OCTOBER 25, 1889.]

ught to be; moreover, Mr. Wright, who was the nanaging director of the Brighton Company, stated at he Institution of Electrical Engineers, that these very poilers, engines, shafting and belting, when used to drive the old fashioned Brush series system, used in combination with storage batteries, consumed 17-6 lbs. of coal per electrical horse-power per hour, measured at the consumer's lamps, whereas when used to drive the alternate transformer system, the consumption was 18.6 lbs., and he then laid the blame on the low efficiency of the transformers during hours of little or no useful load.

Your article has thrown a very clear light on this зubject, and I propose to show that if your calculations are carried out carefully for every month in the year, the total efficiency throughout the year will be considerably lower than stated in the article.

Having very complete data at my command, which shows, among other things: 1st. The proportion which the maximum load on the station bears to the total

number of lamps attached to it. 2nd. The average number of hours which each lamp burns during the year, and 3rd. A set of curves showing the variation of daily load throughout every day in the year, I have been able to compile a table based on the efficiency of the transformer referred to by you in your article. This, I understand, was a 1,500 watt transformer. In other words, equal to supplying a maximum load of 45 33-watt or 10-candle lamps, and therefore a fair specimen of the transformer which would generally be employed in a medium-sized London house.

My data show that throughout the month of December the mean load of such a transformer would only reach 792 watts, or 53 per cent. of its full load for 30 hours in the month. That it would be under 400 watts, or 27 per cent. of its full load, for 190 hours, and the remainder of the output would be at a lower efficiency than 27 per cent.

The efficiency, therefore, of this transformer apart from all losses in the leads, whether in the primary conductors to the house, or in the secondary wiring within the house, will only be 69 per cent. for the best month in the year.

Finding that this was so, I carefully went through all the other months, with the result that I was able to compile the following table, which can be easily verified by those who care to devote as much attention to it as this subject deserves :

Now as to the generating plant :

...

27.0

0.53

Up to the present date, at any rate, as none of the alternating current systems have been able to subdivide their plant and work their engines and dynamos parallel, each district has had to have its own dynamo, and as a consequence, these dynamos and engines driving them have been certainly not loaded so regularly, and consequently not been able to work so efficiently as engines and dynamos generating current for the low tension systems.

In the case of these latter, however, it is found that such is the bad influence of partial loading, that even under the best management and most carefully subdivided system of plant, it is found from data which I have collected from America and from the Continent as well as in England, that during the month of December the best results obtained when calculated from the actual coal bill of the month, show a consumption of coal at least 25 per cent. in excess of the data obtained

487

in full power trials, and in the month of July this difference reaches nearly 60 per cent.

I need hardly say that the main cause of this low efficiency during July is the quantity of coal wasted in getting up steam and heating up the boilers, flues, &c., for comparatively short runs. It appears, therefore, that although the efficiency of the generating plant, i.e., the electrical horse-power of the terminals divided by the indicated horse-power in the engine cylinders, may be as high as 72 per cent. on full power runs, yet if the same efficiency be tested by the coal bill over the whole year, it is probably reduced to some point between 50 and 60 per cent.

If we compound the two efficiences as is done in your article, we get about 29 per cent. as a total efficiency of the whole system exclusive of loss in the conductors.

No doubt these figures will be severely criticised by some of those who are so blindly advocating the alternating transformer system, but I will ask my critics when replying to this letter, to explain how they would apportion the various losses to account for the Brighton figures of 18.6 lbs. of coal per electric horse-power per hour.

If my 29 per cent. be accepted, it still makes the Brighton engines use 5 lbs. per indicated horse, and I think that Messrs. Fowlers will have something to say if any attempt is made to show that these engines use anything like this figure.

At some future date I propose to show you that with the direct supply systems, both with and without batteries, it is quite easy to produce an electrical horsepower, with a consumption of 6 lbs. of coal calculated from the monthly coal bills.

October 16th, 1889.

On Strikes.

