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chamber should be square, it may be polygonal or circular; the only condition necessary is that each magnet shall be powerful enough to throw its sphere across to meet the sphere of its opposite. In applying this principle in magnetism it will be necessary first to ascertain by experiment the magnetic intensity of the ship at the binnacle, or wherever the compass is to be placed, then construct your magnets of a thousand times greater intensity than that of the disturbing magnetism, and arrange them symmetrically around the compass box, so that the compass needle shall swing exactly in the centre, where there will be perfect neutrality. To do this if permanent steel magnets were used two or three dozen would be required, and here the great difficulty of the application would be found. It is very difficult to make two or three dozen steel magnets of precisely the same power, and it is still more difficult to ensure their remaining for any considerable time of that equality. This difficulty could be overcome by using electromagnets, of which about a dozen would be sufficient. These could be excited by a constant battery. Any of the ordinary constant batteries might do, but the sulphate of mercury, carbon, and zinc battery, with plain water, would be perhaps the most suitable, as it can be made so as to continue in action for six months or more. There is this objection to electromagnets, the batteries might have to be attended to by persons who did not well understand them, and any failure of the batteries would render the compass worse than useless. Certainly a battery might be constructed to be excited by the sea water flowing through it, which would require no attention as long as the zinc plates lasted, and if this mode of compensating local disturb ances to compasses should be tried this kind of battery will no doubt be adopted. From what we know of electricity and magnetism we think there is a fair chance of a successful solution of this problem by these means. At any rate the neutral magnetic chamber is worthy of a fair trial, but it can be made in a proper manner only by those who have iron ships at command. As to the truth of the scientific principles on which it is based, any one can convince himself who is in the way of making such experiments. evad ew tea noiteup so

LOCOMOTIVE COUPLING-HOOK. THE number of accidents

To tinually happening from which are continually happening from engines running off the rails and dragging carriages with them, recently led to a considerable amount of discussion in the daily papers. When an engine leaves the metals, carriage after carriage is sure to follow until the couplings between each of them break; then, and not until then, is the mischief at an end. The amount annually paid by railway companies as compensation for injuries arising from accidents of this description is something enormous. It is clear, then, that any invention which would render their recurrence impossible would be as great

The method by which this desirable end is attained is shown in the accompanying engraving, in which the various parts of the

+

the sharpest curves on a line of railway, with- has replaced the ancient covering of tiles upon out a separation or unlocking of the parts the hall of the blast furnaces and many intaking place. But as soon as this slight ternal alterations and improvements have deviation is greatly exceeded, or in other been introduced, yet the handsome façade words, upon an engine running off the rails, has been preserved intact and is ornamented the hook is instantly detached from its with numerous warlike emblems, forcibly resocket. calling to the mind those decorating the gates of Mayence. The post of the large crane is surmounted by the figure of a splendid eagle with wings outstretched, and all the cast-iron frames of the forges are adorned with representations of the various tools connected with the business of the cannon manufacturer; hammers, callipers, squares, and other symbols filling up the whole surface. The pigs produced in the blast furnaces on the premises are, similarly to those purchased elsewhere, broken up, carefully examined, and classed accordingly as they present a lighter or darker colour and varieties in the nature and appearance of the fracture. These home-made pigs, so to term them, constitute 40 per cent. of the different mixtures used in casting; 20 per cent, is supplied by pigs of a second melting, and the remaining proportion by those obtained from neighbouring workshops. A scrupulous attention is paid to the exactitude of these proportions, and only assistants of great experience and judgment are allowed to examine the qualities of the respective pigs, to class them, and to superintend the operation of depositing them in separate charges near the opening of the furnaces ready for instant injection. The furnaces are built in pairs, the brickwork being strengthened by strong iron tie rods, and having the soles of a sand sufficiently fusible to unite into one mass, and become covered with a thin vitreous crust, but at the same time sufficiently refractory to resist the intense heat to which it is subjected.

