From All the Year Round. Few persons who are accustomed to use the pure white candles, delicate as wax in their hue, and known popularly by the name of composites; and the clear oil, almost as transparent as water, which is called paraffine; have any idea that both are produced from a dull, compact coal, totally devoid of tho luster which gives to that mineral the appellation of the black diamond. And yet this seeming miracle is achieved by the aid of chemistry—that strange science which changes and transmutes substances and reveals properties, hidden and mysterious, at the will or instigation of the student. The process by which ths change is effected is complicated and laborious; but,- freed from its technicalities, it may be easily explained. The coal yields four different articles, all of which are largely employed in daily life, and have given rise to a considerable commerce. There is, first, the paraffine oil for burning, at present manufactured by thousands of gallons, which, in many parts of England, where gas is still unknown, is the staple commodity of illumination. Then a second quality of the same oil, considerably cruder and coarser, which, on account of its cheapness and general aptitude, is largely employed for lubricating machinery. Naphtha comes next upon the list—a light volatile fluid, much used by traveling showmen, to light up their stalls and tents. Lastly, there is solid paraffine—a pure, white, shining, tasteless substance, scarcely distinguishable from wax, which is manufactured into candles. These substances, though widely differing in color, properties, and consistency, are all manufactured by nearly the same process, the difference consisting merely in the number of times that a particular operation is repeated. Boghead mineral is the name of the coal employed in the manufacture of paraffine; and this is conveyed from the pits direst into the heart of the works, -by means of branch lines of railway. Arrived here, the coal is passed through a huge iron crushing machine, and broken into small pieces, to facilitate ths labor of subsequent stages. The first result to be achieved is to extract the crude oil from the coal. This is effected by means of retorts, into which t e mineral is put, and the oleaginous matter extracted by burning. These retorts may, for our purposes, be described as huge upright iron pipes passing through furnaces. The coal is filled into the pipe or tube by the top, which is then closed with an air-tight valve and the bottom of the pipe is led into a pool of water to prevent the entrance of air from below. A low red heat of uniform temperature is maintained constantly in the retorts. As the coal is acted upon by the fire, it descends gradually in tlie tube and becomes entirely decomposed. The essential or oleaginous property of the mineral passes off in vapor, and the refuse falls through the bottom of the pipe into the pool of water, and is raked away. The vapor or steam, as it is generated by the decomposition of the coal, is carried off by a pipe in the side of the retort. This pipe again communicates with a series of pipesplaced upright in the open air, and arranged on the same principle as the bars of a common gridiron, after the fashion that prevails in gasworks. The vapor, in traveling through this labyrinth of pipes, cools, is condensed into liquid, and is run off into an immense reservoir sunk into the ground. The crude, oily liquor thus collected is a thick, black, greasy fluid, not unlike tar, which moves with a sluggish motion when stirred, and gives off inflammable vapors at the usual atmospheric temperature. This coarse oil, both in its properties and appearance, closely resembles natural petroleum, and is equal to the rock oil, which, as we have seen, was obtained in Derbyshire. The raw material thus prepared by simple burning is kept stored in the tank, and is only drawn off when required. To the observer nothing seems stranger tkan that this heavy, black, tarry liquid should produce oil as pure as water, and solid paraffine as white as marble. And yet the marvel is wrought daily, and on a scale which supplies distant markets of the world with oil. It is a mere question of refining. The black liquor is, as it were, boiled, washed, and bleached, re-boiled, re-washedj and re-bleached, until the last particle of its darkness and impurity is purged away. The first step in the work of refinement is in some respects similar to the previous process of decomposition. The crude tarry liquid is put into stills, which we may call huge boilers of gigantic strength, with movable doors or lids. When the stills have been filled, the doors are closed, and the joints are stuffed with clay, so as to render the interior perfectly air-tight. Fires are then lighted in the furnaces below the boilers, and kept up to a steady heat, till the fluid inside distills over and is transmitted again into vapor. This vapor, as in the former instance, permeates through another series of condensing pipes, and, during its transit is re-transmuted into liquor, and flows into a second reservoir. Collected in this tank, the oil shows abundant evidence of the severity of the ordeal through which it has been put. It passed into the stills