t C 1st. The immersion in potash is to extract fatty matter. This should be borne in mind when regulating the time that an object should be allowed to remain in the liquid. 2nd. The immersion in water is to extract the potash. 3rd. The arranging being done at this stage is effected easier and better, and is not lost by the after immersions. 4th. The immersion in spirit, is, as before said, to extract the last trace of moisture. 5th. The immersion in ether is to extract the spirit, as well as to, by its permeating qualities, expel any air bubbles that may have got in during the drying and arranging process. 6th and last. The turpentine immersion is to allow some turpentine to take the place of some of the ether, so as to ensure due transparency of the object when immersed in the balsam. [294] SIR,-I send you a description, with engravings, of the Gatling gun, or battery, as it has been more properly called. It is the invention of an American gentleman, and was first exhibited in Europe at the Exhibition of 1867. It differs considerably from the mitrailleuse in construction and principle, for whereas the latter weapon can fire 37 shots, either at once or gradually, and must then be loaded afresh, the Gatling gun fires continuously, so long as cartridges are supplied, but it cannot discharge all its barrels at the same instant. In the mitrailleuse, again, the barrels are fixed, but in the Gatling they revolve. The weapon is made of two sizes-one containing six-the other ten barrels, and according to size will discharge from =200 to 400 shots per minute. As many as 1,000 rounds have been fired consecutively, and when it is mentioned that the gun is effective at ranges of 2,000 and 8,000 yards, some idea of its powers may be readily formed. Its main features are briefly summed up as follows:-First, it has as many locks as there are barrels, and all the locks revolve with the barrels. The locks also have, when the gun is in operation, a reciprocating motion. The forward motion of the locks places the cartridges in the rear ends of the barrels, and closes the breeck at the time of each discharge, while the return movement extracts the cartridge shells after they have been fired. When the ten-barrel gun is being fired, there are five cartridges at all times in process of loading and firing, and at the same time, five of the shells, after they have been fired, are in different stages of being extracted. These several operations are continuous when the gun is in operation. In other words, as long as the gun is supplied with cartridges (which is done by means of "feed-cases," in which they are transported) the THE GATLING GUN. several operations of loading, firing, and extracting the cartridge shells are carried on automatically, uniformly, and continuously. The locks operate on a line with the axes and barrels, and are not attached to any part of the gun, but as the gun is made to revolve, they play back and forth in the cavities in which they work, like a weaver's shuttle, performing their functions of loading and firing by their impingement on stationary inclined planes or spiral projecting surfaces. Second, it can be loaded or fired only when the barrels are in motion-that is to say, when the barrels, the inner breech, &c., are being revolved. Third, it may justly be termed a compound machine gun, since the ten barrels, each being furnished with its own loading and firing apparatus, form, as it were, ten guns in one. This is a valuable feature, ing impaired, those remaining can still be used effecfor in the event of one of the locks or barrels becomtively. As will be seen from the engraving I send, the cartridges are supplied by means of a hopper, or inclined trough, and are of two kinds, the one containing several shots which are intended to "scatter" before a solid bullet or rather shot, the other made up of reaching the object fired at. The "solid" cartridge conand is for use at long ranges; the other is of the same tains a shot of half a pound weight, is of lin. calibre, calibre, and contains 15 buckshot and a terminal ball, and will be principally used against masses of cavalry has hitherto been made of but two calibres, lin. and in., or infantry, or for short ranges in general. The weapon but there is no reason to doubt that mechanical ingenuity will go far beyond this limit. F. G. R., late H.M.R.A. THE MICROSCOPE. [295] SIR,-As my own stock of books is somewhat limited, and as I am in the habit of getting others from only four of the London libraries, it would perhaps be stating too much were I to say that no work has ever been published, giving such a vast amount of interesting and useful information upon so many and varied subjects as the ENGLISH MECHANIC. If, however, any of your numberless readers with greater facilities than myself for procuring books, and more time for reading them, should have come across such a work, they would confer an infinite favour upon your correspondent by forwarding its name for insertion in your next issue. There is not a number of the MECHANIC you have sent out, from its commencement to the present time, that I have not gone over; and I look forward to its appearance almost as anxiously as I do for my daily bread. Not being a "muscular Christian," I have at times thought there has been too much of your space taken up by the bicyclists; and as my experience of astronomy is that the science is more frigid than fascinating, I may perhaps have been a little jealous at the attention the telescope has received in our journal. I myself have a hobby, and I pity the man that has not; mine is the microscope, and I am only too glad to see it receiving more notice in your pages. I should not like to say I have worked at the subject, lest it might imply more than I intended; but after spending many very pleasant hours, I have got to know something about it, and any experience I have gained I shall be happy to place at the disposal of your readers. I was on the point of writing you a few lines after reading the paper by E. R. Lankester a few weeks ago, for I do not agree with him in toto; but fearing it might be construed as an advertisement for certain makers, I refrained. To any one about to purchase an instrument, let me give one word of advice. Get an English stand. The demand is so great, and the competition so active, that, for the more moderate priced ones, nothing is gained by going abroad. Every pattern that has anything to recommend it can be obtained at home; and a person, by paying a visit to the different opticians in town, or writing for their illustrated catalogues if in the country, can find no difficulty in suiting his wants and his pocket at the same time. I know most of the English patterns, and many of the continental ones; I have four different instruments of stands. They may perhaps be a trifle dearer, but they my own, and my preference is decidedly for English are better made, better finished, and more satisfactory in every respect. As regards objectives, however, I time I will state that some of the English makers have can endorse what Mr. L. says, though at the same recently been revising their list of prices, and I have at £4 10s. And here, I think, I cannot do better than seen some very excellent results from an immersion the principle advantages of immersion objectives ?" answer the query of "M. J. C.," No. 4548, "What are the image. 2nd. More light is transmitted to the eye 1st. There is greater clearness, and better definition of than in the dry objective. 