new safety hook are shown. A shows a plan view of the hook complete, the dotted lines indicating the position of the hook when it has reached the extreme angle of safety and is about to leave the frame which is attached to the carriage. B is a side view of the hook detached from the frame; at b is a stud which Coal is the combustible employed in heatis pressed out by a spring and locks into a ing the furnaces, the flame of which runs recess in the back of the frame. By this means along the ceiling and passes over the pigs, the hook is held in position, but is of course which are so arranged that the largest receives easily released when the direction of the pull the greatest amount of heat. Six furnaces, deviates from a right line with the centre of containing each three tons of metal, sufficed the train. C shows the hook in plan, and D formerly for casting the largest cannon in use; is a sectional plan of the frame in which the but latterly, owing to the increased dimensions hook works, E being a side view of the given to pieces of ordnance, it has been necesframe. The action of this hook, as will be sary to erect four new ones capable of holding inferred from our description, is exceedingly each, from four to five tons of metal. All the simple; it cannot fail to hold so long as the furnaces have an opening towards the interior engine does not deviate from its track to the of the hall, which is blocked up with bricks extent indicated in the engraving at A, to do and sand, leaving two vulnerable points where which it is clear that it must leave the rails. metal is to take place. At Ruelle the practice the tapping and subsequent running of the But should it do so, then all holding power rapidly and ceases, the train following is relenged, wed is to carry on the heating, very tapi Practic not a carriage can follow the engine. The energetically, so as to effect the fusion with hooks are easily and inexpensively made, and the greatest possible despatch. One advanif desirable. It is just one of those practical all the scories is disengaged and floats upon might be applied to every carriage in a train tage of this method of proceeding is that the metal is endowed with an extreme fluidity, and contrivances that occasionally make their which are fraught with great results. In the to cool, and its tenacity is thereby considerpublic interest, therefore, we commend this time usually occupied by one melting. appearance in the chapter of small things, but the surface; moreover, it takes a longer time ably augmented. About two hours is the coupling hook to the notice of our railway Whether the better plan is to run cannons in in mind, any calamities that may henceforth managers. With this ingenious contrivance arise from engines quitting the rails we shall assuredly class with "preventible accidents."

NAVAL CANNON FOUNDRY AT RUELLE.

and

Пo expect to discover in any of our en

a benefit to the shareholders as to the public at large. With an arrangement by which the engine on leaving the rails, would become detached from the carriage to which it was coupled, immunity from accident in this respect would be ensured to travellers. The engine, with those upon it, would alone be in To expect to dismanufacturing establishdanger, as the train with its occupants would ments, public or private, the slightest attempt remain on the track in comparative-if not at decoration, elegance, or architectural merit, perfect-safety. Such safety, we think, would would be perfectly futile. They may, without be guaranteed on every railway by the use of a single exception be pronounced hideously a very simple, yet ingenious coupling hook useful. It would, perhaps, be excusable if which we lately examined. It is the patent this utter want of appreciation, amounting to of Mr. Butler, of 418, Old Kent-road, an absolute insensibility to all aesthetical prinand Mr. Dalgety, of Peckham. For the fixed hooks to which the coupling chains and rod are attached, are substituted hooks so constructed that, while the tension or pull on them is in a straight line or nearly so, they have as great strength as those now in ordinary use. The pull may take place at an anglè sufficient to allow for turning

ciples, was confined to the examples in question, but unfortunately it pervades our cities and towns, and furnishes a constant theme for the just reproaches and deserved taunts of our continental neighbours. The imperial premises at Ruelle possess some features, distinct from those of mere utility, in point of construction. Although a corrugated iron roof

tion not yet fully decided. The latter, as may be readily anticipated, is the more ancient

moulds without cores or with them is a ques

method; but so far back as 1740, cannon were run solid by Maritz, who argued that the omission of the core would impart a greater degree of homogenity to the metal, and prevent the formation of blisters and air holes in the interior of the cannon. Many of the con

temporaries of Maritz differed altogether from his views, and at the present time valid reasons and arguments can be alleged upon both sides of the question. Not only in France but in America likewise the core system appears to be in the ascendancy, and the plan adopted by Major Rodman, of the latter country, of passing a continuous stream of water through the centre of the hollow core is well known. It is stated that the cooling action obtained in this manner upon the part of the metal nearest the core endows it with an additional amount of resistance, a quality especially required in the bore of the cannon. This opinion appears to receive a strong confirma[tion from the experiments of Major Palliser

