512

LONG-DISTANCE LIGHTING.

THE lighting of Ottawa, Ill., shows a remarkable example of pluck and energy. Owing to the convenience of water-power which reduced the operating expenses to a minimum figure, the idea of using an expensive steam plant was abandoned, and the company went eight miles east to the town of Marseilles, where ample water-power was secured, and there located the station. The station house having been located, the work of construction was then pushed, and great care taken to have both pole line and house circuits first class in every respect. For the trunk lines only a No. 8 American gauge copper wire was used, insulated with waterproof covering, although the first lamp reached was placed in Ottawa, some eight miles distant from the station. Altogether over 45 miles of circuits have been strung, including some 12 miles of No. 11 insulated copper wire. The distance along the railway following the river is 5 miles from Seneca to Marseilles, 7 to Ottawa, and 10 to Utica.

That the public spirited citizens of Ottawa appreciated the pluck exhibited in carrying the enterprise through to a successful issue is shown by the fact that the first dynamo is now carrying a full load, contracts having been secured for more than 100 15-C.P. lamps, 150 20-C.P., 300 30-C.P., and about 30 of large sizes, ranging to 100 C.P. In addition to this number the company is operating in the town of Marseilles over 100 lamps, and will shortly have 30 more in use for street lighting, and circuits are now being carried into the town of Seneca, some five miles to the east. The important features of this installation are (1) the great length of circuits, seldom, if ever, equalled in incandescent lighting; (2) the great area covered; (3) the comparatively slight investment for copper wire, being the least important part of the total cost of the installation, and (4) the fact that the lights furthest from the station are reported to burn as brightly as lamps placed near the dynamos, all of which tends to indicate both the flexibility of the Heisler system and its adaptation for long-distance lighting under circumstances that are often of the most disadvantageous and disheartening character. should now be in luck's way.

CONTINENTAL NOTES.

Barnet

THE Special Committee appointed to enquire into the lighting of Brussels by electricity has expressed its wish that M. Rysselberghe should be authorised to experiment with his system, in the way of trial, on a space to be indicated to him. A second proposition of the electrical committee was to make an appeal to three of the companies whose tenders appeared to it to include the greatest advantages and guarantees-a Liége company and two German companies-with a view to get them to come to an agreement as to the cost of electric lighting. The Communal Council has yet to consider these propositions.

The permission granted in 1862 to introduce into Russia, free of entry dues, cables intended for the Russian Government telegraphs has been suppressed.

A few nights since, about half-past nine, a curious sight was witnessed at the Eiffel Tower. A large flock of larks, which was passing over Paris, attracted by the electric light in the phare, threw itself in a compact mass on the windows of M. Eiffel's apartments. With their well-known obstinacy, the poor birds struck themselves furiously against the glasses of the phare, and fell stupefied all round. The man in charge of the light was enabled to capture a large number. The next morning the gardeners employed in the Exhibition found a quantity of the birds in the small lakes at the foot of the Eiffel Tower.

M. Marcel Deprez has just made an important communication on the subject of the transmission of power to long distances by electricity. In the first place, he recalls the experiments made at Creil in 1886, which

[NOVEMBER 1, 1889.

demonstrated that the principle of the problem had been found. Indeed, with a 125 horse-power engine placed at Creil, 85 horse-power was obtained at Paris Unfortunately a wire broke during the experiment which, however, was much discussed. It was not pres tical. M. Deprez then studied the method of making his machines more useful, and he thought he ha arrived at a practical result at Bourganeuf, where his electrical machinery worked several months withoz accident. The generating machinery is placed at the St. Martin falls, about 14 kilometres from Bourganeuf. These falls are 31 metres high, the turbines furnish 130 horse-power, and revolve at a speed of 150 revo lutions per minute. The machines are of 100 horsepower; the line is composed of two bronze wires of millimetres, supported by fir posts. The receiving machine is identical with the generator; it is used with a certain number of accumulators. M. Deprez in his communication, enters into details on the working of these machines. There are two for the production of light; but one is sufficient to ensure the service; it gives a daily yield of 50 per cent. in light a yield which might be raised to 60 per cent. Com munication is kept up between the stations by tele graph signals, which are more serviceable than telephones. Two persons are sufficient to ensure the work ing of the machines. Numerous lightning conductors protect the installation and the staff; and the acce mulators, which number sixty, are charged every day The work produced by the machines is absolutely regular, and the light is steady. The accumulators had only been used twice, when a machine was disabled after a storm. M. Marcel Deprez concludes by saying that the new machinery assures in a regular manner the transmis sion of power to long distances. They are applicable in all cases, and a small staff only is necessary. They give a yield of 60 per cent., and their relatively low net price may be made yet lower.