R. E. Crompton.

Labour v. Capital is a question in which I take a great interest, and which I strive to judge dispassionately. As it seems to me you have written your article in a spirit of opposition to the labourer, with your permission I will advocate his cause.

You say, "The horny-handed sons of toil are apparently in a perfectly happy frame of mind," &c., till John Burns & Co. appear on the scene as Tempters in the 19th Century Paradise. In the neighbourhood of the Docks there is a scarcity of clothes and capital amongst the inhabitants which has some resemblance with the state of affairs in the Garden of Eden, but in other respects the difference is considerable. The reason Burns commences his agitation among the labourers, and not the Bishops, is because the former are badly paid and discontented and the latter are not. public, if not you, are aware of this fact, and are also conscious that, till now, capital has been all powerful against rough labour. It is this that makes some people look on the men more as martyrs than combatants.

The

It is

You say the men have a perfect right to refuse to work for less than they think proper. Why, then, call them "poor misguided creatures," "demented beings," &c.? Demented or not, ths, or more, of the population of England are very much like them. very curious that you should see demention in the men just when most people see more of it in the masters. I know nothing of the merits of the Silvertown strike except what is in the REVIEW, but I am sure the time has gone by for high-handed action like that of Mr. Gray to be of avail. Public sympathy is now a very powerful factor. Why you should speak about the evil effects of Mr. Burns's teaching in connection, with the dockyard strike I cannot imagine. The effect was that the men got what they were justly entitled to. You seem to regard all strikers as foolish and their leaders as criminal. We differ in this. I regard all idleness as a state to be deplored whether it is temporary, like during the strikes, or lifelong as in the case of so many rich people in England. I regard, however, with favour everything which tends in the long run to make the division of gains between capital and labour more equal. The successful attempt of the labourers

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to organise had, in my opinion, this tendency. Capital v. Labour is a war in which labour is attacking a fortress. If the attack be made without proper plan or system it will be worse than useless. Both sides will lose, but the attacking party most. Now that Trades Unions are so well managed strikes of a hopeless character will seldom occur. There can be only one end to the struggle: "The poor demented creatures" will, in time, become capitalists and labourers combined. Then those who have a stake in the country will be nearly the whole population, and not a small proportion who contrive to make the others work for them.

As I read in Continental papers how peacefully the great strike had been conducted in England, I felt proud of my native country and confident in her happy destiny. I shall not despond, even if more strikes

In reading an article in this week's issue of your paper, headed, "The Lighting of Public Vehicles," the thought suggested itself to me that I ought to say a word on the subject, and inform you that I was greatly interested a few nights ago, while travelling on a 'bus from Putney Bridge to King's Road, Chelsea, with some little information obtained from the 'bus conductor relative to the lighting of the said 'bus with an electric lamp. The conductor, I must say, was exceedingly polite, and explained to me that the lamp was worked from a battery on the top of the 'bus, &c. The light was beautifully brilliant, and it was quite a comfort, both to myself and all other passengers, many of whom were reading. The lamp was situated under the driver's seat. H. Luttrell-Elward.

October 19th, 1889.

Queries.

In your No. of the ELECTRICAL REVIEW for September 6th, page 280, in reply to a student's enquiry, the amount of condenser capacity required as a shunt to the neutral or non-polarised Stroh's relay is given to be about 10 mf. for an aerial line of 800 miles of iron wire. It is believed, however, that this shunting of the non-polarised relay does not materially aid in bridging over the break of signal on the neutral relay, as the charge taken up by the shunt condensers and consequently the discharge is not sufficient to maintain the high potential, 15 to 20 milliampères, required for the nonpolarised relay during the periods of reversal when the potential of the line falls to zero; though from papers on condensers, if I remember rightly, by Sir William Thomson and Mascart, one would expect otherwise.

For the particular case, what would be the potential of discharge approximately from the shunt of 10 mf. ? In this respect please say what is the experience on the Continent?

2. In the balancing circuit of a differential Dx. or Qdx. on the particular line, would a number of condensers of low capacity, interspersed in the circuit, secure more stability than the sum of them as a permanent set applied at the beginning of the circuit?

