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will be superseded before long by the electric system.
In order to avoid the large amount of leakage which must necessarily take place on a long line, Messrs Ayrton and Perry propose to divide the line into a number of sections, the current being conveyed along the whole length of the line by a well-insulated cable laid alongside the ordinary rails. Each section is put into electrical communication with the cable, automatically by the train as required, and contact broken again as the train leaves the section. Leakage can thus take place only from a section on which a train happens to be, instead of from the whole length of line, the leakage from the cable being practically nil. Such an arrangement may be made to constitute an absolute block system, so that one train cannot possibly run into a preceding one, even if the latter comes to a stop. Imagine three consecutive sections A, B, and C. A train leaving section A, and entering section B, cuts off the current from section A, and receives current from section B. At the same moment the 'going' and 'returning' conductors of section A are automatically connected, and the motors of a train entering on this section are at once 'shortcircuited' and brought to rest, so that no following train can proceed along section A until the train in front has entered section C. Section A is for the time a blocked section, and a train entering such a section is at once powerfully braked, and cannot be started again until the train in front is at a safe distance ahead. Hence, there must always be at least one unoccupied section between two trains. The value and safety of such a system are at once evident, and it is a system which is absolutely independent of signalmen, drivers, or guards.
An interesting line is now in course of construction in London-namely, the Charing Cross and Waterloo Electric Railway. This line is to start from the north end of Northumberland Avenue, opposite the Grand Hotel, pass under the Thames in iron caissons, and terminate at the present Waterloo terminus of the London and South-western Railway. The line is to be double, and worked by a stationary engine, driving the dynamo-electric machines at the Waterloo end. It is proposed to run the carriages separately, and start them as filled, about three minutes being occupied on the journey. Plans and estimates have been prepared and deposited for two other underground electric railways, but they have been successfully opposed for the present. These are the Mid London Electric Railway, from Oxford Street to Cornhill; and the London Central Electric Railway, from Northumberland Avenue to the General Post-office, by way of Piccadilly Circus, New Oxford Street, and Holborn.
Another system of electric propulsion especially suitable for tramways in towns involves the use of secondary batteries. A secondary battery is an instrument for storing electricity electrical energy, not current, being contained in a charged battery. A storage or secondary cell consists of a number of thin lead plates placed close together edgewise in glass or ebonite boxes, but prevented from touching one another by india-rubber plugs. The lead plates are perforated, and the holes filled with oxide of lead in the form of red lead.
The alternate plates in a cell are connected together electrically by soldering, one set being called the positive, and the other the negative, plates. The box or cell is filled up with dilute sulphuric acid. A number of such cells with their terminals connected together, usually in series, constitutes a secondary battery. When the current from a dynamo-electric machine is passed through the cells, the red lead on the positive plates is converted into peroxide of lead, and on the negative plates is reduced to spongy metallic lead. This is effected by the liberation of oxygen at the positive plates, and hydrogen at the negative plates by the action of the current. This process having been carried on for some time, volumes of gas arise from the plates, and the charging is complete. The charged battery is now ready for use, and may be made to light electric lamps or drive electric motors by connecting them to its terminals. The battery is gradually discharged of its energy, the plates return to their original condition, and are ready for re-charging.
As usually made, a one horse-power cell contains twelve pairs of plates, weighs fifty-six pounds, and measures outside about 10 in. x 9 in. x 8 in. Fifty such cells would supply over five horse-power for about eight hours, or a greater horse-power for a shorter time. The charged cells are placed under the seats of the tram-car, and the current from them led to a motor placed under the floor and attached to or gearing with the axle of the car. This system is an exceedingly simple one, and the mechanical and electrical difficulties easy of solution. Numerous successful experiments have been carried out on this plan in London, Paris, Brussels, and other places. The only obstacle to its general introduction appears to be the difficulty of obtaining a reliable and economical form of secondary battery. The waste of horses on tramways is both costly and cruel, owing chiefly to the numerous stoppages and the severe strain on the horses at every fresh start. An economical and reliable electric tram-car would be gladly welcomed.
Electric boats, or launches as they are termed, depend for their existence upon the modern dynamo-electric machine and the still more modern electric storage battery. For driving boats electrically, secondary batteries are a necessity, for it is obviously impossible to apply the current in any other way. The charged batteries are placed under the seats of the launch or where found convenient, and the current led from them by means of short lengths of cable to the electric motor, which is mounted directly on the screw shaft and attached to the bottom of the launch.