In connection with the prize given by the King of the Belgians on the subject of electricity, the International committee appointed to judge the competition known as the King's Prize (£1,000), held a sitting a few days since under the presidency of M. le Sénateur Montifiore. Among the members of the committee figured, for England, Sir William Thomson, whom. La Meuse says, the electricians present justly looked upon as their leader. In addition, the committee was made up as follows:-M. Cornu, professor at the Paris Polytechnic School; M. Roiti, professor at Florence: M. Ponthière, professor at Louvain; and M. Eric Gérard, professor at Liége, who fulfilled the office of secretary-reporter. The Minister of the Interior, M. Devoider, specially went to Rond Chêne, to wish, in the name of the King, welcome to the foreign delegates. After a sitting, which lasted four full hours, the committee terminated its labours by holding its closing sitting in the Montefiore Electro-Technique Institute. The members of the jury visited in turn the labora tories of the Institute, and then separated, after having transmitted the result of their deliberations to the King.

ELECTRICAL TRADES SECTION, LONDON CHAMBER OF COMMERCE AND THE EDINBURGH EXHIBITION.

A MEETING was held on Monday last to discuss the matters given in the agenda published last week. After the correspondent's report had been read, particulars of which will be seen in our "Notes" columns,

Major S. FLOOD PAGE said he had a matter for the discussion of the section, but which was not on the agenda. Some gentlemen have determined to have an International Exhibition of Electrical Engineering, of General Inventions and Industries; there are many of the rules that are extremely stringent, and I think the time has come when members who have been connected with the

electrical industries will agree that exhibitions, especially 400 miles away, are expensive, and we get very little indeed out of them, and it is neither fair nor reasonable that gentlemen in Edinburgh who want to make money for the town should call upon us to bear the vast expense in connection with such exhibitions. It is within my knowledge that one firm at one exhibition say they spent £6,000, and they were unable to trace a single direct order to that. Now I am not for a moment suggesting that we should not exhibit, but I am going to propose a resolution that we shall exhibit on our terms and not on theirs. The first thing we are required to do is to pay for space, and in addition to that we have to bear the expense of delivery, working and the cost of installation. We are obliged to insure to make good damage that may arise. Now, I do not consider that fair; I think the rent should be free, in the first place, and that any case of exhibits sent, the Exhibition should take the responsibility. We are asking what is reasonable, and they must take us on our terms or not have a successful Exhibition. I should like to move "That with a view to the electrical industry taking united action with regard to the proposed Electrical Exhibition in Edinburgh, 1890, a committee of ourselves be appointed to consider the conditions on which it may be desirable to take part in the Exhibition, and that a meeting of the entire electrical section be held on November 11th to receive report, and, if they thought advisable, to take action thereupon."

Mr. SWINBURNE seconded the resolution, which was unanimously adopted.

The following gentlemen were elected on the proposed committee:-Messrs. Garcke, Siemens, Woodhouse and Rawson, Laing, Wharton and Down, Mather and Platt, Marshall, Major-Gen. Webber, and a representative of the E.P.S. Company.

ELECTRICAL TRADES UNION.

A LARGE meeting was held at the Albion Hall, Moorgate Street, on Saturday night last, in accordance with the notice published in our pages.

