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Following our usual course, we commence and from other causes so common to the ordiwith the ground floor department, the sides nary cast-iron roller. Besides securing in one of which are appropriated to the heavy ma- roller a one, two, or three-horse implement at

chinery. Heavy indeed is the first machine pleasure, the increased weight is employed MECHANICS MAGAZINE. that meets the sight, at Stand No. 1, which is directly on the surface of the land, with the

occupied by Mr. II. Sykes, of Upper Thames- highest percentage of crushing power, yet street. Here was a gigantic 20-horse power without increasing the friction on the bearings

---nominal, of course-portable engine, the (and consequently the draught of the impleLONDON: FRIDAY, DECEMBER 11, 1868.

largest we ever saw in the building, and which ment), as is the case when the old clumsy plan in this sense was a novelty. Mr. Sykes also of loading the frame is resorted to. We con

exhibited a very good vertical engine, and sider this such a special improvement that we THE SMITHFIELD CLUB SHOW.

an improved mill for steam power. This is propose in our next number to illustrate and TE all have our landmarks--political, a mill that will be found very useful for mix- describe this apparatus in detail. Messrs. flight of time and announce the close of another to which crushing mills are applied. Messrs. crusher and press wheel roller, into which period of existence. Ours certainly is the Robey, of Lincoln, had as usual a good implement a great improvement has been Smithfield Club Show, and the one which to-day show of engines, which are worthy of some introduced by substituting a solid wroughtsees close at the Agricultural Hall, Islington, thing more than a passing allusion, especially iron frame, with steerage wheel and guide reminds us of the approaching end of another their vertical stationary engine, which pos- rod, for the ordinary wood frame and shafts, year, and the close of another volume. As sesses great advantages over those of the whereby a saving of at least one-third in has been our wont for many years past, we horizontal type. Messrs. Robey's vertical horse-power is effected, and the man is enabled purpose placing before our readers the leading engine is well attached to the boiler, a strong to drive three horses abreast and steer the features of the Show for 1868, as regards the foundation plate carrying the whole. This implement to the greatest nicety without the agricultural implements and machinery. But foundation plate serves two other pur- assistance of a boy. This firm also exhibit before so doing, we have a word to say with the poses, being made to form the ash-pan a corn-grinding mill, in which the grinding Committee of the Smithfield Club. For years and to serve as a tank, in which the feed surfaces are made of cold blast white iron of past, we have been in the habit of receiving- water is heated. Altogether these engines a kind specially prepared, and in this consists in common with our brethren of the press are worthy of commendation. We would the great superiority over all others. Unlike - a pass to the exhibition on the first day of the call especial attention to their single corn- all steel-surface cutting mills, which have Show. On the present occasion, however, we grinding mill, which has been much im- hitherto been known, it requires no re-cutting did not receive one, and when we found that proved in make since last year. This mil deed, not allowing of it; but when the grinding others had, conceiving we had been accidentally is well adapted for large occupations where - the extremely hard nature of the metal, inoverlooked, we wrote to the secretary asking a portable steam engine is employed, as surfaces become dull they can be sharpened the usual favour, in order to facilitate the pre- it will grind all kinds of grain for farm pur- by running coarse sand through the mill, and paration of our notice. After waiting nearly poses. The stones and machinery are fixed in when worn out can be replaced entirely at a à week without receiving either reply or a metal frame of a neat and compact design, very small cost. Messrs. Amies also show a acknowledgment, our representative called whereby it is rendered both strong and port- model of their new combined straw, hay, and on the secretary upon the subject. No ex- able. This mill is simple in construction, being corn elevator. This machine is constructed planation was given to him, but he was briefly thus easy to manage and adjust; the top or to carry straw from the steam thrashing informed that the Committee had issued all runner stone is carried round by the upright machine, and hay, as well as sheaved or loose the passes they intended to issue to the press. spindle, which receives its motion from a pair corn, during the hay and harvest seasons, Of course, the Committee have a perfect right of bevel wheels, one of which is geared with without any separate horse works. This is to admit whom they will free of charge ; but wood. It is fitted with fast and loose pulleys, accomplished by raising the body of the as old servants of the public, and faithful and altogether is very compact and well made. machine, by means of racks and pinions, to chroniclers of the Smithfield Club Show, we Messrs. Garrett and Sons, of the Leiston such a height that a horse can work underdid expect the usual compliment of a pass, or Works, Saxmundham, appear in their usual neath it, and the produce is then delivered at least the courtesy of a reply to our written strength, with seed and other drills, thrashing, to an elevation of 30ft., and the most severe application. However, we waited until the finishing, dressing, and other machines, port- part of the hitherto laborious manual operahour of two on Monday last, paid our five able and other engines. Their chief feature tion is saved a light nag horse being equal shillings, and walked in, feeling perfectly is an excellent agricultural self-moving engine, to the work. When harvest is over, the independent, and glad to have contributed which weighs some three tons less than the machine is let down to the ordinary height, our mite towards the support of an institu- usual engines of this class. In many districts, and is then suitable for being driven in the tion which we have always held to be worthy objection is now raised against the trouble of usual manner from any steam thrashing of every support. And, now, having had moving portable engines from farm to farm, machine. our say, we will turn to the Show itself. and the attempts which have hitherto been