One of the earliest experimenters in electric navigation was Professor Jacobi, who in the year 1838 propelled a boat by means of elec tricity on the river Neva. His boat was twentyeight feet long, and moved at the rate of two and a quarter miles per hour. The motive-power was supplied by primary batteries, which actuated an electric motor of his own invention. About the year 1850, some experiments with an electric boat were carried out at Falmouth by Mr Hunt;
May 16, 1883.]
in 1856 on the Thames by Mr Deering; and in 1866 on the lake in the Bois de Boulogne by the Count de Mollins; but nothing practical came of these efforts, on account of the expense, weight, and trouble of the primary batteries used, and the imperfect construction of the motors, which utilised only a small portion of the power of the batteries. In August 1882, M. Trouvé, an ingenious French electrician, took part in a regatta at Troyes with an electric boat, and easily distanced a four-oared gig. The electricity was generated in a bichromate battery, and led to a motor fixed to the rudder-head. The propeller was mounted on the rudder itself, and driven by an endless chain from the motor. The experiment was a highly successful one, the boat being stopped, started, reversed, and turned with the greatest ease. The foregoing examples are interesting and instructive; but electric boats propelled by means of primary batteries could never come largely into use, on account of the expense of maintaining the batteries. It was not until the introduction of the secondary battery, several years ago, that electric boats on a practical scale became possible.
the same dimensions. In point of expense the two systems would be about equal; but when numerous charging stations are established of suitable size and convenient position, the electric system would appear to have the advantage. The batteries would be charged in position while the boat is moored, cables being carried on board for the purpose. When the cells are once charged, they will remain so for a long time, subject to a small loss through leakage. Hence a boat with charged cells on board is available for use at a moment's notice, while in the case of a steam launch a considerable time is lost in getting up steam. This is a highly important advantage in many cases. One attendant only is required in an electric launch, as all the operations of stopping, starting, and reversing are effected by means of two small levers. In addition, an electric launch is entirely free from dirt, smoke, heat, and smell, which are frequently so unpleasant on board a steam launch. There is almost an entire absence of noise and vibration, and thus an electric launch is the very beau idéal of a pleasure-boat.
For business, pleasure, and war purposes, elecThe Electricity, the first electric launch, pro- tric launches will doubtless be largely used in perly so called, was launched at Millwall in Sep- the future. They are more suitable for light and tember 1882. She is twenty-five feet long, and rapid traffic than for the transport of heavy goods; carries ten passengers comfortably. On her trial their chief advantages being that they are safe, trip she ran from Millwall to Old Swan Pier, are easily managed, and are always ready for use. London Bridge, in twenty-three minutes; and They are specially suitable for harbour, river, and returned to Millwall in thirty minutes. The lake service; for war purposes, whether as torastonishment of spectators on the river and banks pedo boats or as tenders to larger vessels, they at seeing the launch with its load of passengers must prove invaluable. Whether electricity is glide swiftly along without any apparent means destined to supersede steam in large vessels and of propulsion was very great. In July 1883 an on long voyages, is a highly interesting and experimental trip was made on the Thames in important question, but one which cannot at an electric launch forty feet long, made of galva- present be answered with any degree of certainty. nised steel. The power was supplied by about Considering the present rapid advance of scientific eighty secondary cells placed under the seats and knowledge, it would be highly rash to predict a floor of the launch, the current from which was limited use only for electricity in the propulsion conveyed to a motor also placed under the floor of vessels. No less an authority than Dr Lardner and driving the propeller direct. The distance pronounced it impossible for steamships ever to of six miles between Temple Pier and Greenwich trade across the Atlantic; and another eminent was covered in thirty-seven minutes with twenty-public man offered to swallow the boilers of the one persons on board. first steamboat that should accomplish the journey, yet very shortly afterwards several steam-vessels made the trip. Up to a certain point, the constant weight of the batteries would act as the necessary ballast in vessels; but the question arises whether this weight would not be too great in the case of large ocean-going vessels, which require enormous power for their propulsion.
About six horse-power was required to propel the launch at this speed, and the fully charged cells would contain sufficient energy to allow of the boat running six hours continuously. On the occasion of the recent Electrical Exhibition in Vienna, this launch was exhibited there; and in September 1883, he conveyed a party along the Danube from Vienna to Presburg, a distance of fifty miles, accomplishing the journey in four hours. was built by Messrs Yarrow & Co. for the Electrical Power Storage Company, and could accommodate forty passengers with ease.
