their chemical power, and that a compound may not be formed at a temperature which will decompose it. Hence the operator who causes hydrogen to pass over steel at too high a temperature, will not decompose the steel, because he uses a gas or a heat which renders the formation of ammonia impossible. Although it be admitted that the quantity of nitrogen in steel (not yet exactly determined) be very small, it does not follow that the proportions are without influence upon the properties of the compound. We know that an almost imponderable quantity of sulphur introduced into good Swedish iron renders it friable and injures its quality. By combining with gold a 10,000th part of bismuth or lead, it becomes brittle as antimony. Traces of lead or pewter modify entirely the properties of mercury. To demonstrate this theory of the formation of steel, and to show that its production is due entirely to the nature of the substance which acts upon the iron, and which must be nitrogen, the following experiment has been made:-A bar of pure iron has been cut into two equal pieces. One of these pieces was exposed for some hours to the action of ammoniacal gas. The two pieces were afterwards placed in one tube of porcelain and made red hot. After three hours, upon examination it was ascertained that the pure iron was transformed into cast iron, while the nitrogenized iron presented a deep and very regular cementation. Thus two pieces of iron, belonging to the same bar, were heated to the same temperature during the same time and under the same circumstances, but only the piece containing nitrogen had been converted into steel. ANDERSON'S FLUSHING APPARATUS. MR. R. ANDERSON, brassfounder, of Liverpool, has just patented some important improvements in apparatus, which has for its object economizing and regulating the flow and passage of fluids used for flushing water-closets, and relates more particularly to that class in which a small or intermediate cistern is used. M. Fremy claims, in conclusion-1st, Demonstrating the influence of nitrogen in steel-making by a series of original synthetical experiments. 2nd, He claims that he was the first to demonstrate that nitrogen was a constituent of all steel. 3rd, He has proved that nitrogen is always present even in those cases where it was supposed that steel was made without it; and when nitrogen is not present, or there is no substance which supplies nitrogen, the product does not present the qualities of steel. 4th, The melting pots employed in steel-making contain always enough of nitrogen for the forma in applying similarly constructed surfaces to stills, when the pressure is removed or the hand lift left tion of steel, even when they are covered with scoria. 5th, By causing hydrogen to act upon steel, under the conditions stated previously by M. Fremy, nitrogen is always obtained as ammonia; and all substances which act upon carbon as hydrogen does, will also deprive the substance tested of the properties of steel. 6th, The formation of steel depends upon the purity of the metal, the relative proportions of the substances containthe conditions under which their combination is ing nitrogen and carbon which are employed, and effected. At the conclusion of M. Fremy's paper, M. Boussingault stated the results of some experiments made by him at the Conservatoire des Arts et Métiers. A steel wire (42 grammes) exposed for two hours in a tube of porcelain red-hot to a current of steam deprived entirely of ammonia, gave 0.25 milligr. of ammonia, only 5 gr. of the steel used being oxydized. 13 grammes of steel, submitted to the same treatment for 8 hours, gave 0.5 milligr. of nitrogen, and the steel was partly oxydized. This steel, therefore, contained a very small quantity of nitrogen. It contained also sulphur, as M. Boussingault and M. Bouis had ascertained by the smell of the vapour and by chemical tests during the experiments. No conclusion, therefore, can be drawn from these last two experiments regarding the question-Is nitrogen a component part of steel? C. WYE WILLIAMS'S PATENT BOILER TUBES. A VERY important improvement in tubes for the generation of steam, and for cooling and refrigerating purposes, has just been patented by Mr. C. Wye Williams, of Liverpool. The object is to present to the current of hot gases, as it passes through the flues or tubes of boilers, a series of occurs. surfaces, which shall be so placed as to take up as likelihood of any deposit of soot or other matter Where there is a deficiency of water space, or of In the case of marine or locomotive boilers, the ordinary straight tubes are dispensed with, and in flues, of 4 or 5 feet in height, according to the depth their place is introduced a series of vertically-placed of the boiler, and about 3 to 4 inches wide at the narrowest part. Where flues or tubes are used, either for the purposes of evaporation or heating the feed water of boilers, and where they are placed in a vertical position, the projecting face plates may be made to occupy all sides, whether such plates or tubes be circular or angular. In such cases they may be represented by figs. 7 and 8, offering a larger area of face plate, A, A, being the passage for the heated current, and B, B, the face plate for the direct action of the heated matter. The arrangement hereinafter described can be operated by any of the methods at present in use, such as the pressure seat or