work for every conceivable purpose. Electric bells | for the wall, and below, attached to the battery, is the bell naturally form a considerable portion of the earlier part of itself. We have already described and illustrated the the book, and we have some spirited shapes, as of gnomes company's ingenious indicator movement, of which there are several, particularly that to which the name of the "New Era " indicator has been given, so we pass to other matters. Pushes in abundance are well represented in plain and ornamental patterns of ornate design or chased metalwork. Amongst these, besides the innumerable bell pushes, are some special pushes for windows and doors, and for burglar alarms, which we do not remember to have seen illustrated in the technical papers before. We therefore show an assortment of these for various purposes. Fig. 1, 2, and 3 are door and window contacts. Fig. 2 has a separate switch for interrupting the current when the alarm is not required to work; Fig. 4 has a trigger contact. Fig. 5 is a blind contact, and Fig. 6 is the same with pulley. Fig. 7 has a cord contact for safes, skylights, or such places. Fig. 8 shows a useful form of floor or tread contact for office bell-out of sight and handy. Passing to telephone instruments, in which this company have a recognised high position, we show in Fig. 9 the new Mix and Genest multiple switchboard, a separate pamphlet upon which can be obtained. In the usual switchboard systems two wires are required for each subscriber, and the construction of the board is of considerable complexity. The switch board illustrated is of much greater simplicity of construction than that of the Western Electric Company, indiarubber dust-excluding padding and dustproof balllock. A portable micro-telephone specially designed for military, naval, scientific, and mining purposes is shown in Fig. 16. It contains microphone and telephone with switch, induction coil, two dry cells, magneto call and gongs, in oak case furnished with buckle and shoulder straps. Some very handsome sets of batteries for medical, surgical, or small electric light purposes are among the special features, some with cautery and lamps. We illustrate a form of cupboard of primary batteries, Fig. 17, E FIG. 17.-Primary Battery. only one wire being used for each subscriber, and one or two keys being sufficient for 100 subscribers instead of the 40 keys required on the Western Electric system. Testing with the telephone is dispensed with, a galvanometer showing whether the line is engaged or not. The board shown is full-6,000 subscribers with 200 annunciators. It has 5,000 spring-jacks on the upper space, 1,000 general springjacks lower, 200 special spring-jacks, 40 pairs of connecting plugs, 40 switches and closing signal annunciators, three galvanometers, and three ringing-keys. The illustration shows the board in operation, with the special form of operator's telephone adopted. The Mix and Genest microphones as adopted by the German Government, are shown in their various forms in Figs. 10 to 14. Fig. 10 shows the microphone without induction coil for replacing the Bell-Blake transmitter. Figs. 11 and 12 show the model adopted by the German Government a microphone with solid walnut mouthpiece and induction coil. Figs. 13 and 14 show the box form of the microphone with induction coil and terminals mounted in side-hinged walnut case. The spoon-shaped double telephones introduced by this firm, in plain and also in very ornamental patterns, have already been illustrated by us, and are too well known to need further description. We show, Fig. 15, a neat and practical form of telephone station in an airtight case for use in dusty or damp rooms, or in hot and damp climates. The instruments are fitted inside a polished oak case with Earth. FIG. 19.-Water Level Indicator-Maximum and Minimum Contact. We show this in two forms. Fig. 18 is a maximum contact water-level indicator, and Fig. 19 is a similar indicator, with indicator for both maximum and minimum contacts, comprising eight cells, two relays and indicators, with two sets of floating globes and contacts. We have not space further than to allude to the batteries, switches, cables, wires, insulators, tools, and various other electrical necessities comprised in the catalogue. In telephone matters the book is particularly rich, and the large number of different patterns of telephone sets for home, office, and public use should, in these days of free telephones, meet with a large and increasing demand. Bohemia. The construction of the central station at Arco, in Bohemia, is approaching completion, and the number of subscribers waiting already exceeds the supply. THE ELECTRICAL ENGINEER. Published every Friday. Price Threepence; Post Free, Threepence Halfpenny. LONDON, E.C. CONTENTS. Notes Underground Lighting Mains in Paris of Electrical Electrical 505 Institution Engineers 510 Crystal Palace The Brush High-Tension Exhibition.. Mix and Genest's Apparatus 513 516 519 520 522 523 527 Central Station Management Provisional Patents, 1891 Electric Light Companies... 528 517 New Companies Registered 528 518 City Notes. 528 and Finance Rival Systems Correspondence Magnetic Reluctance TO CORRESPONDENTS. All Rights Reserved. Secretaries and Managers of Companies are invited to furnish notice of Meetings, Issue of New Shares, Installations, Contracts, and any information connected with Electrical Engineering which may be interesting to our readers. Inventors are informed that any account of their inventions submitted to us will receive our best consideration. CENTRAL STATION MANAGEMENT AND FINANCE. A short time ago a series of articles bearing the above title, by H. A. Foster, appeared in our American contemporary and namesake. Mention was made of these articles in our columns, and various correspondents made further enquiries with regard to them. A pamphlet based upon this series of articles has reached us, with the imprint of C. C. Shelley, 10 and 12, College-place, New York, who supplies the copyrighted blanks given in the articles. So far as we know, no other systematic attempt has been made to fix a system for the accounts and information of a central