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411 accuracy of the angles of the ends ; they cumstances next to be considered are, the were then laid in a horizontal position placed height of fall, the supply of water, and the at the required angle, and the collar-beam nature of the work to be done. inserted 4 inch deep into each principal, and These positions being laid down, the secured by bolts 3 inch diameter; the mode author proceeds to examine the relative effi. of raising the roof is then described.

ciency of water-wheels of various construcSome of the advantages of roofs of this tions. construction are stated to be, economy in The undershot wheel acted upon by the materials and workmanship, with lightness velocity of the water when confined in a and simplicity, and that all sagging of the rectilinear course, or when hung freely in a timbers may be rectified by screwing up the stream : in the former case the efficiency of nuts of the kings and shoes.

the machine is equal to 32 per cent., or The truss is recommended for buildings nearly frd; in the latter the ratio is 42 per where lofty apartments or coved ceilings are cent, or about şths. required, and also for its presenting so few The breast wheel is generally applied to points for the suspension of heavy weights falls of from 4 to 8 feet; in these the effi. that may subject the timbers to strains for ciency reaches as high as 60 to 65 per cent. which no provision has been made.

of the mechanical effect of the fall of water. From the examinations that have been The buckets being filled to grds of their made, this roof seems to answer satisfacto capacity, their velocity is seldom less than rily : it has been erected three years and a from 7 to 9 feet per second. half, and has sustained heavy falls of snow, The consideration of this wheel led Poncebut the ridge and rafters have preserved let, in 1824-25, to the invention of the their lines perfectly, and the walls show no “ undershot wheel with curved floats,” the signs of having been subjected to undue efficiency of which has been found equal to pressure. The design of the roof is simple, from 65 to 75 per cent. The velocity of its appearance light, and it may be consi this may be 55 to 60 of that of the effluent dered an interesting specimen of the art of water-a velocity equal to that due to nearly simple carpentry, assisted by iron-work. the whole height of fall; hence the effi.

ciency becomes" about double that of the March 22, 1842.

ordinary undershot wheel.” This wheel has

not been much employed in Great Britain, Remarks on Machines recipient of Water

although frequently used in France and GerPower : more particularly the Turbine of

many. Fourneyron.' By Professor Gordon

The overshot wheel is most generally em(Glasgow.)

ployed in Great Britain for falls beyond 10 Notwithstanding the diminished impor feet in height, and some excellent examples tance of water power since the almost uni. occur for work of every description, from versal application of the steam-engine, some rolling iron to spinning silk. Its efficiency situations may still be found, in the mining averages 66 per cent., but has risen as high districts of Cornwall, of Derbyshire, and of as 82 per cent. Cumberland, the Highlands of Scotland, and The economical use of water as a moving generally in the districts comparatively des power, varying in particular cases, rendered titute of cheap fuel, where it is desirable to desirable the discovery of a receiver capable render falls of water available.

of general application, in all circumstances The theory of water power as it now of height of fall, quantity of water, and stands may be announced in general terms amount of work to be done; and after inthus: "The mechanical effect obtained is tense study Fourneyron produced the Turequal to that of the moving power employ bine, the peculiarities of which form the ed, minus the half of the vis viva which the subject of the paper. water loses on entering the machine, and The imperfect horizontal water-wheels minus the half of the vis viva which the which have been used for centuries in the water possesses when it quits the machine." mountain districts of central Europe, and in

Bernoulli recognized the second cause, and the northern Highlands, are mentioned ; soon after, Euler, the first. Borda, in his then are noticed the experiments of MM. "Mémoire sur les Roues Hydrauliques," in Tardy and Piobert, and the allusion by 1767, gave the proposition in precise and Borda to horizontal wheels; then a general general terms: whence he concluded, that description is given of the numerous exto produce its total mechanical effect : “ the periments made up to the year 1825, when water serving as moving power, must be M. Burdin constructed wheels in which the brought on to the wheel with impulse, and water was received at the circumference of a quit it without velocity.'

vertical cylinder, descended in conduits, This principle being admitted, the cir placed in a helical form round the surface of