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upon the manufacture of projectiles, the sur-arrival of the metal at the next orifice. When sent to the mind is, how is this to be accomface of which is suddenly cooled by casting it is desired to stop the running it is effected plished without decreasing the military and them in iron moulds. Solid cores of iron are by closing a valve in the common channel, political strength of our army there, or the used at the imperial manufactory, prepared which is termed the stop valve. The process firmness of our hold on the country? Sir with moulding sand and loam in the usual of casting, nearly always performed with some Henry Havelock meets this question by á manner. As the cannons cast at Ruelle are amount of precipitation, is conducted at Ruelle most ready and happy suggestion, or rather, all on the breech-loading principle and hooped, with a certainty and regularity which seldom we should say, by a well-considered and the difficulties formerly attending the preparahighly practical plan. The object would be tion of the breech and trunnion moulds are more than accomplished by substituting for obviated. The problem is reduced to the the 15,000 or 20,000 of our slow moving insimple preparation of a mould into which is to fantry to be withdrawn thence a body of be run a piece, the upper part of which is to about 9,000 mounted riflemen, armed with the form the chamber, and the lower, of the shape best breechloaders or repeating rifles. And in of an elongated cone, the barrel and muzzle. supporting these views, with which we enAt one time the patterns were constructed of tirely agree, the author touches upon a point iron and even of bronze, but now they are of great interest to many of our readers. We made of pine, with great advantage in point have often insisted upon the value of the of economy. The moulds are of sand conrepeating rifle as a military arm, especially for tained in strong cast-iron cylindrical boxes, cavalry, and here our views are borne out by and when the operation of moulding is comthe later experiences and practice of the Amepleted they are coated with a mixture of rican war. The Northern cavalry adopted powdered charcoal and water, to which is the best repeating rifles-generally the Spencer added a trifling proportion of argillaceous -and reduced to an organised system of drill earth, and subsequently dried in stovės and manoeuvre the practice of fighting with arranged for the purpose. Forty-eight hours them on foot, always, where possible, from beare sufficient to accomplish the drying process, hind cover. The horses meanwhile, each and the different sections of the moulds are held by a mounted man, or never by less than conveyed into the workshop on a small lorry one man to two horses, were kept out of running upon rails. What may be called the reconstruction of the mould or the putting the harm's way farther to the rear, ready to gallop several component parts together in their up at a moment's notice, to pick up their men, proper order is next effected, previously to or to meet them half way in falling back, for which they and the boxes must be allowed any necessary change of position. The author to cool for several hours after leaving the justly observes that the question of the adop tion of this principle has for us a more important bearing than for any other nation in the world, and this, too, in three distinct and separate directions. In the first place, our splendid but small regular cavalry would at tain a far greater efficiency than it can hope to possess without this arm. Then we should have a more economical and yet equally, if not more effective tenure of India. And

stoves.

fail to produce the much desired uniformity
and homogeneity in the contents of the moulds.
A registry of the exact time during which the
operation lasts and the manner in which each
furnace contributes to the general running is
carefully noted, so as to serve for reference
and information on future occasions.

THREE MAIN MILITARY QUESTIONS
OF THE DAY:*

lastly, as a question of home defence, the adoption of the repeating rifle by our yeomanry cavalry and our mounted volunteers, who are now neither good regulars nor good irregulars, but something intermediate and indefinite, would render them a most formidable body of horsemen for all defensivé fighting.

Sir Henry Havelock proves himself to be thoroughly acquainted with the whole subject upon which he writes, and in support of his