The CHAIRMAN, who desired his name to be suppressed, referred to a meeting which had been held on October 5th of electrical operatives, when it was decided that a union should be formed. A great number of names had been enrolled; it would be the duty of the meeting to give assistance in the formation of rules, which would be submitted to a public meeting for approval. It was their business to protect themselves, for they did not intend aggression. The mechanical calling of the future, he affirmed, would be connected with electricity in some shape or form, and when they looked at the great improvements made every year it behoved the men to make a "closed circuit," so that the current was always going round. A union would protect the employers, in the fact that the better men would be found to do the work. A rumour had come to his ears that the union was intended for only one or two branches. That was not so; it would embrace every branch, and be placed on the same level as other associations.

The SECRETARY then read several encouraging letters from various large centres.

Mr. ROWLANDS, M.P. for East Finsbury, who arrived late, then addressed the meeting. He said: As one outside the industry, it is not for me to tell you what to do with regard to things distinctly connected with your own work; what I intend to do is rather to make general remarks of what you can do for yourselves by organisation. I have to congratulate you as a large body of working men in an industry which is of comparatively new growth, and which must in the near future be a much greater industry than it is at the present time. You are again to be congratulated on coming to the conclusion that you think it necessary to organise yourselves. You commenced that movement, not in any combative spirit, not necessarily because you have a grievance here or there, but because you see from experience, and from the illustration of what other bodies of men have done by organisation, that it is an absolute necessity for your own protection. I can say that it is the duty of any large body of men working in a given industry or series of kindred industries, to create an organisation for themselves, where, after subscribing for their mutual protection and assistance they can, in their society, discuss all those questions which have a distinct relation to their own industry, they can thresh out among themselves the position they occupy, and discuss whether there is an opportunity of bettering their position, which, of course, is the ideal we should all have before us. Still, this should not be confined to London alone, but connected with the great number of workers in other large centres, such as London. I hope you will take from me my

opinion as to what should be your action in concert with your fellows. I believe that first and foremost you should follow the example of the large industries throughout the country, and form one amalgamated society for the whole country. A great London branch should have the control over all branches, and in each district of London there should be a branch or a series. I am, of course, rather of opinion, that it seems somewhat difficult, if there is anything like the opinion which seems to be expressed in this room, for having one branch to fulfil the requirements of the whole of the metropolis. So far as I am given to understand there are somewhere about 3,000 whom you consider fellowworkers within the metropolis, and I hope sincerely that out of that number the majority will join, and that is what they ought to do. I am afraid you will find-but you must not be disheartened-like other industries, that it takes some time to convert your fellow-workers to the advantages of an organisation like that which you have commenced to create; but, at least, out of such a vast number as 3,000, you ought to have a a very large accession to your ranks, and if you have, then you might form a gigantic branch in London, or else it might be found better, to meet the requirements of London, to have several branches scattered through the metropolis, where the majority were. When you have organised London, your next duty is to assist in amalgamating a society to co-operate with your fellows in the other great centres, so as to form one of those strong and powerful amalgamated societies for your kindred industries throughout the various parts of the country. You then not only have the advantage of having organised a much stronger body of persons, but you also have this other great advantage, that you are able to concentrate your efforts and to accumulate other resources, so that when you require to fall back upon them, you would have something to support you in any undertaking you might think it necessary to go in for. I consider that that is a very great advantage indeed, and I consider it is the model which you should have before you. Of course, you would have to confer, as I understand arrangements are to be made, by delegation with those who have the same opinion as yourselves, and to mutually aid in building a constitution by which you intend to be governed. The question of constitution-making is rather dry work; it is very difficult, and sometimes it is very unenviable work, because in all bodies of men, we are all alike, there is always someone who fancy they could make something a great deal better than that which is decided upon. We cannot, however, all have our own way, and therefore the constitution must be the best representative union which you can get by this system of delegation in conference. Now, having started on the question of your constitution, some of you may want to commence from the beginning; but I think there is no need to do that, there are many organisations already created which have already gone through the preliminary work which you are about to go through, and you may profit a great deal by the work which they have done if you collect the constitutions which they have already created for themselves, you would find the accumulated wisdom they have had to put in their constitution, and you would be able to get as good a set of rules as it is possible to get, and this would save you a very great amount of time and labour. I am not going to discuss what are the exact things which you wish to obtain when you are organised. I can only say this, that there is one thing that you will always gain by organisation, you can always protect that which you have, even supposing you do not want any increase in the shape of remuneration. A trades' organisation is not alone an instrument for trying to get something else, but what is paid weekly toward your union is also a subscription to an assurance society, an assurance society in this, knowing you are organised; if there was an attempt to break down here or there that remuneration which you are already getting, you can at once make a stand to retain it; that is a feature which is sometimes lost sight of by persons who go into these organisations. They forget that it is sometimes as well to pay on purpose to keep what they have, as to try and get something more, when that may not be attainable. There are other questions, say, for instance, you will find labour of an inferior character underpaid, being forced in to take the place of that labour which has previously been used. You can, of course, through your officials, when you are organised, make a representation against that, in fact, there are one hundred and one ways which, when organised, you will see that you are able to protect yourselves, and to do good for yourselves in the industry which it is your lot to have to earn daily bread in There is one thing I am pleased to see, that in forming this you. are going to manage it yourselves. I am a great believer in all societies managing their own affairs. It is the essence of the characteristic of the English people; it is the essence of our municipal life; it is the essence, without going into party questions, of our attempt to get political power for the masses of people, however they may use it. It is that essence of managing your own affairs. I am sure that the one thing you should strike for is from your midst to get the best possible men, who know the whole of the working, to manage your society; because when you can bring these officers out of your midst, and make competition among members to obtain these positions, you are creating a spirit of emulation, and those who may not achieve the office, in trying to do so, are passing through the ordeal which will qualify them for some future time as leaders of their organisation. But, wherever I look at the successful organisations that have taken place in this country, whether in friendly societies or in big trade union, I find they have been managed by the men who required them. It is because they have been managed