hand lift, and prevents waste by a self-acting stoppage of the flow at freedom. The inventor prefers making the cistern of a for opening and shutting the supply tap. This tap shape, so that the float will have sufficient leverage is fitted through the side of the cistern, and is operated in the usual manner. The tap supports on a joint or pivot the operating balance, the one end of which passes over or through a slot or opening in pull, the other end is jointed with or coupled to the cistern, and communicates with the seat or hand three parts; the one nearest to the centre joint or pivot consists of a guide which passes round the float lever, the use being to shut the supply tap when flushing, thus preventing more than the quantity contained in the cistern from being used; the next in order from the centre joint or pivot is the discharge valve or flushing outlet arrangement, which is formed of a tube fitted with a properly ground valve to fit into a seating in the bottom of the cistern; the tube serves also as an overflow pipe; the third in order from the centre joint or vation. pivot is a balance weight fitted at or near to the end, and sufficiently heavy to close the valve. The above engraving represents a sectional elea shows the cistern; b, the float; c, the tap supporting the operating balance lever d; e, the guide; f, the discharge valve attached to and forming part of the overflow pipe g; h, the balance weight. The engraving shows the outlet or flushing valve closed and the supply tap partly open, but it will be seen that in the event of the lever d being depressed by a moveable seat or other contrivance, the valve ƒ will be opened to allow the flushing fluid to pass. The guide e keeps the supply tap shut whilst flushing by lifting the float b, and the water in the cistern is the only quantity that can be used at one time. The apparatus is therefore entirely beyond the control of the party using the closet, inasmuch as before any further supply than the quantity of flushing fluid contained in the cistern can be obtained, the hand lift, pull, pressure seat or other arrangement must be released, to allow the float to fall and turn on the supply tap. THE MANUFACTURE OF PAPER FROM INDIAN CORN, & JAPANESE PAPER. THE conversion of the fibres of Indian corn into paper has been proved by numerous successful experiments. The discovery is not, indeed, altogether new. In the eighteenth century it was worked with great success in Italy, but the secret died with the inventor. Fortunately, the secret has been re-discovered, not by a chemist, but by a young writing master, of Austria, named M. Moritz Diamant. At present Count Charles of Lippe-Weissenfeld is working the discovery. The principal advantages of this new manufacture are: first, it is possible not merely to make paper from the fibres of Indian corn, but, in several respects, this paper is superior to that made from rags. Second, only a very small quantity of size is required to render it fit for writing, proving that this material contains some natural ingredient easily separated from the other ingredients and which serves as a substitute for size. Third, the bleaching of the paper is done instantly by a very simple and effective process. Besides it is only slightly coloured, and when made into wrapping paper no bleaching is required. This Indian corn paper is stronger and more tenacious than paper made from rags, and has none of that brittleness of paper made of ordinary straw, and which is due to the large quantity of silica in the material. In the process invented by M. Moritz Diamant, no kind of machinery being needed to convert the fibres into pulp, and the conversion being effected by other means than those employed for rags, the manufacture is much simpler, easier, and cheaper. The manufacture of paper from Indian corn is established in Switzerland with good results. The fibres most suitable for the manufacture of paper are those which envelope the corn. Speaking of the Japanese, a writer in Blackwood's Magozine says:-" It was wonderful to see the thousand useful as well as ornamental purposes ence. up. If a shopkeeper had a parcel to tie up, he would take a strip of paper, roll it quickly between his hands, and use it for the purpose, and it was quite as strong as the ordinary string used at home. In short, without paper all Japan would come to a dead lock; and indeed, lest by the arbitrary exercise of his authority a tyrannical husband should stop his wife's paper, the sage Japanese mothers-in-law invariably stipulate, in the marriage settlement, that the bride is to have allowed to her a certain quantity of paper." A LIFE-BELT. AMONGST the machinery in use for affording succour to shipwrecked persons, not the least important article is a life-belt, or life jacket, as it is sometimes termed. A recent melancholy accident to a life-boat occurred, when 11 men out of 12 who formed her crew perished, whilst the only man saved, and who could not swim one yard, had on an efficient belt, has attached to the subject a certain amount of public interest. We shall be serving that interest by publishing a description and sketch of the life-belt worn by the fortunate survivor. Similar belts have for the last seven years been provided to their life-boats' crews by the National Life-Boat Institution. Various descriptions of belts have of late years been designed; but as all are not equally efficient, and especially as all are not alike adapted for the use of a person who must undergo great physical exertion with his belt on-such as rowing in a boat against a head sea-we will offer an observation or two on the qualities which we conceive a boatman's life-preserver should possess. 