3. What arrangement other than the condenser one operates to do away with the sparking in the electromagnetic transmitters, which is considerable, when a large battery of 250 bichromate cells is employed?

4. How would it be best to apply Mr. G. K. Winter's electro-magnetic induction arrangement, described in the TELEGRAPHIC JOURNAL, Vol. II., No. 39, pages 303-305 for the 15th September, 1874, in conjunction with a Dx. or Qdx. system on an aerial line?

5. Beyond aiding in the formation of a signal, would the above allow of the system being worked with less current than ordinarily employed?

6 What difference in action or construction is there

[OCTOBER 25, 1889.

between an 66 alternating transformer" and a "battery transformer ?" How could they be applied to the receiving instrument (Morse), and with what advan tage?

7. When two transformers are joined parallel, how can a nearly constant secondary pressure be achieved A thorough paper by some of your many readers on quadruplex working, with its latest improvements, would be very welcome to not a few. A Student.

Allahabad, September 28th, 1889.

[(1.) Our correspondent should be more careful to read correctly what appears in the REVIEW; there was nothing whatever said in our issue of the 6th with reference to the "condenser capacity required as a shunt to the neutral or non-polarised Stroh's relay (we have never heard of this relay)." The capacity of 10 microfarads is that required to balance the static discharge from the line, and it is the same as that which would be required for ordinary duplex working. Condensers are not used in this country on quadruplex circuits for shunting the non-polarised relays, as it has long ago been found that no benefit whatever is derived from their employment. Only a few quadruplex circuits are in use on the Continent, and the system employed is the same as that in this country. (2.) The condenser in a quadruplex or duplex system is used to counteract the static discharge from the line; to "intersperse the capacity in the circuit" would have exactly the opposite effect to that required; it would be like trying to obtain a balance on a Wheatstone bridge by placing the balancing resistance in the circuit of the resistance being measured instead of in the opposite arm of the bridge. (3.) A condenser will not do away with the spark at the contact points of the transmitter, as this spark is not an "extra current" spark, but is of the nature of the voltaic arc; the only cure is to place a resistance direct in the battery circuit. (4.) The electromagnetic shunt should be used in the place of, and in the same position as, the shunted condenser; it would not be such a satisfactory arrangement, however, as the shunted condenser. (5.) No. (6.) (7.) We do not clearly understand what you mean by these questions; you do not appear to know what a transformer is.EDS. ELEC. REV.]

I wish to ask you for some information on static discharges.

1. If a plate of glass be connected to earth would it not become zero potential? that is, if the glass had been charged, would not the act of connecting the charged glass to earth have dissipated the charge?

2. If such is the case, then if a second plate of glass be placed facing the first, being itself connected with a thunder cloud, would the cloud discharge ? 3. If the second plate were of metal ?

4. Is not the discharge of a cloud into the earth exactly analogous to the discharge of a very small body at high potential into a very large body of zero potential, the tension between the two having been increased by condenser action ?

[Our correspondent's queries are not at all clear, but we will endeavour to reply to them as far as possible. (1.) The plate would become zero in potential provided the whole surface were connected to earth by a conductor, i.e., it would not be sufficient to touch one point of the surface by a conductor; if this were done the plate would be only discharged at this particular point. (2.) The mere use of the second glass plate would produce no effect; whatever took place would be due to the conductor between the cloud and the glass plate and not to the latter. (3.) The metal plate would have the same effect as bringing the cloud down to the position occupied by the plate. (4.) Yes.-EDS. ELEC. REV.]

THE ELECTRICAL TRADES UNION.

THE time has arrived when the employés of the various branches of the electrical trades feel the necessity for banding themselves together for the protection and maintenance of their particular trade interests. We may say that the "union" is already a fait accompli, and it remains, therefore, only to consider, not the desirability or otherwise of having such a combination, but how to handle it on the best lines possible. There can be no doubt that the employed often obtain many advantages from such an institution; it may, and should be, not only a combination for the purpose of regulating wages, but for the mutual aid and support of the members in their relations to one another. Taking, for example, one of the most important trade organisations, we find, there, among the advantages to be obtained by members:-1. Out of work pay; 2. Superannuation allowance; 3. Removal allowance, in case of work being obtainable in the provinces; 4. Emigration allowance; 5. A "house of call;" 6. The use of a reading room, library, &c. ; 7. A funeral allowance, a portion of which may be available on decease of a wife.