black and of the consistency of treacle; it has come out of a dark-green color and of the consistency of pea soup. A large portion of the coal-black has, in fact, been boiled out of it, which is now to be found in tha bottom of the boilers in the shape of a lustrous compact residue resembling coke, for which it makes a very good substitute. The next stage in the process of purification is of a different character. The dark-green liquor is transferred to tanks, and a certain quantity of strong sulphuric acid if? added. The acid is employed in order still further to bleach the oil, and purge it of some more of the impurity with which it is so largely impregnated. To effect this object it is essential that the oil and the acid should be mixed up or assimilated as much as possible:—a work of some difficulty, on account of the tendency of the former to float on the top, by reason of its lighter specific gravity. This tendency is neutralized by the action of a revolving stirrer fitted with blades, which, when put in motion, beats and agitates the two liquids, and causes them to mingle equally. For four hours is this operation continued, until, under the biting influence of the acid, the dark-green oil changes to pale-green, and gives token of having parted with much of the grosser substances that had rendered it dull and opaque. The stirrers being at length stopped, the liquor is allowed to settle, and the organic impurities that have been separated from it by the action of the vitriol, collect in the bottoms of the tanks. The lees in this case assume the shape of a coarse acid tar, which is also used as a substitute for fuel. The oil, thus far cleansed of its foulness, is now transferred to clean tanks, mixed with a strong solution of caustic soda, and again subjected to the beating of the stirrers. The action of the alkali extracts a good deal more of the coloring matter, and changes the pale-green to yellow. At the end of a second period of four hours the liquor is allowed to settle, is drawn off from the lees as before, is pumped into the stills and is redistilled, and is again brought back to be put through the acid and alkali bleachingprocess; the result being its assumption of a clear, pale, yellow color. When in this stage of its preparation the oil contains the elements of no less tfian four different products, each valuable as articles of commerce, to separate which is the next care of the manufacturer. The separation is effected merely by distilling the oil at various temperatures. At the lowest temperature the lightest and most volatile parts of the oil pass off in the shape of vapor. Upon being cooled, bypassing through pipes, this vapor yields a liquid which, upon being distilled by itself, gives a light, transparent, inflammable fluid known by the name of naphtha, the specific gravity of which is considerably less than that of the naphtha derived from coal-tar. This naphtha is largely employed as a substitute for turpentine in india-rubber works, where it is employed to dissolve the materials used in that branch of manufacture. At the temperature next to the lowest, those parts of the oil that are next to naphtha in point of volatility are taken off, distilled, and condensed, and yield paraffine or lamp oil. The processes of purification and distillation are repeated with this oil till it has assumed the requisite degree of purity, and become transparent and almost free from smell. A gallon of this oil weighs about eight and a quarter pounds, and is, in point of illuminating power, nearly equal to one gallon and a quarter of American petroleum. A yet higher temperature than that whjch is necessary for the production of the burning oil produces a thick, Jieavy, lubricating oil, used in vast quantities in the Lancashire fac tories for oiling the machinery, and also by watch and clock and philosophical instrument makers. This oil, when it comes from the still, is largely impregnated with solid paraffine, and when it cools it assumes the consistency of grease, the paraf fine having coagulated into crystals. Before the lubricating oil can be made available for what it is intended, these crystals must be separated from it; and here again another operation, but one of a simple nature is requisite. The oil is poured into thick canvas bags, which are placed in hydraulic presses. Pressure is then applied with such force that the oil is squeezed out of the bags, leaving the crystals within. The oil thus squeezed out is the lubricating oil, and is ready for the market; the crystals are the paraffine in embryo which has so often been admired in the shape of candles. When turned out of the bags the paraffine is in its coarsest state, and is of a dirty yellow color. This hue is the result of the quantity of oily matter which the substance, in spite of its frequent purgings, still retains. Its perfect and final purification is effected by the repetition of a single process, continued till the requisite clearness is obtained. The paraffine is dissolved in heated naphtha, and is kept in solution for a considerable time, after which it is allowed to cool and again assume its crystalline form. The process of squeezing in the press is repeated, and when shaken out of the