washing his hands, however, with very weak nitric acid, and afterwards with water, he obtained more power on squeezing his hands than he had ever done during the most persistent east wind. This led to an explanation of the phenomena as one due to chemical action alone, the act of squeezing the hand violently forcing some perspiration out of the pores. By dipping one hand in a solution of ammonia and the other in one of nitric acid, and then washing both in water, squeezing either hand produced a current in the same direction; and when both hands were placed in the water and a little THE USE OF GLUE. most delicately-operating implement. The hair of his neighbours; but, as a rule, the main prin- acid dropped on one of them, a current was in. A CORRESPONDENT writes to the Coach engine building, and realized an economy in work stantly generated without any muscular exertion. Mr. Varley finds no evidence that electricity exists in or about the human body, either as a source of motive power or otherwise; and would explain all the feeble electricity which has been obtained from the muscles as due to different chemical conditions of the parts of the muscle itself. The nerves are bad conductors, and are not insulated. The force which is transmitted by them cannot therefore be electricity; and the fact that this force is transmitted at a rate about 200,000 times slower than an electric current, is additional proof of their nonidentity. It is to be hoped that a detailed account of Mr. Varley's experiments on this interesting subject will soon be given to the scientific world. A REMARKABLE GEOLOGICAL DISCOVERY. to belong to, of philadelphia, is working up the makers' Journal as follows:-"To do good FLUTING AND FLAT IRON. T of a combined futing and flat iron, in- So far, the investigations have disclosed 22 vertebrates, 5 insects, and 10 or more plants. Among the animals are the following: A large sloth, with gigantic claws, called by Jefferson the Megalonyx; a mastodon, with a tusk 11ft. long; a bear, fully as large as the grizzly bear, but entirely distinct in character from all existing species of North America and the northern regions of the old world, as well as from the cave bear; a tapir, a horse, a wolf, and other skeletons not yet described. Further developments will be looked forward to with great interest. MANUFACTURE OF HAIR-CLOTH IN HE Exchange, an American journal, says:-At factory for the manufacture of hair-cloth, for the covers of sofas, chairs, &c. The hair used is that of horses' tails, and is imported from South America and Russia-mostly from the latter country. It is purchased at the great annual fairs of Isbilt and Nijni Novgorod. That purchased in June at the latter place will be received in about sixty days; and that bought at Isbilt in February in about six months. As it comes of various colours, it is, for the purpose of this manufacture, all dyed black. A certain proportion, however, is purchased in England and France, already prepared for the loom. It is worth from fifty cents to four dollars per pound, according to length, the price increasing in rapid ratio after the length attains 24in. The "rough hair," or that which is imported in its natural state, is hackled, and the shortest sold to the manufacturers of mattresses, it being first curled. After being hackled, the different lengths are combed out, assorted, tied in bunches, and made ready for colouring. After this process, the bunches are carefully inspected, measured, and put away for the loom. The cloth is made in widths of from 14in. to 32in. Contrary to the popular idea, the hair is not, as a rule, round. A section under the microscope shows a form as though a third of a circle had been cut off, and the flat portion slightly indented. This conformation caused some difficulties in the manipulation, which required great skill and the most delicate machinery to overcome. The warp used is made of cotton, and prepared with great care. A bunch of hair which has been soaked in water is placed in position, and the individual hairs are picked up, to be by the shuttle laid carefully in the weft. If the machine fails to take a hair, which ccasionally happens in practice, it continues ts efforts until it succeeds, the other portions of the machinery standing still in the mean ime. The shuttle is an awkward-looking, but FIGI pivoted together at A. When closed, these parts The engineering inspector or adviser, when in charge of extensive steam power on land or sea, exercises great power and influence in reference to steam engine improvement. In too many cases he has, by prejudice and defective training, delayed the introduction of improvements to such an extent that the amount of loss his employers have incurred thereby is quite incalculable. How long some steamship companies opposed the introduction of surface condensation is well known, and with reference to some other changes, such as steam jackets, they are now rather permitted than encouraged. If any one had the courage to record the engineering history of some of the large steamship companies, the facts would be beyond belief. It is sincerely to