63 cube feet


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the cylinder, and made its escape at the Knowing the fall and the volume of water bottom : the efficiency of these wheels was to be expended, the Turbine would be made stated to be 75 per cent., but no exact ex similar to its type. Its linear dimensions periments were ever instituted.

would be those of the type, directly as the The defects in all the previous machines, square roots of the volume of water, and inled to the invention of the Turbine, as it is versely as the fourth roots of the heights of now designed by M. Fourneyron : its construc. fall. Its angular velocity would be to that tion may be compared to one of Poncelet's of the type, directly as the fourth roots of wheels with curved buckets, laid on its side, the cubes of the heights of fall, and inversely the water being made to enter from the in as the square roots of the volumes of water. terior of the wheel, flowing along the These practical rules were first made mani. buckets, and escaping at the outer circum fest by M. Combe, of the Ecole des Mines. ference: centrifugal force here becomes a A general review is then given of most of substitute for the force of gravity.

the Turbines erected by M. Fourneyron at The mechanical construction of the Tur Pont sur l'Ognon, at Fraisans, at Niederbine is then given, and its action is thus bronne, and at Inval, upon which last were described. The water, when admitted to tried the experiments which completely estathe reservoir, rises to a certain level, exer blished the reputation of the Turbine as an cising a hydrostatic pressure proportional to applicable machine. The details of these the height of the column, and on the sluice experiments are given, whence the mean rebeing raised it escapes with a corresponding sults appear to be, that the height of fall velocity in the direction of the tangent to being 6 feet, 6 inchesthe last element of the guide curves, which With an expenditure of 35 cube feet of is a tangent to the first element of the water per second, the efficiency wascurved buckets; the water pressing without shock upon the buckets at every point of the

*(for which it was constructed) inner periphery, causes the wheel to revolve, then passes along the buckets, and escapes at every point of the outer periphery ; by These experiments were tried by the apwhich arrangement the size of the machine, plication of Prony's Brake Dynamometer, even for a large expenditure of water, is to the vertical shaft of the Turbine itself. kept within narrow limits.

M. Arago's proposition for employing the The advantages of the Turbines are stated power of one branch of the river Seine upon to be

Turbines, to replace the wheels at the Pont 1st. That they are with like advantage Nôtre Dame, thus giving about 2000 horse applicable to every height of fall, expending power for supplying Paris with water, is quantities of water proportional to the square then mentioned, as also the results of experoot of the fall, their angular velocities being riments with very low falls; showing that likewise proportional to these square roots. With a fall of 3 feet 9 inches, the effi

2nd. That their net efficiency is from 70 ciency of the Turbine was to 75 per cent.

= 0.71 3rd. That they may work at velocities

10 inches much above or below that corresponding to the maximum of useful effect, the useful

The Turbines at Müllbach and Moussay effect varying very little from the maximum

are mentioned, as are the failures of several nevertheless, and

of these machines constructed by other 4th. They work at considerable depths

engineers, and the paper concludes with an under water, the relation of the useful effect

account of a Turbine at St. Blazeux in the produced to the total mechanical effect ex.

Black Forest, where the height of the fall is pended not being thereby notably dimin.

345 feet, the quantity of water 1 cube foot ished.

per second, and the reported efficiency from These advantages are stated to have been

80 to 85 per cent. realized in the extensive practice of M. Fourneyron, of M. Brendel in Saxony, and of Herr Carliczeck in Silesia, as well as


The vexatious and illiberal opposition A comparison of the theory and practice which the excellent system of Wood Paving of the construction is then instituted, and has met with in the parish of Marylebone, the following conclusion is drawn :-That if where it was first introduced into the metroone Turbine has been constructed which polis, and where the largest, and, on the works well under a known fall, expending a whole, best specimens of it yet laid down, volume of water exactly measured, this are to be seen, has led to the formation of a Turbine would serve as a type for all others. "Marylebone Practical and Scientific Asso

2 feet



413 ciation for the promotion of Improved Street the muscular system. Invalid ladies and Paving," under the auspices of Lord Nu. gentlemen may have it worked by servants, gent, Sir Geo. Staunton, Sir R. P. Jodrell, whilst they themselves are simply occupied General Alexander, Chas. Cochrane, Esq., in guiding it. The propulsion of the car. and several other public spirited gentlemen riage may be aided by the effect of the wind of that quarter of the town.