1st. It should contain as much buoyant power as would support one man, with his head and shoulders above the water, although he might be disabled by injury, or otherwise, from swimming; or as would enable a man, if a swimmer, to support, with ease, another person beside himself. 2nd. It should not be liable to lose its buoyant exposed-such as a heavy blow, or by absorption of water. 3rd. It should be of such a pliant, elastic, or to which paper was applied in the hands of these industrious and tasteful people. Our papier-mâché manufacturers, as well as the continental ones, should go to Yedo to learn what can be done with paper. We saw it made into material so closely resembling Russian and Morocco leather and pigskin, that it was very difficult to detect the differ-power by any accident to which it might be With the aid of lacker, varnish, and skilful painting, paper made excellent trunks, tobacco bags, cigar cases, saddles, telescope cases, the frames of microscopes, and we even saw and used excellent waterproof coats made of simple paper, which did keep out the rain, and were as supple as the best macintosh. The Japanese use neither silk nor cotton handkerchiefs, towels, or dusters; paper in their hands serves as an excellent substitute. It is soft, thin, tough, of a pale yellow colour, very plentiful, and very cheap. The inner walls of many a Japanese apartment are formed of paper, being nothing more than painted screens. Their windows are covered with a fine translucent description of the same material. It enters largely into the manufacture of nearly everything in a Japanese household, and we saw what seemed balls of twine, which were nothing but long shreds of tough paper rolled soft nature as to conform readily to the shape of the body, and not to prevent the free use of the arms and upper part of the person, or to confine the chest, so as to impede the action of the lungs, on which capability of enduring prolonged exertion or fatigue much depends. It seems to have been generally supposed that the least possible amount of buoyancy which would suffice to raise the mouth above the surface of the water was all that was required, and, accordingly, many of the belts which are sold in the shops have only buoyant power equal to 6, 8, or 10lbs. A little consideration will, however, make it apparent that the largest amount of buoyancy which can be obtained without seriously in commoding the wearer, and depriving him of the free use of his limbs, is no more than is requisite. We believe that a life-belt for an adult person, of average size, ought to have, at the least, buoyant power equal to 20lbs., and as much more as can conveniently be obtained. The belts, as used by the crews of the life-boats of the Royal National Life-Boat Institution, and invented by Captain J. R. Ward, R N., its inspector of life-boats, have much greater buoyancy than any kind of cork belt previously introduced; and have other important peculiarities. 1. Their buoyant power is from 20 to 24lbs.* 2. The cork is uncovered, so that its quality can always be discerned, and it is divided into many narrow pieces, each of which is separately sewn on to a strong linen or duck belt, covering the body from the arm-pits to the hips. 3. These pieces of cork are distributed in two rows-one above and the other below the waistthe belt being secured closely about the body by strings passed round the waist, between the two rows of cork, and being further secured by other strings crossed over the shoulders, as men's trowser braces are worn. This division of the cork into two rows is one of the most important distinctions of these belts, as a sufficient quantity of cork to afford double the buoyancy of the ordinary cork belts can be thus attached, and in a manner which is much less inconvenient to the wearer than the lesser quantity in one row, which, not being secured round the waist, but round the chest, interferes with the free action of the lungs, and the muscles of the shoulders and arms. By this arrangement in these belts the wearer is enveloped in cork, so attached as to be perfectly flexible, and to allow of all the ordinary movements of the body without inconvenience, whilst it affords great protection to the body against injury from a blow. We consider it would be a great boon to the merchant seamen of our country if every merchant vessel were to have on board, and stowed in a chest on deck, as many of these belts as formed the number of her crew, so that in the event of having to desert their vessel from wreck, leakage, collision, or fire, and take to their boats, each man might be supplied with an apparatus which, as it would make it impossible for him to sink, would, doubtless, be often the means of saving his life. ASSOCIATION FOR THE PREVENTION OF STEAM BOILER EXPLOSIONS. Ar the last ordinary monthly meeting of the Executive Committee of this Association, W. Fairbairn, Esq., C.E., F.R.S., in the chair, Mr. L. E. Fletcher, Chief Engineer, presented his monthly report, from which we have been furnished with the following extracts: During the past month 210 visits have