Messrs. Hornsby and Sons, of Grantham, Of course, the beasts were the great public made to introduce self-moving engines have having made steam engines their leading manuattraction, and these, although apparently not generally failed, on account of the weight and facture ever since their introduction, of course

as last year, were splendid cumbersomeness of the engines employed. To occupy a prominent position in the Show in examples of breeding. We are, however, obviate the difficulties which have arisen from respect of quality and finish. The resources quite unable to recognize the necessity for the use of such engines (which were rever in- and experience of this firm have enabled them developing pigs to such an extent, that it is tended for anything but heavy road draught), successfully to carry into effect the motto almost impossible to tell which is one end and Messrs. Garrett and Sons have brought out of the Royal Agricultural Society of Engwhich is t'other. To see these semi-animated this light self-moving engine, which will draw land, “ Practice with Science,” so that their masses of fat, spasmodically gasping for a thrashing machine and elevator with ease, patent portable engines have for years past breath, their snouts—where sufficiently promi- and pass over soft land and other places where maintained a high position, and every modern nent-propped up by chocks of wood, and it would be almost impossible to take machinery improvement and appliance of mechanical their organs of vision completely shut in, does by horses. The weight of the new engines skill is employed to keep them in advance of seem to us a condition of things in which is but a few hundred-weights more than a all competition. Messrs. Tasker and Sons, neither purposes of utility nor ornament are portable engine of the same power. It can be of the Waterloo Iron Works, near Andover, attained. On the contrary, a fine healthy steered either by a man in front, or a horse have, amongst other things, a good 8-horse feeding we think-and it may be want of taste can be attached with shafts. The tender power portable steam engine, in which some on our part--would do much more to improve carries water and fuel sụtficient for ordinary details of construction are worth notice. It the interests of the pig market, than the pre- thrashing journeys. Thus we have a step in has a large amount of heating surface, as well sent system of feeding swine up to the condi. advance, which will secure a demand for as ample water space around the tubes and tion of panting ungainly rolls of fat. But engines of these makers. We understand that fire-box, is strongly stayed, and constructed passing on to our more legitimate sphere- Lywood's patent rick ventilator, as manufac- with regard to efficiency and economy in fuel. the mechanical developments—we first note tured by Messrs. Garrett, continues in great But perhaps the chief feature of the engine a decided improvement in the arrangement of favour with agriculturists

is that it is fitted with a new adjustable the Show in this department. The Committee Messrs. Amies and Barford, of Peter- eccentric, which has been patented by Messrs. have done well in preventing that overcrowd- borough, have several matters well worthy of Tasker, By means of this eccentric the ing and commingling of the stands which we attention, the first of which is their adjustable travel of the valve can be altered in the same have observed in past years. The exhibitors, water-ballast wrought-iron field roller. These manner as is usually done by the ordinary doubtless, have also to be commended in this rollers possess the great advantage of being expansion valve, and with the same results, respect, for by not attempting to show every- adjustable as regards weight, one roller secur- viz., a smaller amount of steam is required thing they make, they enable their leading ing the same results as two of ordinary con- for working the engine, and the amount of manufactures to be properly examined. Tak- struction. For light work, the cylinder is fuel consumed is consequently less. The ing the show as a whole, there are not so used empty, for heavy duty it is filled with extra valve, valve rod, and eccentric required many striking novelties this year as usual; water. The cylinders and frames are made for the expansion valve are dispensed with, although upon investigation we discovered entirely of wrought iron, combining great the working parts are fewer in number, the many detail improvements which will interest strength with durability, and are entirely free friction is considerably reduced, and a great our readers.

from the liability to breakage on bad roads, saving is effected in the use of oil. The

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patent eccentric appears in every way as corn elevator was driven off the first blower superior style, and with all the most recent durable as the ordinary one, and is so simple spindle ; it is now driven separately, so that improvements. Messrs. E., R. and F. Turner, that it can be adjusted by a common labourer. the speed of the elevator can be altered with of Ipswich, had a couple of good portable At the adjoining stand we found an altera- out affecting the blast. There is also an engines, but their speciality is mills, cake tion in the name of the firm, that of Barrows extra joggle board in communication with breakers, &c., of which they had a good show. and Stewart, of Banbury, replacing that of the second fan, and altogether the machine In their stone-grinding mills, the upper stone Barrows and Carmichael. We regret to find is very satisfactorily arranged. In the grub- revolves and is made to raise or lower by a this to be owing to the death of Mr. Car-bers a moulding board has been added, by hand wheel, as more or less pressure may be michael, whose name was well known in con- which a very good furrow is made. Mr. required. They are more particularly for nection with agricultural machinery. We Underhill shows a plain but good portable steam power, and are fitted either with Derbyhave nothing new or special to report of the engine.

shire Grey or French Burr stones. Messrs. new firm, who still maintain the high cha Messrs. J. and F. Howard, of Bedford, are, Turners' roller malt mill is made in conjuncracter of the old for engines and machinery, as usual, strong in steam cultivating appa- tion with Boby's screen, and the combination Their portable engines have been improved ratus. This firm has now been engaged in proves exceedingly useful for breweries. The in various points of detail; the boilers are the manufacture of steam cultivating ma- general complaint of bad wear in these kind multitubular, and constructed so as to secure chinery for upwards of eleven years, during of rolls is obviated here by the pressure being unusual strength, and the greatest amount which period they have cultivated their own equalized on both bearings by means of a of steam space, the shell being continuous farms by steam power. With so extensive an compound wedge, and rendered elastic by from end to end, avoiding the divisions known experience both in using and manufacturing, strong spiral springs. The oilcake breaker as fire-box, barrel, and smoke-box.