acting on a revolving umbrella, kite, or sail. It is judiciously proposed, however, that With little fatigue, it will certainly convey the Association shall not confine its opera two or three individuals, on a good hard tions to the consideration of wood pavement surface, at the average rate of about 8 miles exclusively, since there exists but little an hour. By 60 revolutions per minute, a doubt, that in the advanced state of che r1:2 of speed will be attained of upwards of mnistry and mechanics, other materials and 10 miles per hour. A pony may be applied methods may be discovered for the forma. when it is considered desirable not to use tion of carriage ways, equally deserving of the machinery. their attention.

The leading objects of the Association, therefore, are to be, 1. To form a museum

ABSTRACTS OF SPECIFICATIONS OF ENGLISH of all the improved systems for making carriage ways. 2. To collect and dissemi. John EDWARDS, of Cow Cross, Gen. nate the most correct information respecting TLEMAN, for an improved strap or band for them. 3. To invite the co-operation of driving machinery, and for other purposes. men eminent for their practical and scienti. Enrolment Office, May 9, 1842. fic experience on this subject. 4. To adopt The flat straps or bands hitherto comsuch measures as will ensure justice and im monly used for driving machinery, are made partiality to inventors and patentees. And, of leather, or of some woven fibrous sub. 5. To pursue such a course as will lead to stance, as hemp or wool ; and all such the introduction of that pavement, which straps or bands are well known to wear for its general utility and economy, shall be away rapidly under the great degree of fricmost deserving the approbation and support tion to which they are subjected. Catgut of the public.

has been also made use of for the purpose We can anticipate nothing but good from of driving machinery, with great advantage such an Association, and cordially wish it in point of durability ; but it has been so every success.

employed in the form of cords only, consisting of strings or threads of catgut twined together, and solely adapted to run in

grooves. The improvement which the A PASSENGER PROPELLED LOCOMOTIVE

subject of the present patent, consists in REMARKABLE PERFORMANCE.

making flat straps or bands suitable for run(From a Correspondent.)

ning on plain surfaces or drums, of catgut, On Saturday last, a very successful trial and of any required breadth or length, or of was made at Holywell (Flintshire) of a car endless lengths, without any joinings being riage constructed by Mr.P.Williams, surgeon, visible, or at least there being any inequaliof that place, to run on common roads, and ties of surface at the joinings. The strings to be propelled by the passenger or passen of catgut are woven into these flat bands by gers. Two men propelled themselves in it, means of a loom of the sort used by wire with little difficulty, up a hill of considerable weavers, and by following the same methods rise, at the rate of at least 6 miles an hour ; as they practise ; and the joinings are made for a good walker could not keep pace with by any of the well-known methods of splicit, and even had to run to follow it. On a ing, care being taken to cut or burn off the level they attained a speed of 9 and 10 miles ends of the interwoven threads or strands an hour, and returned down the first men. close with the surface of the strap or band. tioned acclivity at the rate of about 15 miles JAMES YOUNG, OF NEWTON LEWillows, an hour. The experiment was most satis IN THE COUNTY OF Lancaster, CHEMIST, factory, and justifies the opinion that this for certain improvements in the manufacture carriage is probably the best combination of of ammonia and the salts of ammonia, and power which has been yet applied to such a an apparatus for combining ammonia, carpurpose.

bonic acid, and other gases, with liquids. The parties to whose use this carriage Enrolment Office, May 11, 1842. seems most adapted, are young people and To obtain ammonia, Mr. Young fills a invalids. The exercise of propelling it is of retort with two parts in weight of the suba nature to call into operation all the co stance called guano, imported into this lumnal muscles in a most effectual manner, country from Peru and other parts of South and thereby to give great tone and vigour to America, (chiefly for agricultural purposes,)