3rd. There is less danger of injuring either the object or the objective, as the distance between the two is increased. And last, but not least, they are cheaper. I have seen several magnificent German 1-18ths at £5 13s. (without carriage) almost, if not quite, equal to an English 1-12th, for which the maker would charge twelve guineas. By introducing a film of water between the object and objective, some of the rays of light from the mirror are made to enter the objective, which would pass outside of it if air instead of water separated the two; because a ray passing from a denser to a rarer medium, is refracted from a perpendicular to the plane which divides them. Again, in employing very oblique light, with a hydro-objective, rays are utilized which would be totally reflected with a pneumo-objective. thrust, BICYCLE RIDING. The ver is the seat a move the seat far from the driving wheels had i makes a good transparent object, showing the rows of pits into which the points of the scales are inserted. There is a moth, tolerably common, which flies in the [296] SIR,-In velocipede riding I at twilight near the ground, called the Pterophora penta(by experiment) that the vertical tread is a tree: dactylus, the wings of which are a pare snow-white, the of driving than either the forward thras both combined. scales are long and thickly set, and intermixed with long or by hand-levers, or compound hairs. Nothing can be more beautiful than have had a little practice, and with your seat eAnd now for a few words on common objects, and this wing, mounted dry, under a low power, with light height (as before mentioned), you will find t how to moant them. I dare say that, like myself, many thrown down upon it from a ball's-eye condenser. tread to allow you to sit upright and plas readers of the MECHANIO prefer to do as much of the Wings of other insects, mounted whole, form valuable weight of your body alternately on the tr work themselves as possible; I will, therefore, just additions to the cabinet, as those of Culex pipiens, where much greater ease and speed than any other give the plan I use for cutting all glasses exactly to one the scales are seen to be inserted on the nervures of the the weight of body, when properly apple size-viz. Sin. x lin. I have a board, along one side wings, and forming a fringe all round the edge. sufficient to drive a light-made machine ap of which is fastened a strip of wood with an accurately Another wing, that of the Psychoda phailenoides, is hill on the common road. A practical pe straight edge; also two rules, which are respectively more thickly covered, and with a dark ground illumin- the saddle but very little when ascending i less than lin. and Bin, by the distance from their edge to ation-as by the parabola, spot lens, or Lieberkuhn- quently very little load, the weight of the cut which the diamond makes (about 1-16in.). The appears almost as if made of silver. This is a tiny as the propelling power instead. glass, which should be thin flatted crown, is placed insect, found at dusk on window-panes, where they not like (as one of your correspondents on the board with one edge close to the ledge; the pop about in all directions, as if they did not knowing the Monument stairs with a half-hunes wider rule is placed upon it, also touching the ledge, whore they were going. A larger insect than the pre- back, but more like sitting on horse-bo and thus the glass is cut into strips exactly 3in. wide. ceding, the Chrysopa perla, found fitting about in unloaded back and his foot in the stirrap foot with the thrust of the The strips are then turned at right angles, and with gardens as it is getting dusk, has clear, pale green the smaller rule, the slides, lin. in width, are ent off. wings, which show all the colours of the rainbow drawing back the foot, and then thrusting t Care must be taken that the ends are square before when the light falls on them in a certain direction. of itself, harder work, at less speed, than cutting, or the angles will not be right angles. Having These are some of the finest, but all are worth examin- down stroke, and with it there is a dead got the glasses, the next thing to consider is whether ing, and are very little trouble to preserve in the dry tinually on the machine. As in moving they they are to be coveredwith paper, or to have their edges way. a lever you must have whereon to rest the ground. The latter process is somewhat tedious; the Next, I come to some objects which require a pro- lever, and that whereon the lever rests ag sharp edge may be taken off on the side of a grind- tection in the way of a cell. The sand from many parts double weight upon it-namely, the work, a stone, and then smoothed by rabbing on a piece of of the seashore contains numbers of exquisite forms of force applied to move it; so when you de For slides Foraminifera ; that from Dog's Bay, Connemara, is par emery paper laid on a hard flat surface. you place back on which are to have cells cemented to them, perhaps the ticularly rich; many kinds too are found in the sand pressure; so in driving with levers ground edges are the best, whilst for objects which only which accumulates in drawers in which sponges are pressure on the machine at the peats of th require the addition of the thin cover, it is perhaps less kept, or they may be shaken out of sponges when they besides the dead weight of your body in the c trouble to cover them with paper; and this is accom are new. I think the best way to proceed is to sprinkle a the time. Those who drive in that way and plished in the following way:-Cut a strip of thin little of the sand on a slide, and place it on the coloured paper, fin. wide and sin. long, paste one side stage, under a low power; I then take a bristle, and place it round the edge of the glass, snip a bit from which is inserted into a bit of stick, and just each corner, both back and front, and then, without moistening the tip between the lips pick out those wrinkles, carefully lay it down on both sides. Other which I require. This is easy enough if the microscope strips of stouter coloured paper should be cut 1-16th has an erector, but if not, a little practice is reless all round than the slide, and a circle should be cut quired, as the movements appear in the opposite or punched from the centre; one of these is then direction to that which you intend. The centre of a pasted on the front, another on the back, care being cell must be just touched with gold size, the least film taken that the apertures correspond; when dry and possible, or with a little gum; the latter soon dries, but labelled, and the glass in the centre well cleaned, the may be moistened again by breathing upon it; on the slide is ready for the cabinet. For cells, vulcanite whole I prefer the former. As the different species are rings are very useful, and can be obtained of various picked out they must be deposited in the cell upon the sizes. The brass button moulds, which can be ob- adhesive medium, and when a sufficient number are tained at furnishing drapers', also answer well, obtained the edge of the cell must be lightly touched and are cheap. To fix them the slide should be put on with some cement, and a cover dropped into its place. the turntable, a ring of gold size struck on the glass, Most of these show best with a dark background, and and after painting one surface of the ring with the sometimes a circle of black paper is first stuck at the same material, it must be dropped on the slide, and a bottom of the cell, or a circle of black varnish is painted little pressure made use of to expel the air, then put on the underneath side; but this prevents the use of the aside to harden. This takes some time it is well, Lieberkuhn, spot lens, or parabola, and can only be therefore, to prepare a number at once. I think, how-used with some of the forms of reflectors, so that on ever, it is the most trustworthy cement that can be the whole the first mentioned method is to be preferred. employed. Other slides should be prepared with rings From the same source, sponge spicules may be obtained, of gold size, others with rings of asphalte varnish of which appear as if made of the clearest glass spun into different diameters to suit the different sized circles a variety of forms: they should be mounted and shown used as covers. Being thus prepared, nothing more is in the same way as the Foraminifera. requisite to commence mounting dry objects, a few of Again, quite a cabinet might be filled with the various which, easy to obtain, and beautiful to contemplate, I seeds, most of which show to great perfection, mounted will now enumerate. in the way last described. I may mention a few of the more striking ones: foxglove, poppy, pink, henbane, thornapple, mignonette, gentian, pimpernel, snap dragon, tobacco, Escholtzia, St. John's wort, ragged robin, catchfly, chickweed: these are for the most part to be obtained with very little trouble. Another series of dry objects may be obtained from sections of different woods. Some amount of skill is required in cutting these sufficiently thin, without any special apparatus, but with a very sharp razor it may be done any one, however, with a little mechanical ingenuity can soon make an instrument for a few pence that will answer every purpose. A shaving of deal from a carpenter's shop will show the pitted tissue, distinctive of the Conifere, admirably, but as a rule wood sections are shown best either mounted in fluid or in balsam. The clematis, which does not require cutting so thin as most woods, affords one of the finest sections, and shows as well, if not better, when dry. I need say nothing about pollen, as one of your correspondents has already mentioned it. Portions of the fronds of ferns, displaying the fructification, form beautiful and interesting objects. There are many leaves, too, as the evergreen oak, Deutzia, Alyssum spinosum, which are covered with the most exquisite hairs, so that under condensed light the leaves appear as if thickly covered with silver stars. Nothing is required but to dry the leaf thoroughly between blotting-paper, and to secure a portion in a shallow cell and cover it like the rest with thin glass. I will mention but one more series, and then conclude. The scales of fishes when thoroughly cleaned and dried form a most interesting and varied collection, some being covered with fine lines, others being furnished with sharp and thick-set spines which give them quite a formidable appearance. Perhaps nothing gives less trouble in mounting than the scales which various insects bear on their wings and bodies; and as butterflies and moths are now abundant, a great variety may be secured. Two kinds of scales are found on the male of the common white butterfly, one of which bears a beautiful little tuft at the end. All that is requisite is to take a perfectly clean cover glass, place a wing or portion of wing upon it, press upon it with the tip of the finger, and immediately a number of the scales are transferred to the glass; remove the wing, take up the cover with a pair of forceps, and invert it over a slide on which one of the asphalte rings has been painted; put on a spring clip, and if it does not adhere, holding it for a few seconds above the flame of a spirit-lamp will soften the varnish sufficiently to unite the two firmly together. A small creature with a glistening silvery surface may often be found swiftly gliding about on hearthstones, or in cupboards, as well as in other places, this is the Lepisma saccharina, or sugar-louse. If one of these is captured and stupefied with chloroform, by gently placing a cover upon it, and moving it about lightly, abundance of scales will be procured; care must be taken with all these that the creature is not squeezed so as to make some of its juices exude, or the slide will be unsightly and worthless. Then again there is a number of species of springtails, some found in cellars amongst sawdust, some in greenhouses, in decaying wood, beneath the bark of trees, amongst moss, and in many other places; and many of these are covered with scales; one kind, the Lepidocyrtus curvicollis, furnishes a scale which is used as a test for the higher powers. As they are small it is best to place a cover gently on one, and by its struggles the scales will be rubbed off, the exquisite markings on which are almost obliterated by the the least trace of moisture. The wings, legs, and body of the gnat, Culex pipiens, are clothed in like manner, and its scales are beautifully iridescent. One of the hunting spiders, the Salticus scenicus, has some scales, but they are not quite so easy to obtain. Many British beetles, as the Curculionide, have their whole surface covered with scales of the most resplendent colours. To mount the scales separately, they must be scraped off; but a far finer slide is made by mounting the whole insect, or the wing-covers only in a cell; it is improved too if the cell is filled with balsam; but of this hereafter. Portions of the more brightly coloured wings, as of those of the Alpine Blue, form gorgeous objects when the light is thrown down on them from above. A part of a wing, from which the scales have been removed, I have not by any means got to the end of my subject, A FELLOW OF THE ROYAL MICROSCOPICAL SOCIETY. [297] SIR,-Although I am simply because I am an old man-e▼ ene say, in behalf of young men, one *rizards! Let me ask, for what purpose ar febrer kept? Is it not, for the most part beat rese or for amusement? Of coure Est ZERİsymit KL The farmer and the soldier meas horses, but there are thousands d va have no hope of ever being able to bag a bird, 1 whom the delight of whirling along on the border perhaps, even greater than that of the 31 ED a horse. I was astonished and delighted a few day ago at seeing a man, apparently between that d forty, with the most astonishing command t bicycle. It must be comparatively easy to mod when tearing along on a level road, but the rider a I saw was moving very leisurely through the : that one usually sees about the station near the wat ing-place at Ramsgate; he was really "walk horse," and occasionally stopped to look about apparently without an effort, keeping the two-st machine balanced. It was a beautiful one to los with a little step by which to mount; and, mors® the rider had evidently "come into town on busies his purchases being strapped safely on the spring know a young apprentice in my own neighbo whose master-a wheelwright-made a bicycle, as young fellow goes many an errand thereon to s time, and when he gets a holiday, instead of k about, or even going on an excursion by rail, his master's bicycle, and makes pleasant exped about the country, which otherwise he could a and to places of interest where "the rail" will help him. If a little fatigue is incurred, what th If you cannot do everything on a bicycle that could do in a "trap," what then? I am aste that more young men do not get a bicycle. Od am, I think I must begin. The L HOW TO SKELETONIZE LEAVES. [298] SIR,-Before the autumn passes should like to lay before the readers of our Mc a method of making some beautiful parlour o which may form a pastime for their winter although the materials must be collected now. leaves are among the most beautiful objects i and as they can be arranged either in group glass shades, made into pictures, as it were, gai ha against the wall, or placed in either blank tw! albums, they come within the means of all, and co used to decorate the palace or the cottage. suitable leaves for the purpose are those from * botanists call erogenous plauts, and may be know the veins of the leaf branching from a central v midrib; those from endogenous plants rising from base and curving towards the apex of the leaf. object in view is to destroy what may be called t fleshy part of the leaf, as well as the skin, leaving the ribs or veins. The most successful, and proba the simplest, way to do this is to macerate the les in rain-water till they are decomposed. For this p pose, when the leaves are collected they should placed in an earthenware pan or a wooden tub, i covered with rain-water, and allowed to stand int sun. In about a fortnight's time they should be amined, and if found pulpy and decaying, will be rea for skeletonizing, for which process some cards. camel's-hair brush, as well as one rather stiff (a toot brush for instance) will be required. When all is pr pared, gently float a leaf on to a card, and with the soft brush carefully remove the skin. Have ready a basin of clean water, and when the skin of one side is completely removed, reverse the card in the water, and slip it under the leaf, so that the other side is uppermost. Brush this to remove the skin, when the fleshy part will most likely come with it; but if not, it will readily wash out in the basin of water. If particles of the green-coloured