bags this time the paraffine is seen to have changed from yellow to dirty white, and is consequently so much purer. The operations of dissolving and straining are repeated till perfect pureness and whiteness are obtained. This result achieved, the odor of naphtha which clings to the substance is driven off by steam, and the paraffine, in a liquid state, is run into molds, which form it into thick round cakes. In this shape it is sent off to the candlemakers. Engineering under Ground. We learn from the Artizan, London, that a new length of the line of the underground railroad of that city has 1)6611 completed at a cost of $3,500,000 per mile.the bulk of which has been applied towards compensation for damages. The length of new line is nearly three miles, and has six stations—one at Westminster bridge; one in the Broadway, at St. Jamess park; one at Victoria, where it-joins the Chatham and Dover line; one at Chelsea, near Sloane square; one at South Kensington; and one in the Gloucester road, West Brompton. Of the whole length of line about one-third is tunnel and the rest open cutting. No very special engineering difficultieswere met with in the construction of the line except the continued presence of water, as some parts of the works are below low-water mark. The greatest depth below the surface to the rails is not more than 82 ft., the quickest curve is 440ft. radius, and the greatest in cline 1 in 250ft. Considerable difficulty was experienced during the construction of the line, from water, both from the sewers and from the surface drainage. On one very wet day in the early summer no less than six sewers burst at once, and gave the pumps enough to do to keep their contents, with the surface drainage, from flooding all that was then built of the line. To this day, and as long as the line is in use, there must always be permanent pumping stations for the mere surface drainage, there being no outlet toward the river without raising it to a higher level. This water difficulty, however, is very ingeniously met by Messrs. Fowler and John-stone, the engineers of the line. The side walls both of the arched tunnels and open cuttings are made of extra thickness, and, above all, are connected beneath the ground by an inverted arch of concrete nearly three feet thick. This effectually prevents the water rising up through the floor of the line, and equally prevents the surface water from draining off. For this surface drainage, therefore, special provision is made, by means of pipes laid in the center of the line, which carry the water on to the pumping stations, where it is raised and sent away into the Thames. Passing under the middle of the Broadway the line is carried, not in a tunnel, but in a broad, lofty, square chamber, with a flat roof, on massive wroght-iron girders. This is a beautiful piece of work, both in its design and flnish,and is of the most unexceptionable character from beginning to end. While.passing along the Broadway special precautions were taken to guard against any possible vibration affecting Westminster Abbey. The walla on the Abbey side are here made seven bricks thick. Behind this comes the Victoria sewer in a tube of iron, and behind all a bed of peat seven feet thick. The peat checks all vibration, but as the nearest point at which the line passes is more than 90ft. from the Abbey walls, its deadening properties are scarcely required. After Westminster bridge the first station is St. Jamess park, and leaving this the line continues in an open cutting to Buckingham row, where it enters a tunnel of about 500 yards in length. Here the water occasioned so much difficulty that engines had to be kept going night and day, pumping at the rate of nearly 4,000 gallons a minute. The tunnel at this point passes but a few feet below the surface of the ground, yet it forms the foundation of the brewery belonging to Elliot, Watney & Co. above. This building is now carried on a series of girders, but the work had to be done with great care, for the superincumbent weight was immense, and the soil below poor.and treacherous. After finishing this portion of the line a fresh difficulty arose withthe Kings. Scholars Pond sewer, the largest sewer next to that of the Fleet in London. This had to be entirely diverted and reconstructed in an iron tube, 11 feet;wide by 14 feet high. So very limited was the space at command that this sewer had to be built over the up and down line in a deeply arched form in order to make room for the funnels of the locomotives. Tkis most difficult of all the tasks on the line has been admirably executed by Mr. T. A. Walker, the resident engineer, who has had charge of the works throughout. A few yards from this point is the station at Victoria, which, like all the others on the line, is open, or rather only closed in with light glass and iron roofs. From this point the line passes on to Sloane square, a wide and lofty station, but the architectural effect of 163 which is much marred by the Eanelagh sewer being taken in a huge cylinder of cast iron right across its very center at the springing of the arches. Continuing westward, the next station is near the site of the Exhibition building of 1862, and to this a new road will be made by