point, called the magnetic pole. That tendency may be resolved into two parts, by the peculiar mode of balancing the needle in common use; the horizontal one thus becoming the mariner's guide. According to the relative situation of the needle so balanced, towards the place of the magnetic centre, it is evident that this tendency will increase or diminish; or, that in the case of the increase of dip, the only part of the magnetic intensity which is serviceable to the mariner will be weakened. Independently of this force, or the polarity of the needle, the magnet is also acted upon by the presence of iron, or of substances containing it, which, abounding in the construction of a ship, produce the effect here termed the deviation; a force which must vary in its effect, according as the attracting centre is, during the manoeuvring of a ship, turned round that point where the compass is situated. If the stowage of a ship remains unaltered, this force may be considered as a constant quantity; although even this local attraction may be influenced in its intensity, by other as yet obscure causes which affect the general polarity of the needle. But assuming the simplest view of the case, it is to be expected, that as the horizontal energy of the needle diminishes, the quantity of the deviation will increase; and accordingly, that when the dip of the needle is most considerable, the deviation will also be the greatest. This fact is confirmed by the observations detailed in this paper. But the results are not constant, nor could that be expected; as the magnetic intensity is subject to other influences, which interfere with those differences of horizontal tendency arising from the comparative force and angle of the dip. The causes which affect the intensity of the magnetic force, have never been fully investigated; but it is apparent, partly from previous knowledge, and partly from deductions contained in this Journal, that the most conspicuous of them are, variations of the temperature, of the humidity, and of the pressure of the atmosphere, and changes of its electrical condition. These causes are often such as materially to affect the conclusions that might otherwise be drawn, respecting the probable amount of the deviation, from a previous estimate of the horizontal tendency; and it thus becomes necessary, in every ship, to ascertain that error by careful experiments, repeated under all probable circumstanees capable of interfering with the effects resulting from the chief cause. It is obviously necessary, that in such experiments, both the position of the needle should remain unchanged with regard to the ship, and that her stowage, particularly in the case of anchors, should not be disturbed. It is moreover plain, that the goodness of the needle, and its steady maintenance of its original power, should be as far as possible ensured; as it by no means follows, that the influence of a neighbouring centre of attraction, and that of the polar centre, will exert a corresponding action in needles of various powers, or on one of which the power is influenced by other disturbing forces. We shall conclude this sketch of the subject, by hinting to Captain Ross, that in future experiments it would be proper to carry on a set of simultaneous experiments on the magnetic force, by the method of oscillations. We have often had occasion to regret, that, in the appointment of expeditions of this nature, so little attention has been paid to the selection of persons competent to conduct those seientific inquiries which must be expected to arise on such occasions. Whatever knowledge of navigation a naval officer may possess, it would be unreasonable to expect from him a capacity to decide delicate questions of science, altogether out of the sphere of his profession. Even were his education such as to give him that extensive information, which he must possess unusual opportunities or uncommon talents to have acquired, it is plain that his decisions would not be received as of authority. In all such cases, the confidence to be reposed in an observer must obviously depend on his previous reputation and acknowledged accuracy. It is vain to expect, that it will be placed in those whose very profession must disable them from acquiring that which in such cases is indispensable. It must be recollected, that in all expeditions of this nature, a most perilous responsibility rests on the commander. It is he who must watch for all, and think for all. The ordinary calls on his attention are so frequent and so important, that even the scientific acquirements of a Maskelyne would, in such a case, prove useless. It is enough for the commander, to attend to the navigation of his vessel, and to preserve the discipline and the health of his crew: and, as in this case, it is further necessary to be perpetually on the watch amidst the new and perilous situations in which he is every minute liable to be placed, it is much if he can carry on correctly the ordinary hydrographical and geographical observations which are more peculiarly his duty. If this be true even of astronomical and meteorological remarks, it is more parti cularly unreasonable to expect that he can attend to the department of Natural History; to the collecting or preserving of objects, of which, but by an extreme chance, he can know nothing; and to the numerous philosophical questions of an incidental nature, which may come in his way at every step of his progress. In reading the instructions, we observe, that a Captain Sa bine of the artillery was recommended to the Admiralty as a gentleman well skilled in Astronomy, Natural History, and several branches of knowledge.' Now, this recommendation does not seem to have been very correctly given; and we think we can discover that Captain Ross does not set a high value on the acquirements of Captain Sabine. He has evidently expressed himself with much caution; for reasons which we do not know, -but which are probably very good, as our countrymen are noted for their prudence. But we can easily deduce from one of his remarks, that Captain Sabine did not wind up his chronometers, and, consequently, that one of them very naturally ran down. As far as we can discover from the Journal, this is the only experiment in Astronomy for which Captain Sabine is responsible: But a much stronger decision is ready on the subject of Natural History. There is a Botanical catalogue, no doubt; but it is professedly drawn up by a botanist at home, whose celebrity could acquire no addition from any praise of ours. There is, further, a very awkward correspondence on Zoology; and an article appended, which has been drawn up as well as could be expected, by the surgeons of the ship, and corrected by Dr Leach. From this curious correspondence, it ap pears that the Naturalist