office. Factory accounts have been admirably treated on this side by Mr. Garcke and others, but factory accounts differ somewhat from central station accounts. This pamphlet contains some very straight and some very true remarks. Compared with the States, we are numerically far behind with central stations, but it matters little. whether the number of such stations be sixteen or sixteen hundred, the necessity for organisation and maintenance upon strict business principles is imperative for success. In his second paragraph Mr. Foster says: "The central station business was so new that very few well-established business men could be persuaded to take hold of its management, and it gradually fell into the hands of younger, untried men, who too often were more prone to experiment with the business than to spend the necessary time in organising it thoroughly on an economical basis. Again, the majority of those placed had not the previous business experience to understand fully the necessity of systematic organisation and strict discipline.” There is no single word here but which applies with tenfold force to what has gone on and what is going on in this country. In America, however, the young man means business. ledge with eagerness, and he beaten by any competitors. many nice young men are trained in the technical schools and technical colleges, are put into the market as experts, not one of whom can tell the general run of wages in various trades, know nothing of prices, of tariffs, of railway rates, of specifications, or of any one of the hundred business points that go to make up a business man. They wonder why, after having spent so much time and money in piling up a certain kind of knowledge13s. Od. which their teachers honestly believe is the be all and end all of an electrical engineer's requirements— why we say they are shunted for men whose education in many ways is defective. But when matters are more closely examined, it is no wonder that the sprinkling of business men who have got into the profession look upon the man from a standpoint different to that of the teacher. Business men attend to business matters not from motives of Vols. 1. to VII. inclusive, new series, of "THE ELECTRICAL Philanthropy, but for the purpose of making money. ENGINEER" are now ready, and can be had bound in blue cloth, gilt lettered, price 8s. 6d. Subscribers can have their own copies bound for 2s. 6d., or covers for binding can be obtained, price 2s Their assistants are chosen with a view to fitness for this purpose, and there is a decided refusal to accept the services of the greenhorn. is singular that a kind of fashionable run has been made, in and around London, on a particular type of boiler. It seems that electrical engineers need some education in these matters, and we doubt if such engineers as Mr. Massey or Mr. Maw would under any circumstances recommend the fashionable type of boiler for central station work. But they really know their business. We have wandered wide from the text of Mr. Foster. The necessity of calling attention to shortcomings is a necessity, though distasteful. Gradually opinion is gaining ground, that we don't want electricians so much as we want electrical engineers. If it were euphonious, the compound word should be engineer-electriciansthat is, engineers first, electricians second. Some of our managers on this side might find it advantageous to send for the pamphlet and a few sets of the blanks, which we have referred to in this article. RIVAL SYSTEMS. Many failures have undoubtedly been caused because of absence of simple business knowledge. We have always contended that successful companies almost always owe their success to the ability of one man under whose guidance directors-brother directors possibly and officials are willing to act. The one mind directs, the others carry out details. There is no other road to success. Mr. Foster points out how 'knowledge comes" "in many cases-for example, not long ago it was thought a day's work to trim forty arc lamps, now the normal number is getting to be 100, some stations piling 120 upon the man. But to do this number properly, the man and the circumstances must be exceptional. Without attempting to follow Mr. Foster into other important matters, we will direct attention to some remarks upon the necessity of regular boiler-room reports. In his opinion this department is one of the most important of all, “as great waste is so easily made if firemen are careless. or ignorant. By all means have the best fireman money can hire, as he is the man who shovels away your dollars." Those who would understand the great importance of firing, and the most perfect I point to which the art can attain, should attend a Royal Agricultural Society's portable engine competition. Men who witnessed the stoking of Mr. Paxman at the Newcastle competition were amazed at the manner in which the work was done, and although we can expect to see such hardy I masters of the art at central stations, we may to see men who understand the business, and not those whose sole recommendation is ability to shovel on coal. Further, Mr. Foster says: "A good chief engineer will find plenty to do to keep the motive= power department up to the best conditions of efficiency. As a general thing, more trouble and waste takes place in this department than in the electrical, and largely from the fact that few station managers understand the advantage of employing a good chief engineer." Not only have we to go to America to get a text for adverse criticism, we can find it nearer home. What, for example, is the general opinion of electrical engineers as to the, if true, damning criticism of Mr. W. H. Booth in the correspondence columns of last week's Engineer? Mr. Booth was writing upon another subject, but incidentally he says: "To appreciate fully the real lack of knowledge of the whole subject of boilers and steam production, especially amongst London engineers, one need but glance at the latest examples about London, which will as often as not be found in the electric installations, and compare those with a Lancashire cotton factory's engineering." And more to the same effect. Another correspondent