a continuation of the Exhibition road from Kensington. The last station is at 01oucester road, West Brompton, where the junction is effected with the Metropolitan Extension. The District line then branches to the south and forms a double junction with the West London, by means of which a communication is gained with most of the southern lines. American and European Woolen Manufactures. BY E. R. MUDGE, U. S. COMMISSIONER TO THE PARIS UNIVERSAL EXPOSITION OF 1867. We cannot be said to occupy a national position in the woolen manufacture except in card or clothing wool fabrics, our success in other departments being exceptional. Our work has been in the direction demanded by the prime necessities of our people and the peculiar character induced by the nature of our raw material. Our peculiarly national wool manufacture is comprised in the production of all the varieties of card-wool tissues from flannels inclusive to the finest-faced broadcloths, which are only exceptionally included. Within this range, comprising plain, fancy, domet, and opera flannels, blankets, woolen shawls, satinets, the infinite variety of fancy and silk-mixed cassimeres, sackings, repellants, tricots, beavers Esquimaux, escredons, cloakings, our success has been complete, and our progress within the last five years traly astonishing. In nearly all these productions we can vie with any nation in excellence, soundness, and taste of manufacture, and in some of them in cheapness. These goods, it must be remembered, furnish all the absolutely necessary card wool-clothing for our population, and all that the great majority of our people are iecltned to wear at any time, a very small part of the population of the cities wearing occasionally, only, the fine and high-priced black cloths. A small part of our population, it is true, prefer to purchase cloths of foreign make to distinguish themselves from the masses, but they are of the same class who in France, under the empire, when cotton stockings were prohibited, preferred smuggled cotton stockings to silk, becauss they could be only obtained at double the cost of the latter. Fashion all over the world demands the use for common wear of the medium mixed and fancy cloths in place of those of high finish. These we can produce from the admirable medium wools grown upon our own soil, and thus the American clothing-wool manufacturers and wool-growers are able to perform their part in one of the first duties of a nation, that of clothing its own people. In the class of goods referred to there is no need whatever of foreign supply, and none would be sought abroad if there were among us that national sentiment in favor of home production which prevails among the nations of Europe. Not withstanding the freedom of exchange among European nations, the national sentiment is found to be tie most efficient encouragement of domestic production. The lustrous German cloths so freely sold here find no sale in England. The London tailors who visited the Exposition reported that there was nothing on exhibition which would compare with the cloths of England. How different is the practice with the tailors and retail dealers in this country who persistently foster the unpatriotic prejudice in favor of foreign goods, because they can obtain larger profits on the foreign article than on the domestic, as the cost and quality of the former are less generally known than of the latter. To specify more minutely the comparative qualities of American goods: In the whole range of fancy cassimeres, including the mixed goods of silks and wool, in style, taste, perfection of manufacture, and strength of material, we excel the English, and nearly approach the manufactures of France. The same may be said of the whole range of flannels, colored and plain, and of the Esquimaux and Moscow beavers, which we have imitated from the Germans. In the low cost pilots, used as substitutes for the beavers, sightly to the buyer, but trashy in wear, it must be admitted that we can hold no comparison with the English. In all the grades of woolen shawls which can be fabricated of American wool we successfully vie in fabric and cheapness of price with the Scotch, who are confessedly at the head of this branch of manufacture. In the class of all-wool goods of light weight, made in all varieties of colors, denominated sackings and cloakings, and largely sold for womens wear, the fabrics are now sohfln this country, at prices reduced to a gold standard, cheaper than any similar fabrics are sold in Europe. Goods of this character, displayed in the American quarter of the Exposition, and marked at their net gold prices, attracted great attention for their cheapness, and constant applications were made for their purchase. In some other branches of the woolen industry, beside that of card wool, especially those where we have equal facilities with the European manufacturer in obtaining raw material, our productions bear a favorable comparison. American carpets are fully equal, if not superior, to the English. carpets of similar grades. In the American Brussels and tapestry carpets there is no inferiority in designs, colors, or texture. In fact they are woven here and in England by the same machinery. The