they have of necessity acquired an intimate by this firm breaks cake for lambs equally as Passing on to the next stand—that of acquaintance with the subject of cultivation well as for beasts or sheep. Besides the Messrs. John Fowler and Co., of Leeds—we by steam. They have re-arranged some por- ordinary rollers, which by reversing the find the usual array of steam ploughing ma- tions of their engine; the steam cylinder, direction enables it to break for sheep or chinery, for which they are so justly cele- which was formerly mounted on the boiler, is beasts, it has a second pair intercepting the brated. The special novelty at this stand is now placed under it, as in the locomotive. cake as it falls from the sheep rolls and reMessrs. Fowler's improved patent cultivator The crank shaft and gearing are attached to ducing it to a suitable size for lambs; these to turn at the ends. The construction of the framework, and are independent of the rolls admit of adjusting to vary the sample, this implement is simple and effective, com- boiler, which relieves the strains on the latter. and may be instantaneously thrown in and bining strength with a minimum of weight; Another important feature is that the wind- out of use. the appliances for steering, lifting the imple- ing drums are both geared direct from the Messrs. Woods, Cocksedge, and Warner, ment out of work, and turning it, are so well crank shaft. This engine will work upon any of Stowmarket, have some excellent examples adapted and nicely arranged thatit is managed system, either fixed or moving. Messrs. of vertical engines, and a large assortment of with the greatest ease. This implement can Howard exhibit a great variety of mowing mills, root cutters, &c. We especially noticed be made any breadth, to suit the varying re- and reaping machines, which they construct a very complete 24-horse power engine, fitted quirements of different farms, and by aid of almost entirely of iron and steel, and fit on with a new horizontal two-ball governor. moveable parts, each implememt of itself is the interchangeable system. This firm also The feed apparatus was very neatly arranged, adapted to meet these requirements; the body showed a full-sized model of their safety a circulating pump being åtted. The great of the implement can be made 6ft. or 8ft. steam boiler on the tubulous principle, which advantage of these engines is that they occupy wide, it is then adapted for strong land; when has been fully described and illustrated in less room than any other form of engine. on lighter soils, sides or wings can be applied our columns, and which is meeting with every They require no fixing ; brickwork or foundato make it any breadth required. The plan success in practical use. Messrs. Holmestion is not necessary ; they can be readily of working is as follows: The rope on each and Sons, of Norwich, show some excellent removed and worked by an ordinary labourer, engine is attached to a straight lever in front portable combined thrashing and dressing and may be used in places which would be of the cultivator, this lever is fixed on an machines. In their last new machines, Messrs. Otherwise excluded from using steam power. upright spindle, on which is a segment con- Holmes have retained all the valuable patented The boiler is of the best description, and nected by a chain to the road wheel axle improvements of their. 1862 machine; but tested to a very high pressure. The ash-pan (which is a double crank and carries the have, in constructing this machine as a finish- is provided with a door for removing the frame); when the cultivator is pulled up to ing machine, had special regard to the best ashes and regulating the draught. The flythe headland by one engine, the other engine position of the finishing apparatus, so as to wheel shaft is on bearings separate from the across the field starts away immediately, the have the corn delivered in that part of the boiler, so that they never get heated. Mr. rope pulls the lever in front round, the seg- machine free from dust, and the least affected C. Burrell, of Thetford, exhibited a traction ment draws up the chain, which turns the by the wind, and in the most convenient posi: engine, single cylinder, of 10-horse power, crank axle and lifts the implement out of tion for taking away. The arrangement of for agricultural purposes. This engine is work, the rope continuing to pull brings it these machines is simple, due regard being well finished, and is fitted with a driving round into new work; the man (who has had in the fittings to durability and facility chain on each side, which distributes the never left his seat) drops it into the land, and of repairs. This firm also exhibit a very power, being driven from each end of the when across the field the same operation is good small portable engine ; a great number crank shaft. The driving pinions are of repeated.

of these engines have been sent abroad. wrought iron, case hardened; clutches with Messrs. Clayton, Shuttleworth, and Co., are The Beverley Iron Company, of Beverley, expansive levers are attached, so as to be well represented by their portable engines, continue to put in a strong appearance under the control of the driver when turning which they make their speciality. They as regards carts and reaping machines. corners. The driving wheels are made of have now manufactured some thousands of Their clod crusher, too, continues in great cast and wrought iron, combined with a these engines; the number on one in the show favour, having taken the first prize at Leices- wrought-iron tyre on the outer edge of the was 8,864. In this engine the cylinder ter and a first-class silver medal at Wetherby rim. It has a large tank to supply the is steam jacketed, and all the working during the past summer. This company have boiler, and the man stand has ample room parts are on the outside or top of the boiler, also brought out a very efficient grass mower for carrying coals. The steerage is very and can be seen and got at by the person in at a low price. They exhibit their patent good, being worked by a pitch chain round charge at a moment's notice. It may be iron wheels and axle, in which the naves are a segment to take up the slack chain. All readily reversed, so as to drive in either of cast iron, chilled so hard inside the box or the working parts are well arranged, and direction. The exhaust pipe is on the outside bush part as to resist the file; and fitted with the workmanship is sound. Mr. Burrell of the boiler, and is formed with a branch, patent wrought-iron oil boxes, bevelled spokes, also exhibits a machine for drawing clover to which a tube is attached for conveying a and convex tyres. The axles are forged from or trefoil seed, with a patent separating screen portion of the steam to the feed water, thus the best scrap iron, turned, and case-hardened. for taking out stone, glass, &c., from the treeffecting a considerable saving in fuel.' We Their carts and waggons are admirably con- foil seed. This machine is well finished in would also call attention to the fixed steam structed and fitted; it only requires a glance all its parts. engines made by this firm, which are well to see that both workmanship and materials