and one part of slaked lime. He then closes draw it in a hot state through dies. Again, the retort, and mixes the two materials tho. as in the process of drawing the metal beroughly by means of an agitator. The comes hardened, the patentee directs that (if retort is next subjected to heat, (of a mode necessary) it should be annealed by heating rate degree at first, but heated till the bottom it in a furnace, and after the oxide has been is nearly red hot,) which not only sets free removed from it by means of diluted sal. the ammonia of the guano, but decomposes phuric acid, that the process of drawing should the uric acid contained in it, which yields be repeated when cold. When a band of also a considerable portion of ammonia. considerable length is required, it may be But as other gases besides ammonia are necessary to unite two or more bands to. liberated by this process, in order that the gether. "Various methods of effecting this ammonia may be separated from them, the junction are pointed out and illustrated by whole of the gaseous products of the retort drawings. Scarfing the ends and riveting are passed through a condenser of a pecu are considered to be much preferable to weld. liar construction, filled with water. The ing or brazing, as the operation of hammer. ammonia is absorbed by the water, while ing in welding gives a brittleness to the the other gases being insoluble, make their metal, which no subsequent process of anescape through a pipe provided for the pur nealing can remove, so as to give the ham. pose, at the top of the condenser.

mered part the same strength which it had To form solutions of carbonate, sesquicar before ; and in brazing, the union of the bonate, and bicarbonate (salts) of ammonia, two metals is not such as can be depended the condenser is filled with a solution of on or should be trusted to. These bands, ammonia, and carbonic acid passed through when of iron, may vary in thickness from it.

to to of an inch, and in breadth according To form solutions of the sulphate or to the strength required. Flat bands manuinuriate of ammonia, diluted sulphuric or factured in the way described, are stated to muriatic acid is employed for the condensing possess greater strength and durability than liquid.

those of hemp or any similar material of the And for combining generally all soluble same weight; and if extreme lightness, with gases with liquids, the patentee states, that the greatest degree of strength, be required, he finds a condensing apparatus of the par steel may be used instead of iron. In some ticular form described by him, superior to situations where the iron becomes rapidly all others. The advantage peculiar to it, corroded, the bands may be made of copper appears to be that the gases are made to instead of iron or steel. traverse over or through a very large body The patentee's second improvement conof water, by means of inclined shelves, sists in manufacturing flat bands of a com. while the head of water, the pressure of bination of narrow bands or strips of iron, which has to be overcome, is extremely or other metal, which bands, for some pursmall.

poses, particularly in deep mines, possess Robert STIRLING NEWALL, or GATES advantages over the flat bands before deHEAD, IN THE COUNTY OF Durham, for scribed, on account of the greater security improvements in the manufacture of flat against accident or sudden breaking which bands. Enrolment Office, May 16, 1842. such a combination presents. The strips of

The improvements of the present patentee metal are arranged side by side and fastened consist in manufacturing the flat bands used to cross pieces. Metal drawn through dies, in mining operations, and for driving machi. as before described, is used; or metal rolled nery, exclusively of iron or other metals. in strips, taking care to select such as are Three processes are described. According straight and free from flaws, and, if neces. to the first, a flat band is manufactured, by sary, to cut their edges true and parallel, subjecting a piece of iron or other metal of which may be done by circular shears. The good quality, preferring that known as the pieces of which the flat band is to be combest charcoal iron, manufactured in the usual posed are laid side by side, and kept in a way by rolling, to a process of drawing state of equal tension by weights acting over through rectangular orifices, or dies of hard pulleys, while the cross pieces are riveted on ened steel, in the same manner as in the and joined at the end by a butt or by an ordinary and well-known operations of tube overlap joint. The cross pieces may be from or wire drawing. The patentee considers 18 inches to 5 feet apart, the breadth and it to be of importance that the piece of thickness of the component pieces of the metal to be operated upon should be drawn band varying according to circumstances. through the die in a straight line at right The third improvement consists in form. angles to its edge; and as it is difficult to ing a flat band, by weaving narrow strips or roll iron beyond a certain length, he sug wires of metal in a loom, the strips or wires gests that it may be found convenient to which constitute the warp being wound on

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separate bobbins and kept at a uniform tension during the operation of weaving. It is stated to be, in most cases, advisable to have the wire used as the weft of smaller size than that used as the warp.


favour of some one of our Western friends to furnish us with such particulars as may be known to them, of its present state of forwardness? The three principles I allude to are, 1. The fitness or suitability of sheet iron for such enormously large structures. 2. Has the practice of transatlantic steam ship-building, been carried far enough to justify the experiment of magnitude attempted in this case, and is it necessary in a mercantile point of view? (The recent voyage of the Great Western to Liverpool with 28 passengers, appears to prove otherwise.) 3. What are the advantages expected to result from the use of the “ Trunk Engine?" Does it consist in cheapness of first cost, simplicity of parts, compactness and taking less room, or less consumption of fuel ?