been made. 556 boilers, as well as 407 engines have been examined, and the following defects discovered. Fracture, 11. Corrosion, 18 (two dangerous). Safety valves out of order, 33. Water gauges out of order, 15 (one dangerous). Pressure gauges out of order, Blow-off cocks out of order, 11. Fusible plugs out 10 (one dangerous). Feed apparatus out of order, 3. of order, 1. Furnaces out of shape, 18. Deficiency of water, 3. Boilers without safety-valves, 1 (danger ous). Total, 124 (five dangerous). Boilers without glass water gauges, 10. Without pressure gauges, 2. Without blow-off cocks, 32. Without feed-back pressure valves, 26. One boiler was found to have its safety-valve placed between the stop valve and engine, instead of directly on the boiler, so that if at any time the stop-valve should become closed, and accidentally held fast, either by the gland, or other cause, the communication between the boiler and its safety-valve would be entirely cut off. Three boilers have exploded during the past month, neither of which, however, was under the inspection of the Association. These accidents have been attended with loss of life, as well as serious injury to several persons, and considerable damage to property. I examined the scene of the explosion of one of these boilers, the day after the accident had occurred, *To test its buoyancy, attach a weight equal to from 20 or 24lbs., which it will be found to sustain. and found that the ruin to the engine and boilerhouse, as well as to the chimney, was absolute, the bricks being scattered like grape-shot in all directions. One half of the boiler had been blown nearly one hundred yards from its bed, and the remainder torn into as many as eight pieces, which were scattered more immediately around its original position. The cause of the explosion was obvious, the plates had been so reduced in thickness by corrosion, that, although originally 7-16ths of an inch in thickness, they had become in places literally no thicker than a shilling, and although the bursting pressure of this boiler would not have been less than 400lbs. on the square inch-had it been in good condition-it was so weakened as to explode when working with steam at somewhere about 25 or 30lbs. The dangerous condition of this boiler would at once have been apparent upon internal inspection, and none should be worked for any length of time without this, since corrosion is often in action when least suspected. THE BOILING-POINTS OF DIFFERENT LIQUIDS. THE laws relating to the boiling-points of different liquids at the ordinary pressure of the atmosphere have lately been investigated by Mr. Tate, and the results of his experiments are published in the last number of the Philosophical Magazine. He has made experiments with solutions containing the chlorides of sodium, potassium, barium, calcium, and strontium; the nitrates of soda, potassa, lime, and ammonia; and the carbonates of soda and potassa. He has found for all these salts that the augmentation of boiling temperature may be approximately expressed in a certain power of the percentage of the salt dissolved. The salts enumerated may be divided into four distinct groups; namely, first, the chlorides of sodium, potassium, and barium, and the carbonate of soda; second, the chlorides of calcium and strontium; third, the nitrates of soda, potassa, and ammonia; fourth, the carbonates of potassa and nitrate of lime. In each of these four groups, the augmentations of boiling temperature of the solutions have a constant ratio to one another for an equal weight of salt dissolved. He has also ascertained by experiments that for an equal weight of salts, the boiling temperatures are (approximately) in the inverse ratio of the chemical equivalents of their bases, and in the case of the nitrate of lime and the carbonate of potassa with the equivalents of the entire salts. Although the law thus indicated is not strictly true, it is sufficiently exact to warrant further inquiry, and the cases in which it is found to apply are too numerous to be referred to accidental coincidence. Future researches may extend these laws to other substances, as it is quite consistent with analogy to suppose that the chemical composition of a substance affects the boiling temperature of its solution. It will readily be acknowledged that the prosecution of these experiments may throw additional light upon the generation of steam, the economy of fuel, and kindred questions of great practical importance to engineers. PERATURE. temperature is highest, the difference sometimes of warm air ascending during the night, and in the country. A Literature. Rudimentary Treatise on the Acoustics of Public Buildings; or, the Principles of the Science of Sound applied to the purposes of the Architect and Builder. By J. ROGER SMITH, M.R.I.B.A., Architect. Illustrated by Twenty Engravings on Wood. London: John Weale, 59, High Holborn. 1861. In this manual, of 155 pages, Mr. Smith has embodied the latest and most reliable information accordance with the principles of the science of regarding the construction of public buildings in sound. After a brief, but comprehensive, introconsiders its application by the architect. First, duction upon the science of acoustics, the author he considers three general maxims-viz., 1st. Buildings always modify the normal diffusion of the diffusion of sound;-3rd. Buildings may sound; 2nd. Buildings may present obstacles to afford auxiliaries to the diffusion of sound. The obstacles and the auxiliaries to sound being the most important part of the science of acoustics to architects, are considered fully. Under the class of obstacles are ranged the decay, or naturally diminishing strength, of sound; its absorption by large unoccupied spaces, and by soft, dull substances; its obstruction by intervening obstacles THE WRECKS ON OUR COASTS.