of the Expedition confesses himself ignorant of every thing in this branch of knowledge except what relates to Ornithology; and it is further pretty plainly insinuated, that in this department he means to be indebted to his brother, who is considered an ornithologist. Future naturalists will therefore be at a loss to know, whether Larus Sabini marks the path of Joseph or of Edward Sabine through the regions of air; or which of these philosophers is to rise to ornithological immortality on the plumes of a sea gull. In Geology, or Geognosy, the Geognost of the Expedition seems to have been equally deficient; and we have accordingly another exposé in the cautious nature of an apology also. This is followed by a catalogue of specimens, drawn up by a well known member of the Geological Society. An account of various Instruments, most liberally furnished to the Expedition, is found in the Appendix; and of these a few require notice. Among the various Compasses for different objects which formed part of the scientific furniture of the Expedition, due praise is given to Kater's Azimuth Compass, and to a Steering Compass constructed by Alexander of Leith. In consequence of the better adaptation of the weight of the needle to that of the card, and the superior method of suspension, it was found to traverse in foggy weather, near Lancaster Sound, when all the rest had ceased to act. Of the several DippingNeedles, it appeared that Nairne's alone was worthy of being VOL. XXXI. NO. 62. A a : relied on From various defects, no results could be obtained from the others. There is an amusing attempt to trim between the importance and the inutility of Dr Wollaston's Dip Sector. We do not pretend to judge of an instrument which we have not seen; but the objections seem unsurmountable,―arising from the inequality of the refraction on various parts of the horizon, and form its extreme inconstancy in situations where ice is present. The most obvious results (although, we may presume, unexpected by the inventor himself) were obtained from Troughton's whirling horizon. The minute vibrations noticed in the Appendix, where these remarks are contained, must have arisen from imperfections in the workmanship, which are perhaps unsurmountable; but the inventor seems to have forgotten, that the ordinary movements of the ship must have communicated to it motions incapable of being counteracted by the quantity of its centrifugal force; and accordingly it deviated from the horizontal position, even in moderate motions, above half a degree. An instrument called a Sympeisometer, is praised as likely to supersede the use of the Marine Barometer. This appears to be a variation of the Manometer, and is obviously subject to the same defects. If it is more quick in indicating the approach of a squall, it also indicates changes which do not depend on the increase of the wind, while it is affected by differences of tempe rature, which the correcting thermometer does not check so rapidly. Hence the sails may be often taken in when no difference but that of temperature has occurred. We do not, for our parts, think that a manometer of any construction, will ever supersede the marine barometer, imperfect as that may be: And, that the sympeisometer does not accord with the barometer, is evident on inspecting the meteorological table, where the lines are very often far asunder. There is no great reason to doubt that these barometers acted well, as will appear in the Journal, and by the fact that calms were for a long time prevalent. Other instruments are described in this Appendix; but some of these seem not to have been used for want of opportunity, and others for want of competent observers. ART. VI. L'Alfabet Européen appliqué aux Langues Asiatiques; Ouvrage élémentaire, utile à tout Voyageur en Asie. Par C.F. VOLNEY, Comte et Pair de France, Membre de l'Academie Française, Honoraire de la Societé Asiatique, séante à Calcutta. Paris, chez Firmin Didot. Α LL the alphabets now employed, from the western extremity of Euro Indus, may be traced with historical cer tainty to one original,-the Phenician, Samaritan, or Syriac. Of these contiguous countries, the letters and the languages always analogous, were once probably the same. Phenicia and Palestine,' says Mr Gibbon, will for ever live in the memory of mankind: since America, as well as Europe, has received Letters from the one, and Religion from the other.' It was in that primitive character, and not in the Hebraic, that the sacred historian delivered to posterity the only authentic records. of the creation of the world, and the primeval transactions of the human race. About the same period, the Phenicians communicated to the savages of Europe the knowledge of letters. The testimony of Herodotus, and the general current of tradition, attest the Phenician origin of the Greek alphabet. We are aware that the former is ambiguous; and that the passage may mean merely that the followers of Cadmus introduced certain letters previously unknown to the inhabitants of Greece, and in which their alphabet was deficient; not that they first taught the use of letters to an illiterate people: Yet the contrary is the more obvious construction; and, in the absence of any testimony, we should be disposed to draw the same inference, and that with considerable confidence, from the relative position of the letters which constitute the alphabet. In an arrangement wholly arbitrary, it is scarcely possible that the same order should be generally observed, as we find it in the Syrian and Grecian alphabets, unless the one were borrowed from the other. A, B, C, D, &c.-there is no reason why these letters should follow in this order: one is a vowel, and the other three consonants, and each produced by different organs of speech. The order might consequently be inverted, without violating any conceivable principle. The general agreement is therefore a conclusive proof of the origin of the more modern. Like its original, too, the Greek was first written from the right hand to the left. Yet it is singular, that of the four characters which, as Pliny informs us, were subsequently added by Palamedes, three existed in the Syriac alphabet, and might have been introduced from the first. The most singular thing, however, is, that the Greeks were no sooner in possession of this new instrument, than they brought it to a degree of perfection, which it never attained in the country of its birth. There the short vowels are uniformly omitted, and left to the sagacity of the reader to supply; but we believe that, in the most ancient and rudest of the Greek inscriptions which have been preserved, the vowels are regularly inserted. The Pelasgi, says Pliny, first brought letters into Latium. Now, the Pelasgi had originally occupied that part of Greece, A a 2. |