taken account of this, but neglected the for external pressure P., assuming that influence of the pressure in the direction collapse is out of the question, of the cylinder axis, as have also Barlow & Brix. The author, in developing his formulæ, avoids the inaccuracies mentioned, and arrives at the following results: for internal pressure p THE FAILURE OF A DOCK WALL IN THE EAST INDIA DOCKS. By LIEUT. H. D. LAFFAN, R. E. From the Papers of the Royal Engineer Institute. ABOUT the beginning of July, 1879, a shown no sign of settlement; this may serious settlement took place in the south be accounted for by the fact that they wall of the East India Import Dock. were built on a solid layer of concrete, The wall in which the failure occurred 13 feet thick. The dock wall in which was built of brick and stone lime mortar. The brickwork was apparently very good, the wall having in one place sheared straight through the bricks, leaving the joints undisturbed. For a length of about 700 feet the wall had sunk down to a depth of several feet, and in its final position had assumed an irregular wavy outline, the greatest bulge (at the footings) being 7 feet 3 inches, and the greatest subsidence 5 feet 3 inches. The forward movement, however, was almost entirely confined to one point, and was probably caused by a heavy crane fixed just behind the top of the wall on an iron framework. As the wall sank the crane fell backwards, acting with a leverage upon the wall and driving it forwards. At the western end of the settlement the wall had sheared downwards, leaving a fissure 1 foot wide, with a step 2 feet high at the top; at the east end the shearing was distributed over a number of smaller fissures. No part of the stuff at the back of the wall had found its way into the dock, but had sunk down, forming a trench behind the wall, in which, in some places, there was a depth of as much as 15 feet of water. A large warehouse, only 50 feet distant from the edge of the wall, had the failure occurred was built without a foundation of piles, upon cross planking, laid on gravel and sand some 2 feet deep, overlying running sand, and the settlement appears to have resulted from the sand being drawn away from under the wall. The immediate cause of the settlement appears to have been the tapping of the running sand in the course of excavating works in connection with the Midland Railway Docks, about a quarter of a mile distant, when a "blow" ensued which covered in the works with sand to a considerable depth. The sand was allowed to run for several days, and while it was running the settlement occurred in the wall of the East India Dock. At about 5 A. M. one morning the wall sank down suddenly without any previous warning, the greatest subsidence at first being 3 feet, but it afterwards continued to sink gradually as long as the flow of sand in the Midland Railway Works continued, and when this was stopped the settlement ceased. At one time there was a channel from the bend of the River Lea, into the River Thames, about where the Midland Railway Docks now are, and although the channel has been stopped, there is probably still a creek of sand running in this direction through the East India Docks; it has, therefore, been thought Import Dock, and under its south wall, desirable to widen the wharf on this which has been tapped by the Midland Railway Company. The sand had thus, in all probability, been drawn away from under the wall, which, after supporting itself across the gap for a time, after the manner of a beam, eventually gave way suddenly under its own weight. This accident has occurred at a time when there is a pressing want of acom modation on the quays of the East India quay, as well as to restore it as rapidly as possible. For this purpose a wooden staging is to be erected about 30 feet to the front of the present wall; the wall itself will be left as it is, and a mass of concrete, resting against its base and sloping up to the top, will be laid between the wooden staging and the wall, in order to prevent any further forward movement. will be gathered from the following particulars: The Anglo-American Light Company will fix their lamps on separate posts, not less than 13 feet above the ground. Overhead wires will lead from the company's Victoria Works, Vine Street, Lambeth, where the power will be located, and then from post to post, overhead, except across the streets, when they will be carried underground. Messrs. Crompton & Co. suggested employing lamps capable of sliding up and down posts, or suspended across the streets, and to be lowered by cords and pulleys. Upon the bridges the lamps would have been carried on posts 35 feet high. The electric and Magnetic (Jablochkoff) Company will carry out the same system as on the Embankment, the wires being hung from lamp to lamp, and carried over the crossings, on high posts. Messrs. Siemens Brothers will employ large lamps in clear glass globes, with umbrella-shaped reflectors, placed on posts 70 feet or 80 feet high, and small lamps in partly or wholly frosted glass globes, on 20 feet standards. The wires will be laid underground, and the light-producing plant will consist of two 12 horse power semi-portable engines, seven medium-sized dynamo-electric machines, and the alternate current machines, with their excitors. In making their report and recommendations, the Street Committee stated that they had been guided not only by the prices given in the tenders, but by the effect produced with the different systems in actual operation, all of which they had seen. The papers presented at the meeting of January 15th, were the following: "Canal Routes Across the Isthmus of Pan ama," by Col. James Worrall. 