theories advances statements and facts which

The

The form of the foundry is that of a quadrilateral figure, with three sides rectilineal and one of a semicircular shape, round the periphery of which are arranged the furnaces with their openings pointing towards the centre. In front of the openings, and parallel HE three most important questions of milito the circumference of the semicircular side, an upright bed of sand is formed, about 3 ft. tary organisation in the present day, as in height, into which channels are let, com- laid down in the work before us, are:-A municating with the furnaces. These trenches home reserve army; the more economic military or channels are about 9in. square, have an in- tenure of India; and cavalry as affected by clination of 1 in 25, and all run into one breech-loading arms. common channel. Concentrically with the Henry Havelock is right in assuming for these bank of sand is a deep trench, into which the questions the first importance. They have moulds are placed, having a depth of 24ft. formed the themes of discussions in various which causes its bottom to be 5ft, below the quarters of late, and, unquestionably, will level of the river; and notwithstanding all continue to be agitated until some specific attempts to render it watertight with cement, solution is arrived at. The author justly obconcrete, and every conceivable description of serves upon the first point that the events of waterproof compositions, the water gets into the last few months in Germany teach no it, and it requires the use of a pump to empty more forcible lesson than that no amount of prove the soundness of his ideas. it. To deposit the moulds in this trench and bravery or military spirit alone will avail a cavalry armed with the repeating rifle, and great practical proof of the superiority of to raise them and their contents, a crane of nation in its hour of need. That there must trained to act as infantry or cavalry as cirgreat power has been recently erected. By be a carefully organised system, thoughtfully cumstances might require, is to be found in its aid six men can raise and move in any of peace, so that each of the constituent ele- the American war. The result was the over elaborated and fitted in all its parts in time the final conflict between Grant and Lee in direction a weight of nearly 40 tons. It is fixed in the centre of the semi-circular space ments of national defence may fall at once, throw and surrender of Lee, and this was in front of the trench, and in combination at a few hours' notice, into its allotted place, brought about by Sheridan's cavalry, which with smaller machines of the same character, familiarly and habitually known long before- had had both cavalry and infantry training, and with a system of tramways and turntables hand, before a nation can, in these days, be and which, moreover, was armed with the performs all the heavy operations connected justified in calmly awaiting the approach of Spencer repeating rifle. Indeed, the Spencer with the working of a foundry with compara-war. Having laid down this broad proposi- rifle practically determined the American war, tive facility. The moulds being in position, tion, the author proceeds to bring together a for, as an American friend recently observed they are connected at the bottom and at dif- mass of historical facts and figures which he to us, "it chawed the fellers up quicker than ferent points in their height with the common has collected, and which bear upon the ques-death." In the celebrated battle of Five channel already alluded to, by means of iron tion. These facts and figures placed in new Forks, which is graphically described in all pipes strongly coated on the inside with fire-connection and juxtaposition form the material its military details by our author, not only was clay. Everything being ready for the in- whereon the proposition is based, and from no ground lost, but the defence of the cavalry portant operation of casting the cannons, the which the author draws his inferences. The dismounted, using Spencer rifles, and sheltered signal is given, and the tapping of the furnaces first main question, the formation of a home from fire behind rails and slight earth banks, accomplished by a vigorous blow of a pointed reserve army-is to be solved as follows:- with their horses kept well under more solid First, discharged "ten years' men" are to the vulnerable part left for the purcover farther to the rear, was so effectual and pose. To moderate the rush of the molten be re-engaged; second, from 15,000 to 20,000 stubborn as to cause severe loss to two Constream, one of the workmen partially closes of our slow moving line infantry are to be gradu-federate infantry divisions, who at nightfall the aperture with a stopper, which is someally withdrawn from India; third, the reserve drew off thoroughly foiled. The loss sustained what different in shape from that usually would be augmented gradually by ten years' by the cavalry was next to nothing. We canmen, so that about ten years hence the not too strongly recommend the perusal of Sir adopted. It is represented in fig. 1, and consists of a bent iron rod, surmounted at one ex- author calculates that, with regard to our Henry Havelock's work to our slow moving tremity by a small cone of fireclay. Another reserves, we should be placed in a position military authorities, who will there find matworkman skims off from the surface of the as strong as that of Prussia at the present ter which if rightly pondered upon, must lead metal the impurities by means of a shovel of moment. them to see the necessity of adopting a rethe shape shown in fig. 2; while a third partly peating arm for home and foreign cavalry closes the mouth of the iron pipe with a service. With this arm, too, the efficiency of the Irish constabulary would be vastly in stopper of the kind described. The metal enters the mould by the lowest orifice, and rising within it carries the scories upon the sur"Three Main Military Questions of the Day." By have shown much better for the cause of law creased, and recent events in Ireland would face, which is raised again higher by the London: Longmans, Green, and Co. 1867. Sir HENRY M. HAVELOCK, Bart., Major unattached. and order had the force been thus equipped.

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The withdrawal of so large a body of troops from India may appear at first sight rather startling, and the question at once pre