Some information on these general heads, as soon as they can be collected, will much oblige many of your readers, as also, Sir, your obedient servant,

May 17, 1812.



CUTED IN THE WOOD-CUT MANNER. SIR,-I here submit a new method of lowering the “ lights” on the surface of some particular engravings executed in the woodcut manner, as, for instance, the copper blocks produced by electrography, and those formed by Mr. Woone's stereotype process : the lines of the pictures in both styles being all one height, on account of the design being engraved on a flat even surface. The metal casts or blocks are first “stopped" out in the darkest tint by the application of a hairpencil dipped in some strong varnish, as that of copal, asphaltum, or seed-lac, the first mentioned being the most preferable ; and then attached to and immersed as positive plate in the single-cell voltaic apparatus used in electro-metallurgic experiments, letting it remain until the parts untouched with varnish have been corroded to the requisite depth. It shonld then be taken out, dried, and the varnish-brush applied to those portions which may be considered deep enough, repeating alternately the varnishing and corrosion, until the cut is graduated to your desire. The character of the engraved lines will not be much injured by the electroetching process, as the corrosion proceeds with evenness and regularity. The more simple application of nitric or other suitable acid, might probably be found efficacious when the design is of a bold or rude character, and strongly lined.

As a mode of lowering blocks of the above description for typographic printing has long been sought for, the insertion of this little bint may be of service to some of the readers of the Mechanics' Magazine. I have the honour to be, your obedient servant,


NOTES AND NOTICEI. The "Locomotive" Steamers.-A new steamer has made its appearance in the river, with the name of the "Locomotive No. 1," and is to be speedily followed, it is said, by several others of the same description. It is a small boat, of the class that ply between the bridges, and is called the “ Locomotive," from the circumstance of its being fitted with boilers of the same sort as are used in railway locomotives - namely, high-pressure tubular boilers. There is much fairness in this choice of a name, since it indicates at once to all concerned the degree of danger to which they are about to be exposed in embarking in the vessel. People accustomed to travel by the River boats, which are generally worked at 4 and 5 lbs. pressure, might but for this warning, have justly coinplained that they had been entrapped into a travelling proximity with a pressure of from 70 to 80 lbs. Whether there is any actual danger or not attending the use of such high-pressure boilers, may be matter of question; but there can be none about the perfect propriety of letting every one know what he has to look to. А correspondent (Vulcan) suggests, that it would perhaps be still fairer if the boat were called “The High Pressure No. 1."

X Floating Manufactory.-Amongst the strange craft to be seen navigating the Ohio, is a floating “Glass works." "A large boat," says Mr. Le Cras, “is fitted up with a furnace, tempering oven, and the usual apparatus proper for such an establishment. It is on full blast every night, melting glass ware, which is retailed all along shore, as the • Works' float down the stream."

Quick Packing.--A workman at the Sandwich (Mass.) Glass Factory has been known to roll in separate papers in one day five thousand three hundred and sixteen tumblers. Some one noticing the pumber by a watch, saw him pack twelve dozen in six minutes!-Le Cras.

Weaving and Patriotism Extraordinary.— The Limerick Chronicle has a strange story about a ar ryowen weaver, of the name of Lyons, who can produce “a man's apparel complete from the loom without stitch or seam."

“We have seen," says our contemporary, coats and trowsers, with but


Sir,- I have, in common, I dare say, with many of your readers and subscribers, been for a long time expecting to see some account of the progress made in the building of the above vessel, particularly as it is understood there are three great principles in the course of being tested in her construction. Will you be kind enough to allow me to ask the

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