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AN ACCOUNT OF THE FILLING OF A SINK-HOLE. By Charles Paine, C.E. At a marsh about one mile east of Lawrence, upon the “ air line ” of the Michigan Southern and Northern Indiana R.R., there occurred, during the construction of the line, a sinking of the embankment which had been nearly completed across the marsh, the fibrous superstratum, of from six to eight feet in thickness, having broken off at each side of the bank, letting the whole drop into a lake of semi-fluid peat below. Efforts at filling up the hole were continued for a long time ; but making very little show for the amount of material absorbed, the work was finally abandoned, the track having been carried around the edge of the marsh by very sharp reversed curves. The incon venience of this interruption of the straight line, and the de struction of rails on these curves, became considerable, as the traffic of the road increased, and it was thought very desirable to complete the embankment across the marsh. Upon sounding, the peat-bed or lake was found to be about forty feet deep, or from grade about forty-five feet to hard bottom, for a distance of about thirteen hundred feet;—where the embankment had once been built the soundings were only from ten (10) to twenty (20) feet below grade; but at two places, two hundred and three hundred feet long, respectively, no filling had been done. As the only earth to be procured in the vicinity was a clay which would stand in water at a comparatively low angle, it was evi dent that an earth bank would require a large quantity, even where a core had already been formed by the work previously done, to complete the slopes. I therefore determined, for that portion of the bank under water, to use materials always at hand upon railways, viz : the decayed sleepers removed from the track in the course of repairs. The height of grade above the water being five feet, a plat form thirty-five in width would carry an embankment fourteen feet wide at grade, leaving a leerme three feet wide at each foot of the slopes ; such a platform was accordingly laid down and then built upon, each course sinking those below it, until the bottom was reached, the succeeding layers crossing each other, the sleeper also breaking joints longitudinally and alternately, so as to bind the whole together as firmly as possible, keeping the outer edges of the platform somewhat higher than the mid dle, so as to give the outside sticks a tendency towards the centre. This work was begun during the winter of 1865-6, and com pleted during the next winter, at times when the working-train could best be spared for such labor, the earth filling and ballast ing having been done during the past summer. Some difficulty was experienced from the slow settling of the platform through the peat, at the points where no earth embankments had previously been made, as the bank which was first made upon the sleepers sunk the platform too far below water, where the earth had to be removed and the platform raised with additional courses of sleepers ; but the whole appears now to have reached the bot tom. The trains have been running over the new line for about two months, and the settling is not greater than upon any new embankment. The economy of this mode of forming the bank will be seen to have been considerable, the estimated cost of an earth bank having exceeded $30,000, while the cost of con struction has amounted to not quite one-third of that sum.— Franklin Institute Journal. THE RELATIONS OF GEOLOGY WITH ARCHITECTURE* By Professor D. T. Ansted, M.A., F.R.S., F.G.S. Constructive material is so important, not only in the practice of architecture, but as affecting the nature of designs, that every department of knowledge capable of throwing light on the nature and properties of such material, cannot but be worthy of the attention of the architect. No one who has watched the pro gress of art and the history of architecture, can fail to perceive the influence of material. Granite was a fit material for Egyptian temples ; marble and the white stones of the South of Europe, especially Italy and Greece, are the best materials for expressing classical feeling and style; the coarser and warmer- * Read before the Royal Institute of British Architects, November, 1867. tinted stones of Northern Europe lend themselves much more to Gothic forms; while the grand constructions of the low countries, and other places where brick is easily to be had and stone is scarce, exhibit a style of their own derived from the constructive material, or, at any rate, growing side by side with its general use for less important buildings. No excuse then is needed, when I presume to occupy your time this evening with some account of the nature and position of those materials, with which all architects have so much to do. If it were merely a matter of curiosity and general interest, the subj ect would deserve your notice, but involving as it does grave practical conclusions, it demands your most earnest attention. In addition to that knowledge of material, which every educated person should possess, the architect will find it eminently useful to know the composition, the mode of formation, the position in the earth, and the mode of quarrying all the principal varieties. It is precisely this knowledge that geology teaches. Origin of Constructive Material.—Most of the materials used for building purposes have been originally deposited as mud or sediment from water. They consist, therefore, of frag ments and grains of various substances, water-worn and water- carried, at first heaped together confusedly, and afterwards con verted into clay or stone of various kinds. Of some stones, the component parts, whether calcareous or siliceous, are small and of uniform size, and the grain of the stone is fine. In others, they consist of concentric layers of carbonate of lime round a minute nucleus, the stone being formed by the cementing together of a vast multitude of these egg-shaped particles, each not much larger than grains of sand. In others they are larger, and include among them many fragments of shells of marine animals. In some they contain entire shells or corals, or even consist entirely of these organic bodies cemented together, and either changed in their texture or entirely replaced by carbonate of lime or silica, having the form of the original shell. Even where the strictly mechanical character of the deposit is not proved by this evidence, it may be inferred by the way in which the particles are aggregated. They are in horizontal beds sepa rated by some bands of different character to the others ; or, they are associated with such horizontal beds above and below; or, they are mixed with rolled or angular fragments of other stones, the whole being cemented in one mass. According to the mechanical condition in which they are found, these materials are of finer or coarser grain, and more or less adapted for cer tain purposes. When we know how they were formed, we may form some idea as to how they will behave under given circum stances. But there are varieties of stone that have certainly not been formed in this way. The stones called lava and basalt are little more than slags, such as run out from an iron furnace. They are natural glasses formed by the melting together, in the inte rior of the earth, of certain earths and fluxes. They are some times in layers, but this is only because of successive outpourings at different times. Owing to their hardness and brittleness, and the irregularity of their fracture, they are quite unfitted for ornamental work, and could not be used for most architectural purposes ; although sometimes valuable for foundations and for certain kinds of rough work, they are little considered and altogether unimportant, in a practical sense, to the architect. But there is a large and most important class of intermediate materials, of the greatest use to the architect, and of which the origin is by no means so clearly made out by a mere inspection. While many stones, exhibiting their mechanical and aqueous origin, are easily recognised, and those which have been poured out from volcanoes in a fluid state also tell their history without difficulty, these intermediate substances, partaking to some ex tent of the peculiarities of both, are referred sometimes to one, sometimes to the other. They include the finest qualities of marble and alabaster, and the various granites and porphyries under whatever names they are spoken of. All these belong to a class spoken of by geologists as metamorphic, having undergone change or metamorphosis, which has masked their original character and communicated their essential characteristics. We thus have all rocks, yielding constructive material, grouped under three general heads, as aqueous, igneous, or metamorphic, these names describing their origin as determined from their appearance. The stones in common use as free stones, are mani festly aqueous in their origin, but are generally somewhat meta morphosed. The stones used for ornamental and decorative purposes, such as all kinds of marble and many porphyries, are