knots, but what would happen if one of them venel as

66

The knowledge even of the fact that each man asking redress. We are, therefore, glad to see eight or ten shots without staying to reload called the attention of the House to the position Agincourt," which already went 15 knots, would probably have inspired a lawless mob of the naval engineers. On a former occasion with guns at least as powerful and sides quite It seemed that depart. with terror. At the worst, in any collision, he called attention to this subject, and the result impenetrable to shot? no matter how inferior the numerical strength had been that now for the first time the widows ments were liable to the drawback of not being of naval engineers received pensions, and some able to realise a correct and stable policy, and of the constabulary, they would have proved small additions had been made to the pay of the this being the case, it was their duty to take their infinite superiority by the rapidity as well inspectors of machinery afloat, for which they counsel of those who had practical experience in as the precision of their fire. To conclude, were very grateful. But by an oversight no pro-ship-building, which they might easily do in the words of our author-"If our splendid vision had been made for increasing the half-pay through the medium of a commissioner or othercostly cavalry are kept up for no more effectual of the inspectors of infot inery on their retire-wise. action or mode of fighting less ruinously ex-ment. An engineer entering the service at pensive of the lives of brave men and magnifi- twenty-one years of age could not expect to cent horses than the present system ensures, become chief engineer before the age of fifty-six, the sooner a little of the light of modern change and by the Admiralty regulations he must retire breaks in upon the directors of their organisa- when he became sixty, so that he had only four tion, and alters their training for one more years for the enjoyment of his rauk. They were capable of producing results bearing some placed in a very disadvantageous position as compared with surgeons, although before adslight proportion to the expense of their main-mission to the navy they had to pass a very tenance, the better. Better both for the men strict examination on several branches of science. and officers concerned and for the military An increase of their pay took place at the end reputation of the nation whose defence may of every five years, but he would suggest that any day be committed to their worthy and instead of the addition being made at once at the gallant, but at present almost helpless and un- end of every such period it should be spread proporavailing keeping." tionately over the whole five years. All he asked was that engineers should be placed on the same footing as officers of a corresponding rank in the service. He wished further to ask why the names of engineers should not appear in the navy list as well as those of other officers.

Parliamentary Notes.

IN the House of Commons on Thursday last, the question of rewards to War Office inventors cropped up. Sir G. Stucley asked the Secretary of State for War how he proposed to divide the sum of £22,000 as a reward to inventors, and who were the inventors to be rewarded. This question, however, did not receive a direct answer, all that Sir J. Pakington could say was that one of the most important parts of the answer related to the reward to be allowed to Major Palliser for his valuable services. The amount had not yet been decided, and was still under consideration, and his hon. friend would therefore excuse him from giving a final answer until they came to the items of the vote to which

it related.

Lord H. Lennox said he had received no infor. motion from the hon. baionet as to the grievances of which he complained. With regard to in. sion was under the consideration of the Admispectors of machinery having half-pay, the ques. ralty, and no decision had been come to. It was asked that engineers should be allowed to count full time for every year of their service, but the hon. gentleman could hardly argue that they were entitled to equal advantages in this respect with assistant-surgeons, chaplains, and naval instructors, all of whom had to pay for their the engineers, having to pass through dockyard education, and a very expensive one, whereas factories, had not to pay for theirs. Last year the Admiralty had raised the pay of two classes of the inspectors and engineers by £100 and £50 respectively. There was every disposition on the part of the board to consider any substantial grievance of the engineers that might be placed

before them.

Admiral Walcot thought no consideration could be too great to give to the best construction of our ships. There were great objections to the large ships of the "Warrior" class; they were not handy in rough weather and cross seas, and if they got on a lee-shore, would be in the The size of our ships greatest possible danger. ought not to exceed 4,000 tons. Since 1827 we had had no less than seventeen First Lords of the Admiralty; and he asserted that, with such fluctuations of opinion, economy was a matter of impossibility. From the year 1818, till almost the Crimean war, the large number of admirals, captains, commanders, and lieutenants who had been put on half-pay were prevented from obtaining honours and from being employed in any way. If they had wives and families, the sorry pittance which they received compelled them to live in penury or to incur debt. admirals received £400 a year, the captains about £240, the commanders, he believed, much less, and as for the poor lieutenants, he felt for

them.

ARMED PEACE.