by those who required them that their success has been attained, and they have met the wants of those who required them. Now, it is therefore with great pleasure, indeed, that if I can be of this little assistance to you in trying to guide you, not in trying to teach you what I do not know with regard to your industry, but in trying, with my best experience, to give some little information of the road you should take, if I can give you, in the same spirit that I am sure you will accept, that little amount of advice I am able to give as one standing aloof from you, but who wishes you to take that road which will lead to success, and which, I am sure, in the future will be a blessing to you who come into the organisation. I am sure that many evils which men complain of to-day can be overcome if they were only organised, at any rate a great many difficulties could be solved, and I am pleased to see the spirit which is abroad at the present time amongst those who hitherto have neglected organisation, that they are wanting, and are going to join, the large organisations which have existed through the country for such a large number of years in connection with some great industries, and which have been such a blessing to those who have become members of them. You are asked possibly to make a temporary sacrifice in the way of subscription, and there are always unfortunately some men who look at this small sacrifice they are called to make as though they were giving something away for the benefit of others. There is not a greater mistake; they are only putting their little with some others little for the benefit of the whole. They are only doing that which has had to be done in the past before anything whatever has been achieved in England. Some may not see so speedy a benefit accruing from joining organisation-some people want to see the millenium at once but supposing they do not happen to see it at once they must remember that some of the reforms and some of the advantages-which, perhaps, seem to linger a long while on the road-when they are attained, are the most beneficial, and are the most stable of any advantages that could be obtained by any body of men. Now, I do not intend to occupy your time any longer. You are here for a business meeting; you are here for business purposes, to give your new child another lesson, and I hope the child will be able to walk very successfully. I must congratulate you on a meeting like this on a Saturday evening, when some men are generally drawn away by other attractions. You have taken a wise course in meeting in this hall, where your minds could not be diverted from that business which you have in hand. I can only say in conclusion that any service I may be to you in your proceedings, before you get thoroughly organised, I should be only too pleased to give. I hope that as soon as you get thoroughly organised you will be able to do like other big organisations, walk alone, because you have in yourselves that spirit of organisation, that desire to do good to one another, and that cooperative instinct which can only be developed by organisation, and which means prosperity and benefit to all who heartily and sincerely enter into it.

an

A vote of thanks was proposed, the speaker considering that the best vote of thanks to Mr. Rowlands was to join the organisation. Cheers were then given for Mr. Rowlands.