be hoped, in the interests of true steam engineering, that with the new era of steam engine economy, a more progressive spirit will be infused into those who advise the large steam users on land or sea. One other class of men must be referred to as exercising an influence on the rate of progress in steam engineering. The engineer in charge of steam power is sometimes the only authority the steam user consults in judgment either on alleged umpovated, occasionally not even a mechanie by improvements or new machinery. Partly or wholly trade, property is wasted, and changes are obisting, and yet these men, in the case of a steamjected to, in direct proportion to the ignorance exship, may have the spending of from 3,000 to 10,000 tons of coal per annum, and have the power in their own hands of obtaining an efficiency that may save or lose their employers thousands of pounds yearly. The grossest ignorance of the elementary principles of steam-engine economy can only be inferred when men deliberately prefer low pressure and a minimum expansion to high pressure and a maximum expansion. On the other hand, in what may be termed all the obstructive classes, highly able and intelligent men are found, who are open to conviction, and give every possible assistance to the improver. It is important, in alluding to steam engineering, to separate the creation of power in the boiler from its application in the engine; and it is the more so in the present case, as the progress of improvement has been so much less in the former than in the latter; and not only so, but evaporative duty has, in marine engineering, been actually lessened by the introduction of the compound engine and higher pressure. On land and sea the purchase cost of a steam horse power has increased during the past twenty years from 20 to 30 per cent., the pressure has increased 50 to 500 per cent., while the weight of fuel per each horse power has been reduced from 7lb. to 24lb.; and if we take the past ten years only, a pound of coal now develops twice the power it did in 1861. Successful steam engineering does not mean For light laundry purposes this implement will merely the production of an engine economical in answer a good purpose, and take the place of ex-working, but the production of one at a cost that pensive machines, where rapidity in the performance of the work is not a desideratum. STEAM ENGINEERING. The other three classes may, and sometimes do, shall be remunerative to the purchaser. That the improvement previously named is of this character in marine engineering is easily proved. In 1861, marine engines of 400 indicated horse power could be purchased in the north for £3,500, requiring 44lb. of coal per each horse power; in 1871, the same power can be purchased for £4,500, requiring 24lb of coal for each horse power. Such engines would average at least 200 days' steaming each year, and allowing 20s. per ton for the coal saved and additional cargo-a very low estimate-the owner will receive nearly £2,000, or 200 per cent. on his extra purchase outlay of £1,000, while assuming the value of 1861 ship and engines to be £16,000, and those of 1871 to be £17,000, and the first ship just cleared her expenses, the saving in fuel alone would give a dividend of nearly 12 per cent. on the capital of the second and higher priced ship. This great reduction of fuel, and the certainty that a large margin is left for further saving, gives a most encouraging prospect of the future of steam navigation; while a saving that is important in short voyages, becomes a gigantic profit on long ocean routes, when coal is £2 or £3 per ton and freight the same. HOSE of our readers who have followed us be curved and have a curved batter or face simi represented by the straight line C B, or may TE so far, will perceive that we have concluded lar to that indicated by the curved line CDB. the description of the preliminary operations in Let us investigate these different lines of wall connection with preparing the ground for the faces a little in detail. Except for walls poss erection of the dock proper. We have now arrived at the constraction of the walls or of the ing comparatively a very insignificant height dock itself, and we would here remark that, fore we may consider that walls built with a fa they are rarely made perpendicular, and thes to the particular class of wet or floating docks, for the construction of dock walls. The tw although we have hitherto confined our attention as represented by the line A B are not admissi yet much of what we have described will be also lines or forms in which dock walls may be erud therefore, of the other descriptions we shall curved one C D B in Fig. 12. Of these two the applicable to dry or graving docks. In treating. are shown by the straight line C B and the avoid recapitulation, and merely notice the es- former presents some facilities in actual constr pecial features belonging to each separate class. tion over the latter. As the batter is unie made for a wet or a dry dock, for, cæteris paribus, the wall to be of that material, but the curve Evidently it is immaterial whether a dam be