American retail purchaser is invariably compelled to pay a higher price for a foreign carpet of the same grade; that is, he can purchase a better American carpet at the price of the foreign article. The American ingrain carpet, which is much more largely consumed, is unquestionably superior to the English. This is evinced by the fact that the yarns used in English carpets are not sufficiently strong to admit of their being woven in power looms, as is done in this country. There is a prevailing prejudice against American dyes in carpets & well as in other fabrics. No prejudice could be more unfounded. The same chemical agents and the same processes are used here as abroad. We have in our establishments the best dyers that the better prices of labor paid here can seduce iibm Europe. One manufacturer of opera flannels exhibits patterns of eighty different hues on one card. In the present state of the art of tincture in Europe and this country bad dyeing results not from want of skill, but the intentional use of cheap materials, and the risk of getting evanescent dyes is much greater in purchasing cheap imported goods than in buying the products of well-known American manufacturers, who only use inferior dyes when purchasers insist upon cheaper goods. Imperfect Boilers. Under the head of Why Boilers Sometimes Explode, we compiled a statement from the Locomotive, published in Hartford, Conn., and published it on page 75 current volume. The statements there made were of a sufficientlyalarming nature, but we copy the following in addition-iirom the same publication for February: During the month of January, 275 visits of inspection were made, and 536 boilers examined—445 externally, and 166 internally—and in addition, 37 have been tested by hydraulic pressure. In thess boilers 403 defects were discovered —51 of them being regarded as particularly dangerous. Furnaces out of shape, 21, and 1 dangerous. Fractures, 60, and 12 dangerous. Burned plates, 22, and 2 dangerous. Blistered plates, 48, and 6 dangerous. Cases of incrustation, 68, and 3 dangerous; the scale was so thick in these three cases as to keep the water entirely from the fire sheets, and they were consequently badly burned and weakened, and hence were positively dangerous. Cases of external corrosion, 53, and 6 dangerous. Where boilers are bricked in, we find this latter difficulty frequently, and if the joints of the steam pipes, running from and over the boiler, are not tight, the leakage dripping down on to and through the brick covering, silently, but surely makes trouble. Internal grooving, 7. Water gages out of order, 22. Blow-out apparatus out of order, 3. Safety valves over-loaded, 29, and 6 dangerous. Pressure gages out of order, 70, and 5 dangerous. Boilers without gages, 27—all of which we regard as dangerous; and one boiler is reported without either safety valve or gage The comments made by our various inspectors are as follows: One says: The dangerous defects noted in my report were two safety valves—one of them the lever was corroded in the socket so fast that it could not be moved without bending or breaking, and the pin could be got out only by drilling. The other, valve had, in addition to its own proper weight of 160 pounds, another weight of 90 pounds on the lever. The pressure of steam required to lif t this valvewould be 140 pounds to the square inch. These safety valves were each put in good working order, and properly weighted. Another defect was a very bad blister over the fire, which was repaired at once; and three mud drums were found so far gone that the inspector could drive his hammer through in various places; these also were put in good order. Another inspector writes that, in his territory, he finds a great many low-water indicators out of order and inoperative. And further, that in some places so much reliance is placed upon them that the gage coeksare seldom used; and in many instances, have become entirely useless from corrosion. Now, we most emphatically advise all parties to see to it that their safety valves and gage cocks are in the very best condition—no matter how many patent attachments there may be—by no means fail to see that those most important appliances—steam gage, safety valve, and three-gage cocks—are in perfect working order. One inspector reports thirty-three steam gages incorrect; the variations are not large, except in two instances, where one indicated fifteen pounds, and the other twenty-one pounds less than the actual pressure carried. Our Home Office inspector contributes the following, which we commend to the careful perusal of paper manufacturers : The proprietors ol paper mills, as a general thing, pay too little attention to the condition of the check valves of their bleach boilers. Where these check valves are out of order, the pulpy matter passes over into the steam boiler. And we have sometimes found it at and about the water-line, in places three inches thick. The lime also, which passes over, is deposited in the form of scale upon the sheets and flues, rendering them liable to be burned, beside causing great waste of fuel from its non-conducting character. The valves must not be left until there are positive indications that they are in a leaky