Mr. ROWLANDS, replying, said that if he came to their annual meeting and they told him nine-tenths of the men were in the organisation he should be delighted.

The meeting was a very representative one, and 300 names were given in during the evening as members. Delegates have been elected to meet the Manchester Union. We are requested to ask that all communications be sent to the Secretary, Paul's Head, Finsbury.

[NOVEMBER 1, 1889.

ABSTRACTS

OF PUBLISHED SPECIFICATIONS, 1888.

12609.

"

Improvements in or relating to electrical locks." W. P. THOMPSON. (A communication from abroad by E. Lemonon, f France.) Dated September 1. 8d. Claims:-1. An electric bi bolt having a circuit controlling device consisting of a knob pushed by the door to which the lock is attached, and closing the eircet by bringing into contact two springing strips, the electrical s tact of which is insured by a frequent and automatic cleaning substantially as described. 2. In a lock bolt such as described the armature providing against remanent magnetism, and carrying a stirrup which releases a lever held under the heel piece of i releasing device, which lever when released allows a head piece to swing round, thus permitting a spring bolt to emerge and the door to open under the pushing force of a knob, thus breaking the ar cuit, which is only re-established by again closing the door, by which means the said knob is again pressed back, substantially s described, and for the purposes set forth. 3. The improved lock bolt taken as a whole, substantially as described and shown.

12856. "Improved apparatus for converting electrical er rents." C. ZIPERNOWSKY and M. DERI. Dated September 5. 81. Claims-1. An apparatus for converting alternating into cotinuous electric currents, the combination of a stationary divided iron ring wound with one pair or with several pairs of coils for the alternating currents, so connected that the current in one of each pair has its phase one quarter of a wave length differing from that of the other, a set of coils for induction wound on the ring and connected, as in a Gramme machine, to plates of a stationary commutator, an electro-magnetic armature revolving and carrying suitable pairs of brushes around the commutator, contact ring: connected to these brushes and springs pressing on the rings to convey the continuous currents which are induced in the Gramme coils, substantially as herein described. 2. The modified form of apparatus wherein the coils are on a divided iron drum revolving within a stationary electro-magnetic armature, the revolving dras carrying contact rings for the alternating currents, and carrying also a revolving commutator which is rubbed by stationary brushes to convey the induced continuous current, substantially as de scribed. 3. The modified form of apparatus wherein a stationary divided iron drum is surrounded by a stationary iron ring, either the drum or the ring being wound with one pair or with several pairs of coils for the alternating currents, and either the ring or the drum being wound with the coils for induction, having that stationary commutator on which rub suitable pairs of brushes revolving with an iron anchor along with rings pressed on by stationary springs for conveying the induced continuous current 4. The use of apparatus such as are referred to in the preceding claims for converting continuous into alternating currents by leading the continuous current through brushes and commutator to the continuous coils, providing the anchor with a coil closed on itself, and also with a continuous current coil, and connecting the alternate current pairs of coils so that the current in one of each pair is in a phase differing by one quarter of a wave length from the other, substantially as described.

14963. "Improvements in electric bells and signals and in appliances for use therewith." E. Cox-WALKER and A. A. CAMPBELL SWINTON. Dated October 18. 11d. The inventors employ for the receiving mechanism of an electric bell or signal an armature which may be of H or similar section wound shuttle wise with insulated wire or may be of the other forms commonly used in dynamo machines and motors, and is pivoted on an axis so that it can partially rotate between the poles of a permanent or electro-magnet or several such magnets, the said magnet or magnets being preferably fitted with soft iron pole pieces suitably hollowed out so as to leave a cylindrical chamber between them in which the armature moves. 14 claims.