AMUSING BREVITIES. NEVER was a time when brevity was more the fashion and more constantly insisted upon than at present. As an American paper says, we insist that all art, all literature, and all emotions shall be brief. It is the age of epigram. Even the universal impatience engendered by the restlessness and hurry of the time, should be satisfied with the terseness, for instance, which describes
An electric launch possesses many important advantages over a steam launch, and even in its present stage of development might replace the latter with advantage in many cases. In an electric launch the accumulator cells and motor are placed under the seats and floor, are quite invisible, and occupy no space which might other wise have been available for passengers or goods. In a steam launch, on the other hand, a consider a bad cook as one who makes a hash of everything able portion of the centre and most convenient-except mutton; an unsatisfactory meal, as a space is taken up by the boiler and engine. It domestic broil; and the average prize-fight of the is at once evident that an electric launch will day-a paper mill. We are reminded that it is carry more passengers than a steam launch of harder for a woman to hold her tongue than for
a man to hold a baby; that in a game of cards a good deal depends on good playing; and good playing depends on a good deal; and that getting into a passion is a great deal like getting into a barberry bush. The bush comes out all right, but you don't. The hardness of the world is laconically hit off in the saying, 'Every rose has its thorn, but not one thorn in a hundred has its rose.'
Not a bad answer was made by a sportsman returning from the marshes, when asked if he had shot anything. No;' he said; but I have given the birds a good serenading.'
'Yes, sir,' said Jenkins; 'Smithers is a man who keeps his word; but then he has to.'—' How is that?' asked Jones. Because no one will take it.''Mercy me! what are those horrible sounds up-stairs?'Oh, that is nothing but dear George. I suppose he has lost his collar-stud again.'
The art of condensation was evidently studied by the journalist who reported: A coloured gentleman went into a blacksmith's shop with his coat-tails full of powder. He came out through the roof.' This reminds us of-A quarryman said he couldn't see any danger in smoking while he was handling powder. He can't see anything A poor American who complained that he was like the moon-at his last quarter-was as witty as the man who advertised a clock for sale which kept time like a tax-gatherer. A good advertisement appeared on a sign in the Far West: 'Here's where you get a meal like your mother used to give you.' But for graphic illustration of the multum in parvo, what could beat the sign of the travelling dentist in the United States, which bore the startling announcement, 2th pullin'?
As pithy as some of the foregoing, but more satirical, is the description of a man said to be so mean that he wishes his landlord to reduce the price of his board because he has had two of his teeth extracted. Severer was the remark of a man, who, hearing that an acquaintance had married again, exclaimed: 'Stupid donkey! He didn't deserve to lose his first wife.' A famous preacher remarked that it is possible for a man to be a Christian and belong to a brass band, but that it would be difficult for such a man's next-door neighbour to be a Christian.
Nothing makes a bald-headed man madder than to be accused of never cleaning the hairs out of the comb, says an American; and an old darkey observed that 'a man would be a heap better off if he was as particular 'bout de whisky he drinks as he is 'bout de water.' Somewhat satirical is the announcement that there is a man in New York who manufactures diamonds for actresses to lose. They are sold at so much a quart.
There is a good deal of quiet humour in the few lines in which a certain country paper commented on political affairs: "The scarcity of new hats in the street shows that very little interest was taken in the election.' Another humorist observes: 'It takes eight hundred full-blown roses to make a tablespoonful of perfume; whilst a shilling's-worth of cooked onions will scent a neighbourhood.'
pleaded in extenuation of his offence that he wanted it for his collection of curiosities, it being the first cake of soap he had ever discovered in a Chicago hotel. Equally sarcastic was the reply of one of the auditors of a political orator, speaking of a certain general whom he professed to admire, and said he was always found where the bullets were thickest. Where was that?' asked one of the crowd. In the ammunition wagon!' shouted another.
'I'm from Mr Brown, mum-gentleman what lives across the way. He says: Won't you please shut them windows when the young lady's a-playing?'-But I thought Mr Brown was musical himself?'-'That's the reason, mum.'
At a party, a young lady began a song, 'The autumn days have come; ten thousand leaves are falling.' She began too high. Ten thousand,' she screeched, and stopped. 'Start her at five thousand!' cried an auctioneer present.
A lady in a registry office observed: 'I am afraid that that little girl won't do for a nurse; she is too small. I should hesitate to trust her with the baby.'-Clerk: 'Her size, madam, we look upon as her greatest recommendation.' Lady: Indeed! But she is so very small.'Clerk: 'I know that she is diminutive; but you should remember that when she drops a baby, it doesn't have very far to fall.'