one template serves for all the stones, suppo the object is the same, viz., to lay dry a certain batter CDB is theoretically superior to of the walls will differ, yet the same general given to the best specimens of dock walls. Its area for excavation. Similarly, though the form straight one C B, and is the contour stay principles apply to all. What will make bad served it as having a slightly raised elliptical in-work in one instance, will do the same in the a little more troublesome to work than the other, terior, which, with the depression itself, is well others. The size of the dock must be regulated since it does not consist of one curve but the seen on De la Rue's photogram of February 22, according to the number and tonnage of the ves- quently has two or three or even four ma 1858, but is given indifferently by Lohrmann. Í also record "a small crater near the summit of sels it is intended to chiefly accommodate. As separate portions according to their respective the raised portion," and remark that the border safe rule it may be stated that a wet dock is given to the face of the wall upon the principle height above low-water mark. This curved ister of Triesnecker is lower on the north. "The having an area of ten acres will hold one hun- that the pressure of a mass of fluid upon any surface of the Sinus Medii slopes gently towards dred square rigged vessels, and so on in propor-mersed surface varies with the height of the a rugged region in which Rhæticus, and a fine tion. In mentioning the principal points to be mountain chain on the S.W., are situated; and it is on this gently-sloping surface that the clefts occur." When viewed under a suitable illumination, and as seen on De la Rue's photogram, Triesnecker appears as a crater opening on the summit of an elevation of moderate slope, with a depression on its N.E. side. This elevation is situated between two very rugged tracts, Triesnecker being equidistant, or nearly so, from each; indeed, the whole region appears as a distinct and individualized formation. The most remarkable features to notice arefirst, the depression in the border of the crater in the north; second, the occurrence of Gaudibert's three craterlets on the north-west. I have placed In consequence of the readiness with which the them in the engraving between the border and straight batter walls could be built, it will be Mädler's cleft, which he gives as unconnected tude and direction the rate of the current per expected that the older examples of docks with the crater. In my sketch of January 4, 1865, hour, and let CD be equal to the rate at which constructed in this manner, and so we find the this part of the great ramifying cleft joins the a vessel can be worked or hauled in or out of to be. Fig. 13 represents the general festures border, indicating that the crater is the origin of the dock; then the line CB represents the di- the wall of the old dock at Hull, which has since the system. M. Gaudibert does not give this rection, or as it is called the set of the entrance. been destroyed to make room for a more moder portion of the cleft, so that it is uncertain as to Attention to this rule in laying out the entrance successor. Previously to its destruction it had whether his craterlets coincide or not with the to a dock has been practically demonstrated to betrayed many and unquestionable signs of weak cleft which had been observed independently by be imperative, for if neglected it will sooner or ness, particularly in the foundations, which is t the Rev. T. W. Webb, who obligingly pointed out later occasion disastrous consequences. Both to be wondered at, considering the peculiar less to me its existence between the N.W. border of the East India and London docks have their en- that were carried out in the shape of the piles Triesnecker and the bifurcation of the two main trances arranged in conformity with these require- Instead of being made of a uniform section branches, and which I observed on January 4, ments of the theory, but the West India docks throughout their entire length, their top dir 1865; third, the two great branches of the cleft, have not, and a large amount of damage and loss sions, which were 12in. by 9in., were reduced by two arms running to the southward and two to- has been the result. a regular taper to 3in. square at the bottom, wards the north. It is to be remarked that the All retaining walls in whatever situation they where the shoes were fixed on. The inner square point of divergence of the main branches lies in a may be placed, are designed and constructed upon in Fig. 14 shows the shape at the bottom; the crater line; and I have a record that "at the the same principle. They have all to resist a outer lines representing a plan of the top. The point of division into the two main branches there pressure from behind tending to force them for consequence of this peculiar method of diminish is a slight depression not unlike Hyginus in mini-ward, whether by causing them to slide upon ing the strength of the timber where it was atnre. There is also another depression of the their joints or to move bodily outward. Dock