:

It will thus be seen that a properly-constituted Society combines many useful features it is an insurance society as well as a wage regulator; it is to some extent a club, and also a place where work may be obtained; it aids the living, and helps to pay for the decent interment of the dead.

There is, perhaps, one disagreeable result of a trade society such as that sketched above, for where the wages are uniform the tendency will always be for the employer to take the best man available, and the weaker must consequently tend to "go to the wall;" but where the wage is according to the skill of the employé, it is not necessarily so, as an inferior hand (whether his inferiority results from mental or physical weakness matters not) may get work at less wages than his stronger confrére; yet he still gets work.

The employers, too, have some advantages in dealing

with the members of a trade society: (1) In furnishing estimates and in the making of contracts they have a fixed scale to rely upon; (2) They have the "house of call" from which to obtain hands; (3) They have a recognised body to deal with, in the elected committee of the society.

In the Electrical Trades Society we hope that the committee will collect the "rules and regulations" of other bodies, and then base their own on the best of them; a good start in this respect is of immense importance to its future; it is even of more importance than the mere enrolment of names, for on a well secured base the rest will be sure to follow.

There can be but little doubt that, although unity of the electrical trades throughout the country is desirable, it will probably be found that branch societies in important districts, affiliated to the London organisation, will be found the more workable method of dealing with the matter. Rates of living and other conditions may prevent the same regulations being desirable, or even applicable to provincial towns, and to London alike.

The movement seems strongly supported, and we trust that it will be guided wisely and well to the benefit and prosperity of the whole industry.

HIGH TENSION-DEATH CURRENTS.

WHATEVER doubt we, in England, may have as to the precise meaning intended to be conveyed to his hearers by Mr. Preece in his endeavour to minimise the danger likely to be incurred from high-tension currents, in America his words have been taken literally, and the independent Press on that side has not been backward in taking him to task. Listen to what one of the daily papers prints on the occasion of another fatal accident from an electric lighting current of high potential :"How small must Mr. Preece, the English elec

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trician, feel! He, the great scientist, could not kill a pig with a high voltage current, and we in this city (New York) kill three persons in a month by currents passing through insulated wires. Or was Mr. Preece not aware that the pig is by nature enveloped with an insulating material, i.e., 'fat,' and so can not only afford to withstand Mr. Preece's high voltage currents of feeble electrical energy, but also the highly dangerous Westinghouse alternating currents which are used in this city and have to serve electrocution purposes. Henceforth the pig should be made the symbol for electrical insulation. But man, the highest animal in creation, has to fight the elements and Nature's forces uncovered and unprotected." Horror upon horror! the sins of the high voltage combination, their coadjutors and abettors, are visited upon the innocent. The misrepresentations of the electricians employed in the high voltage interest have proven to be falsehoods purposely made."

On the other hand, Mr. Preece's remarks have been. turned to good advertising use to prove, on the authority of so experienced an electrician whose reputation is world-wide, the comparatively harmless nature of what we all must know to be currents whose employment is fraught with so much danger, that at any moment, and in the most unexpected manner, a human life may be sacrificed; and under the particular circumstances attendant on the use of these dangerous currents in the United States, it is well put by a contemporary, "Another victim offered up at the shrine of greed." The unfortunate misconstruction that it has been possible to put upon Mr. Preece's words only emphasises once more how essential it is to weigh every sentence before it is uttered, and to express one's self in such language that no other interpretation can be given to his words but that which the speaker intended.

