times; but our happiness was incomplete. Of the 91 persons who were shut up in the mine, only 70 were restored to their friends; of the whole number 127 who were in the pit at the irruption of the water, 33 saved themselves by the corf, 22 were drowned, 70 escaped by the drift. Goffin and his son ascended the last, with M. Migneron, who had been 24 hours in the pit, and conducted himself with a zeal worthy of the highest recommendation*. The air was now rent with acclamations of joy; but in this moment of strong feeling it was necessary to prevent the relatives of the persons restored to life from rushing in upon them in a body. The Colonel of the Gendarmerie was everywhere exerting himself to restrain the imprudent populace. M. Mathieu, who had attended most of the operations, and shared the responsibility of the recovery of the men, partook of the blessings of the multitude. Migneron and myself returned to town at 4 o'clock; but M. Mathieu remained on the spot till 8, giving directions about another visit to the pit; but the air, already highly impregnated with noxious gas, did not permit the men to go, even without a light, beyond the scene of our labour.

Such is the faithful account of events which has caused so deep an interest in all ranks of society. The difficulty of obtaining information from common workmen, who cannot speak in French, the desire to meet the impatience of the public, my constant occupation, and want of time, must be my apologies for any defect in style; but facts have been collected with scrupulous care, the deposition of every workman having been se parately taken; yet we give but feebly the energetic expressions of veneration which the workmen have for Goffin.

Sir FREDERICK Mонs, Professor of Mineralogy, in Vienna. FREDERICK MOHS, formerly Professor of Mineralogy in the Mining Academy at Freyberg, and Counsellor of Mines, was born in the beginning of the year 1770, in a little town in the

* The king of the Netherlands bestowed the decoration of the Legion of Honour on the active, energetic, and noble-minded Hubert Goffin.

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Dukedom of Anhalt-Bernburgh. He was very young when he lost his father, who was a merchant; and he also was designed to follow the same profession, but was prevented by his inclination to science, particularly to mathematics. The arrangements of those schools in which he received his early education, obliged him to walk about five miles two or three times a-week, to receive an hour's mathematical instruction. In 1796, he entered the University of Halle, where he studied science and philosophy under his countrymen Klugel and Gren; and two years after, went to Freyberg, where he became a devoted disciple of the celebrated Werner. Dissatisfied with the geological theories of the old naturalists, he was forcibly struck with the opinions of Werner upon geology; particularly because they were founded on observation, and required that knowledge should precede explanation.

Practical mining engaged much of his attention, and he soon received an appointment in his native country, which he shortly afterwards abandoned, to take a charge in the foundation of a scientific institution projected in Dublin by Kirwan, which was soon broken up, owing to the death of those persons who possessed the chief influence in it. About a year after, he returned to Freyberg, where he became acquainted with Jameson, then prosecuting his studies at that place, and now Professor of Natural History in Edinburgh; and wrote an admirable description of the mine of Himmelfurst, which was published some years afterwards. In 1802, he went to Vienna, where he enlarged his acquaintance with the literati of that place; and undertook a description of the mineralogical collection of the Banker von der Nüll. In this work (Vienna 1804), are contained the elements of those views of natural history which he has since developed. At the same time, he also wrote single essays on various mineralogical subjects, which made their appearance in the "Ephemerides" of Baron Von Moll.

His enthusiasm for geognosy and mining caused him to undertake very extensive excursions into Stiria, Saltzburg, Carinthia, Carniola, Hungary, Transylvania, &c. In 1810 he was appointed by the Austrian Government to examine the districts in Austria and Bohemia, where porcelain earth is dug up, and

252 Sir Frederick Mohs, Professor of Mineralogy at Vienna. where hopes were then entertained of finding this mineral. A number of the results of these investigations have been published in the Transactions of the Polytechnic Institute of Vienna, and have given rise to several new manufactories in Bohemia. He became known to the Archduke John, who at that time contemplated the establishment of the Johanneum at Gratz. At the suggestion of the Archduke he undertook another journey into Stiria, upon which the State of that place appointed him Professor of Mineralogy in the Johanneum. In the extensive and excellent mineralogical collection in the Institute, the whole of which, together with the apparatus, was a donation from the founder, he had an opportunity of proving and applying his principles and opinions regarding mineralogy.