Although we have noticed the stands of a constructed, special regard being had to are of the best kind.

great many exhibitors, our task is but half economy, efficiency, and simplicity. Their Messrs. Aveling and Porter, of Rochester, performed. We shall, however, resume the traction engine, too, is worthy of notice. An show a 12-horse power steam ploughing en- subject in our next number. We cannot, important feature here is the self-acting gine, and an 8-horse power agricultural loco- however, close our present notice without redifferential motion, which enables the driving motive. We also found at their stand a very ferring to a novelty in umbrella construction, wheels to accommodate themselves to the light but strong engine which has been con which we met with in the arcade when leavsharpest curves, without strain or loss of structed for the purpose of drawing heavy ing the show. This is the invention of Mr. power; both wheels at the same time are guns and other matériel for the War Depart- Henry Smyth, of No. 21, Little Trinity-lane, kept in gear, and receive the full power from ment. This engine is fitted with differential Cannon-street, City, and is a very perfect the engine. The absence of this feature in gear for turning sharp corners, and is steered umbrella. It embodies an entirely new prina traction engine is a defect, detrimental from behind by the driver. The engine isciple of action, by which wire springs and alike to its efficiency and durability. Mr. named the “ Prince Arthur," and on leaving connections are all dispensed with. It is W. S. Underhill, of Newport, Salop, has inn- the Show will be handed over to the Royal exceedingly strong, and will bear very rough proved some details of his thrashing machine, Engineer Department. It is fitted and finished usage without fear of dislocated joints, and which has added to its value. Formerly, the in Messrs. Aveling and Porter's well-known from its construction is not liable to be turned

when not required; the cord traverses the en- ing fan. If we remember aright, this platill placed in different positions, and first sup

“inside out" by the wind. It is, in effect, Eastern train, fitted with Walker's electrical the test of time? Certainly not. With constructed on sound mechanical principles, system, was tried. This consists of a wire run- regard to the different plans of electrical and waits only to become known to render it ning throughout the train, connected to each communication, we find, in examining them, popular.

compartment with a small instrument, which, that they not only fulfil all the necessary re

when pulled, releases an indicator outside the quirements, but that they also have stood the COMMUNICATION BETWEEN PAS- carriage, and makes electrical contact between test of time-of time not of days, but of years.

the wire and rails. It is connected also to a The principal objection to them in railway SENGERS AND GUARDS.

bell and battery on the van, and to an indi- eyes is, it seems to be, that the plan is elecA? T length it seems that some steps are to cator and semaphore on the engine. When the trical, and railway managers have not yet got

be taken by the different railway com- apparatus in the carriage is pulled, the bell to look upon electricity with great confidence. panies to provide the long wished-for com- in the van immediately rings, and the indi Let us see how the electrical system has munication in trains in motion between pas-cator on the engine is moved. It is possible stood the test of time. Since May, 1865, the sengers and guards, and between guards and throughout the journey for the guard to in-up and down Exeter expresses have been drivers. By the Act passed in the last session, terchange communications at any time by running, fitted with Preece's system, it was enacted that communication should be means of this bell. The trial was not satis- with perfect success, communication being carried out in certain trains after the 1st of factory with this plan, as signals were weak, continuously kept up from one end of the January; a clause for this purpose being and the bell would not ring; this was evi- train to the other. The trains are still runspecially introduced, the bill for a similar dently due to the fact that the train had been ning with the same success. On the South purpose, brought in by Mr. H. B. Sheridan, allowed to run the night before, and experi- Eastern, the Dover express was fitted with was, in consequence, not proceeded with. The ments tried with it; the apparatus was left Walker's plan, a plan almost identical to the near approach of the stipulated time will ac- with the battery on, so that it got exhausted above. It ran with such success that the count for some little energy on the part of It cannot be said to be due to the faults of the South-Eastern have now running four up and railway managers, but we may expect some system, as it has stood for some time the four down trains daily, running in the aggrelittle time yet to elapse before any definite practical test of time. The remainder of the gate 624 miles per day. For this purpose, scheme is settled upon. We must, however, journey was occupied with experiments on 200 vehicles of various kinds have been fitted make some exception in favour of the South-Harrison's plan ; in these trials it was found up. On the North-Western, the London and Eastern Railway, who have eight of their ex- that the whistle would sound, but it required Wolverhampton express has been fitted up press trains fitted up with an electrical system great force to pull the cord, and it was quite with Martin's plan since January last, and of communication; the South-Western have possible to raise the alarm without disturbing has been running 250 miles per day with also for a long time had both their up and the indicator.