'Progess and Methods of the Geological Survey of Pennsylvania," by Charles A. Ashburner, M. E. Rodman Wharton, C. E. "The Use of Dynamite for Blasts," by W. "Notes and Illustrations of Mine Topography," by Charles A. Ashburner, M. E. "Estimates and Improvements in Diamond Drilling," by Chas. E. Billin, M. E. HE AMERICAN SOCIETY OF CIVIL ENGI TRS. The growth of the Society leads to a demand for more ample space. A circular has been issued to members, and is to be extended to others who are interested in the advancement of engineering, the purport of which is, that the Board of Direction solicits contributions to a building fund, the amount of which shall be $25,000 or $30,000. The names of contributors to the in the proceedings. A subscription of $100 fund will be regularly enrolled and published entitles the giver to a copy of the monthly publications for life. POLYTECHNIC ASSOCIATION OF THE THE POINTAN INSTATE held its regular weekly meeting on the evening of the 6th inst. Thomas D. Stetson, presiding. A newspaper scrap was read announcing a of dead bodies, originated in Germany and newly-discovered process for the preservation patented here; but the patentee had been induced to abandon his patent and make it public property for the benefit of the world. A liquid was made by which the bodies were embalmed by being saturated and impregnated with it, Three thousand parts water, one hundred alum, sixty potash, twenty-five common salt, twelve saltpetre and ten arsenic acid was made the first composition. Then to ten parts of this, four parts of glycerine aud one of methyl alcohol were added. Bodies preserved by this were alleged to fully retain their form, color and flexibility for years. In the discussion it was doubted that the color would be preserved. There were compounds which would preserve human bodies Very prefectly, if they could be thoroughly company in this city, the New York Sanitary Company, furnish a fluid and instruments for thoroughly impregnated before decay comapplying it, by which the interiors are very mences. Then a moderate treatment on the surface with the same or other preserving fluid insures the preservation of the body in a high degree of perfection for a loor, Mr. body of the well known actor, Mr. Porter, who was killed in Texas, was preserved by the aid of this process and brought to this city, and seen by his friends at the funeral fourteen days after death. An account was read from Iron of a process of printing many colors at one operation, alleged to be in successful operation in France. A solid block was formed in Mosaic of differ. ent colors, using blocks of pigments all capable of being acted on by a chemical or combination of chemicals. A thick mass of this is mounted in the press, planed off smooth, and then wetted rapidly on the surface with the proper fluid, and the paper or other material placed thereon and pressed. A clear impres sion is thus obtained in all the colors, and in the case of textile fabrics the color goes completely through their substance. After exposure for a brief period to heat, to drive off the fumes of the chemicals employed, the work is finished. Mr. MacDonald said he had assisted in trying similar experiments in this country. In those experiments glycerine was used, and the printed impressions had the peculiarities due to the presence of glycerine, that they remained damp. The process, so far as he had known it, had been always a failure. The sharpness of the impressions would be satisfactory to some, but not to a good printer, and the character of the work generally was inferior. Shipping moves under both bridges through the Menai Straits. An extract read from the editorial correspondence of the Philadelphia Press of last summer, developed a long conversation with one of the leading silk manufacturers of Lyons, in which he sadly admitted the competition, dangerous to their industry, of Americans, in the silk manufacture. In the discussion which followed, it was stated that there are now about 200 separate manufactories in America for woven and sewing silks. American manufacturers load their silks with less foreign matter and make an article which is superior in wear but not as brilliant in gloss. Paterson, and other points, manufacture ribbons with eminent success. Hartford manufactures dress goods of sombre colors superior to any in the world. We import about 7,500 