A physician much attached to his profession and his own skill, during his attendance on a man of letters, observing that the patient was very punctual in taking all his medicines and following his rules, exclaimed in all the pride of his heart: Ah, my dear sir, you deserve to be ill!'
None of these, however, may be said to match the following. 'My dear,' said a husband startling tones, after awaking his wife in the night, I have swallowed a dose of strychnine! 'Well, then, for goodness' sake lie still, or it may come up.'
A Chicago hotel-keeper recently had a man | Printed and Published by W. & R. CHAMBERS, 47 Paterarrested for stealing a cake of soap. The man noster Row, LONDON, and 339 High Street, EDINBURGE
All Rights Reserved.
LITERATURE, SCIENCE, AND ART
ESTABLISHED BY WILLIAM AND ROBERT CHAMBERS, 1832
CAN THE 'ROLLING' OF SHIPS BE
are weighing down together; then the force of the wind and waves makes the vessel start off for the roll over to the other side; but it is clear that, until it has passed the point of perpendicularity and commenced to incline to the left, the water in the chamber will be tending to prevent it from doing so, by still weighing down to the right. In fact the water does not 'come' so quickly as the ship, but has a tendency to lag behind. When the vessel has rolled leftwards, the floor of the water-chamber will have become sloped, and the water will run leftwards too. But almost
will have become reversed, and the water in the chamber will once more check the motion of the hull and tend to hold it back leftwards. And so it goes on, there being a constant force in the hull which goes to counteract the motion of the ship tossed by wind and sea.
THE designing of Her Majesty's ship Inflexible was regulated by certain conditions which had the indirect effect of making her a very heavy roller; and the question arose: 'Is it possible to devise some means whereby the steadiness of a vessel tossed by wind and waves can be promoted?' At once Mr R. E. Froude-who had already made certain experiments and investigations that had a bearing upon the question-immediately the lateral momentum of the ship set to work to study it thoroughly, and with him was associated in the work his colleague in the Admiralty, Mr P. Watts. It had already been noticed that the presence of what is termed a bilge-keel in a vessel did much to increase her steadiness while at sea, though it was also known that there were serious obstacles to the use of this appendage. In the first place, in large ships it would have to be of a great size, and consequently much exposed and liable to injury; in the second place, it offered a considerable impediment to a vessel's progress; and in the third place, in the case of large ships like the Inflexle, the addition of a bilge-keel, which is the ordinary keel deepened, would make a passage into and out of existing docks impossible. So the mere use of a bilge-keel did not meet the case, and other methods of reducing the rolling tendency of a ship were discussed. Finally, the 'water-chamber' method found favour; and it was proposed to put it into practice.
The water-chamber method is briefly this: One tank or more is fitted into the hull of the vessel, stretching from side to side; and into such tank or tanks a certain quantity of water is admitted, it being found that the motion of the water produces a force which acts in opposition to the rolling of the ship, which it consequently tends to check. A little consideration will show how this is the case. A ship rolls on one side-say to the right-and the water in the tank follows; so, for a moment or two, the ship and the water
This method of checking the rolling of the vessel while at sea having been decided upon, two water-chambers were fitted into the Inflexible, one forward, and the other aft. The one forward measured twenty-two feet across, and extended from the armour-deck to the upper deck. The one aft measured fourteen feet across, and extended from the armour-deck to the main-deck. As the work of building the vessel proceeded, however, it was found necessary to appropriate the first-named chamber for purposes of storage; and so only one water-chamber was left for Mr Froude to experiment with. Nevertheless, with this he arranged a programme of operations which included the testing of the rolling of the vessel with and without water in the chamber, both in a comparatively smooth and in a rough sea. Another disappointment was, however, in store for him. He had but completed his experiments in the Mediterranean with the ship in still water and without the chamber in use, when the order was flashed from Westminster that the Inflexible was to proceed at once to Alexandria, to take part in the operations there that had arisen in connection with the Egyptian troubles. However, on the 16th of June 1882, while lying about
twenty or thirty miles off Alexandria, some experiments as to the way in which the ship would behave in deep sea with and without the water-chamber in use, were made. The result of these experiments was to show that the chamber was most effective when about half full of water, and that when in this condition, it reduced the rolling of the vessel by about 37.5 per cent. This result had reference to the ship while in regular waves.
provoked an indignant response from Mr Martell, who, having traced the fatality in question to carelessness, declared, amid applause, that it could not possibly be used either as an argument for or as an argument against the use of waterchambers.