matter still adhere to the skeleton, endeavour to remove them with the soft brush; but if that is of no avail, the hard one must be used. Great care will be necessary to avoid breaking the skeleton, and the hard brush should only be used in a perpendicular direction (a sort of gentle tapping), as any horizontal motion or "brushing" action will infallibly break the skeleton. Never attempt to touch the leaves or the skeletons in this state with the fingers, as when they are soft their own weight will often break them. A very good way of bleaching the skeletons is to prepare a solution of chloride of lime, which must be allowed to settle, and the clear liquid poured into a basin in which the skeletons may be put by floating them off the card. It is as well to have half a dozen ready to bleach at once, as they require watching, and if allowed to remain in too long will fall to pieces. From two to four hours will generally suffice to bleach the skeleton of all ordinary leaves, after which they should be washed in several changes of water, and finally left in clean water for half an hour. After the leaf has been sufficiently washed it should be floated on to a card and dried as quickly as possible, care being taken to arrange the skeleton perfectly flat, and as near as possible to the natural shape. This can be done with the assistance of the soft brush. When dry the skeleton should be perfectly white, and should be mounted on dark backgrounds, as black velvet or paper. Well grown leaves should always be chosen, and be thoroughly examined for flaws before maceration. Leaves containing much tannin cannot be skeletonized by this process, but are generally placed in a box with a number of caddis-worms, which eat away the fleshy parts, when the skeletons can be bleached in the usual way. Holly-leaves must be placed in a separate vessel on account of their spines, which would be apt to damage other leaves; they make beautiful skeletons, and are sufficiently strong to be moved with the fingers. It is not necessary to give a list of leaves suitable; but the leaf of the poplar, the apple, the pear, and the ivy may be mentioned as easy ones to commence with. Various seed-vessels may be treated in a similar manner and by precisely similar means, and thus greater variety given to the groups. Wishing our readers success in their experiments, I would remind them that what is worth doing at all is worth doing well, and that "a thing of beauty is a joy for ever." SABBAS. THE "PHANTOM " WHEEL. [299] SIR, It will be interesting to see the promised illustration of what is the "Harmonious Blacksmith's" notion of a perfect suspending wheel, but pending its appearance I should like to ask your readers not to take for granted his assumption that the "Phantom " is not to be relied upon as a driving wheel. Your correspondent falls into the same error in that respect as Mr. Edmund Tydeman, of Brighton, from the fact that like that gentleman he writes without having seen or tried the wheel in any way. Your editorial shears will I know remorselessly dispose of whatever I may say which tends to import an advertisement into your general columns, so I will simply ask those who are in any doubt about the "Phantom" to await the longpromised further letter of Mr. Tydeman, which will now be written after an extended trial of the wheel. It will be recollected that it was a most circumstantial condemnation from the pen of that gentleman which first impugned its value. At the risk of anticipating the fertile suggestiveness of our sledge hammer friend, perhaps you will let me point out that the winding of the axle in suspended wheels (which after all, is, in our case at least, quite theoretical) may be entirely prevented by carrying a light steel bar from one side of the rim to the other straight through the middle of the axle. J. A. MAYS, Secretary, Phantom Wheel Co. [300] SIR,-In looking over your journal of August 12th, I read a letter upon wheels, signed "Harmonious Blacksmith;" perhaps you will allow me to correct a statement in his letter. He says, "Suspension wheels-i.e., phantom wheels, are not rigid enough for driving purposes." I have ridden a veloce with phantom wheels in and about Birmingham for two months, up hill and down, often forty miles in a day, without a slip, and the driving wheel is as firm now as when new. Perhaps "H. B." knows Snowhill in the town, and Soho-hill, Handsworth, or your readers may. I ride up and down about five times a week, and the driving wheel is rigid enough to carry me up as fast as my strength will permit. If the "Harmonious Blacksmith" would like to be convinced, let him come and see, and make the trial for himself. I know very little about science, but practical experience is always better than paper sketch experience. J. T. DAWSON. THE PHANTOM" VELOCE-AN ACT OF JUSTICE. [301]-SIR,-In "our" MECHANIC for April the 15th I published some strictures upon a form of wheel patented by the "Phantom" Company, which I then considered to be an adoption of my invention, described in Vol. III., and christened the "Spider Wheel." Some time after the publication of those letters I obtained a "Phantom" on trial, as I hinted in my last letter, and it at once became evident that my wheel and the company's could not be considered one and the same, and that the latter was free from the defects inherent in the former. I then made a draft of a letter to forward to these columns which pressure of business and illness caused me to thrust aside. The letter of our esteemed friend the "Harmonious Blacksmith " in a recent issue (p. 495) again drew my attention to the subject, and I consider it nothing more than an act of justice towards the "Phantom " company to state that, in my estimation, after a fair trial, their wheel and veloce can have no competitor, and I feel bound to confess that I was simply mistaken in ever associating the "Phantom " with the "Spider." I have tested mine (I refer to the "Phantom ") in every conceivable way, and find that the correctness of the principle is only equalled by the beauty of the workmanship and cleverness of the design. I should now be loath to ride any other, and any one who will only take the trouble to thoroughly master their peculiarity in steering will never, I am sure, get astride one of the old kind again if he can help it. They certainly do require a much larger amount of practice at first than the old kind, but this is abundantly compensated for by an ease and grace of carriage afterwards, that cannot be attained upon others; and of all machines that one would choose for " doing" a long spin this is the one. Perhaps some may say, "But how about the objections you raised in reference to this form of wheel in your letter of April 15th ?" This is particularly what I wish to refer to, and I answer, " that they were real defects in the original form devised by myself, but that only the first and third can possibly apply to the "Phantom." The one I possess has been in use now for several months, principally by my brother, of 4, Pelham-square, Brighton, and has seen some very rough usage too, but the most scrupulous examination fails to detect any flattening at the spokes-of which by the bye there are upwards of 30 in the front wheel. The wheels, if turned round upon their axis (the machine being fixed), appear still beautifully true as at first, and as I am informed they are finished by turning in a lathe, and the rims are made each in one piece, it would be a wonder if they were otherwise. So that my first and third objections are effectually disposed of in reference to this wheel. My second objection, grounded on the wires being drawn up "taut," does not obtain at all here, these spokes being quite slack, and both more numerous and of much thicker wire than the "Spider." In fact it seems almost impossible to fracture them by any blow they are ever likely to be subjected to. They will bend but not easily break. And now for my last objection, at once the most serious, and one that was again dug up from its grave by the Harmonious Blacksmith" last week-the unfitness per se of wheels made on the