unvaried success. These three plans, or, down Exeter expresses fitted with a commu On the following day, experiments were indeed, we may with safety say, the same nication between passengers and guards ; the tried with a train made up partly of South- electrical system, as applied to communicaNorth-Western also have been running a Western carriages fitted up with Preece's tion between passengers and guards in trains train fitted with communication, but as re- electrical system, and partly of North- in motion, is at the present moment fitted gards the other railways they have done but Western carriages fitted up on Martin's plan, to trains which are now doing, and have little. With a view to find out some parti- The system adopted in the latter is identical been doing for some time past, an aggregate cular plan that might be recommended for with the former, differing only in detail. A journey of over 1,300 miles per day. We have general adoption, å meeting was lately at- wire is carried through the train, connected here as strong a practical proof of its success tended at York, by most of the general ma- between the carriages with double couplings; and its perfect adaptability to the requirenagers, to experiment upon a variety of plans in the vans are bells and batteries, and in the ments of the case as can be wished; of its fitted to various trains, specially sent there to carriage is an apparatus for raising the alarm. test as regards time we have stated sufficient be experimented upon. The meeting was under In Martin's, it consists of a handle, which is to convince the most sceptical. The three the presidency of Mr. Allport, general ma- to bo pulled, and then becomes locked. In plans, with but a slight modification, can be nager of the Midland, and lasted for two days. Preece's, the hand is moved as indicated, but invariably worked together, so that the inMr. Allport has been well known for some before it can be moved it is necessary to break sertion of foreign stock will have no effect. time as being greatly opposed to the public the glass face of the case. The object of the Can we say the same of any other plan? having means placed in their possession for glass is obvious—to prevent mischievous per We have watched the various plans brought exercising any control over a train, and it, sons from raising an alarm unnecessarily forward from the first, and have, on more than therefore, may be well imagined that the ex-These plans were tried every way, and one occasion, brought the subject before our periments were of a crucial nature.

answered admirably. They were then joined readers. We again bring the matter forward, The following is a concise description of together and were equally successful, com as being now in a more advanced state than the various plans experimented upon :-On munication being maintained from the one heretofore. The new Act is already beginning the first day were tried the plan of Mr. Rams- van to the other; in fact, the results perfectly to bear its fruit, and we may trust that soon, bottom, fitted to a North-Western train ; Mr. justified the anticipations formed from the whenever our readers may wish to travel exWalker's system, fitted to South-Eastern statements given of the amount of experience press, they will always have within their stock; and Mr. Harrison's, fitted to a North- obtained from them. Signals were readily reach a means of communicating, when absoEastern train. The first and last are purely received on the engine and answered back. lutely necessary, with the guard. mechanical, and in some respects similar; the In Preece's, an indicator was used; in second is purely electrical. In the two me- Martin's, a bell only—the latter, in the clatter chanical systems, a rope is used; in Ramsbot- and noise of the engine, being rather difficult EFFECT OF THE POSITION OF tom's, each vehicle or coach is fitted at the to hear when not expecting it. A plan of

THE LOAD UPON CONTINUOUS ends with a heavy iron hook, projecting out Mr. Kiersley's was also tried. This consisted about 15in., and made so as to fall inwards of a gong in the carriage, struck by a revolv

GIRDERS.No. IV.

ET us now examine the action of a load tire train, about mid-height, from the rear has been largely tried in Norway. We will van along these hooks to the front van and not trouble our readers with this plan, as it pose it uniformly distributed over one of the to the engine, where it is in connection with has been proved over and over again that side spans, A B. Manifestly, the influence of apparatus for raising an alarm ; it is always any system depending purely upon sound is this load will be felt to some extent upon both kept, by means of weights, in a state of ten- not to be relied upon.

of the other spans, the intensity of it diminishing sion, so that when it is required to give an We may remark that with regard to the as the span is situated more remotely from it, alarm it is only necessary to cut the cord. In first plans tried—those of the cord—there are until it becomes at last inappreciable. If, in Ilarrison's plan, a cord is also used along the many objections. In Ramsbottom's, the cord addition to the load upon the side span A B, train, from the rear van, along the carriages, is in the way of the door, and projecting another is placed upon the central and adjaabove the doors, into the different vans, to the hooks must be objectionable. In starting cent one B C, the strain upon the former beengine, to the whistle of which it is attached; trains and making them up in a hurry, adding comes diminished, as the load upon the to each carriage is also fixed an indicator in carriages on at the last moment, it is almost central span strengthens that part of the connection with the cord; when it is necessary impossible to keep the cord perfect. We girder between B and F. This is also perto raise an alarm, the cord has to be pulled, have ourselves seen it over and over again ceptible from the similarity that exists beand the whistle sounds. The similarity of with the common bell and cord plan. When tween loading the central girder, and fixing these plans is in using a cord, but the mode the train is heavy the force necessary to apply the part over the pier firmly and immoveably. of raising an alarm is exactly opposite. In the sufficient tension is frequently, from hitches In the latter case, the girder A B would beone case, the cord is kept at a certain ten- and other causes, sufficient to break the cord. come converted into a beam with one of its sion, which has to be destroyed; and, in the We have been assured by men having prac-ends firmly fixed, and would thus be stronger other, the cord must be maintained somewhat tical experience of many years, that the cord than if both ends were free. Consequently, slack in order that the alarm might be raised cannot be depended upon over a certain num- the greatest strain upon the booms or flanges by applying tension.

ber of carriages. Looking upon the require- of the side spans occurs when they are covered Experiments were first tried with Rams- ments of the case, and the necessary ends to by a moving load, and the central span unbottom's plan, running from York to Scar- fulfil, we unhesitatingly give our opinion that loaded. By similar reasoning, the greatest borough, and answered satisfactorily, although the cord system falls short of anything like a strain will occur upon the flanges of the when the cord was cut it took some time to perfect means of establishing communication central span B C, when it is uniformly loaded, repair it. On the return journey, the South- between passengers and guards. Has it stood and the two side spans free from the action of

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advantageous position she occupies with EFFECT OF LOAD ON GIR DERS.

respect to fuel, it is no wonder, accustomed

as we are to be foremost in all matters of a FIG.I.

remunerative commercial character, that we

have almost a monopoly of this indispensable B

aid to construction. Mr. Reid has followed in the wake of Mr. Grant, and has added to our very scanty practical information upon the manufacture of Portland cement by the excellent treatise* he has lately given to the public. Without desiring to accuse our engineers and architects of being remiss in their

duties, yet it must be acknowledged that the FIG.2.

