these substances being both imperfect conductors of caloric. If we apply two bodies of the same temperature to the hand, or any other sentient part, the degree of heat we feel depends entirely upon the conducting power of the substances applied: if the bodies be a piece of iron and of wood, the former at high temperatures will feel much hotter than the latter; and at low temperatures, it will feel colder. Liquids, as well as solids, possess a conducting power, although some have endeavoured to establish a contrary opinion. When liquids are heated, the portion in contact with caloric becomes specifically lighter than the remaining part of the fluid, and ascends to the surface, whilst another portion occupies its place, and, becoming heated, rises in the same manner. It was supposed therefore that caloric was propagated by the motion of the fluid only, and not by its own conducting power. Dr. Hope made some experiments on this subject in one case, he made use of a vessel 11 inches in diameter, and on the application of heat to the surface of the vessel, which was filled with cold water, caloric was conveyed downwards, and was indicated by a rise of the thermometer. Care was taken to prevent the sides of the vessel from conducting the heat, by causing a stream of water to circulate around them. Dr. Thompson also found that caloric was conveyed downwards when heat was applied to the surfaces of water and quicksilver. Mr. Nicholson, and other chemists, have made experiments of the same kind, and have obtained similar results. The conducting power of fluids is now therefore fully confirmed. Aeriform bodies are also conductors of caloric. Count Rumford attempted to prove that these are non-conductors: No. 31. VOL. III. the experiments which he made in order to prove their non-conducting power, are similar to those which were made to disprove the existence of the same power in fluids. He attempted to prove, that whatever obstructed the motion of air, retarded the passage of caloric through it. Berthollet, however, in opposition to Count Rumford, has advanced the opinion, that aëriform substances, so far from being imperfect conductors of caloric, conduct it with rapidity: he conceives that the air thermometer, which quickly indicates slight changes of temperature, confirms his opinion. He brings forward also the fact of the sudden dilatation of an air-balloon, which aëronauts have experienced upon the appearance of the sun's rays: he observes, that the particles of air which are contained in the balloon, cannot be brought successively to its covering; nor can the particles at the inferior part of the covering be heated in this manner, since the rays of caloric do not impinge upon that part. he infers, that these phenomena indicate, that the elastic fluids, far from being imperfect conductors of caloric, receive and transmit it with great rapidity. Hence By the agency of fluids, elastic and non-elastic, caloric is distributed through the atmosphere. When the sun's rays heat a portion of air in contact with the earth, it becomes specifically lighter than the superincumbent air, and ascends; whilst the colder air rushes in to supply its place. When the air is much expanded, a quantity will be forced towards a colder climate, where it serves to render the extreme cold more tolerable. So that there will be a current from the poles to the equator, and vice versâ, from the equator to the poles. Count Rumford supposes that currents exist in the ocean similar to those which take place in the atmosphere: the water which is cooled by a current of air passing over it, becoming specifically heavier, sinks; whilst another portion ascending, and parting with its caloric, descends in a similar manner: he supposes that these descending portions, spreading on the bottom of the ocean, flow towards the equator, which will produce currents on the surface in an opposite direction, so that the ocean may moderate the ex 3 E |
