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Mechanism of the motion of glaciers
Subterranean River.--31oliou of Glaciers.
353
laid down with the utmost precision, and one of the conclusions to which M. Paillette has been led is, that all rocks of igneous origin have accidentally modified the sedimentary soils, according to circumstances which are unknown. The modifications produced by granite are a crystalline appearance, a development of the characteristics of talc, and the formation of garnets, staurotides; and those occasioned by p o r p h y r y are generally simple induration, sonorousness, and feldspathic injections. To this memoir M. Paillette has added a series of the most ingenious experiments, by which he wishes to prove the agency of electrq-chemical phenomena in the daily formation of minerals in the different veins o f B r e t a g n e , and the A c a d e m y have requested him to continue his observations, in the full persuasion that they may lead to good results. ~lining Journal.
Singular Discovery of a Subterranean River. A singular discovery was made in Blaen-y-nant lead mines, near Mold, Flintshire, a few days ago. T h e workmen at the end of one of the levels were surprised, and obliged to run for their lives, in consequence o f a n immense rush of water suddenly b u r s t i n g in upon them. After three days the water totally d i s a p p e a r e d ; and, on cautiously proceeding to the place, they found an o p e n i n g o f a b o u t four inches diameter,through which the water had issued. H e a r i n g a sound as of a heavy run ot water inside, they enlarged the aperture so as to admit of their passing through, and found that it was the bed of a subterraneous r i v e r , w h i c h in all probability affords the principal supply to the far-famed St. W i n i fred's Well, at Holywell, from which it is distant about twelve miles. T h e stream being then shallow, they explored it about sixty yards down, and were astonished to find several large caverns to the right and left, from the roofs and sides of which were suspended numerous and beautiful specimens of white spar or stalactites. T h e company are in high spirits, these appearances being considered favourable for a large lodgment of ore,--Shrewsbury Chronicle. Ibid.
Mechanism of the )llotion of. Glaciers. Mr. Mallet, at the British Association, made it evident that many phenomena of these singular masses had been hitherto overlooked; and although described by many eminent observers, no solution had been given to the question of their movement but that of their weight, which he showed could.have only a partial operation, as they often rest on rugged beds, and these not always of much inclination. He proposed a very ingenious explanation of their movement by means of hydrostatic pressure, arising from the fact of the lower part.of the glacier being of a hig'her temperature than the upper: this causes a melting of the under part, and a consequent raising of the mass in a perpendicular direction to the e a r t h ' s surface, while its descent was at right angles to the inclined surface: a progressive motion downwards ensues, following the law o f the resolution of forces. H e then spoke of certain causes of the rents and fissures in glaeiers, these being often convex downwards, owing to the operation taking place in the middle part of the mass, which descends soonest, while the whole is held in its place by the upper and lower extremities: also tubular fissures are formed by blocks of stone 5o •
354
Mechanics' Register.
sinking by degrees in the glacier, owing to their h i g h e r temperature gradually melting the surrounding ice. H e then alluded to the singular accumulations of detritus on the glaciers, which are locally termed too. raine~ and are formed by ~boulemens in winter and covered by the snow. These he found to assume linear directions parallel to the axis of the glacier; and, from the regularity of their arrangements, he conceived it possible to discover the site of old glaciers from the moraine which had remained on the ground after their destruction. Analyst.
On the Floating Masses of Fucus occurring near the Cape Verd Islands. M. Kunth lately presented to the A c a d e m y of Sciences of Paris, in the name of M. Meyen of Berlin, a specimen of the Sargassura natans (Fucus natans, Linn.) brought from the celebrated Mar de Sargasso, near the Cape Verd Islands. M. Kunth remarked, that this individual, like all the others observed by M. Meyen in these latitudes, does not present the slightest trace of a polnt of attachment. It was therefore never attached to rocks or to any other s u p p o r t i n g body at any period of its growth, but must have been developed floating on the surface of the sea. T h e opinion generally adopted by voyagers, that these plants have been torn from their original situations by the waves, and collected by currents in the M a r de Saragasso, appears to M. Meyen to be inadmissible; and he is inclined to believe that they have been produced at the place where they are observed. T h e same naturalist maintains that such individuals formed at the surface of the w a t e r , n e v e r e x h i b i t fructification. Edin. New Philos. Jour. Mechanics'
Register.
Girard Collegefbr Orphans. As this is an Institution in which mechanics have a deep interest, and one to the completion of which all must look forward with great anxiety, the ibllowingdescription of the main building and of the state of the works at the present time, by the able architect~ Thomas U. Walter, Esq. cannot tail to be acceptable to our readers. Cola.Pub.
Description of the main Building of the Girard Collegefor Orphans. By THo~As U. WAI.TER~Architect. T h e Girard College is situated about one and a half miles northwest of the centre of the City, on a tract of land containing forty-five acres; the whole of which was appropriated by Mr. Girard exclusively to the purposes of the institution. T h e main building, which is the subject of this description~ is composed in the Corinthian order of Grecian architecture; it covers a space of 184 by 243 feet, and consists of an oelastyle, peripteral superstructure resting upon a basement of eight feet in height composed entirely of steps extending around the whole edifice; by which a pyramidal appearance is given to the subslruction, and a means of approach to the porticoes afforded from every side. T h e dimensions of the stylobate (or platform on which the columns stand,) are 159 feet on the fronts by 217 feet on the flanks, and the cell, or body of the building, measures 111 feet by 169 feet 2 inches. T h e whole heightj from the ground to the apex of the root, is 100 feet.