suspensory system to act as drivers or crank-wheels. This, though it may be considered, and is, a serious defect in very slight wheels with few spokes, like the Spider," if looked at straight in the face will be seen to be more fanciful than real. Given a wheel with a stout rim, having a number of springs for spokes, nearly the same principle will be brought into action here as is developed in the case of india-rubber tires. At first sight it would seem, from the way in which they flatten on the road, that they would be only equivalent to a number of flat surfaces filed upon the periphery of the wheels, and would thus impede their motion. We know this is not so; india-rubber is a highly elastic substance, and that action and reaction are always equal is a law in mechanics, and it must be remembered that precisely so much of the force as is swallowed up in flattening the parts underneath is given out again as these elastic parts are successively set free; in other words, their efforts to recover their original form develop as much force as is required to flatten them. So also is it in the case of elastic spokes to a nearly rigid tire or rim, the amount of energy at first absorbed in bending them is given out again by them at the end of the stroke; it is, in fact, only so much force stored up to be utilized when the pressure is about to be removed. I think I am right in my theory, and believe that the "Harmonious Blacksmith" will, upon further consideration, bear me out in this view of the case. But however this may be, I find by actual experiment, that the crank of my "Phanton" deflects but 18 of an inch with the whole weight of the body upon it, and when all the spokes have been loosened to allow of its full effect (I question if any veloce wheel will deflect less than this); nor is this surprising when we consider that to do this no less than thirty-two steel wires, each 3-16ths thick, have to be acted upon at once. In short, commend me to the "Phantom " veloce for ease, for speed, and quick obedience to the helm. The sharp curves which this velocipede is capable of making, with but a slight movement of the fork, peculiarly fit it for "professional" gyrations and display. EDMUND M. T. TYDEMAN. [We have received about forty other letters on the machine.-ED.] "Phantom" Veloce, all of which speak highly of the thing touching too, in the mode of its commencement, which, if possible, deepens my regret. Surely less bitterness and prejudice might be justly expected of age. Many of your readers know quite as much about the flute as himself, some of them evidently a great deal more, and the result of their knowledge is far more agreeable both to themselves and others. "He knows all about the abortion," and his conclusion is well worthy of the presicate; he vituperates the instrument and sneers at its great professors-maybe, because he was disgusted with his own failure. With all due deference, I would submit to him the singular value of the instrument which could sustain the interest of talented men under such heavy disappointment, and eventually reward them for such thought and labour. But I forget; he writes, "nothing shall convince me," a blissful state truly: heart or brain can do little under such circumstances. A man with a smaller stock of obstinacy than this might go through life and prove as tough a subject as an inferior beef-steak, and perhaps quite as disagreeable. I am ready to admit that the discussion of the flute may be out of place in your periodical. I am not a young man in years or feelings, and I have been associated with all ages, classes, tastes, dispositions, and capacities; but I am free and grateful to confess I never "chin chinn'd" with the double of "F. F. C." I leave his attack on "the flute and flute-playing," to those who deem it worth comment, and turn to his uncalled for and unjustifiable remarks in holding up to ridicule a body of gentlemen who are at least entitled to the same courtesy and consideration as their fellow men. He is guilty of this in the opening of his letter, and I must say it is unpardonable. He quotes also from an imbecile novel to strengthen an undignified position. There is no reproach in being a curate; all men are, or ought to be curâtes,— right honourables and right reverends, too, are they in the fullest sense if they be but faithful. Neither is there any harm in being mild: mild men and mild ale are not such despicable company after all, but sour men and sour beer I—well, I hand them over to those who like them. If "F. F. C." cannot adorn the pages of the ENGLISH MECHANIC he can at least refrain from gibbeting himself in them. A CLERGYMAN. ARROWROOT. [303] SIR,-May I ask Mr. G. Davis if he obtained the arrowroot of which he gives us a plate (No. 196, p. 495) from the Maranta itself, as it differs from what I have hitherto taken for the Maranta starch? I drew my information from the examination of two plates in two different works; both professedly representing the appearance of true arrowroot under the microscope. Now the specimens of starch sold as arrowroot, which I have examined, contained two kinds of grain; one I knew to be potato-starch, having obtained the same from the potato myself, the other presented the same appearance as that represented in the above mentioned plates. Potato-starch is said to be one of the chief adulterations of arrowroot. For these reasons, I felt justified in regarding it, as the true Maranta arrowroot. All the other kinds of starch mentioned in my article (No. 48, p. 395) I obtained from the plants producing them. I have not been able to obtain a piece of the arrowroot plant itself as yet. All are liable to mistakes, from over confidence or otherwise, and if it has fallen to my lot I should like to know it. May I suggest that plates of magnified objects would be of very much greater utility if the real size of the object, or the magnifying power employed, and the circumstances under which viewed, were named? INDUCTION COIL. J. C. [304] SIR,-For medical purposes I find the primary superior to the intense current from the secondary wire current from the ordinary medical coil" generally of an induction coil, and wishing to construct a medical coil, which shall be capable, if possible, of giving intensity effects, I shall be obliged if Sigma induction coil be used for medical purposes, by opening will answer the following questions: Can a Rhumkorff the secondary wire, and working from the primary ? in other words, is an induction coil with secondary wire disconnected, equal in every respect to a simple primary single coil machine, having the same size core and same length and size of wire ? Does the tension induced in the open secondary wire leave the primary less Will the effect on the core be strong in consequence ? suggested by "Sigma" in letter 256 (p. 522) ? increased by building up the primary coil, in the form Would there be any advantage in making the primary coil conlines of the core describe), and then the secondary coil form to an ellipsoid (or whatever figure the magnetic to a similar figure of less excentricity (which would probably be the shape of the curves of the primary in duction force)? W. H. COFFIN. HOW LL.D.'s AND Ph.D.'s ARE MADE. [305] SIR, I noticed some time ago an inquiry as to how degrees in art, &c., were got. I enclose you copy of a circular received by a friend of mine, and which gives all the information needed. It is to be regretted that there are some people so destitute of honour as to become mediums, whereby these degrees be bought, and that the officials of some of these may institutions second their efforts, no doubt for pecuniary motives, instead of allowing them to be earned [302] SIR, I cannot refrain from expressing the honestly. And this, no doubt, accounts for the fact regret with which I read the letter of "F. F. C.," page that many men, who have gained these degrees by 515, more especially as it emanates from an old man, their own individual efforts in the fields of science or and one claiming to be a musician. There is some-art, are so disgusted with this pettifoggery as to have THE FLUTE-UNCOURTEOUS CORRESPONDENCE. discarded them-preferring to remain a plain Mr., | It is obviously most natural for every shorthand writer "Degrees.