-Last year was and adverse currents of air; its reverberation, almost unprecedented for a continued succession of owing to defects in the proportions or form of bad weather, and the number of wrecks and casualties the building, or to the dampness of the walls, on and near the coasts of the United Kingdom was 146 above the annual average for six years. spaces above the ceiling, below the floor, or There beyond the walls; and echo, the causes of which, loss, in all, 1,379, the vessels being of 215,000 tons were 541 involving total loss, 838 involving partial in many instances, have not hitherto been satisburthen, and employing 9,816 hands. At least 368 factorily explained. The auxiliaries to the proof these wrecks and casualties occurred through inat-pagation of sound are numerous, but may be tention, carelessness, or neglect, and another hundred classed under three divisions-namely, resonant from defects in the ship or equipments. The loss of bodies, reflectors, and conductors, of which the 817 of the vessels, and on 258 of the 1,095 cargoes, violin, the speaking-trumpet and the reflector, was estimated at £603,065; only 514 vessels and 57 are well-known examples. cargoes were reported to be insured, 280 vessels and 145 cargoes were reported to be insured, and as to the happily there were no cases like those of the Pomona rest the fact was not known. 536 lives were lost, but and Royal Charter, in 1859, when 870 lives were lost in two casualties alone; and, in fact, the loss of life in 1860 was 264 under the average of the last nine years. 1,383 lives were saved from shipwreck by assistance rendered from the shore-viz., 326 by lifeboats, 408 by rocket and mortar apparatus and ropes, 635 by coastguard boats, luggers, and small craft, and 14 by individual exertions. The Board of Trade expended 5,861 during the year in providing and maintaining lifeboats, rockets, and mortars, and rewarding services happened to ships of the collier class; but the greatest at wrecks. As usual, more than half the casualties loss of life is not on our north-east coast, but in those seas and channels which are most frequented by large foreign-going ships, especially in the district from Skerries and Lambay to Fair Head and Mall of Cantire, where 1,456 lives have been lost in the last eleven years. It is remarkable that the greater portions of and under 8 ("fresh gale "), or under circumstances the casualties happen with the force of the wind at in which a ship, if seaworthy, and properly manned and found, ought to be well able to keep the sea.Times. PHOTOGRAPHIC SCULPTURES. For some time THE INFLUENCE OF TREES UPON TEM- past rumours have circulated of a marvellous application of photography to sculpture, made by a young Belgian artist, François Willême by name, which, in M. BECQUEREL has lately read, before the French the absence of full particulars, was looked upon with Academy of Sciences, a paper regarding the influ- doubt and suspicion, as seeming impossibility was inence of trees upon the mean temperature of the volved in it. Nothing more nor less than the actual atmosphere. From experiments, made with an production of statues, &c., by the agency of photoordinary thermometer and two electric thermome-claimed for this new discovery or invention. At first graphy, without the aid of the sculptor's hand, was ters in the Jardin des Plantes, he ascertained that sight this proposal would really seem to involve a 0° 63 C. represents the heating of the air from the contradiction, as two arts, based on entirely different action of the sun's rays, 11° 53 C. being the mean principles and methods, were ostensibly combined in annual temperature ascertained by the electric therone. For how could it be supposed that by any mometers, and 10° 90′ the mean temperature with graphic process whatever a plastic work could be an ordinary thermometer placed facing the north. obtained, seeing that one produces its results on a One electric thermometer having been placed above plane surface by means of light and shade, and the a horse-chestnut tree, and the other in the middle other by relief? However, M. Willême appears to of an open plain, it was ascertained that the mean have solved this singular problem, and the results, temperature of the atmosphere above the tree, the pronounced by competent authority to be unexcepthermometer being exposed to radiation from it, tionable, are now before the public. He claims to have demonstrated that, by the aid of photography, he can was only o° 23' C. above the temperature in the open produce sculptures from nature, from the living space, and 0° 86' above the temperature of the air as shown by a thermometer with a northern exposure. enlarged, sculptures of the same size as the model, or model, from the inert model, from microscopic objects Comparing the observations made at different hours enlarged or diminished, grotesque sculptures, and bas of the day, it was found that about 3 P.M., when the or alto-relievos.