353
laid down with the utmost precision, and one of the conclusions to which M. Paillette has been led is, that all rocks of igneous origin have accidentally modified the sedimentary soils, according to circumstances which are unknown. The modifications produced by granite are a crystalline appearance, a development of the characteristics of talc, and the formation of garnets, staurotides; and those occasioned by p o r p h y r y are generally simple induration, sonorousness, and feldspathic injections. To this memoir M. Paillette has added a series of the most ingenious experiments, by which he wishes to prove the agency of electrq-chemical phenomena in the daily formation of minerals in the different veins o f B r e t a g n e , and the A c a d e m y have requested him to continue his observations, in the full persuasion that they may lead to good results. ~lining Journal.
Singular Discovery of a Subterranean River. A singular discovery was made in Blaen-y-nant lead mines, near Mold, Flintshire, a few days ago. T h e workmen at the end of one of the levels were surprised, and obliged to run for their lives, in consequence o f a n immense rush of water suddenly b u r s t i n g in upon them. After three days the water totally d i s a p p e a r e d ; and, on cautiously proceeding to the place, they found an o p e n i n g o f a b o u t four inches diameter,through which the water had issued. H e a r i n g a sound as of a heavy run ot water inside, they enlarged the aperture so as to admit of their passing through, and found that it was the bed of a subterraneous r i v e r , w h i c h in all probability affords the principal supply to the far-famed St. W i n i fred's Well, at Holywell, from which it is distant about twelve miles. T h e stream being then shallow, they explored it about sixty yards down, and were astonished to find several large caverns to the right and left, from the roofs and sides of which were suspended numerous and beautiful specimens of white spar or stalactites. T h e company are in high spirits, these appearances being considered favourable for a large lodgment of ore,--Shrewsbury Chronicle. Ibid.
Mechanism of the )llotion of. Glaciers. Mr. Mallet, at the British Association, made it evident that many phenomena of these singular masses had been hitherto overlooked; and although described by many eminent observers, no solution had been given to the question of their movement but that of their weight, which he showed could.have only a partial operation, as they often rest on rugged beds, and these not always of much inclination. He proposed a very ingenious explanation of their movement by means of hydrostatic pressure, arising from the fact of the lower part.of the glacier being of a hig'her temperature than the upper: this causes a melting of the under part, and a consequent raising of the mass in a perpendicular direction to the e a r t h ' s surface, while its descent was at right angles to the inclined surface: a progressive motion downwards ensues, following the law o f the resolution of forces. H e then spoke of certain causes of the rents and fissures in glaeiers, these being often convex downwards, owing to the operation taking place in the middle part of the mass, which descends soonest, while the whole is held in its place by the upper and lower extremities: also tubular fissures are formed by blocks of stone 5o •
354
Mechanics' Register.
sinking by degrees in the glacier, owing to their h i g h e r temperature gradually melting the surrounding ice. H e then alluded to the singular accumulations of detritus on the glaciers, which are locally termed too. raine~ and are formed by ~boulemens in winter and covered by the snow. These he found to assume linear directions parallel to the axis of the glacier; and, from the regularity of their arrangements, he conceived it possible to discover the site of old glaciers from the moraine which had remained on the ground after their destruction. Analyst.
On the Floating Masses of Fucus occurring near the Cape Verd Islands. M. Kunth lately presented to the A c a d e m y of Sciences of Paris, in the name of M. Meyen of Berlin, a specimen of the Sargassura natans (Fucus natans, Linn.) brought from the celebrated Mar de Sargasso, near the Cape Verd Islands. M. Kunth remarked, that this individual, like all the others observed by M. Meyen in these latitudes, does not present the slightest trace of a polnt of attachment. It was therefore never attached to rocks or to any other s u p p o r t i n g body at any period of its growth, but must have been developed floating on the surface of the sea. T h e opinion generally adopted by voyagers, that these plants have been torn from their original situations by the waves, and collected by currents in the M a r de Saragasso, appears to M. Meyen to be inadmissible; and he is inclined to believe that they have been produced at the place where they are observed. T h e same naturalist maintains that such individuals formed at the surface of the w a t e r , n e v e r e x h i b i t fructification. Edin. New Philos. Jour. Mechanics'
Register.
Girard Collegefbr Orphans. As this is an Institution in which mechanics have a deep interest, and one to the completion of which all must look forward with great anxiety, the ibllowingdescription of the main building and of the state of the works at the present time, by the able architect~ Thomas U. Walter, Esq. cannot tail to be acceptable to our readers. Cola.Pub.
Description of the main Building of the Girard Collegefor Orphans. By THo~As U. WAI.TER~Architect. T h e Girard College is situated about one and a half miles northwest of the centre of the City, on a tract of land containing forty-five acres; the whole of which was appropriated by Mr. Girard exclusively to the purposes of the institution. T h e main building, which is the subject of this description~ is composed in the Corinthian order of Grecian architecture; it covers a space of 184 by 243 feet, and consists of an oelastyle, peripteral superstructure resting upon a basement of eight feet in height composed entirely of steps extending around the whole edifice; by which a pyramidal appearance is given to the subslruction, and a means of approach to the porticoes afforded from every side. T h e dimensions of the stylobate (or platform on which the columns stand,) are 159 feet on the fronts by 217 feet on the flanks, and the cell, or body of the building, measures 111 feet by 169 feet 2 inches. T h e whole heightj from the ground to the apex of the root, is 100 feet.