-M.A., Ph. D., &c.-in absentia or præsentia -Qualified Gentlemen desirous of proceeding to degrees in arts, law, theology, medicine, &c., receive official instruction and advice by writing to ASH-BOX FOR LOCOMOTIVES. [306] SIR,-I beg to send you a sketch of an ash-box for locomotives, which I think has some improvements upon the method in general use. Fig. 1, is a part of ash-box with a portion of side removed so as to show the shutter C. A is a connecting rod for moving arms F, as shown in Fig. 2. B is a double arm, one end being attached to the rod A, and the other to the rod D. C is one of the shutters which compose the bottom of ash-box as shown in Fig. 2. E is a piece of bottom for shutters to butt against when closed. F is the arm which connects the rod A with the shutter C. A', B', C', &c., &c., show arms connecting rod, shutters, &c., when opened. At the end of a locomotive engine's work, when the fire has to be put out, instead of dropping the fire into the ash-box, and then raking it out as is now done, it can be dropped right out on to the ground without any extra work, and in case of an accident the fire can be got rid of altogether, and so cool the fire-box sooner than if only dropped into the ash-box. ASH-BOX. may be. to omit all useless letters, the object of his art being to combine brevity with celerity. As I said before, I quite agree with all "W.'s" remarks on phonography; I should never think of comparing a merely stenographical system for clearness and rapidity with a phonographical one. The letters ng, as in wrong, running, &c., can never occur without a preceding vowel, so that all such words may be written either in the ordinary way or by "N.B. These degrees and diplomas are guaranteed using the termination ang, ing, ong, ung, as the case bona fide. Only the applications of authors and other decidedly qualified candidates will be replied to. UnThe sound of most of the diphthongs may be accnqualified men, busybodies, and Editors of catch-rately represented by the vowels; the characters of penny newspapers,' need not trouble themselves to write, the latter may therefore often be used for the former; and their personal applications will not be attended to." for the three, au, oi, ou, which cannot be so represented, a short vertical stroke may be used. Such words P.S.-I can give the address of this medium if "Am- as people and leopard should, in the Lewisian system, bitious One" would like it. be written with an e, as sounded, instead of with the diphthong eo; words like pleasure and breath cannot be misread by using the character for sh or that for 8 and 2 in the former word, although neither is the exact sound, and the single character for th in the latter. No mistake could possibly be made by transposing Pitman's diphthong characters in such words as sound and journey. With the least ordinary care in writing, Lewis's vowels can neither be misplaced nor mistaken, because as each vowel has a distinct character all that is necessary is to write them as near their proper position as convenient, on either side of the consonant-that is, they must only be written in the same order as in longhand: thus no guessing is required, for the order in which they are to be read is as plain as that in which they are to be written, although their exact position is quite immaterial, nor is it of any consequence whether they be thin or thick. I have never heard any one complain of the system being illegible, nor have I found any difficulty in reading it. I cannot admit Mr. Clarke's assertion that the freedom of position of the vowels in this system is a "very prominent defect; " I look upon it as a very great advantage. Mr. Clarke states that, by "own admission," I have no means of ascertaining whether a vowel in Lewis's system should be read before or after a consonant, because I wrote that in that system "it is not of the least consequence on which side of the consonant a vowel is placed," &c. I [307] SIR,-No system is phonetic, in the most admit nothing of the kind; the position of the vowels strict sense of the word, unless every sound in the in Lewis's system being the same with respect to the language has a separate character. Mr. Pitman consonants as in longhand, there can be no difficulty in clearly points out the difference of the sounds, but as reading them rightly. In the word endear, for example, some of them are very similar a separate character is the first vowel is placed near the commencement of the not required for each; for it is practically found that letter n, the second and third near the junction of the the legibility is not in any way injured by using one cha-d and the r; these letters form a very acute angle, so racter for two similar sounds, such as f and v, sh and that the vowels are placed outside the angle, it being zh, &c. One of the advantages claimed for Pitman's immaterial on which side of the consonants they are system is that should the thick and thin characters be written; it is almost impossible to make a mistake. It carelessly or accidentally misplaced no mistake can has been stated more than once that Pitman has only possibly occur; this cannot be claimed for the letters r three positions for his vowels, but these three positions and w, n and ng, 1 and y, which have the same characters are on each side of the line; thus there are six posithin and thick respectively. In Lewis's system, where tions when compared with Lewis's system, in which the no two characters are similar, misplacement of them vowels may be written on either side of the line. Mr. is impossible. As no mistake can occur from the mis- Moseley acknowledges this. This system admits of the placement of such characters as f and e, why not have omission of as many vowels as any other, since the one character for both these letters? The number of method of representing them does not in any way affect characters is thus reduced, and the system at once be- this feature. comes simpler. "W." is altogether wrong in saying the Lewisian system is only as much phonetic as our "ABC" alphabet, and no more, for although Mr. Lewis writes of his system as one of stenography-as, of course, all systems of shorthand are, whether phonetic or not-yet one of the first principles impressed by him on a learner is never to write an unnecessary or mute letter, but always to write a word as sounded, not as spelled. This is why I called his system one of phonography, or phonetic, which words mean "according to sound," so that I used them in their ordinary sense. SHORTHAND. my The fact of the majority of Pitman's prefixes and affixes being disjoined from the word necessitates the lifting of the pen from the paper, an evident loss of time, which, in the case of the affixes, is avoided by Lewis without loss of clearness. The difference of sound between many of the affixes and prefixes respectively is so slight that no mistake can arise from using the same sign for more than one, so that Lewis's signs can safely be used for many more than thirty. nine. Everyone must admit that by itself no character can occupy less time in being formed than a dot, but as it is absolutely necessary, when wring, s A large number of persons learn shorthand having any intention of becoming reparten are not, therefore, very careful to discover system, but naturally obtain Pitman's, it being known and cheap-Lewis's is neither. Mr. Moseley states that by merely altering in ness a mark of any size and shape, it become!! character. Evidently one character cannot be another by being varied in thickness; the charar representing any letter must remain the same ever be its thickness, although it may be sad to present another letter when altered in thiness, be sides, thicknesses are but comparative. The thick che racter of one writer is the thin one of another, so that, according to Mr. Moseley, every differnt this d a mark forms a new character; therd, as number of different characters must be satt various writers. I notice that Mr. Caribb no