condition, but they should be examined frequently and be replaced by new ones, in case there is serious leakage. Never trust to grinding by inexperienced persons for a tight valve—there are very few who can grind in a Valve properly, and in many cases the leakage will be greater after the attempt. We have not referred to the danger resulting from vitriol, used in bleaching, being carried over into the boiler, as it must be obvious to every user, that such a mixture cannot be otherwise than injurious. The only way to keep things in a good and safe condition, is to pay attention to all the parts and appliances about the boiler. Had we space, much could be said of other defects, detected by the months work, but the record speaks for itself. Some persons have been disposed to intimate that the com pany has an object in making an array of alarming facts and figures; but we can assure gueh that our monthly reports do not begin to show the actual facts in the case. Any person who will examine the correspondence which we have with our various agents and inspectors, will be convinced that our reports are far from being exaggerated, The Phosphoric Light. So far as principle goes, it is dependent on the fact that when ordinary wax-like phosphorus is burnt in air white and solid phosphoric acid is produced, and this combustion is attended by the production of an intense light. Every schoolboy knows that the light emitted when phosphorus is burnt in pure oxygen is still more brilliant Mr Winstanley sought to utilize this fact with the design of obtaining a poweriul light for photographic purposes, and carried out the idea in the following way: A quantity of the wax-like variety of phosphorus was placed in a suitable vessel; through this ves-seV-a current of common coal gas was passed, the direction of the stream being so regulated that it could pass over the phosphorus and then escape through a jet fitted for the purpose. When the coal gas is passed over the phosphorus at ordinary temperature, and then ignited at the jet, it, of course, burns with its usual flame; but when the phosphorus is heated it commences to volatilize, the luminosity of the flame greatly increases owing to the combustion of the phosphorus vapour, and fumes of phosphoric acid are produced. Mr. Winstanley pointed out that, though this phosphoric gas flame gave a light of much greater brilliancy than that of ordinary ignited coal gas, yet the intensity of the light could be greatly augmented by feeding the phosphoric flame with pure oxygen. When this was done, the report says: The brightness of the flame was enormously augmented, and the ample room in which the experiment was conducted became brilliantly illuminated. We congratulate Mr. Winstanley on his ingenious and successful experiment, and hope that further results may flow frdm such well-directed efforts. There are just two points that we must for humanitys sake touch upon here. Those of our readers who have not had much experience in the more dangerous class of chemical experiments little know what a disagreeable substance phosphorus is to manipulate with; and it is only good and careful experimenters like Mr. Winstanley who may venture to use this new gas flame. We must confess to a great antipathy to employ any more phosphorus than is actually necessary, as in our juvenile days we received a burn of such sevcri-ty that the strong scar still remains to warn us when chemical proclivities would tempt us to forget our former experience and meddle with this dangerous body. We would, therefore, caution the more inexperienced of our readers against meddling with our new but treacherous ally. Again : the product of the combustion cf phosphorus with free access of air is a highJy irritating acid, or, rather awhite smoke, which becomes a powerful acid on coming in contact with the moisture always present in the air. A little of this smoke, when allowed to escape into the atmosphere of an apartment, gives rise to a most disagreeable choking sensation. This latter objection to the use of the phosphoric flame could of course be to a great extent removed by the employment of a suitable chimney communicating with the air ex ternal to the apartment. We may add that any disagreeable fumes escaping removal by the chimney can be quickly rendered harmless by a little liquid ammonia placed in a shallow dish near the apparatus. Having said so much about Mr. Winstanleys plan, we now come to the suggestion of a friend, to try the effect of volatilizing magnesium by heating the metal very strongly in a stream of hydrogen, and then to ignite the gas as it issues from the vessel containing the heated metal. It was anticipated that in this way a brilliant magnesium light would be obtained, owing to the combustion of the metallic vapor along with the gas. It is obvious that zinc might be employed in the same way, since it is about as volatile as magnesium. In the first instance, we placed some metallic magnesium in powder near the end of a tube of very hard and infusible glass, the portion of tube immediately beyond the metal having been drawn out to a fine jet. A current of hydrogen gas was then passed through the tube and ignited at the jet; of course the gas then burnt