credit is due to our professional brethren, on the other side of the water, for directing attention to the admirable qualities possessed by cement for foundations under water and damp and spongy situations. As a rule, the French were long before us in the use of cement,

concrete, “pierre perdue,” bêton, agglomere, K

and, in fact, every description of artificial masonry. We for some time refused to

abandon stone, and bricks and mortar, and a moving weight. A load upon either of the of the independent girder S, we have S :

adhered to the ancient types of construction, adjacent spans, at the same time that the

L central one was loaded, would tend to con- (L-2y)=1.7325 By these equations the with true Anglo-Saxon obstinacy and per

versity. Gradually, however, we were brought vert the latter into a beam with both its ends firmly fixed. The action of the web in a con- points of contrary flexure can be accu- to see the error of our ways, and the comtinuous girder, if the spans be equally and rately fixed, and, from them, the spans and mercial element mingling strongly with the uniformly loaded, is precisely analogous to loads being given, all the pressures can be adoption of cement, we now not only manuthat in a detached and independent one. found in the same manner as for a continuous facture it on a very extensive scale, but use it Where a uniformity of loading does not exist, girder of three spans. Taking the span B C, also to a considerable extent in subaqueous the position of the points of inflexure vary, and regarding it as an independent girder of and other works. The application of this and also the individual proportions of the a span equal to L, we shall have the strain at important material appears to be almost cantilever and girder parts of the structure. the centre, to the strain at the centre of the illimitable even at present, and it promises to The greatest strain upon the web must, there- girder of a length equal to S, to which B C embrace a still wider sphere of action. All fore, be calculated in accordance with this is reduced by the principle of continuity, as the engineers, foreign as well as English, variation. If it be determined

concur in coinmending it highly in whatever upon

L’: S

, or as L’: (1-7523)". sumption that the cantilever and girder seg

or as 2.99 works they have availed themselves of its ments remain of a constant length during the to 1, practically as 3 to 1. If the reactions the strength and quality required, there is no

services; and now that it can be obtained of transit of a passing load, the strain will be of the abutments and intermediate piers be longer any doubt remaining regarding its less than its proper value. A very little re- given, the positions of the points of contrary being a thorougly reliable and trustworthy flection will suffice to point out that the fexure may be deduced from them, as was

material. greatest shearing strain or vertical pressure exemplified in the case of the girder of three over either of the intermediate supports B C,

Mr. Reid 'enters at full length into the spans. As the character of these articles practical manufacture of the article, and will take place when the leverage acts upon has been of a practical tendency, it describes in detail the various processes it has both sides, and the pier becomes a kind of would be foreign to cur purpose to inquire to pass through before its raw constituents, pivot upon which the two opposing forces deeply into the question of the deflection of the chalk and the clay, can be presented to balance one another. The greatest vertical continuous beams, more especially as their the public in a marketable form. Washing, pressure upon a pier, therefore, occurs when determination involves the use of the higher mixing, burning, and grinding constitute the the two adjacent spans are covered by the mathematics. So far as the general case repassing load.

presented in fig. 2 is concerned, it may be principal phases of the ordeal it is submitted examples, differing only from one another by in its continuity, the deflection of any span operation, there exists a difference between

It would be to no purpose to multiply stated that supposing the girder to be perfect to, and in the first and second of these, which the number of spans, so we will now consider will be only one-fifth of that which would the plans adopted by the English and the the general case of a continuous girder with be undergone by an independent girder of the German manufacturers. The former use the any number of equal spans. In fig. 1, let same dimensions. For bridges of large span, the end spans, and B C, C D, two of the cen- be considerable, and its own weight would and it is perhaps as much å matter of habit A B C D be a continuous girder ; A B one of where the vis inertice of the structure would wet and the latter the dry systems. Each of

them have certain advantages of their own, tral spans. From what has been previously bear a very large proportion to the rolling and national individuality as of any practical stated respecting the action of the web, it will load, the advantages of the continuous prin- superiority. Our author, on the whole, gives not be difficult to perceive that under a uniform ciple are incontestable. In this case, the ac: the preference to the wet system, although he load it does not differ from that in an inde- tion of a rolling load exercises but pendent girder, and when the load is variable, influence upon the position of the points of fairly admits all the advantages that may be provision must be made in the manner alreadly contrary flexure, and the range of their mo- German method. The necessity for sampling described. The position of the points of tion is bounded by very narrow limits. There the cement, that is, testing it after the operacontrary flexure in a continuous beam, such as is in consequence little or no ambiguity tions of washing and mixing have been carried represented in fig. 2, does not vary much respecting the strains, and but comparatively three spans, and without any practical error designed, so as to withstand the strains of tions in which the chalk, clay, and water from those already found for a girder of a very small portion of the flanges has to be out, is strongly insisted on as one that should they might be regarded as identical. It will, both tension and compression. For bridges should be mixed are not discovered at this however, be well to give the means of finding of small spans, and in large ones where there them accurately: , Let L equal the span, and is any doubt or uncertainty about the solid juncture, it will be too late to remedy the

the distance of the points of contrary flex- nature of the foundations, the continuous namely, the water and the air or dry test, are ure from the intermediate supports of the principle should be unhesitatingly discarded. central spans. Thus, in the span B C, y The subsidence of one of the supports of an

employed, and the experienced hand can tell B x. The value of y may be ascertained independent girder, provided it is not exces: mixture has been properly accomplished, and

by the united aid of the two, whether the from the equation, y= L- L. Reducing sive, is of little or no moment, but it would whether it should be allowed to pass on to

V3

cause injury to, and possibly dangerously the kiln. With respect to this latter part of affect, the security of a bridge designed upon the machinery employed, it does not appear

the former principle. The French engineers to have arrived at the condition of comparathe double fraction, we have

are strong advocates for the continuous sys- tive perfection it should have done. The y (1.7325 x L) — L.

tem, and have adopted it for a railway bridge original lime kiln shape has not been much

at Asnières, carrying four lines of railways, departed from, and the whole operation is 3.464

and having five spans. This value for y also gives the length of the

conducted in a very rough unscientific manner. two separate cantilever portions of any one

In the appendix-or, rather, the second porof the central spans, as Ba, Cx, Dx, &c. The length of that portion of any central

PORTLAND CEMENT.