-Photographic News. The practical application of the principles stated is illustrated by descriptions of a few buildings celebrated for their good qualities, such as some of the ancient Greek and Roman theatres, and the excellent imitation of them in the theatre of the Royal Institution in Albemarlestreet; also our Law Courts, which are generally defective, many of them being cubical, which is the worst of all possible forms for speaking and hearing. The application of these principles to churches and large halls for music, &c., such as the Manchester Free Trade-hall, the Surrey Music-hall, the Metropolitan Tabernacle of Mr. construction of large buildings, like those menSpurgeon, deserve the notice of builders. In the tioned, and, indeed, of all structures for similar purposes, we must be guided chiefly by our past experience, for no laws or principles can be laid down which will render it unnecessary for the architect to proceed with care, judgment, and adapted to qualify architects for this department tact. The study of the present manual is wellof their profession, and we recommend it te their notice as one of the best manuals in Mr. Weal's excellent rudimentary series. The work, though small, will be found more comprehensive than any other in the English language, regarding the acoustics of public buildings. THE RATTAN CANE TELEGRAPH THE novelty in this new telegraph cable consists It has been found by experience amongst the Eastern nations that the cane is not affected by sea-water when thoroughly submerged. It grows in vast luxuriance in immense tracts of country throughout Bengal, Burmah, China, Ceylon, and the Islands of the Eastern Archipelago. It is to a great extent a non-conductor of heat; no risk is to be apprehended from the insulating media becoming overheated in the hold of a vessel, as it unquestionably does where the covering is metallic. The abundance of the material, and its low price, render the use of the cane an important consideration where thousands of miles are to be manufactured. In aerial telegraphy it will also take its place, as the cane rope can be strained quite taut, and will resist the burning rays of the sun in hot climates, and also resist the influence of heavy winds and the corroding action of atmospheric changes, instead of depending upon materials that are constantly rotting and requiring a heavy annual outlay in repairs. It is stated in Royle's work on Indian Botany, that in "China, as also in Java and Sumatra, and indeed throughout the Eastern Islands, vessels are furnished with cables formed of cane twisted or platted. This sort of cable was very extensively manufactured at Malacca." The species employed for this purpose is probabably the Calamus Rudentum of Lorireiro, which this author describes as being twisted into ropes in these Eastern regions, and employed, among other things, for dragging great weights and for binding untamed elephants. And Mr. G. Bennet, in his "Wanderings," says he remarked some Chinese making ropes. "The rattans were split longitudinally, soaked, and attached to a wheel which one person kept in motion, whilst another was binding the split rattans together, adding others to the length from a quantity round his waist, until the required length of rope was completed." EDGE'S IMPROVED STEAM-ENGINE. MR. J. EDGE, of the Tipping Iron Works, Boltonle-Moors, has just patented certain improvements in steam-engines, which are chiefly applicable to direct-action compound steam engines, and consists in the first-place in an improved arrangement of the valves and passages by which the steam is conveyed to the high-pressure cylinder, from the high to the low pressure cylinder, and from thence to the condenser. The steam is admitted to the high-pressure cylinder through passages in the valves, the opening of which passages is varied by means of expansion valves actuated by hand, or by the action of the governor on a plate furnished with shoulders, the said plate being drawn to and fro according to the load on the engine, and thereby giving more or less opening to the passages in the valves, Fig. 1 is an elevation in section of part of a direct-action compound steam engine to which these improvements are applied; figs. 2, 3, and 4, are detached views of the improved wedge-shaped valve, fig. 2 being a view of the face for the highpressure cylinder; fig. 3, the cut-off steam valve face; and fig. 4, the face for the low-pressure cylinder; fig. 5 is a detached view of the cut-off or expansion valves; and fig. 6 is the valve box. In fig. 1, a is the high-pressure cylinder, and b, the low-pressure cylinder, both of which are furnished with pistons, connected in the usual manner to the crank shaft, or to the beams of the engine; c, the upper passage, and d, the lower passage, for conveying the steam from the valves e to the high-pressure cylinder; and f, f, are prolongations of the passages c and d, for conveying the steam from the high-pressure to the lowpressure cylinder and from the latter to the offpipe g, which is in communication with the condenser. The valves e are wedge-shaped, and they are connected together so as to act simultaneously by the stem or rod; to the upper end of the valve is connected a rod, which has the requisite to-andfro motion imparted to it by an eccentric or cam in the usual manner. The steam from the boiler enters the steam chest h through a pipe, and