with its usual nearly colorless flame. The glass tube was now [heated close to the jet so as to melt the magnesium; but the only difference observed in the flame was a tinging with yellow. The blast of a powerful gas table blowpipe was now brought to bear on the tube, and the temperature so raised as to render the glass tube very pliable; the gas flame had now become of a bright yellow color, with occasional flashes of bright white light—probably due to particles of the magnesium having been carried forward by the current of gas. The yellow color was found, on examination with the spectroscope, to be due solely to the presence of sodium. The amount of magnesium vapor which ultimately reached the flame was extremely small. Having failed on a small scale, we repeated the experiment with the aid of a powerful wind furnace and a stout metallic tube, but the result we obtained was little superior to that ah ready mentioned; so that, for all practical purposes, Mr. Win, Stanleys plan fails in the case. of magnesium. The principle of the method followed in the above instan= ces has received less attention than it appears to deserve at the hands of those interested in the production of cheap and brilliant artificial lights, and we hope now to see it extended. in some useful direction.—British Journal of Photography, POISON FOE THEHEADS OF THE PEOPLE.—The results of an analysis of a new hair lotion described by its vender as perfectly innocuous, shows that this precjous mixture is composed of rose-water, sulphur, and sugar of lead, the latter in sufficient quantity to cause paralysis, or painters colic. The directions were that a dessertspoonful should be daily brushed in the roots of the hair, until the whoje head was moistened CONDUCT is at once the aim and test of all our learning, our thinking and striving, 164 Improvement in Railroad Switches The object of the invention herewith illustrated is to provide a combined switch and frog for railroads, the parts of which are operated simultaneously, and which offers a perfectly smooth track for the passage of trains. It may be easily explained and readily comprehended. A A represent the rails of a main line, so curved as to form the outer rails for two diverging branches. B, B, are the inner , rails of the branch lines, having pivoted, at the vertex of their angle, a swinging frog or section of rail, C. This may be moved so as to make a connection with either of the branch lines by means of an ordinary switch, to which it is connected by the transverse sliding bar, D, and the intermediate jointed bar, E, as plainly seen inthe engraving, which is a plan view. P, P, represent fixed sections of rail to which the points or switches, Gt, are pivoted, which are also connected with the sliding bar, D. It is evident that as this bar is moved the points and swinging frog must be simultaneously moved, insuring perfect connection with either branch from the main. The advantages, as claimed, are these : The wheels are not required to run upon their flanges, as in passing over the froga ordinarily used, thus making the track much smoother, the wheels having a fair bearing on the tread as it has on other portions of the track, thereby lessening the danger of breaking them. As commonly made the frogs of a road wear out very fast. The connecting switch bar can be placed either above or under the sleepers as is that of the ordinary switch. Patent pending through the Scientific American Patent Agency, by B. C. Bell.who may be addressed at Duncans Mill, Sonoma Co., Cal. Improved Capped Double Rail. The following is the inventors description of a novel rail which was patented January 5, 1869 : The base of the-rail is made in two parts, A and B. These two parts are exactly alike, having, each, one perpendicular side from a to 6 which are placed together. The upper side from 6 to e is beveled, the outer corner, e, being higher than the inner corner, 6, so that, when the two pieces, A and B, are placed together, the center of the rail is depressed, the upper sides forming an angle. The outer corners, e, are rounded, and the sides of the rail bent inwards, forming a curved groove, d; the lower part of the base spreading out the same as an ordinary T-rail. The cap, B, is made of such a shape as to conform to the shape of the base when put together; that is, the under side being beveled from the center,- x, to near the sides, where are formed curved grooves, y, y, corresponding in size with the curved corners, e e, of the base-pieces A and B. The sides of the cap,B, are turned down and bent inward. The rail is placed together in the following manner: One of- the base-pieces is secured in its place, when the cap, or top, is placed on, the other base-piece inserted in the cap, and the two bases pressed together, and secured, as in ordinary rails. The rail, when together, is in appearance similar to those in present use. In this rail, the leading objects are to have a rail with a movable top, and fulfilling the following conditions : The top to be easily removed by simply pressing the lower part of one base-piece from the other, the spikes having first been withdrawn from one of the bases. Yet at the same time when in its place it securely holds all