CORRESPONDENCE.

Energy.

MY ideas on lightning conductors are already known, having been communicated to the "Inst. Elect. Eng." during the recent discussion on this subject. I have, however, given more attention to the practical, than to the theoretical side of the question; and therefore read the articles appearing from week to week in your columns on "Lightning Conductors," so ably written by Mr. S. Alfred Varley, with much interest and profit. When, however, I caught sight of his article headed "Energy" in last week's REVIEW, my interest was doubled, for, of all others, this is my "hobby." I say I read it with interest, though assuredly not with profit, although it may seem at first glance that where there is a question of "interest,"

NOVEMBER 1, 1889.]

there is also one of "gain." Whither have Mr. Varley's thoughts wandered? He seems to me to have mixed

up energy, electricity and matter in such a way as to puzzle most physicists to unravel the mystery he has made. Although he opens his subject with a declaration that all is mystery, that mystery is nevertheless entirely of his own making.

That force which Newton discovered in matter-the force of attraction-is the origin of all known forms of energy. That one force can be changed into all the other existant forms. We certainly see it "unlocked in the firegrate" in the form of heat, but it just as certainly, does not disappear. It simply acts on the force of attraction or cohesion in the particles of water in the boiler, giving it a thermo-electric form of a repelling nature (like electrics repel each other), and causing the molecules or particles of water to break away from each other. As soon as this force of breaking away becomes perceptible, it is then called mechanical energy. In the same way it may be shown how the mechanical energy affects the force of attraction in the particles of matter in the wire and iron forming the dynamo system, producing the electric current; but in no case does the energy literally disappear. When we seemingly lose sight of it, be assured that it is a case of reaction, and that some form of energy having been imparted to some body by the energy in another, that other is affected by the reaction. In paragraph two, comparison is made between energy and electricity. Mr. Varley ought by this time to know that electricity is but a form of energy, and therefore cannot be compared with it, except that the energy be in another form. It is, then, the forms of energy which are compared, not energy with its forms.

Again, the statement is made that energy can be added to, or taken from matter. This fact is only partly true, and then even only in a special case. Energy can be given to a body by impelling it against another. This is the only case of which I know; and I am not at all sure that it is true here. The body is moved, but the particles of that body receive no energy whatever. The prevention of further motion changes the energy of the molecules of the moving, and of the resisting body. The original statement, as above, is most absurd. Where inertia exists, there is also latent energy (generally in the form of attractive or cohesive force), and if acted on by energy in some active form, it will itself become active, causing work to be overcome; but this is by no means adding energy. It is simply making it more active. The law of "Actio et Reactio seems to have been forgotten. If a body be internally affected by an active force (for instance, giving out heat), that force is but seemingly lost when the body cools, and a second one becomes heated. The latent energy of the second has evidently become transformed to heat; but, on the other hand, the energy of the first body has not been taken away. It has been changed to a form of attraction, and under its influence the body contracts. Energy then cannot be added to, or taken from matter.

In paragraph three, and about six lines down, we are told, that for energy to be available, it must be associated either with matter or electricity. I dare say that from the context, I might guess at what Mr. Varley is driving, but he assuredly does not express it. I have already shown that electricity is but a form of energy. Neither electricity nor any other form of energy can exist independently of matter, nor can one conceive of matter without energy-either latent or active-so that the above statement, of available energy being associated with matter, is self-evident.

The law, then (if it is worth calling one), which we find in the last lines of paragraph three, should now read as follows:-The more active or useful the energy in a body becomes, the greater will be its effect in influencing the form of energy in another body. After modifying, this, too, becomes almost an axiom, so that so far Mr. Varley's information does not go for much.

The end of paragraph four, and the entire of five, seem filled with the same curious, though erroneous notion, that energy and electricity are two distinct

515

things. The wonderful part of it all is, that with false data, Mr. Varley has been able to jump at correct conclusions, and on this I sincerely congratulate him.