The

HE Belgian War Office having instituted an

inquiry respecting the armanents which are going on in Europe, the following informa tion, which appears in the Star, has been obtained:-France.-480,000 Chassepot rifles are in course of manufacture, the greatest portion The needle-gun and riffed cannon system to be to be finished before March 1, 1868. Prussia.-. maintained. The gun manufactories are very busy in completing the stores for the arsenals. 1,100,000 breech-loading steel barrels have been ordered since the war. Austria.-The altera tion of 600,000 guns on the Wanzl principle; 300,000 to be completed by the end of the year. South Germany.-Bavaria, Wurtemberg, Certain railway companies are seeking the In the course of a long discussion upon the Baden, Hesse-Darmstadt adopt the breech-loadaid of Government to extricate them from their navy estimates, several members offered some ing gun, on the understanding that the system pertinent remarks upon our ships of war and may be changed if the experiments which are financial embarrassments, consequent upon the their armament. Among others was Mr. Samuda, going on at Munich are not found to be satisfac. tory. The Prussian rifled cannon is preferred, recent decision as to the validity of debentures who observed that £2,751,000 was the sum as a security. Mr. Edwards touched upon this which under these estimates the country became and large orders are in course of execution. point, and asked the Chancellor of the Exchequer engaged to expend in ship-building. Of that England.-150,000 Enfield rifles are already sum it was proposed to spend £1,850,000 in the converted on the Snider principle; 350,000 whether any applications had been made to the present financial year, of which sum again only guns of the same kind will be ready in the course Government for relief, and with what result; £744,000 was due to the iron-clad portion of the of the year. 1,000 guns are being converted and whether he would state to the House the fleet. He considered that the sum taken in the every day in the Government manufactories. 426 rifled cannons of various calibres will be nature of any such application, the extent of present estimates for the purpose of augmenting manufactured by the end of the year. Russia. relief sought, and the terms proposed by the their iron-clad fleet was much too small, aud-600,000 guns are being converted on the Carle company or companies who had applied for such complained that money voted in previous years principle (a modification of the needle-gun). relief. The question was rather indelicate, and under this head had been applied to a purpose 300,000 will be ready by the beginning of next elicited a very appropriate reply from the Chan- for which it had not been designed. He depre- year. 900 breech-loading cannons are in course cellor of the Exchequer, who said that no doubt cated the policy of expending so much money as of construction to complete the field batteries. applications had been made to the Government was proposed on gunboats. He deprecated the Denmark. The Chambers have voted a large for the consideration of the very perplexed cir-destruction of the wooden line of battle ships, cumstances which exist with reference to that breech-loaders, but the model gun has not yet sum for the conversion of the present guns into class of property. But when the hon. gentle. been decided upon. Holland.-The conversion man asked the result of those applications, of the present arm into guns ou the Snider prin

whether he would state to the House their na

ture, the extent of relief sought, and the terms proposed, he was bound to say at the present moment her Majesty's Government had entered into no engagement whatever. It would not be proper to mention the names of those who had made applications, especially as the applications had not been completed, or to refer at all to the terms proposed by the companies who had asked for relief.

Mr. Crawford said that when the question as to the condition of those railway companies that were unable to fulfil their engagements was brought forward, he would take the opportunity of proposing a plan by which he thought the Government might assist those companies with great advantage to the State. We are glad to find that some one has taken a practical view of the matter and that there is a hope of some advantageous remedial measures being proposed. In the MECHANICS' MAGAZINE for February 22 Jast, under the head of "A Plea for the Royal Naval Engineers," we discussed certain griev ances for which that able body of men were

ciple.

breech-loading gun adopted. Spain and Greece Italy, Spain, Portugal, Greece. The have ordered cannon from the manufactory of M. Krupp, of Essen, in Prussia. Belgium will continue the use of the rifled Prussian cannons adopted in 1864, and will bring into use the breech-loading small arm.

although it might not be good policy to convert
them at once. In the event of war their con-
version could be accomplished within six months,
at an expense of £100,000 each, and would en.
able the Government to get up a much larger
force within that time than they could attain by
any other means that might be adopted, even by
throwing money into the hands of the contrac-
tors to bring forward fresh vessels speedily.
They would be capable of carrying 5-inch plates,
with two turrets, each armed with two 12 ton
guns, and would be most formidable in case of
emergency; but if the hulls were now to be
The health of the English troops in Bengal dur.
broken up, and the public property thus sacri.ing the past year has been unusually good. Dr.
ficed, the plan he had suggested would no longer Bryder's tables show that the mortality was only
be practicable. The method of carrying out the 2014 per thousand, or four per thousand less than
construction of iron-clad ships by the Admiralty last year. In all the discussions in England on the
afforded no evidence of settled principle or secu- recruiting of the army each writer assumes that the
rity. We had already almost as many different strength of the force in India is so great as 70,000,
classes as there were of individual ships, and yet and so often vitiates his conclusions, while doing
new classes were still proposed. He had great prets to say that last year the strength was only
injustice to India. The Times correspondent re-
doubts as to the propriety of building any such
61,672 men and non-commissioned officers, and
vessels as those of the "Inconstant" class,
3,615 officers,-a reduction of 5,000 in one year.
which, not being armour-clad, would be quite This year the number will not be found to be more
aufit for fighting ships of the present day. They than 60,000, while, on the other hand, the atten
were to depend upon their great speed and their tion paid to hygiene and barracks has greatly
powerful guns. Their speed was to be fifteen diminished casualties.