required was, that the piles were little better same kind at the point at which the S.W. branch walls, when the water is let in, derive a support mere sticks for nearly half of their length totally unequal to perform their proper duty. It is difficult to comprehend how so great a waste of material should have been allowed to occur. Had there been any saving effected by the plan there would have been some little excuse, but not only was timber, but labour likewise wasted to a large amount. Referring to the figure we have longitudinal timbers 12in. by 6in. shown in section, laid upon and bolted down to the piles, and upon the longitudinals cross planking 9in. by 3in. spiked down to them. Sometimes a portion of the space D D between the piles is dredged out and filled out with concrete level with the under side of the planking, but the nature of the ground will determine when this operation is absolutely necessary. It would not be a bad precaution to do this in every instance, except where the ground is rock or very hard and clean gravel. Upon the planking, the wall A of brickwork is erected, and is carried up to about 4ft. above high-water mark, not inclading the depth of the coping, which is usually 1ft. in height, making a total height above highwater mark of 5ft. This is quite sufficient to prevent the banks being flooded by extraordinary high tides or by storms and hurricanes. To prevent the face of the wall being injured by vessels, fenders, as they are called, are attached to them. They are generally of oak, and are shown in the diagram by F; they are fixed to strong oaken wall FIC.14 least, so the inventor says. However, his method of applying the springs will be seen in the engraving, where A indicates a socket in two plates H H, or blocks let into the wall, and pieces, 1 and 2, composed of two parts, the upper bolted to it by long inch or inch and a half bolts. one turning on its lower fixed part. This socket Counterforts are always built at the back of all receives the bar or rod b which moves up and long retaining walls, at the back of the abut-down within it, at will, according to the increase or decrease of pressure on the spring. The rod ments of bridges and all structures of masonry is also assisted in this movement by means of and brickwork. They are shown by C in Figs. 13 the opening C made for the passage of the pin d and 15, and are not built continuously with the which permits the spring to work freely. The wall, but at intervals of about 10ft. or 15ft. apart rod b is nevertheless held in its rotary motion by (see plan in Fig. 15), varying with the height of this same pin d, itself fixed to the upper revolving part (1) of the socket, and thus the wheel may be turned to the right or left by the steering bar; g, hole to receive steering bar; i, hole for receiving a pin to fix the two parts of the socket together, and permitting the upper part (1) to turn on the lower fixed part. This pin may be replaced by an exterior clutch enclosing the two bossed parts; L, hole to receive the spring bar supporting the saddle; B, spring fixed to the lower part of the socket and through which passes the rod b; this spring does not turn. The velocipede travels without shaking or shocks, and is about one-third lighter, no longer having to overcome in a direct manner the resistances met beneath the wheels, these being here deadened in the springs without any shock to the body of the vehicle. FIC.15 A the wall. They may be regarded in the light of backing, and provided they be made of good sound strong work, there is not the same amount of care and neatness required in their construction as in the case of the actual wall itself, although they do constitute a component part of it. The total batter or slope given to the wall is represented by the line A C in Fig. 12, and denotes the distance its top is set back from a perpendicular line A B let fall upon its toe or extremity B. The latter is always denoted as so many inches to the foot, or as one in so much. Thus a batter of lin. to the foot, that is, a set back of lin. from the vertical for every foot in height, may be also written 1 in 12. A batter of 1in. to the foot may be called 1 in 8. The batter of the wall in Fig. 13 is 1 in 5, which is not quite 24in. to the foot. This is a stronger batter than is usually required in simple retaining walls, but is not more than is wanted in the particular situation of a dock wall. For the sake of practical facility, we should certainly make it 1 in 6, or 2in. to the foot. Foremen and practical workmen much prefer a batter being given to them in this manner, instead of in the former. They at once understand what so many inches in the foot means; but they do not by any means so easily comprehend the same measurement when it is expressed as a fraction. VELOCIPEDE SPRINGS. The inventor also claimed the adaptation of treadles actuating the hind wheel, and an arrangement of the connecting bar which enabled a lady to ride a bicycle, to which he affixed mudguards in such manner as to protect the dress. But unfortunately the ingenious device was vitiated by the absurd notion of