* "A Practical Treatise on the Manufacture of Portland

." By HENRY REID, C.E. To which is added a span, considered as a detached or independent

ITH

material for manufacturing cement Method Adopted in Germany, of Manufacturing that readily determined from y. Calling the length possessed by England, together with the demonterin Bec Post i BEAD. London: E. and F. N. Spon,

2

Ceme

route.

tion -of the volume, a description is given of its kind, and one very much wanted. It is expended in the voyage from India to England an endless kiln, which would supply some of true that the experiments of Mr. Grant can- renders unproductive for a longer time the money, the deficiencies found in those of ordinary not be overrated, but they do not supply the represented by the cotton bales; and four months construction. Notwithstanding the practice practical information afforded in the volume interest is of no small consequence in these days of matter, he confesses that it is quite impos- manufacturer, authority for the professional of expense, and that every detail of cost and inand experience that the author has had in the in question, which is a complete guide for the close competition. It will be seen, therefore, that sible to calculate the time for burning a kiln, man, and a book of reference to every one who cidental outlay is of greater importance to him and he mentions an instance that came under desires to become acquainted with the theoreti- than to his more highly-favoured rival in the United his own immediate knowledge where the dif- cal and practical history of Portland cement. States. If the Suez Canal were but open, the ference between the periods of burning the The plates are very well lithographed, and voyage by the Cape would be avoided ; but opinions same kiln was as four to one. After noticing the type clear and well chosen. It is not often differ as to the ultimate success of that scheme, the grinding process, and the machinery that we have reviewed a book with so much and the route certainly does not exist at present. adopted for effecting that somewhat arduous pleasure as the present, and we can cordially The Isthmus Railway was intended for the same task, the author proceeds to the question of recommend it as a capital text book and purpose, but the cost of transhipment and land testing the cement. It is not too much to manual of the subject upon which it so ably carriage is so great that there is practically little assert that had it not been for the Metro- treats.

advantage in bringing cotton that way, and till

lately politan Board of Works, and the energy and

was only silk and other expensive goods decision with which Mr. Grant carried out the THE METROPOLITAN MEAT AND POUL-able amount of cotton has been sent across the

that were brought overland. Recently, a considerprovisions of the main drainage contracts, we

TRY MARKET.

Isthmus, but until better arrangements are made should never have been able to procure the cement that can now be had with facility. We structure saint paulo comparing foundhis

E this week give further engravings of this for its transport by the Suez Railway, only an in

appreciable quantity of cotton will come by that It was at one time considered impossible to manufacture it of the strength required, and showing the entrance to the central avenue.

partial longitudinal section through the roadway,

On

It will be seen, therefore, there is every inducesome firms openly expressed their disbelief page 471 we show a half elevation and half section ment to save, if possible, in the cost of freight. in the possibility of the results. But after of the central roadway. In this engraving, A are Now, the freight payable on bales of cotton is calsome quiet discussion on the matter, and curved wrought-iron girders 12x7x}; 'B, tie culated by the ton of measurement, and not by the finding that the engineers would not yield, beams, 10x7; C, lower principal rafters, 12 x7, ton of weight; and therefore the more cotton that they betook themselves seriously to the task, intermediate, 12 x 4; D, uppor principal rafters, can be compressed into a balo of given size, the and speedily discovered that they had been 11x7 to 10x7, common raft, 4x2; E, straining lower the rate becomes per lb., and the greater

The foregoing making a mountain of a mole hill, and that beam, 10x7; F, struts, 6x6; G, pitching plate, becomes the amount of profit. the difficulty was easily surmounted. The 5x1); H, curb plate, 4x10, with wrought-iron shows the important service that can be rendered by needle test is still used in France, but it is fitch at entrance to central avenue ; K, pole plate, powerful baling presses; and while this is espofast becoming altogether obsolete, and has 5x5; L, purlins, 10 x6, trussed with wronght iron cially the case with India and Australia, it is true

M, ridge-piece, 10 x2. In the same engrav- also for Egypt and other less distant places, where been replaced by the tests referring to the ing we also show a plan of the ground floor of the the expenses of irrigation and tillage may form a tensile strength of the cement, the relative towers. We hope in our next to give the remaining large proportion of the total cost. Moreover, it is solidity or resistance to fracture, and the drawings of this important work.

desirable that no time should be lost at the port of compressive strength or resistance to a force

shipment, but that the packing process should be · tending to crush it. In Germany, they test

performed speedily. Considering that for many Portland cement against equivalent blocks of

years America had almost the monopoly of the

SOCIETY OF ENGINEERS. stone and brick ; but this is evidently but

cotton supply, it might be expected that as the comparatively worth little, since nồ two A1 December 2, 1 865, Ser. Baldwin itham, pre for the requisite apparatus could be at once copied specimens of either stone or brick possess sident, in the chair, the following paper on the from America. As is well known, invention does constant qualities in this respect. With