the quantity of steam admitted to the valve e is regulated by the cut-off or expansion valves i, which are fixed to a spindle. These valves are moved to and fro by their friction on the face of the valve e, and their traverse is varied by hand by means of lock nuts, or by means of the governor. The ports in the valves e convey the steam to the passages c and d, and thence to the high-pressure cylinder; the ports / in the valves e form alternately part of the direct passage for the steam from the high to the low pressure cylinders, and the ports in the valves e are alternately opened to the passages f, f, to convey the steam from the low-pressure cylinder to the off-pipe g, and thence to the condenser. The mode of operation is as follows:-High-pressure steam is now supposed to be entering the upper part of the cylinder a through the upper port and passage c, while the steam under the piston is passing through the passage d, lower port, and passage f, to the lower end of the cylinder b, at the same time the steam above the piston is escaping along the upper passage and off to the condenser. As soon as the pistons arrive at or near the end of their strokes, the position of the valves e is reversed, and the steam then enters the cylinder a through the lower port and passage d; at the same time a direct passage is opened for the steam above the piston to enter the cylinder b. The cut-off valves i are held against the face of the valves e by the pressure of the steam, and move to and fro with the said valves until their motion is arrested by the lock nuts; consequently, by increasing or di minishing the distance between the lock nuts, more or less traverse is given to the cut-off valves, and the amount of steam admitted to the highpressure cylinder is thus regulated. Another part of this invention consists in an improved reversing motion applicable to marine and locomotive engines; the eccentric for working the valves is loose on the shaft, and to it is fixed a bevel wheel gearing in a pinion loose on a stud fixed to the shaft; this pinion gears in a wheel which is also loose on the shaft; this wheel is connected to a friction apparatus by which it is turned partly round when required, so as to change the position of the eccentric, and thereby to reverse the motion of the engine. GARDNER'S PAPER MACHINERY. THIS invention relates to a peculiar construction and arrangement of apparatus commonly known as the "knotter," for straining the pulp used in the manufacture of paper, and consists in the employment of a vessel or vat, in the interior of which is a strainer having the perforated or straining surfaces in a vertical position. These surfaces are combined with closed ends, so as to form a hollow receptacle with slotted sides, and is connected to a vibrating or rocking shaft, which receives a constant oscillating or vibratory motion by any suitable mechanical contrivance. A diaphragm of vulcanised india-rubber, leather, or other suitable material serves to connect the upper edge of the vibrating strainer with the sides of the vessel or vat, so that, whilst perfect freedom of vibration is allowed to the strainer, all communication between it and the vat is closed, excepting through its perforated or slotted sides. The pulp after leaving the "stuff chest" enters the "knotter" vessel, and percolates through the perforated sides of the strainer, after filling which it flows over the edge in a fit state to be manufactured into paper, the knots or other refuse matter retained in the vessel being removed at intervals when requisite. In the feed pipe which supplies the pulp to the vessel, it is proposed in some cases to fit a self-closing valve, which will act in such a manner that when the strainer is vibrated it will effectually prevent or check the tendency which the pulp may have to flow back or rise in the feed or supply pipe. In order that the invention may be better understood, the annexed engravings are given. Fig.1 represents a longitudinal vertical section of the "knotter;" fig. 2 is a corresponding end elevation; and fig. 3 a vertical transverse section. A is a stationary vessel or vat, and B the vibrating or oscillating strainer connected to the overhead rocking shaft C, working in bearings D, secured to the ends of the vat A; E is the perforated or openwork side of the vibrating strainer; and F, F, are the closed ends which unite the two open sides and form a rectangular box. A rock ing motion is imparted to the shaft C, by means of the lever arm G, connecting rod H, and slotted disc and crank pin I, disposed at each end of the apparatus. The two discs I, I, are carried by the driving shaft working in suitable bearings carried by the standards L, L, and provided with a fly-wheel M, a rotatory motion being imparted to this shaft by means of a strap passing over the driving pulley N. O, is an india-rubber or other suitable flexible diaphragm, which connects the edge of the vibrating strainer with the edge of the stationary vat, and prevents all communication between the two, excepting through the perforated sides of the strainer; P is the bottom of the strainer, which is formed with flanges, to which the perforated sides are secured. The outer vat or vessel A may be supported on standards Q, Q. The pulp to be strained is fed into the vat A, through the pipes R, R, each pipe being supplied with a self-closing flap valve S, S, for