cogwheels-an error often pointed out in this journal; and as the inventor has not proceeded with his invention, whatever of value there may be in it has now become public property. COACH PAINTING. ALL riders whether bicy. to the general outline of the art, avoiding cles or tricycles, which are steered by a handle fixed in the fork or bar over the front wheel, are aware of the unpleasant sensation produced by the constant vibration of the machine, particularly when passing over the ordinary paved roads. The india-rubber tires afford some relief in this direction; and we now illustrate a method of applying springs to velocipedes, taken from the specincation of M. E. V. de Forville, of Nantes, France. The inventor has not proceeded with his application for a patent, one portion of which contained a description of a bicycle possessing no fewer than eight toothed-wheels, and worked by treadles, by means of which a rider might ascend the "most rapid inclines," and was enabled to put on either speed or power at will-at MUST premise that the art of coach paintin a practised by some of the West-End firms of London, is not to be learned by merely reading "how to do it" by any amateur or aspiring tyro, though taste and a harmonious blending of colours will cover many defects in the execution; it is moreover one of those arts of which a learner can gain more real knowledge from seeing it done once than from whole pages of printed instructions. I will, however, endeavour in as concise and plain a manner as possible much as possible all technicalities. In the first place we will begin with a carriage in the state known as the "iron and wood," that is, as it leaves the "body" loft complete, and it will be seen that before it is finished painting it will have received at least fifteen coats of different sorts. We commence by giving the whole of the body and iron-work two coats of lead colour, which is made up in the following proportions, by weight: -81b. of wet white lead, 8oz. of patent driers, 13lb. of linseed oil, 1lb. of turpentine, 2oz. of vegetable (lamp) black. This is a good drying colour, and will take, in a tolerably warm loft, about eight or ten hours to dry. It is best, though not absolutely necessary, to sand-paper the body and carriage over after the second coat of lead-colour, when we proceed to lay on suecessively five coats of "filling" on the woodwork of the body-that is, the sides, front, and back-but not on those parts underneath that are out of sight, and two or three coats on the under carriage, if there is much wood; though the present style of under-carriage is nearly all iron, consequently the filling is dispensed with, and an extra coat of lead-colour is given and well sandpapered off, except the wheels, which get one or two coats of filling in first-class shops. The "filling," as its name implies, is used to fill up the grain of the wood, so that a smooth and level face may be got on the work in a later stage. The filling is made up in the proportion of 4lb. patent filling powder, 2lb. wet white lead, lb. carriage varnish, 1lb. gold size, 14lb. turpentine. This filling dries pretty quickly; but it must be remembered in every case, whether the coat be colour, filling, or varnish, it is of the greatest importance that the previous coat should be dry and hard before another is laid on. In the process of filling up" a considerably thick coat is deposited on the work, and consequently partially fills up or obliterates the "quirks," that is, the grooves or angles of fine beads, which much mars the effect when finished, if not removed by the stone in the after part of the work, to do which is a tedious and long job; therefore, it is best when the third, fourth, and fifth coats are laid on to scrape the quirks of the beads out, either with a piece of thin hard wood squared at the end, or a puttyknife ground off square. It is not necessary to scrape out down to the wood, but only to remove as much as will come away easily, and leave the edges of the beads sharp and distinct. which all nail-holes, screw-holes, dents, bruises,. &c., are filled up. follows:-1lb. dry white lead, loz. gold size. This "stopping" is made as This will, with an average sample of gold size, be quite hard enough, but there is hardly anything that varies more in quality than gold size; it is, therefore, necessary sometimes to add a very small quantity of varnish, but it is safest always to try it without, as a little too much varnish. makes the stopping so hard that the stone will... hardly bite it. The stopping is applied in little dabs with the putty-knife, well pressed into the holes and smoothed over the dents and bruises, taking care to always leave the stopping rather prominent, so that when stoned off, it shall be level with the surrounding surface; and it is expedient that this stopping should be done before the last coat of "filling" gets quite hard; it is then less likely afterwards to shake or work out. Having allowed the stopping to become quite hard, we give the whole of that part of the work which has been filled up a quick. drying coat of "staining," and this is done so as to