Accumulator Cotton Press, by Mr. #wing Matheson, not sleep in the United States, and it might be preregard to tests for durability, the cement has was read : -The trade in cotton, under its many sumed that for any production in which the people so lately been manufactured of a really reliable different aspects, forms so large an item in the are engaged, the best appliances would soon be discharacter, that it is premature to indulge in commercial activity of this country, and is so covered and made use of in that country. It is not them.

largely increasing, that every incident and process surprising, therefore, to hear that for all the details Most of the applications of cement, in production and manufacture possesses a corre

of pressing cotton a great variety of plans have whether in its pure state, or any one of its sponding interest for all concerned. Although for been tried. As has been shown, there is no such numerous combinations, are known to our very many years the importation of cotton and its urgent inducement to the merchant in America to readers, especially its recent application to manufacture into fabrics have been among the compress so much cotton into a bale for the short the construction of dwellings, warehouses, greatest industries of Great Britain, it is only more voyage to England. The cotton itself also differs and other buildings of large size. There has recently that the production of the raw material from that produced in India. It is, as a rule, one been made which is not so very generally capital and enterprise. The immonse importance more power to compress the same number of pounds

has engaged any considerable share of British cleaner and moro elastic, and would require much known. It is the application of the material now, however, of the cultivation of cotton in India into a cubic foot than is necessary with Indian cotton. to prevent oxidization in the holds of iron and the colonies, and through them to the mother While the cotton culture in India was in its infancy, vessels, and also to the external use of it in country, is, of course, manifest to oll. The growth the quantity produced was too small to create a coating ships. Captain Cowper Coles, C.B., of cotton' in India, Egypt, and elsewhere was demand for any special apparatus. Baling machines has applied it in the latter manner upon formerly so small in comparison with that of the were sent out from England, but they were of a several vessels, and apparently with much Southern States of America, that it needed the very primitivo kind. Screw presses, something success. Another comparatively novel method artificial stimulus given to it by the American war, like those used for making cheese, were contrived. of utilizing this valuable material is in con and consequent closing of the cotton ports, to pro- The next stop was to work the vertical screws by

bevel gearing and a winch. Then, as the cotton crete for the construction and repair of the duce a commercial success. surfaces of roads. Although partially this

This success has survived its immediate cause, trade grew in importance, there was devised a experiment has been successful, it has also and Indian, Egyptian, and colonial cotton now take number of inventions and contrivances, some by

a permanent place in the British market. The engineers, and others by the cotton growers, whose failed lamentably in one or two instances. rapid increase and present enormous extent of this ingenuity was stimulated by necessity, the mother Mr. Reid candidly admits that it proved a trade may be seen from the fact that in the first of all invention. Lovers, screws, and wodges wero failure in St. James's Park, although he gives six months of the year 1866, 119,000 tons of tried alone and in combination. The use of a ready explanation of the cause of failure, cotton were imported into the United Kingdom hydraulic pressure naturally suggested itself for of the reason why the surface broke up under from India, and 30,476 tons from Egypt. The trial, but it was not very successful; no very great the action of the rapid traffic over that part shipment from India for 1868 shows an apparent power was obtained, and the process by pumping of the Mall. We do not consider that a decrease ; but this is owing to the fact that a great was slow. Gradually, improvements were made second attempt would also necessarily prove a quantity of cotton that was formerly sent from in the lever presses, and these were generally profailure ; on the contrary, it would probably Bombay to the United Kingdom for ro-shipment forred. Some of them may be mentioned." A turn out a success, but until further experi- elsewhere. The Indian cotton exports are really baling machine, and patented soveral of his im

to the Continent is now sent direct to France and Mr. M'Comb took great pains to make a good ments have been undertaken, and more re- increasing annually. From Egypt, the amount provements. His cotton was forced up by two liable data supplied, we should be careful of exported to this country in the first six months of compound lovers, drawn together by a chain expressing a decided opinion. The second portion of this valuable and the present crop promises to allow a still furthe present year was 7,000 tons more than in 1866, worked by hand or steam.

Mason's press had somewhat the same principle treatise is devoted to a translation of ther increase.

of levers, but was worked in a different way. “A the work of M. A. Lipowitz. It is There are several disadvantages with which horizontal engine drove two machines, the crankin a more condensed form than the pre- India has to struggle. Assuming that the first cost shaft running right and left from the engine. By ceding portion, and is not by any means of of tillage and agricultural labour is the same, gearing, a shaft parallel to the crank shaft was the same value. In fact, it would do the there then remnins the immense difference between driven at a reduced speed, and by means of right work not the least harm if it were omitted India and America in distance and time of transit and left-hand screws on these shafts two powerful altogether, as a portion of it must of neces: From New Orleans to Liverpool, the distance is against the follower of the cotton box, . Both these

from the port of departure to the port of arrival. levers were drawn together and forced upwards sity be repetition. It treats principally 6,000 miles, and twenty days’ voyage for a steamer. presses are still in favour, and are used in considerof the German methods and class of ma- From Bombay to Liverpool (round the Cape) the able numbers; yet, however well they may be chinery, and contains some good plans and distance is 12,000 miles, and takes 120 days. Thus mado, it is obvious that there must be severe strains sections of those employed in that country in the race India is heavily handicapped. The upon the points through which the power is transMr. Reid's volume is, in fact, the only book of carriage of the cotton costs more, and the time

(Continued on page 467).

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