tons per annum of raw silk and manufacture it here. The raw silk made in this country is slight. Wages are too high. It requires cheap labor as in Italy, China, &c. Machinery has not yet succeeded in reeling cocoons. But immense areas of our country have mild winters and are every way favorable for the silk worm. We can raise cocoons and ship them abroad to be reeled and returned. We are producing cocoons largely in North Carolina and California. Mr. Blanchard developed on the blackboard a mode-original with him, for computing the strains on the different parts of bridges. Eddy, Stoney, Dubois and others had analyzed with immense fineness, but their methods were too complicated. It could be done much more simply. The relative strains on every part were ascertained by geometrical figures. A paper read by Professor De Volsen Wood The operation was rapid and sure. It was an opened the main subject of the evening, the improvement on the ordinary diagram for the decomposition of forces. The vertical strains were represented by horizontal rather than vertical lines. He Relations of Machinery and Labor." held that the present era of machinery has induced great revolutions in labor and laborers, but the general effect is eminently beneficial. The discussion following developed singular | The farmers of Ohio opposed railroads in anomalies in the failure of bridges. The Mont- the belief that they would diminish the demand morenci bridge, near Quebec, after bearing for horses and oats, until it was shown that immense loads for a long period, fell suddenly the introduction of railroads resulted in an inwith nothing on it. It appeared that the frac-creased price for both, in every instance. A ture, of iron wrought under continued strain, machine which made one man do the work of was a gradual process, the catastrophe occur- ten, at first sight appeared to dispense with the ring as the result of a slow failure which had labors of nine, but labor is more constantly in been initiated much earlier. Mr. Hudson re-demand and better paid than before machinery ferred to the failure of the chain bridge across the Merrimack River in 1826 after a heavy snow storm. The President referred to the great perfection which theoretical and practical science has been brought in modern bridge building, as exemplified in the costly East River Bridge, which we hope will prove, as it promises, a master-piece of the art. He also mentioned the two famous bridges near each other at North Bangor, in Wales-one, a suspension bridge completed in 1825, before the superiority of small wire cables for such purposes had been established. Wires were immensely easier to stretch across one at a time and were found much superior in strength for a given weight when completed. That bridge was built with what are sometimes termed pitchchains, bars of iron laid three or four abreast and knuckled together by transverse pins through their ends. It continues to be used for general carriage traffic. Near it is the famous tubular bridge engineered by Stevenson & Fairbairn, which carries the railway trains between Anglesea and the main island of Great Britain. VOL. XXIV. No. 2-12. was introduced. A farmer's wife in the West told him that their reaping machine, by reducing the number of men to feed during harvest, had lightened her work more than her sewing machine. The increased production of the earth must result in greater wealth to the world. Fifty thousand reaping machines involve in the first instance, a quickened demand for metal, wood, skilled labor and means of transportation. It calls for buildings, clerks, and agents. The wealth it produces calls for buildings, stock, carpets, music, books, and works of art. Thus, apparently unconnected branches of business are benefited by the reaping machine. The discussion following questioned one proposition: It was doubted whether the reign of machinery tended to narrow the faculties by confining a man to one branch of labor. Formerly a long aprenticeship trained the faculties to the production of a wrought-nail or a pin-head and there stopped. The apprentice system is gone. There is danger from its absence, but so far, in America at least, the intelligence developed by the schools, gen eral and technical, have successsully taken its ished with an oblique branch directed upplace, and all are mobile. Our great manu- wards, and bent round to terminate in an iron factories, with their hum of machinery are or brass funnel, under which the gas or petroschools to every young man and warn him leum flame burns. The heat then passes into that he should be ready for emergencies. We the inclosing tube. In the air box above holes have no indolent rich, no idle class except the are provided to let the air escape, and good tramps, and they are disappearing. All can, ventilation may thus be secured. and do, work with head or hands, and nearly all can change successfully from one business to another with only three weeks of special training. ENGINEERING NOTES. AFETY ARRANGEMENT FOR WATER PIPES. | SA