show when the work is stoned all over, as nearly all this is removed by stoning or rubbing down. The "staining" is mixed up as follows:1lb. of the mixed filling; 1oz. vegetable black; 2oz. gold size; 8oz. turpentine. When this has been put on and is dry, the work is ready for "rubbing down” or “ stoning;" this is done with pieces of pumice-stone, rubbed flat on one side. on a slab of some gritty stone with wateran old worn-out Newcastle grindstone, laid on its side, answers admirably for this. We then rub the panels and woodwork off as evenly as possible, wiping the face of the work frequently with a sponge and water, so that we may see that it is being done evenly; and as the face of the pumice-stone gets clogged with "filling" it is rubbed on the slab with water to clean it, and so on, until all the "staining," or very nearly all, is removed, when the face of the panels, &c., should be as smooth to the hand as a piece of polished marble, but of course no gloss on it; and in passing the hand over the places that have been "stopped " the "stopping" should not be perceptible to the We now come to the "hard stopping," with being accomplished, the work is ready for two coats more of lead-colour, and must be well sandpapered down between each coat, and then it is ready for the ground colour. This is usually made up like the lead-colour, substituting the colour desired for the black, except those parts intended to be black, which are now given a cont of shiney black; this is simply japan with a small quantity of vegetable black put in it, on the score of economy-which is doubtful-but plain japan is frequently used. Two coats of this are given, and also two coats of ground colour; the second coat of this should be made up thick and then thinned down with varnish: it is then termed "varnish colour." When it is dry it is followed by a cont of varnish, that known as "extra durable," for the body, and "carriage" varnish for the under away, and after a while each single bristle splits up, and the brush becomes softer and more even. objects exhibited at the late competition of the minution instead of an increase of the post. washing his hands, however, with very weak nitric acid, and afterwards with water, he obtained more power on squeezing his hands than he had ever done during the most persistent east wind. This led to an explanation of the phenomena as one due to chemical action alone, the act of squeezing the hand violently forcing some perspiration out of the pores. By dipping one hand in a solution of ammonia and the other in one of nitric acid, and then washing both in water, squeezing either hand produced a current in the same direction; and when THE USE OF GLUE. most delicately-operating implement. The hair of his neighbours; but, as a rule, the main prin- CORRESPONDENT writes to the Coach both hands were placed in the water and a little A CORRE Jamal as follows:-"To do good A REMARKABLE GEOLOGICAL DISCOVERY. FLUTING AND FLAT IRON. The engineering inspector or adviser, when in charge of extensive steam power on land or sea, exercises great power and influence in reference to steam engine improvement. In too many cases he has, by prejudice and defective training, delayed the introduction of improvements to such an extent that the amount of loss his employers have incurred thereby is quite incalculable. How long some steamship companies opposed the introduction of surface condensation is well known, and with reference to some other changes, such as steam jackets, they are now rather permitted than encouraged. If any one had the courage to record the engineering history of some of the large steamship companies, the facts would be beyond belief. It is sincerely to be hoped, in the interests of true steam engineering, that with the new era of steam engine economy, a more progressive spirit will be infused into those who advise the large steam users on land or sea. E. D. Cope, of Philadelphia, is working up the HE annexed engraving is a representation improvements or new machinery. Partly or wholly animals, Mr. Horn will describe the insects, and it is hoped that Professor Newbury, of Columbia College, will study the plants. So far, the investigations have disclosed 22 vertebrates, 5 insects, and 10 or more plants. Among the animals are the following: A large sloth, with gigantic claws, called by Jefferson the Megalonyx ; a mastodon, with a tusk 11ft. long; a bear, fully as large as the grizzly bear, but entirely distinct in character from all existing species of North America and the northern regions of the old world, as well as from the cave bear; a tapir, a horse, a wolf, and other skeletons not yet described. Further developments will be looked forward to with great interest. MANUFACTURE OF HAIR-CLOTH IN AMERICA. THE Archangels, .., there is an extensive THE Exchange, an American journal, says :-At factory for the manufacture of hair-cloth, for the covers of sofas, chairs, &c. The hair used is that of horses' tails, and is imported from South America and Russia-mostly from the latter country. It is purchased at the great annual fairs of Isbilt and Nijni Novgorod. That