During the week ending October the 11th two fatalities occurred in New York, both victims being linesmen who were struck down whilst performing their ordinary duty. One of these cases was accompanied with such horrible details, and took place in full daylight in the presence of a large crowd, that a kind of panic has struck the people, and terror reigns supreme. The public press has taken the matter up, and is asking, how long will this indiscriminate slaughter be suffered to go on? How long will the companies with systems working at high pressure be allowed to evade the law? It is not improbable, therefore, that popular clamour may compel the various electric light companies to put their plant in order, and to carry on their business with some regard for the lives both of the public and their own employés.

A CORRESPONDENCE has recently been carried on in the Globe on that never-failing subject, the cost of Letters patent. The general consensus of opinion is, as it always has been, that the fees demanded are very much too high, and that £10 ought to cover the whole period during which a patent can last. The usual

[NOVEMBER 1, 1889.

argument is brought forward, viz., that invention i stifled by excessive fees, and it is further assumed that if the excessive cost were brought down to the figur named, not only would the Patent Office not suffer it its income, but invention would be enormously stim lated, so that our American cousins would no longer have the race all to themselves as they are stated t have at present. We imagine that people who argu in this manner do not entirely understand the cor ditions which have so stimulated invention in Americ Have the recent changes in the English patent lav advanced useful invention to any appreciable extent Of course the number of patents taken out has great increased, but has the total number of those which have proved useful and brought hard cash into the pocke of the inventors increased to a like extent? We doub it. Desirable as it may seem to assimilate the English to the American system, we certainly think we require considerably more sound and logical evidence than we at present possess to prove that as much wide-spread benefit would result from such an assimilation, as į imagined by many.

IN the early days of telegraphy, when the wires were placed underground in pipes, and upright test boxes were used for connecting the cables together, it was not an unusual thing for an explosion of gas to occur, wher a light was accidentally allowed to approach too near one of these boxes or posts, as they formed not only re ceptacles for the joints, &c., but also for the gas which escaped from the mains. Explosions in the streets of London from underground telegraph pipes have pract cally ceased, due to the facts that the gas companies are more particular as to the manner in which their mains and connections are made, and that the telegraph pipes are also jointed in a very careful manner; so, on the one hand, there is less escape of gas, and on the other, a greater difficulty in the leakage finding its way int the telegraph pipes and the joint boxes; these latter being usually "flush," or below the surface, do no offer the same opportunity for the gas to accumulate a the old vertical boxes.

BUT the gas does still escape from the company's mains and connections, as any opening in our streets makes one painfully aware, and it appears to that with the large sized conduits now being laid down for electric light conductors, there is a possibility of a renewal of the subway explosions formerly prevalant in London, and now so frequently happening in New York and other American cities unless some preventive means are adopted by thos companies now laying down open conduits. The matter is looked upon in the United States as a special field for the inventor, for the technical journals ar weekly recording the patents which are being applie. for for cleansing the conduits, and keeping them free from gas. It is not too much to say that the advent of gas into our street electric conduits is extremely probable, if not absolutely certain; have our electric light companies thought of it?

It is, however, of no very great avail to puzzle one's brains over "air-propellers" and other forces to cleanse the conduits, whilst very simple and practical methods will accomplish all that is desired. We give here an extract from the annual report of the Brooklyn Tele phone Company, recently published, which, under the

REVIEW

ircumstances we have pointed out, will be found of ome practical interest :-" The practice of ventilating he conduits and manholes, as they are constructed, by ateral branches to poles and housetops, and to which we ascribe our freedom from explosions, has been exended considerably during the past year by placing hree-inch iron pipes from manholes to the columns of he elevated railroad, which serve the double purpose f ducts and ventilators. The quantity of gas in conLuits and manholes has been sensibly reduced, and, in wo instances, where conduits entered central office asement, the odour of gas, which it seemed impossible o entirely exclude, disappeared entirely after the manoles outside were connected to the elevated railroad tructure by a number of three-inch iron pipes. A arge tube, leading to a dead chimney at the Brooklyn ffice, in connection with pipes to elevated railroad near py, usually keeps the large tunnel through which the conduits enter the building pretty free from gas. We believe ventilation of this kind is the easiest and best method of preventing the explosions in manholes occasionally reported from other cities." With this concluion we quite concur.