checking the backward motion of the pulp in the pipes when the strainer vibrates towards them. The strained pulp passes through the perforated or openwork sides of the strainer, and flows over the edge thereof by the overflow spout T, to the paper-making machine. U is an aperture in the bottom of the vat A, provided with a hinged or other suitable lid or cover packed with indiarubber, to facilitate the emptying of the vat when required; V, V, are holes in the ends of the vat, for the purpose of enabling the perforated or open work sides to be cleared of knots or obstructions adhering thereto. LORD ASHBURTON's second reception as president of the Royal Geographical Society for June 5th is unavoidably postponed, limited to that amount. The consequence was a suspension of the works. In the meantime everything was done by the officers of the company to promote its interests, and at the time of its suspension the chief engineer wrote to say that he had no reason to doubt the sufficiency of his estimate for the completion of the whole work (£1,000,000), and would at once proceed with the first section. The directors, in closing their report, said that, convinced that it was for the interest of the shareholders that the company should not be precluded from completing the entire work, and finding all their efforts to secure the desired guarantee fruitless, they attempted to obtain the sanction of the Secretary of State to the following:"That so much of the whole Toombuddra scheme as could be properly separated from the rest so as to form a distinct and complete work, though capable of improvement by being added to the remainder, and which might, according to reasonable expectations, be constructed for £1,000,000, should be considered as the work to be carried out by means of the existing guaranteed capital, and that the company should be at liberty to reduce the portions so selected if during progress it should appear that the estimate could not be maintained; that the company should be entitled to raise such further capital as might be required to construct the remaining portion without a guarantee of interest, and upon the understanding that the whole profits derived from the works constructed with such unguaranteed capital should belong to the company." In this attempt, however, they were unsuccessful, and they were still engaged in endeavouring to arrange the terms upon which further capital may be raised if required. Accounts of receipts and expenditure were appended to the report. Proceedings of Societies. ROYAL INSTITUTION OF GREAT BRITAIN. Friday, March 15, 1861.-Sir Henry Holland, Bart., M.D., F.R.S., in the chair. ON ELECTRICAL QUANTITY AND INTENSITY. BY THE modifications of the strength of the electric current in dynamic electricity, and in the amount of charge in static electricity, are at present usually defined by the terms quantity and intensity. The speaker pointed out that the expression intensity, as ordinarily understood, really involved two perfectly distinct qualities, and dwelt on the advantage which would accrue to electrical science by the habitual separation of the complex idea of intensity into its two component parts, viz., that of tension, as propounded by Ohm, in his celebrated mathematical investigation of the galvanic circuit; and that of quantity, as developed by Faraday, in those valuable researches in which he established the definite quantitative character of electro-chemical decomposition and the action of electricity on the galvanometer. The term "tension," as here used, is intended to convey the same idea as the expression "electromotive force," or as the term "electric potential," employed by Green and other mathematicians, and is entirely disassociated from the idea of quantity; both terms are equally applicable to electricity at rest or in motion. The quantity of electricity, both in its static condition and in its motion through conductors, usually varies directly as the tension, and hence their joint effects have been ordinarily confounded together and attributed to one cause, under the name of intensity; but since the tension and quantity do not, under all circumstances, cessity for their clear separation before any numerical vary in the same ratio, there exists an absolute nereasoning can be founded on them. Cases of the independent variation of tension and quantity were shown, and it was pointed out that all the most striking properties of electricity, such as the decomposition of water and salts, the combustion of metals, the deflection of the galvanometer, the attraction of the electro-magnet, and the physical effects of the current were really dependent, as regards their magnitude and energy, solely on the quantity of electricity passing. Their greater energy when the tension tension, but to the increased quantity which passed in was increased, was an indirect effect, due not to that a given time by reason of the increased tension. A galvanometer wound with a few turns of thick wire was shown to be deflected as powerfully by one cell as by six, or even by 600 cells of the same size, because by reason of its shortness the wire conveyed freely the whole quantity which one cell could produce which was the same as that produced by the whole 600; but any alteration in the size of the cell pro duced a consequent change in the quantity and in the deflection of the galvanometer. On the other hand, a |