There can be no doubt that the admission under certain conditions of a large quantity of free water into a ship does represent a very serious element of danger. But this fact is recognised by no one more readily than by Mr Froude and Mr Watts; and of course, before water-chambers can come into general practical use, the character and conditions of this element of danger must be ascertained, in used against the employment of water-chambers is, that they must necessarily take up a large amount of space, which should be applied to other purposes. But this argument loses all its force when we are reminded that the water-chamber can be utilised for the storage of the fresh-water supplies of the vessel, or for the water-ballast which is so frequently used. While, however, we can very safely leave the matter to be thoroughly investigated by Mr Froude, Mr Watts, and the other scientific gentlemen whose sympathies it has enlisted, and while we may look forward hopefully to the obstacles that may now exist || being overcome, we may congratulate ourselves that science is in a fair way to effect a means by which not only our sailors will be enabled to fire their guns at sea with infinitely more precision than they have ever been able to do in the past, but also a means by which in passenger ships sea-sickness-one of the most abundant sources of human discomfort, and even misery— will be, at anyrate, considerably lessened.
In 1883, Mr Watts read a paper before the Institution of Naval Architects setting forth the results of the experiments that had been made with the water-chamber. The matter was not received with unqualified approval by the mem-order that it may be avoided. Another argument bers of the Institution, and the danger of introducing free water into a ship was referred to by Sir Edward J. Reed, M.P., Mr J. D'A. Samuda, Mr W. John, Mr B. Martell, and other gentlemen well versed in shipping matters. It was, however, frankly admitted on all hands that the subject was only as yet in its undeveloped infancy, and that it was impossible to pronounce judgment upon it before further investigations and experiments had been made. In the paper referred to, Mr Watts said that such further experiments were about to be made, both with models and with the ship artificially rolled in still water; and he promised that, at a future date, he would put before the Institution the result of those experiments. Hence, in the March of the present year, at the sessional meetings of the Institution of Naval Architects, held in the hall of the Society of Arts, he read a paper On the Use of Water-chambers for Reducing the Rolling of Ships at Sea.' In this paper the history of the method was continued.
It appeared that, though it had at first been intended to pursue the experiments with the Inflexible, this was not found to be convenient, and the Edinburgh had been selected as a substitute. In the Edinburgh, the water-chamber is fourteen feet across, and runs from one side of the ship to the other, with a capacity of two hundred and ten tons. Mr Watts had to communicate very satisfactory results as the outcome of his experiments with the waterchamber in the Edinburgh, and he concluded with the following words: In this paper I have not had time to consider how the safety of a ship must limit the extent of the space or spaces set apart for this purpose; but it appears that, supposing the safety of the ship not endangered, rolling may be reduced by this means to almost any extent.'
Mr Watts' second paper met with a warmer reception at the hands of the members of the Institution of Naval Architects than his first one had done. It was criticised, it is true; and a naval captain, having apologised for speaking on a subject which did not properly come within his province, said that, though, on going into action, he should be anxious above all things to secure a steady gun-platform, yet he should be very loth to let a volume of free water into his ship, for he believed the enemy would do that for him quite soon enough. In discussing the question of danger, the case of the ill-fated Austral was mentioned-as it had been two years before-as an evidence of the fatal results attending the letting of free water into a ship; but this
A HOUSE DIVIDED AGAINST ITSELF.
FRANCES remembered little of the journey after it was over. She was keenly conscious at the time, if there can be any keen consciousness of a thing which is all vague, which conveys no clear idea. Through the darkness of the night, which came on before she had left the coast she knew, with all those familiar towns gleaming out as she passed-Mentone, Monaco on its headland, the sheltering bays which kept so warm and bright those cities of sickness, of idleness, and pleasure, the palms, the olives, the oranges, the aloe hedges, the roses and heliotropes-there was a confused and breathless sweep of distance, half in the dark, half in the light, the monotonous plains, the lines of poplars, the straight highroads of France. Paris, where they stayed for a night, was only like a bigger, noisier, vast railway station, to Frances. She had no time, in the hurry of her journey, in the still greater hurry of her thoughts, to realise that here was the scene of that dread Revolution of which she had read with shuddering excitement that she was driven past the spot where the guillotine was first set up, and through the streets where the tumbrels had rolled, carrying to that dread death the many tender victims, who were all she knew of that great convulsion of history.
Markham, who was so good to her, put his head out of the carriage and pointed to a series