means admits the eleventh of "Pitman's Phonography" to be in any red if Levis': system, and at the end of his er hecme of passing an authoritative opinia Fis His tona gred without having learned it. less, for I used to write Pitman's, and made on of it but have changed it for Lewis's to my shrstag. whereas Mr. Clarke knows nothing of Les syste and yet expresses an authoritative opinion on Rather inconsistent. Had he known Levi's of was he would have accepted the challenge in my last and have floored me at once if he could. Unimas none of your correspondents know the Lever system, so that, admitting for argument's sake eve thing claimed for Pitman's, not one can say Len not superior. Among your six defenders of Fi every advantage-real and imaginary-of his sys well advocated; Lewis has not this good fortune: probable I have not stated all the salient points system. That it has been found necessary to so alter and improve Pitman's system is complained. many writers of it as a great nuisance. The exis of this necessity is a clear proof that the system brought before the public long before it was perfe whereas the present edition-the ninety-seventhLewis's is the same as the twentieth of thirty y ago, this system having been matured before published. In this edition are to be found the r for joining many words together, which rules Pit now has, having adopted them, I have been told, er that time. I am not aware whether Lewis's twent edition differs in any way from those preceding The chief objects of shorthand are speed, brus and legibility; by using as few characters as clean requires, and their thickness being immateris!: speed is increased, and the memory less taxed. Le combines these essentials the most manner. in The final sentence of "Mac D.'s " letter doubt presses our common sentiment. FRANK W. GRIEP DYEING, ETC. [308] SIR,-Many of us are obliged to you article "On the Use of Phosphates in Dyeing." articles I am sure are much prized by those com with calico printing, and when you consider '100,000 mechanics (in the strict sense of the wor engaged in this branch of industry in Great Br I only hope that I may have the pleasure of e more of them in your valuable journal; and, the collapse of the British and Foreign Mechani have only you to look to as the exponent in our bra of industry. Anything new in dyeing, colour-mai or chemical discoveries, will be hailed by a now . large section of your readers. And as the French pass us so much in this particular line, I trust you give us your assistance, and put us on a par with o nations. Would one of your readers explain what meant by an acid solution of phosphate of lime、 what acid)? Also, can you give the degrees in Ts dle's hydrometer equal to 50° Baume. I can get t degrees of Fahr. equal to the centigrade thermome easily, but cannot fall on what Baumé's propart bears to Twaddle's hydrometer. ALEX. S. YOUNG. LULL'S IMPROVED FRICTION CLUTCH. = [809] SIR,-The convenience and freedom from ock in the use of friction clutches have rendered em almost essential to many kinds of machinery. any devices of this kind have, however, proved un-tisfactory in use, as they were likely to get out of eder, had in some instances no provision for taking the inevitable wear, and otherwise proved troubleme to manage. I send you from the Scientific nerican a perspective view, with portions broken away show details of construction, of a new clutch, cently patented by Orrin Lull, of Rochester, New ork, U.S. A is the shaft, and B a pulley arranged to revolve on ad independently of the shaft when not clutched. C is an annular disc, or ring, attached to the inside the rim of the pulley by screws, or in any other esirable manner. D is an interior disc, and E an uter annular disc or ring. The disc, D, is made to pproach and gripe the fast ring or disc, C, and therey produce the required friction. The friction discs D and E, are connected with the Sisc F, by a link system, F being keyed to the shaft. The triangular plates, G, are attached to F by screws, And these plates have also adjusting screws, H, which Fake up the wear of the friction discs. Led St tha The hub, I, revolves with the shaft, and is made o slide thereon by the forked lever, J. This lever -aas its fulcrum at K, and is connected with the hub by a band, L, fitting a groove in I. The band L is made like an excentric band, in two parts, and has lugs with which the lever, J, engages. The inner friction disc, D, is connected with the sliding hub through links, M and N, the links, M, being bent, as shown; M being pivoted to D, and N to the hub, and the two being pivoted together at O. The outer triction disc, F, is connected with the links, M, by the inks, P, pivoted at both ends. The links, P, are placed at an angle with the links, M, so that when the outer ends of the latter are moved away from the shaft, the lisc, D, is pressed against the ring, C, drawing it and he pulley, B, against the friction-disc, E, producing riction upon both sides of C, and thus clutching the Pulley to which C is fixed. A collar, Q, is pulled back by the bolt, R, which connects it with the disc, D, whenever the pulley is released from the action of he friction discs, and draws the pulley away from the disc, E, so that it revolves without friction, or emains at rest, as the case may be. The principle of the toggle-joint is embodied in the ystem of links, so that great purchase is obtained, nd the motion of the lever necessary to clutch or rease the pulley is very slight. WIL. K. HIBBET. TO WHAT HEIGHT MAY CLOUDS OR EXHALA TIONS ASCEND? [310] SIR,- In reply to a correspondent, about the subject of the "Exhalations of Air," I may remark to him, having the same books - those of Shaw's Boyle,-that the author endeavours by experiments to prove that such occurrences are only produced by reflection, and in some meagre way by refraction. Let "S... r" consult Vol. I., p. 427, and also Vol. I., p. 673. Let him also refer to the index at the end of Vol. III., and refer to the subject of air, &c. Α ΜΑΝΧΜΑΝ. FREE REED ORGANS. HARMONIUMS. [311] SIR,-I trust you will be able to find me space for a few remarks on the letter of Mr. Eustace Hinton Jones (No. 239), which appeared under the above heading, August 19th. It appears to me that Mr. Jones has come to his conclusions on this subject rather too hastily, led away (no doubt) by the undeniable sweetness of tone and advantages (for certain purposes) of Messrs. Mason & Hamlin's organs. Now it is a fact, not perhaps generally known, but no less a fact, that the harmonium is, with hardly an exception, the most difficult instrument to play well now extant. I do not of course refer to the violin and instruments of that class, which belong to quite a different branch of the science, but to instruments of its own species, viz., the organ, seraphine, &c. No instrument, perhaps, of any class requires so much management to display it to advantage as the harmonium. But this difficulty once overcome, the firstclass harmonium affords to the musician an almost endless field of beauty and variety. That this is the case will not be denied by any one who has heard a decent harmonium really well played. I will proceed to take Mr. Jones's objections seriatim. In the first place Mr. Jones says, "the tone is of the reed, utterly and irretrievably reedy." This doubtless is the chief objection to the harmonium, but there is the greatest difference in this respect between one harmonium and another, and even in instruments by the same maker the quality of tone varies very perceptibly. In this point even the player has much in his power; for example, in a 13-stop Alexandre the use of the two 16ft. tone stops (the clarinette in the treble, and the bourdon in the bass) played an octave higher than the music is written, will give a very agreeable diapason tone, which will render a return to the more reedy stops an agreeable variety rather than not. Endless are the pleasing changes thus to be extracted from even the 18-stop Alexandre. Mr. Jones's next objection, viz., that the bass overpowers the treble, is an unfair one. It only applies to the six-guinea