From paragraph six we receive the startling announcement that a difference exists between electrical motion and matter in motion. As far as I know, electrical motion and matter in motion (under certain conditions) are synonymous. Electrical motion is essentially matter in motion. Energy in the form of electricity gives a certain motion to matter. This motion is perfectly analogous with electrical motion-the two are one and the same thing. I could go on criticising at some length, and in a similar strain, the first half of next page; but it is quite unnecessary to travel twice over the same ground.

In the middle of paragraph three, and in column two of the same page, certain phenomena are said to be due to a composition of laws or forces. Is this statement not rather mixed? How can phenomena be due to laws? Forces act under certain conditions, which for want of a better word, we call laws; but it is the forces which are the cause of phenomena. The word phonomena was invented by the Greek Permenides of Megro; and by it he signified fleeting appearances, to distinguish it from noumina or known facts or truths. Now, the fleeting appearance may be caused by one force, while the true effect may be caused by another; but neither the one nor the other is caused by two or more forces; nor is any single force bound by more than one law. Every force has its law, and every force has its separate effect; although we may not at once be able to detect it. I will not longer trespass on your valuable space; but thanking you in advance for the insertion of this letter. Leonard Joseph.

The London Tramways Company.

In your "Notes" of last week's issue, you state that the above company intends "not only to drive Jarman's cars, but to light houses from its depôt by electricity." As I see from a not very old price list of the Jarman Company that Mr. Jarman is an inventor of dynamos, lamps and accumulators, I am very curious to learn whether these are to be used in the proposed work announced by you. Probably your correspondent and my namesake, Mr. John Willis, can inform me.

October 28th, 1889.

Lightning Conductors.

Harry Willis.

I am not surprised that a laudable desire to expose error, combined, possibly, with a keen sense of the ridiculous, should have led you to make merry at my expense, and to somewhat exaggerate, by the way of emphasis, the bad logic at the end of my last contribution.

The blunder perpetrated was the less excusable that the song I have been endeavouring to sing is harmony and continuity in all things, and I ought certainly to have recognised that, as you cannot possibly destroy matter by repeated subdivision, so, also, a difference of potential cannot be altogether annihilated by a process of halving and halving.

The only excuse I can plead is Nemo mortalium omnibus horis sapit, especially when he burns the midnight oil. I am sorry to have to confess my last contribution was written during the small hours of the morning. Being far from happy as to what I had written, I called on an eminent scientist who is strong on those points where I am admittedly weak. friend unfortunately was not in when I called; had he been in the way my bad logic would certainly have been set right in time to prevent its publication.

My

I may, perhaps, be allowed to state what has been omitted in the leaderette, viz., that the blunder did not escape the Lynx eye of the scientific editor. It was detected by him just before going to press at a period

516

too late even to insert one of those editorial notes which occasionally appear in the Journal, and which are so consolatory to "esteemed correspondents."

I remember my father once saying, sternly, by way of reproof, "Fools learnt by their own experience and wise men learnt by the experience of others." I replied that the knowledge obtained at their own cost by those he had termed fools, I ventured to believe, was more valuable to them than that which was obtained at the cost of others by those he had called wise men. Be this as it may, the offence I have been guilty of has afforded the occasion for a very interesting scientific discussion between myself and friend, which has been certainly profitable to me, and I think not altogether valueless to him. S. Alfred Varley.

"No patent invention has ever been offered to the public of such intrinsic service to mankind as Dr. Cavallo's Electric Girdle, for effectually curing ruptures of every description, debility of the longest continuance, and all weakness, obstructions and relaxations of the whole system, connected with these complaints. In these, and numerous other cases, Dr. Cavallo has applied his electric girdle with invariable success, during thirty years extensive practice, and has never once known it to fail, even when every other known remedy had been previously tried without effect. So certain and safe is its application adapted to every constitution, that the doctor will forfeit £50 if it produces any disagreeable sensation even in the most delicate infant. Dr. Cavallo and Son (member of the Royal College of Surgeons, &c.) being the only proprietors, it is not to be had of any other person in the United Kingdom. The electric girdle, price £3, may be had, by applying personally, or by letter inclosing £3, from any part of Great Britain, directed to Dr. Cavallo and Son, No. 28, King Street, Bloomsbury Square, London. N.B.-Advice every day on all other cases; and all post-paid letters, stating cases from the country, immediately answered. From the rapid demand for this girdle, and the great difficulty in procuring the materials, the price will be raised to £5 after the 1st of January, 1811."