enough of support under certain conditions, and serve to demonstrate to the public what can be achieved-in fact, are, from the trades point of view, good advertisements where it is the eye of the public which it is intended to catch. These advertisements may, however, be purchased too dearly, and when such a time arrives, as it appears to have done now, it is desirable that the electrical trades should consider well the costs and advantages to be derived, and when a decision is arrived at that the industry generally should either give as far as possible its support or withhold it. From the original International Exhibition of former days to the present so-called International Exhibitions there is a wide difference; then, they were destined to inform the whole world, now mainly, to inform a neighbourhood and to make money locally. We have no doubt that the committee appointed by the section of the Chamber of Commerce will be able to arrive at a wise decision in the interests of the electrical trades, and have genuine pleasure in seeing so important a question obtaining the chance of a proper settlement. Our own opinion is that the electrical trades have little to gain at this time by exhibiting, while the Exhibition will lose much by their not doing so.

THE electric light has been adopted with success by the Cheshire Lines Committee; particulars as to the system employed will be found in our "Notes" columns. A good light in a railway carriage is a great luxury, and it seems strange the lighting of trains generally is so far behind the times. This was painfully obvious when returning from the recent British Association meetings at Newcastle by the Great Northern Railway. The entire compartment was lighted by a feeble smoky oil lamp, rendering reading impossible. We trust our great railway companies will soon see the necessity of adopting the electric light, or at any rate a much better light than is at present in use.

IT might have been thought that in this year of grace, 1889, the electric light engineer would have known by name the quantities with which he deals; but apparently this is quite an unwarrantable assumption, the tendency seeming to be towards the invention of new terms, rather than towards the better comprehension of old ones. Referring to an article in an electrical contemporary of last week, we learn that the London Electric Supply Corporation was to charge by meter for the City lighting at 3s. 6d. per unit of 10,000 watts, and it is implied, in parenthesis, that a Board of Trade unit is 1,000 watts, which, of course, it is not. In the same article we are told that the Metropolitan Electric Supply Company was to charge 6s. 8d. per unit of 10,000 ampères, which is declared to be equal to 8d. per Board of Trade unit. From another paragraph we learn that the Anglo-American Brush Corporation was to charge 8d. per unit of 1,000 watts. The italics are

our own.

WE presume that in the case of the Metropolitan Company the printer's devil has transformed watts into ampères, but either is equally incorrect, for it so happens that we measure work neither by watts nor ampères, the former merely telling us the rate at which work is being done in joules per second, and the latter the rate of current flow in coulombs per second. It is somewhat remarkable to find such glaring errors published in a technical journal without comment, but unfortunately it is by no means uncommon. In the very last number of the Electrical Engineer, of New York, we find the International Electrical Congress reported as having adopted the joule as the practical unit of work, "being the energy generated by an ampère through an ohm." Surely it is time that these units were thoroughly understood. The contemporary first alluded to asks, in a leading article, why this question of lighting the City is again referred back. We suggest that it is in order that electricians may have a little more time to master their units.

WE are glad to see that the Chamber of Commerce has under consideration the question of a uniform standard for small metal screws, and that the British Association standard screw threads are likely to be brought more prominently forward. We have on previous occasions drawn attention to the want of a recognised standard, and from the remarks made at the meeting of the Chamber last Monday by Mr. A. Le Neve Foster, of Messrs. Davis and Timmins, Limited, it would appear that the B.A. screw thread is being used to a larger extent and becoming more general than many people are perhaps aware. Messrs. Davis and Timmins should be authorities in this matter, for besides being the largest manufacturers of this class of work, and they have now for some time past taken up the B.A. standard, stocking a large assortment of these screws, and must therefore be in a position to form a very correct estimate of the rapid manner in which this standard is being introduced. It is somewhat astonishing that some of our principal electrical instrument makers still adhere to their old threads, only departing from them to a standard size when executing contracts for the Postal Telegraphs. Probably this question of gauge is considered by manufacturers as a minor detail, to be left in the hands of a foreman, and workshop ideas are often very conservative,