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inst, A. Williams, Esq., in the chair, a paper Twas read on "Water and its Effects on Steam Boilers," " by Mr. H. K. Bamber, F.C.S. After noticing at some length the chemical composi tion and character of water, as well as its general properties, the author arrived at the description t of the different sources from which natural -waters were obtained, and also the properties of the water in each case. The author continued: We will divide the several natural waters into rain, river, well, and sea waters. The principal Fource of these, except the latter, is rain, snow, dor hail. Rain as it leaves the clouds is to doubt almost pure ; but in its passage through the air it absorbs certain gases, and carries with solution in the water by the presence of free organic matter. The nitrates would arise from

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asit small particles of matter which are Hoating edabout in the air. This is the case more especially with the rain which falls first after a long time of dry weather; that which falls after several days baof wet being comparatively free from these. The substances thus dissolved by the rain in its 3dpassage to the earth are the gases, oxygen, sanitrogen, and carbonic acid, a little ammonia, bor rather carbonate of ammonia, nitric acid-this latter more especially after a thunderstorm, it being formed from ammonia and water by the passage of the electric spark through the air. a The particles floating in the air which are carried down with the rain are for the most part organic. The above would be the principal, not the to only, impurities found in rain water if it were docollected before it had touched the earth, in the baopen country. In or near large towns, especially manufacturing towns, the case is different. sloSeveral other substances would then be found in ebit, as sulphurous acid, sulphuretted hydrogen, to &c., &c., varying with the kind of manufactures so carried on near the spot. Again, if rain water is ic collected after having fallen upon the roofs of ishouses, it will be still further contaminated by ed various substances with which it came in contact, more especially where leaden pipes or bogutters are tised. This latter contamination is lo most dangerous where the water is to be used for to domestic purposes.

ni noAll waters which are free from certain earthy salts are sure to become contaminated with lead

assif exposed to that metal in the presence of air; ed and the purer the water the greater the quantity Jdissolved, generally speaking. Rain of us course, from the absence of earthy salts, is very soft, and on that account is, for some purposes, i preferable to hard waters; but it has a disagreeable taste, and, for this and other reasons,

Janreaches the earth, for drinking. Rain, after it 3 reaches the earth, soaks down into it, and during aits passage through the various strata dissolves nicertain salts, &c., the quantity and nature of ed which vary, of course, with the nature of the da strata with which it comes in contact. When this takes place on high ground, the water perhocolates the strata, and very frequently finds an gooutlet at some lower point, as a spring. One or 00 more of these springs is generally the source or Commencement of rivers; which, as they flow on sqin their course, become increased in size by the seo Various additions of water received from rain, iles drainage from the surface of the earth, &c. The eld springs above mentioned generally yield hard so waters, that is, water containing earthy salts in bstisolution, the most frequent of which are carbonate of lime, carbonate of magnesia, sulphates of lime and magnesia, common salt, 60 and organic matter. These are the sub. stances which the rain, containing a considerable 10 quantity of carbonic acid in solution, dissolves Spring waters

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direct addition of rain water. We may take the wells in the different strata in and around London as fair examples. In the first place, there are wells in the gravel above the "London clay." The water found in these is principally or entirely surface water, and often receives the drainage from sewers, churchyards, &c., so that the composition of the waters from these wells differs very greatly, even in short distances distances most generally found in river water, the quantistituents, carbonate of lime and magnesia, and some of them containing only the ordinary conties per gallon and the relative proportions of sulphates of lime and magnesia, common salt, the constituents varying according to circum- with a moderate quantity of organic matter, stances. The hardness of water is generally de- while others again are very impure, and totally termined by a solution of soap in proof spirit, unfit for domestic use of any kind, on account of made of such a strength that every degree of the great quantity of organic matter and hardness shall be equivalent to one grain bonate of lime in a gallon. This is known as Dr. nitrates produced by the oxidation of nitroClarke's soap test. The hardness before boiling genous organic matter and salts of potassium, of the Thames water above was 15-18 deg, and with the quantity of common salt greatly increased, and also frequently some ammonia that of the Colne 164 deg. In the above and formed from the putrefaction of nitrogenous similar waters, the carbonate of lime is held in carbonic acid. When the water is boiled this carbonic acid escapes, and the carbonate of lime is deposited; and it is this deposit which forms the principal incrustation in kettles, steamboilers, &c. The removal of this lime, or the greater portion of it, of course ton. ders the water softer than before boiling. The hardness after boiling of the Thames water above was 675 deg., and that of the Colne 65 deg. Another important ingredient in river water which is to be used for domestic purposes is the quantity of free oxygen gas it has dissolved in it; for, as long as there is the average quantity of this gas present, putrefaction of the orgong or Although ter likely dinary air contains four volumes of nitrogen to one volume of oxygen, that which is dissolved in of oxygen over nitrogen, one volume of oxygen water should be, owing to the superior solubility to two volumes of nitrogen. When the proportion of oxygen is less than one-third that of the nitrogen, the water must be looked upon as imperfectly aërated. Of course it is necessary that, when the quantities of these gases are to be determined, the glass bottles in which the water is collected should be perfectly filled, and have well-fitting glass stoppers; and even then the determination should take place within twentyfour or certainly forty-eight hours after the sample was collected, for the organic matter present will speedily remove a considerable quantity of the oxygen. One hundred volumes of water will and a half of nitrogen. A solution of permandissolve three volumes of oxygen and one volume ganate of potassium of a certain strength is often used to determine the quantity of organic matter present in waters, but it is at the best very uncertain and unsatisfactory, and only useful as an