parts of the rail together. To have no bolts, keys, pins, or holes, in it, to work loose or weaken the rail. To allow of unequal expansion of all its parts, thereby preventing one of the greatest causes of broken rails. To allow of being made a continuous lap joint rail, as shown in the drawing. The impossibility of a broken rail throwing a train from the track; or the breaking of a rail byunequalexpansioQ. Theformof the rail issuch that, even though it should be broken in a number of places, it would remain securely together. The greater the weight placed on it, the tighter will its joints fit together, as the an. jjular corner, x, along the center of the cap, will have a tendency to press in between the corners, 6, of the base, thus jwessing the upper edges of said pieces outward making the joints, c, d, e, and y, e, perfectly firm and tight. To be easily rolled and placed together, and to require no hand or other extra work on it, but to be finished when it comes from the I rollers. Also the repairing or replacing of a rail at much less expense and time than any in use, and the top can be turned around when worn on one side. While possessing all the good qualities of the steel and iron rail, it is cheaper and stronger than either, and there being no wear of the bases, they will last indefinitely. For further information address Geo. W. King, Georgetown, D. C. A Good Example. The Boston and Albany Eailroad Company have provided a library of a thousand volumes of reference and miscellaneous books, and have fitted up a hitherto vacant apartment in the second story of the Boston passenger station for their reception. The library is divided into two departments, styled the Consulting and Circulating. The first named comprises railway enactments, English and American, encyclopedias, reports, scientific works, etc., to the number of four hundred, which are never to be removed from the building, except by permission of the library committee. The circulating department embraces standard works of interest, instruction, fiction, bound volumes of the most valuable periodicals of past years, etc., five or six hundred in number. Any person in the service of the company on the line between this city and Albany is privileged to take books from this department, two at a time, and to hold them two weeks—the train baggage masters and station agents along the route transmitting them to and from the library on Tuesday and Thursday of each week. Wednesday being the library day for reception and delivery. How to Stretch Drawing Paper. The Building iVewsgives the following directions, which the writer says have been used successfully by him for fifteen years: Have your boards perfectly clean and dry, free from dirt, grease, or gum. Have your paper clean on both sides, as the wet sizing will fix pencil marks or dirt in the grain of the paper. Use gum arabic, dissolved in water, for mucilage. The mucilage should always be kept in readiness for use, and of consistency which will permit a ready application with a bristle brush. If too thin, it. will lack strength and be slow in drying, and if too thick, the properties will be the reverse. The remaining preparations are a clean sponge, bowl of clean water, napkin or towel, and a paper folder or similar in-strument- The tools and materials in readiness and within reach, we will proceed to strain the sheet. On a flat board,-with all parts accessible, lay the paper with the back up. Wet the entire back of the paper, including the edges. This must be done by passing the sponge over the surface rapidly, and but once, leaving it well moistened, but with out puddles or floating water. Wait a few moments until the first wash has been absorbed and distributed through the grain of the paper, and then apply a second wash in the same manner. As soon as the second wash has been applied, wipe the water and a part of the moisture from the outside edges and apply the mucilage. The paper should now be limpid, but not soppy. Turn the paper and place in position on the board. This operation is easily performed by taking hold of the paper at the two opposite corners with the thumbs and forefingers, catching the paper inside of the gummed edges, the thumbs being on the surface side. In raising the paper from the board, let it bag moderately, which will prevent the corners from dropping, and the same precaution will keep the paper in shaue during the operation of turning, and afterwards. The sheet turned, fix the same in position, first one comer, following up with one side and the whole sheet. The paper should now lie flat om the board, with the surface and edges evenly extended. Press the gummed edges to the board rapidly with the paper-folder, taking care to work the surplus gum outside the sheet and not under. Wet evenly the face of the paper with the exception of marginal edges about one inch wide. This last operation enables the gum to dry first. When dry, the sheet will be found clean and evenly strained, with smooth edges, and the sizingless disturbed than by any other method. A little practice will enable one to get the exact, tension desired, and one person can more readily perform the entire operation than two, even for such sizes as—DOUBLE ELEPHANT.