in the same paper, and in the next column to the one just quoted, says: "I know of several fine old examples of engineering skill and architecture being replaced by the ugly, low, scrawling, More than once-we can give the occasions if screaming, and clattering Corliss engines of necessary-electrical work has been delayed for the present day." Evidently, then, Mr. John years by the untimely interference of quasi-authoSwift's opinions as to the Corliss engines do not rities. In this case of electrical traction at the agree with those of some electrical engineers. It present moment the daily press is doing a vast It is, of course, a phase of human nature that every patentee has no eyes for the beauties and advantages of anything not controlled by or in the direction of his own patent. direction of his own patent. Another phase is that no opportunity is neglected of pushing forward his own production, although such pushing may at the particular moment be detrimental to the prospects of some rival scheme. Thus Mr. F. Wynne, in the Times of November 20, discourses-through a long letter, a tiresome historical iteration of patents— against Edison's latest, which might be called the wizard's latest hoax. Of course Mr. Wynne commences with a tirade against accumulators — or, or, as we prefer to put it, a "selfcontained system." This attack is met by the Earl of Albemarle, who points out that if Mr. F. Wynne is "accepted as an authority" his words might damage others," the others, of course, being the company with which the Earl is connected. The letter of the latter is intended to prove that the self-contained system, instead of being a failure, is a success. But the point made in the reply is that patentees who would pose as authorities often do an incalculable amount of harm. The example given in the letter is as follows: "The Glasgow Corporation are about to change their system of tramway traction, and although it would not be right to speak positively on a matter still under discussion, I may mention that both in public meetings and in official documents the Glasgow authorities have in unequivocal terms expressed opinions which leave but little doubt that they will adopt the accumulator system. Now, Sir, if Mr. Frank Wynne is to be taken as an authority, those who are negotiating that large and important contract might lose it. There is, therefore, good reason for a protest." amount of harm in giving currency to opinions, the correctness of which the managers of such papers are utterly unable to determine. In fact, the best technical authorities are in a somewhat similar position. There can be no sweeping condemnation or approval of channel, overhead, or selfcontained system. Each in its proper place has advantages. Mr. Wynne's attack upon accumulators carries to those in the know its own refutation, in that his statements are not in accord with practice, and he argues as if there were only one accumulator to be considered. The Times article upon recent practice in Paris, referred to in our last issue, ought to have prevented so sweeping a condemnation. It is no valid argument against the utility of a steam engine to say that if you ask a 20-h.p. engine to work at 200 h.p. it will break down. If, then, business men know what accumulators will do, why should they ask them to work to the point of breaking down? If a horse accidentally falls and is injured, or is otherwise injured, the individual car has to be otherwise assisted. If the company with which the Earl of Albemarle is connected can properly work their accumulators, doing the work as a commercial speculation with a fair profit, of what use is any argument founded on "ifs" and "buts"? The outsider says "No," the insider says "Yes." Whom are we to believe? The one wants to get his system in, the other wants to prevent it. That is a purely business matter, but prevention must not be obtained by misrepresentation. CORRESPONDENCE. One man's word is no man's word This bilinear characteristic curve of reluctivity is not confined only to iron. Fig. 6 shows the same general outlines in the case of nickel, taken from the observations of Rowland and Ewing. Here the initial reluctivities are higher, and the descent to the critical points much sharper than in iron, while the ascending lines are also steep but nearly straight. Taking the equation p = a + bH in the ascending curve, the first term a only disappears in one known instancethat of nickel under a mechanical stress of 19.8 kilogrammes CHARGING ACCUMULATORS. SIR,-In your issue of November 13th, in an article on charging accumulators from an alternating-current system, you mention a system which you say was suggested by me. I should be obliged if you will allow me to state that I remember having had a conversation with a representative of your paper about a system combining storage batteries with alternating-current distribution, of which I am the joint inventor, but it is a very different one to that described by you last week. I quite agree with you that the system described is a great deal too complicated, and I think it would be even less economical than an ordinary alternating-current system working under very bad conditions. Yours, etc. G. E. B. PRITCHETT. London, W., Nov. 19, 1891. MAGNETIC RELUCTANCE.* BY A. E. KENNELLY. (Continued from page 473.) Fig. 5 shows that the minimum reluctivity for soft iron is about 0.15 M.U., while its initial reluctivity is about 30 M.U. The critical value of H is also in the neighbourhood of 2. If any critical H can be said to exist for glass hard pianoforte wire it would be in the neighbourhood of 35 units, and every description of hard or impure iron met with in practice not containing much manganese appears to have its critical H between these limits. These reluctivity curves also illusPaper read before the American Institute of Electrical Engi neers, October 27, 1891. * H Last Cobalt Rod under stress of 18.2 kg per sq. min.(Ewing) &0024 6.0000800 1 per square millimetre, or 28,160lb. per square inch-as seen in Fig. 7, taken from Ewing's results. The lowest ascending curve prolonged downwards almost meets the origin. Consequently the flux equation for such nickel would be |