harmonium, and even then by a judicious use of the upper octaves, and by carefully studying how to keep the bass subordinate to the other parts, great perfection of playing may be arrived at. And on the large harmonium the division of the stops into treble and bass renders it entirely the player's own fault if he suffers his right hand to be overpowered by his left. It is the almost invariable habit of the majority of lady players and inferior performers on the harmonium to take the bass in octaves with the left hand, and let the right hand play or slur over the other parts as best it may. It is this which throws the bass into such prominence, as the lower notes on the manual of a six-guinea harmonium are very powerful on many instruments, indeed, inordinately so. Mr. Jones says that the sluggish intonation of the harmonium renders it useful for only the slowest of music. This is certainly not the case, as I have not only heard performed on it the most brilliant accompaniments to operatic airs in public, but have also myself accompanied many of the airs and recitatives in the "Creation," most of which are very brilliant indeed. I have also witnessed a very creditable professional performance of "Faust," in which some of the most brilliant passages were beautifully executed on ordinary 24-stop harmonium. This will, I hope, convince Mr. Jones that he has condemned the harmonium too hastily. He next says that the harmonium, though better for a church than the discordant instruments it often displaced, is still very bad, both from the impossibility of distinguishing the air, and the impurity of the tone, which causes it to cut through the voices, and drown them with its buzz instead of supporting them. Mr. Jones must really not be angry if I ask him, after this sweeping condemnation, whether he has ever heard any one play the harmonium besides the village schoolmaster, or some fourth-rate lady organist. I can tell Mr. Jones, from my own experience, both as a vocalist and an organist, that the ordinary 13-stop Alexandre, decently played, makes a most pleasing and efficient accompaniment for the most delicate solo voice. This is not merely my own opinion unsupported by the evidence and experience of others; and as an example of my meaning I will mention a circumstance which not long ago came under my own notice. A new church having been built in the town near which I at present reside, a 13-stop Alexandre was hired for such time as should elapse before an organ could be procured. A young man, pupil-teacher in the school of that parish, used to play upon it. The music was not liked; the choir were drowned. "But," said the friends of the musical genius (for such he was widely considered), "what can the poor fellow do with a wretched instrument like that? Wait till we get an organ." Well, an organ was procured, and the harmonium went back to the shop from whence it came. Shortly afterwards the professional organist of the parish church in the town gave Handel's "Judas Maccabæus," with the accompaniment of the harmonium and piano. He accompanied all the solos himself on the harmonium. When the concert was over, all present, among whom were many excellent judges, were unanimous in admiring the beautiful quality of the harmonium upon which the conductor had played. Imagine their astonishment on learning that it was the identical instrument which they had so often condemned at the new church, and that it had not been tuned or otherwise altered since its removal thence! Now I wish it to be understood that although I thus stand up for the harmonium, I am clearly alive to the beauties of the Hamlin organ. To a person for whom the mastery of the expression stop has proved too much the American organ will indeed be a boon. But for many purposes, such as the performance of the accompaniments of operas or oratorios, where the societies by which they are performed cannot afford a full band, the Hamlin organ will, never, in its present form, supplant the harmonium, for none but the largest of the former have sufficient power for chorus accompaniments. Finally, as for the £100 Hamlin organ being equal to £300 pipe-organ and superior to anything smaller, I must say that that also is not true as a general affirmation. I will not deny that most small pipe-organs are bad and weak, but there are others not so. Forster & Andrews, of Hull, build an organ from £100 to £120 which contains the dulciana, gamba, flute, principal, open diapason, and fifteenth, pedal pipes (8ft. stopped bourdon, 16ft. tone) and pedal coupler, enclosed in a swell, which is equal in point of quality and tone to any large organ I have ever met with. The stops are all voiced on equal scale with those of the same name in a large organ. This organ is superior to any Hamlin organ now in existence. Finally, if a person has thoroughly mastered the expression stop of a large harmonium, and is tolerably skilful at combining the stops, he will go back to the harmonium for certain purposes, even after having tried a Hamlin organ. For drawing-room and church purposes, where ladies are concerned, the latter is a charming instrument; but the feeling and expression to be extracted from a good harmonium by a good player, by a skilful use of the expression stop, would astonish many, and I fancy among the rest Mr. Eustace Hinton Jones. Everything has its use, and the harmonium and the American organ have each their own special office to perform. We may be quite awake to excellences of the one without depreciating the other and condemning it as useless. R. H. NASH. [312] SIR,-If "C. D. C." had given information simply as to the means of cheapening gas, I should either have said nothing or applauded him, even if I found 1eason to criticise his remarks; but when he took up a foolish cry and imputed dishonesty, I, as knowing the truth, felt bound to protest. It is, however, quite out of my wish to maintain a discussion in any form of recrimination, or to say anything with any other view than giving sound information. Thus I may point out that the supposed discrepancy indicated by "C. D. C." (p. 452), is only apparent. In the process of condensation certain light-giving elements contained in the gas as it leaves the retorts are removed, yet it is quite true also, as I said, that the luminous value is not affected, because, as I pointed ont before, when leaving the retorts the gas is of no use as a light-giving agent; to make it practically available the theoretical loss is necessary; but the real point, and that which alone made me intervene, was the unfounded suggestion that this removal, instead of an absolute necessity of the manufacture, was a dishonest and wilful lowering of the value of the gas. The gas referees have recently published a report discussing these subjects, in which they state exactly what I did-viz., that the required purification involved of necessity a reduction in luminous power. If the other chemists who differ from me as "C. D. C." says on this point, will only prove what they say, their fortune is assured, for "C. D. C." is only just to the companies in admitting their eagerness to adopt any improvement; the addition, as to its being in their own interest and not in that of consumers, is merely one of those jaundiced views common among those who see only public enemies in the companies. In the name of common sense, what is to be expected? Are we to look for self-sacrifice in commerce, or are we not to admit at once, as intelligent men, that the first object of the companies, as of every merchant and every tradesman, is their profit or dividend? The real point is, do they seek to gain it as wise tradesmen, knowing that honesty is the best policy, and that what benefits their customers is to their interest; or do they seek it in the spirit of the adulterating grocer who sands his sugar, &c.? A bargain was specially made by Act of Parliament, and if the companies do fulfil the conditions it is nonsense to complain of them; if they do not, prove it, and the penalty is provided. Now the companies are justified even by the worst case put forth: they have to give according to the |