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organic substances which had passed into the water some time previously, and had had time to become oxidised by the air dissolved in the water, whereas the ammonia would arise from more recent contamination, and very likely putrefaction still taking place. Those pumps seen in the streets of London receive their supply from these sources, and are often placed olose to churchyards, from whence they receive the drainage, and hence the contamination. From the decomposition of organic matter large quantities of carbonic acid are formed, and this, being dissolved in the water, makes it sparkling and very pleasant to drink. On this account theso waters are most deceitful, and in hot weather most dangerous, and were most wisely closed during the late visitation of cholera, many cases of serious illness having been at various times The following analysis will give some idea of the clearly proved to arise from drinking these waters. nature of these waters :

Composition of solid matter per imperial
gallon.

Bishopsgate-street Fenchurch
Within.

Carbonate of lime and magnesia 24'70
Sulphate of lime...
Alkaline sulphates

Alkaline chlorides
Alkaline nitrate...
Silica, alumina, &c. ...
Organic matter

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street.

21:00

917 00

18 30

17.50

14.20

20:20

22.40

1.30

0 60

5:30

6.60

83 10

89.00

The wells in the "London clay" are few and unimportant, the water being frequently very bad and small in quantity. The wells in the chalk and the sand above the chalk are the next, and are the most important of all, from the large supply and the temperature of the water, which is pretty constant all the year round and is used by brewers for cooling pur

poses.

These wells, of which there are very many, vary from 300ft. to 600lt. in depth, but the water from them all is very nearly of the same composition, varying perhaps a little in different years. The most remarkable thing about these wells is the fact that, although the water comes from the chalk, there is scarcely any carbonate of lime or magnesia in it; the principal constituents being carbonate of soda, sulphate of soda, and chloride of sodium (common salt). The following analyses will show the average composition of these waters :Composition of the solid matter in imperial gallons.

Towns that are supplied by water companies
generally use river water; and the object of the
filtration through beds of sand, &c., is to remove
all suspended matter, and perhaps a little of the
organic matter when the filter beds are freshly
made. The only means of removing the greater
quantity of the organic matter present in the
water is by filtration through charcoal, animal
charcoal being the best for this purpose. These
waters, containing earthy salts in solution, are
not so good as soft water for certain culinary
purposes, and for making infusions-as tea-and
for this occasion many persons add a small quan-
tity of carbonate of soda, which increases its
solvent power without injuring the water, if care
be taken not to use too much. River water,
when properly filtered and comparatively free
from organic matter, is generally the best for
domestic and other purposes, from the fact of
its not being very hard, and that the salts dis-
solved in 'it prevent the possibility of its being
rendered poisonous by dissolving lead from cis-
terns and pipes; and for these latter reasons Carbonate of soda
perly filtered, especially after filtration through Chloride of sodium
charcoal, is far preferable to those which are so Carbonate of magnesia
free from earthy salts-as the water of Loch Silica......
Katrine, &c., which have frequently been put Phosphoric acid.
forward as standards of good waters. A good
water for domestic use should contain enough
carbonate and sulphate of lime in solution to
prevent contamination with lead, and be as free
as possible from organic matter, especially
animal.

in its passage through the earth he described water, such as that from the Thames, when pro-Sulphate of soda ....

resemble well waters, and to more particularly further on. The river water, 115 receiving supplies from those other sources which do not contain earthy matters, is, or course, softer than spring water. Esed River water usually contains from 10 grains oto 20 grains or 25 grains of solid matter per ad Timperial gallon of 70,000 grains. The quantity, en however, varies with the time of the year, and the dryness of the "season. The average composition of the Thames water is as follows, in -grains per gallons:

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