In 1812 he commenced his lectures on mineralogy, in which he considered the natural history of the mineral kingdom, and at the same time attempted an elementary method for determining the natural arrangement of the mineral species. In these lectures he always expressed the highest esteem for his celebrated instructor Werner, without, however, generally following his views. The arrangement and distribution of the mineral collection according to natural principles, met with great applause; and Professor Mohs himself, in his later writings, mentions this arrangement as a principal cause of the rapid progress of his pupils. His attempts to make out the specific differences that characterize the divisions of his natural system being at first attended with great difficulties, obliged him to make innumerable experiments on the hardness and specific gravity of minerals. In mineralogical writings he found these characteristics entirely omitted, or if they were mentioned, it was but very inaccurately. This induced him to draw out a scheme of his scale of hardness, and of a system of crystallography, which should be more fundamental than that generally prevalent in Germany, and at the same time simpler and more agreeable to nature than that of the celebrated French mineralogist Haüy. In 1816 Mohs wrote an essay to Professor Jameson in Edinburgh, with the design of communicating a general explanation of his natural mineralogical method, which this gentleman printed in the Edinburgh Philosophical Journal.

Mohs, by his lectures, had attracted many students from the Imperial States to Gratz. Count Brunner, Hereditary Chamberlain of Austria, was among the number. He engaged in the subject with peculiar enthusiasm, and invited the Professor to accompany him in a tour through England and France, a proposal which met with the concurrence of the Archduke John and the State of Stiria. The travellers arrived in London in the beginning of January 1818, went to Cornwall, and then from London to Edinburgh. Here Mohs found his friend Professor Jameson occupied with views similar to his own regarding the natural history of the mineral kingdom. They soon agreed as to the principal points; and Mr Jameson, who was then engaged in revising the third edition of his "System" of Mineralogy," adopted part of the views of Professor Mohs.

Mohs first published his "Characteristick" in German and English merely as a fragment. In the following year appeared "Jameson's Manual of Mineralogy," in which the author adopted the natural method, with but few alterations in the nomenclature, and thus introduced it into England.

Mohs, upon his return to Edinburgh from an excursion to the Highlands, found an invitation to the chair of his immortal instructor Werner, which he accepted, provided the consent of the Archduke John could be obtained. This he received in a letter written by the Archduke himself, from Dresden, and he entered into his professorship in the autumn of 1818. The above mentioned "Characteristick," which was published in 1820, passed through a second edition in the following year, accompanied with an explanatory introduction. In 1822, Mohs published the first part, and in 1824, the second part, of his Elements of Mineralogy, the most remarkable work on mineralogy which has appeared in our time. Three or four years ago, Mohs was invited by the Emperor of Austria to Vienna. He accepted the offer of Professor of Mineralogy there, and has been succeeded in Freyberg by Nauman, the celebrated mineralogist, from Halle.

JULY-OCTOBER 1829.

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Extraordinary Case of Atmospheric Refraction. By JOHN CRUICKSHANK, Esq. Professor of Mathematics in the Marischal College, Aberdeen. Communicated by the Author.

SIR,

MARISCHAL COLLEGE, ABERDEEN, 15th August 1829.

HAVING been informed lately by my friend, the Rev. Dr Forbes of King's College, that you were desirous of collecting facts respecting extraordinary cases of terrestrial refraction, I send you the subjoined account of phenomena which I observed here on the 10th June 1826. I am, &c.

To Professor Jameson, &c. &c.

JOHN CRUICKSHANK.

On the morning of the 10th June 1826, there was a thick fog at Aberdeen, with a slight breeze of wind about south-east by east. Between eight and nine A. M. the fog vanished from the land, and bright sunshine succeeded, which continued till late in the afternoon; but fogs, apparently dense, remained at a distance on the sea, and occasionally extended to the shore at some points till after mid-day. From the observatory of Marischal College at noon, the rocks about Slains Castle, on the Buchan coast, and distant about twenty-four miles, attracted my attention, by appearing more elevated, and with much greater distinctness of parts, than usual. Places beyond Slains Castle, which are not visible from Aberdeen in ordinary states of the atmosphere, were at some instants distinctly seen. The rocks, and the adjacent land, to the distance of about two miles, west of them, seemed to vary in altitude almost every ten seconds, the whole tract appearing alternately to rise gradually to three or four times its ordinary apparent height above the level of the sea, and subside again into itself. Thus far the phenomena were observed with the naked eye, and during the space of about five minutes. But, upon examining the same tract of country with a telescope, a three and a half feet achromatic with a low power, I found the appearances presented by smaller objects to be still more interesting, particularly those objects which