[NOVEMBER 1, 1889.

Transformer Tests.

My attention has been called by the talented reviewer himself to the review of Dr. Fleming's book on trans formers which has been lately appearing in you Journal.

I see that, with his customary relish, he has faller upon and torn to pieces some tests of a Gaulard and Gibbs transformer given by me. I am sorry to spell fun, but must really point out that the assumed deduetion of 2 per cent. for loss in iron has no existence in my figures. I merely give the measured quantities and all the elements of the calculation, and your_reviewer might have discovered the mistake in Dr. Fleming') book with half the expense of labour that he bas devoted to making hay of the tests. Further, how do he know that the lamps were voracious?

I do not give the candle-power, as it happens the lamps were very good ones, and I should be glad to see their like again. P. Cardew.

October 29th, 1889.

Should It Be So?

One by one the larger so-called supply houses, impelled by the desire of obtaining a double profit, oper installation departments of their own and undertak the erection of electric light installations, so that at the present time an electrical contractor (not already i manufacturer) can hardly find a single firm from whom to purchase material who does not at the same time compete with him for the contract.

It is clear that he cannot put in the manufacturer's material and compete with him at the same time, sc that each contractor must manufacture his own switche and cut-outs, &c., and so saddle himself with the grea: detail work manufacture implies.

Surely the supply houses are able to sell enough material without making outlets of their own? In any case, there should be a good opening for a house entirely devoted to supplies.

In all other trades the tendency is towards subdivision, and I cannot but think that we are moving in the wrong direction, when every contractor is almost compelled to double his staff and troubles by adding manufacture to his business.

It might be advantageous to hear what both sides have to say upon this subject, and I know that your columns are always open to anything that may tend to the benefit of the electrical industry.

Enquirer.

Teachers and Students.

I have been lately very busy, and my attention has only now been attracted to your notice of my address to the Junior Engineering Society. The address was prepared very hurriedly, and I was glad to insert in it bodily some sentences from my previous published utterances on the historical part of my subject. One of these sentences, taken from my introduction to "Electricity in the Service of Man," began: "In that year Varley and others. I had previously been speaking of Sir Wm. Thomson, and I hastily interpolated, after the name Varley, the words: "who was Thomson's partner." I acknowledge that in this I was very forgetful. Messrs. Cornelius and Samuel A. Varley were the patentees of whom I meant to speak. But I was even more forgetful than this, for I am quite sure that the readers of the ELECTRICAL REVIEW know that the Varleys did not complete their patent in 1866, and that it was presumably for this good reason that Hjorth, in his English patent of 1854, had described with much greater fullness the principle in question. John Perry.

October 28th, 1889.

Accumulators at the Paris Exhibition.

The Commelin-Desmazures accumulator may be seen in the well-known building devoted to the War Depart ment on the Esplanade des Invalides, where 50 little 12 lbs. cells are used to work a six-ton breech-loading gun of the "Canet" type, by the Société des Forges et Chantiers de la Méditerranée, in the carriage of which two motors are concealed.

The gun and carriage, weighing some 10 tons, are instantly moved into any required position by a diminutive lever moving both vertically and horizontally-according to the motion required in the gun. The battery, arranged in two boxes 30 inches x 1 x 8, holds 200 ampère hours, say a useful discharge of 50 ampères at 35 volts for 3 hours.

The motors, gearing, and switch, all of which are perfectly protected within the gun-carriage, are the invention of Captain Krebs.

The accumulators were taken to the Exhibition fully charged, and have been only once re-charged since, s heavy discharge for a few seconds only being required to show the working of the gun.

October 28th, 1889.

P. Bedford Elwell.