In to obviate In order to facilitate repairs, the water pipe, at the middle of the doors of the inclosing pipe, is formed with brass connecting screwsBut the use of the ordinary soldered junction does not present any hindrance by rea. son of the zinc tube. Nor are any other serious difficulties, it is said, encountered in the working of the system. work of the United States Government was undertaken with the object of determining the exact relation of the fauna of the Atlantic Ocean with that of the Gulf of Mexico and the Carribean Sea. The deep sea soundings ranged chiefly between 450 and 800 fathoms, and the work begun in June last, was carried on about 120 miles from the coast, and, generally parallel to it, commencing south of Cape Hatteras. The sea bottom has been shown, by these explorations, not to be gently sloping, but there was found the continuation of the plateau of which the northern portion extends as far as Cape St. George, the southeasterly limit reaching to the Bahama Banks. The work of exploration was confined during the past season to the western slope of the plateau, the sides of which are so steep, that in the distance of a few hundred feet, the depth of soundings increased from 100 to 450 fathoms. This side of the plateau is covered with a rich deposit of mud and alluvium, gathered from the discharge of numerous rivers and washed off the top of the plateau by the action of the Gulf Stream. The result of this action bas been, that while no animal life has been found to exist on the top of this submarine highland, except certain coral formations, the conditions of the slope are highly favorable, and the numerous specimens obtained showed that, generally, the animal life corresponds with that in the Gulf of Mexico and the Carribean Sea. During the course of the survey, work was continued day and night, and eight dredg ings were generally made during the twentyfour hours. winter, Herr Weissbarth has contrived an arrangement (we learn from the Deutsche Industrie Zeitung) by which any water that may escape thus is carried off into the street drain or a cesspool, and, at the same time, a cheap mode of heating the whole pipe system with a single gas or petroleum flame is rendered possible. The entire system of water pipes, which, as in every right arrangement, must have, in all its branches, falls toward the ascending pipe, is inclusive of the ascending pipe) inclosed in sheet zinc pipes of 5 to 8ctm. internal diameter; so that water finding exit at any part of the system gets into the inclosing pipe, and is carried away. The inclosing zinc pipes, about 1 meter long, are not soldered at the joints; but stuck into each other like gutter or waste pipes, and the water pipes, of lead or iron, are fixed in the others by means of rings with small projecting pieces bent at a right angle, which catch in metallic tholes soldered on the interior of the zinc pipe. The lowest inclosing pipe has a bottom, through which the water pipe passes tightly, and close above this is the tube by which the escaping water is carried off to the drain. In order to get at the water pipe without having to take the zinc pipes out of each other, some of these are furnished with doors 70 to 75ctm. long and 5 to 6ctm. wide, which are easily slid within the tube, as they are led above through a soldered metal ring, and below through packing; the latter at the same time prevents the water flowing out between the doors and the pipe; moreover, the longitudinal borders of the doors are packed interiorly, so that the water follows the packing and does not issue by the door. The fixing of the zinc tubes to the walls is effected THE NEW TAY BRIDGE. The sketch plans with rings on which they are supported with prepared by Mr. W. H. Barlow, C. E., noses. Branch pipes are soldered into the London, in connection with the Parliamentary main pipe. When, in a branch pipe, stop- notices already published for the erection of cocks occur, the inclosing pipe is there perfor- another Tay Bridge, have been issued. While ated for the spindle and stuffing box. In these plans do not show the structural details, the longer branch pipes, as in the vertical as- it is understood that the bridge is to be of cending pipes, doors must also of course, be sufficient width to admit of a double line of introduced in the inclosing pipes, the openings rails being laid, and that in the arrangement being naturally on the upper side. At places of the girders the rails will be laid partly along where the ascending pipe is exposed to cold, the lower and along the upper booms, the peras, e. g., in water closets or entrance halls, the manent way being enclosed on each side by a arrangement permits readily of a warm air- strong iron parapet. The new bridge is to be current being produced in the inclosing pipe, erected a little to the west of the present one, by means of a gas flame (which may also serve the intervening space between the centers of in illumination). To this end the pipe is furn-he bridges being about 50 feet in width, and |