purchased in June at the latter place will be received in about sixty days; and that bought at Isbilt in February in about six months. As it comes of various colours, it is, for the purpose of this manufacture, all dyed black. A certain proportion, however, is purchased in England and France, already prepared for the loom. It is worth from fifty cents to four dollars per pound, according to length, the price increasing in rapid ratio after the length attains 24in. The "rough hair," or that which is imported in its natural state, is hackled, and the shortest sold to the manufacturers of mattresses, it being first curled. After being hackled, the different lengths are combed out, assorted, tied in bunches, and made ready for colouring. After this process, the bunches are carefully inspected, measured, and put away or the loom. The cloth is made in widths of from 4in. to 32in. Contrary to the popular idea, the hair is not, as rule, round. A section under the microscope hows a form as though a third of a circle had been ut off, and the flat portion slightly indented. This onformation caused some difficulties in the maniulation, which required great skill and the most elicate machinery to overcome. The warp used is hade of cotton, and prepared with great care. A unch of hair which has been soaked in water is laced in position, and the individual hairs are icked up, to be by the shuttle laid carefully in the eft. If the machine fails to take a hair, which casionally happens in practice, it continues s efforts until it succeeds, the other portions the machinery standing still in the mean me. The shuttle is an awkward-looking, but of a combined fluting and flat iron, in- pivoted together at A. When closed, these parts One other class of men must be referred to as exercising an influence on the rate of progress in steam engineering. The engineer in charge of steam power is sometimes the only authority the steam user consults in judgment either on alleged uneducated, occasionally not even a mechanic by trade, property is wasted, and changes are objected to, în direct proportion to the ignorance existing, and yet these men, in the case of a steamship, may have the spending of from 3,000 to 10,000 tons of coal per annum, and have the power in their own hands of obtaining an efficiency that may save or lose their employers thousands of pounds yearly. The grossest ignorance of the elementary principles of steam-engine economy can only be inferred when men deliberately prefer low pressure and a minimum expansion to high pressure and a maximum expansion. On the other hand, in what may be termed all the obstructive classes, highly able and intelligent men are found, who are open to conviction, and give every possible assistance to the improver. It is important, in alluding to steam engineering, to separate the creation of power in the boiler from its application in the engine; and it is the more so in the present case, as the progress of improvement has been so much less in the former than in the latter; and not only so, but evaporative duty has, in marine engineering, been actually lessened by the introduction of the compound engine and higher pressure. On land and sea the purchase cost of a steam horse power has increased during the past twenty years from 20 to 30 per cent., the pressure has increased 50 to 500 per cent., while the weight of fuel per each horse power has been reduced from 71b. to 24lb.; and if we take the past ten years only, a pound of coal now develops twice the power it did in 1861. Successful steam engineering does not mean For light laundry purposes this implement will merely the production of an engine economical in answer a good purpose, and take the place of ex-working, but the production of one at a cost that pensive machines, where rapidity in the perform ance of the work is not a desideratum. STEAM ENGINEERING. THE The other three classes may, and sometimes do, shall be remunerative to the purchaser. That the improvement previously named is of this character in marine engineering is easily proved. In 1861, marine engines of 400 indicated horse power could be purchased in the north for £3,500, requiring 44lb. of coal per each horse power; in 1871, the same power can be purchased for £4,500, requiring 24lb of coal for each horse power. Such engines would average at least 200 days' steaming each year, and allowing 20s. per ton for the coal saved and additional cargo-a very low estimate the owner will receive nearly £2,000, or 200 per cent. on his extra purchase outlay of £1,000, while assuming the value of 1861 ship and engines to be £16,000, and those of 1871 to be £17,000, and the first ship just cleared her expenses, the saving in fuel alone would give a dividend of nearly 12 per cent. on the capital of the second and higher priced ship. This great reduction of fuel, and the certainty that a large margin is left for further saving, gives a most encouraging prospect of the future of steam navigation; while a saving that is important in short voyages, becomes a gigantic profit on long ocean routes, when coal is £2 or £3 per ton and freight the same. |