The specialities that cannot under any circumstances be used are: Until September 17, 1892: Powdered carbon in combina tion with a metallic or metal-covered diaphragm. Until January 21, 1893: Blake's method of holding diaphragm by springs; Blake's special form of adjusting lever; and Blake's combination of two contacts mounted on separate springs, being respectively Blake's claims Nos. 1, 3, and 4. LIGHTING OF THE S.S. "SCOT." The following details of the s.s. "Scot's" electric installation will be interesting. There are 680 lamps of 16 c.p., and 10 electric fans. Two of these latter are Blackman meter. In the dynamo-room there is a main switchboard, Fig. 1, designed by Mr. Malcolm, Sutherland, and made in the electrical department of the Leven Shipyard, Dumbarton. It is 6ft. by 3ft., and is made of white marble steeped in paraffin. The lower part is occupied by three angle bars, which run from end to end, and to each of which a dynamo is connected through a fuse and ammeter clip. The upper portion is occupied by two rows of fuses and two-way switches, to which the fan leads and 14 main leads are attached. As has already been said, the switches are twoway, and to each of them two flexible electrodes are attached, one on each side, having clips on their ends by means of which they may be attached to any of the three bars. As each switch has two electrodes, one of which must always be idle, when it is necessary to change any circuit from one dynamo to another, the idle electrode is fans driven by Crocker-Wheeler motors, and are used for extracting the foul air from the engine-room skylight. Of the other eight, which are made by Messrs. King, Brown, and Co., Edinburgh, two are downcast and supply air to the engine-room, the remainder exhaust the foul air from SLATE FIG. 2. the cabins, etc. Current is supplied by three dynamos, by King, Brown, and Co., capable of giving about 200 amperes at 100 volts, driven direct by three compound engines, by Brown Bros., Edinburgh, at a speed of 200 revolutions per minute. Each dynamo has a tachometer attached, and the potential is measured by Sir Wm. Thomson's marine volt clipped on to the dynamo wanted and the switch reversed. In this way any circuit can be changed from one dynamo to another without interrupting the light. By means of the ammeter clips the current can be measured at any time by either of the two Siemens ammeters which have been mounted on the board. From this board the mains are led to 14 distributing-boards, also made in the shipyard works, placed in different parts of the ship. These boards contain switches and fuses, from each of which a wire is run to a group of lamps, the maximum number of which is eight. As the sectional area of the wire is kept uniform throughout, it is unnecessary to have any other fuses. Single wiring is used, except in the vicinity of the compass, where double wires are run; and to simplify the wiring, and make testing and repairs easier, soldered joints are superseded by a patent screwed junction made by W. McGeoch and Company, Glasgow, as shown in Fig. 2. This consists of a small brass pan about an inch in diameter over all, screw threaded inside, and with vertical slots cut in the sides. This is mounted on a slate base, and placed inside of a metal watertight junction-box, on the sides of which are small stuffing-boxes. To join two or more wires together, they are brought through the stuffing-boxes. The insulation is then removed, and the bare ends inserted through the slots and coiled up inside the junction pan. A soft tin washer is then laid on top of them, and a brass button is screwed hard up on them. As the diameter of the screw is very large compared with its length there is no fear of it coming loose, and the surface of wire used in the joint being large, there is no heating. A very good joint is thus obtained without the trouble and danger of carrying heated bolts or blow-lamps about. It is also much easier to disconnect portions of any circuit when searching for a fault which may have occurred. One of these boxes is used for each lamp, the stalk of the lamp being screwed through the cover of the box and forming the return, the current being carried to the lamp by an insulated metal rod in the centre, at the upper end of which is a spring contact which presses against the button of the junction. All joints in the small wires are made inside of junction-boxes, and there are no joints in the main cables. All the wires are of high insulation, the mains being Silvertown vulcanised rubber, leadcovered, and taped. Most of the small lamps are wired with vulcanised rubber-covered wire, made by the International Okonite Oompany, and the remainder, comprising the engine-room, stokehole, deck lights, etc., are wired with Fowler-Waring lead-covered armoured wire. TELEPHONE TRANSMITTERS. A short time ago, having occasion to call upon Mr. Lewis, the genial manager of the Western Counties and South Wales Telephone Company, we noticed a diagram This bell is being introduced by Mr. B. Townley. From the claims made by the inventor, Mr. J. Townley, it bids fair to supersede the old form. Having little tension in the spring carrying the armature, it requires less battery power; having the magnetism retained in the armature until it does work, allows longer stroke and a more agreeable tone. It has sliding contacts, making it less liable for them to oxidise; it has an automatic make and break circuit; and the cost does not exceed that of the ordinary form. Its description is as follows: The circuit is completed in the ordinary way by means of a push. The current passing through the terminal T on to the contact pin, P, along the bell crank, C, through the coves and out through terminal T1 to the battery. The usual magnetic field is 8 Townley's Duplex Alarm. The box, B, contains the battery, on the front of which is fixed the bell. Set the set hand of the clock to the time the alarm is required. Should it be desired to use the two together, simply wind the clock in the ordinary way, but this is immaterial; place the legs of the clock, L and L1, on the contacts, P and P1, and when the hands of the clock agree with the set hand, the lever which releases the hammer of the clock makes contact simultaneously with a spring which is fixed, but insulated, on the frame of the clock, from which is taken a wire, and led to the insulated leg, L1, on to the battery through coves and contacts of the bell, return to battery through leg, L, to where contact was made; the circuit being thus completed, rings the bell until the clock is moved off the contacts, P and P1. THE ELECTRICAL ENGINEER. Published every Friday. Price Threepence; Post Free, Threepence Halfpenny. 139-140, SALISBURY COURT, FLEET STREET, TO CORRESPONDENTS. All Rights Reserved. Secretaries and Managers of Companies All communications intended for the Editor should be addressed TO ADVERTISERS. Advertisements should be addressed to the Publisher, 139-140, TO SUBSCRIBERS. "THE ELECTRICAL ENGINEER" can be had, by Order, from any Newsagent in Town or Country, and at the various Railway Stations; or it can, if preferred, be supplied direct from the Office, on the following terms: United Kingdom............................. 3 months1 Within the Postal Union 4s. 4d. 48. 10d. 6 months (Post Free Payable in Advance.) 12 months 17s. 4d. Cheques, Post Office and Postal Orders for Subscriptions BOUND VOLUMES. CAMBRIDGE. It is with considerable hesitation we refer to this question again. The report of the proceedings of the Council, as given in our last issue, is sufficient to prove that all we have previously said upon the matter was warranted. Even now we do not believe the last has been said, and many a keen sportsman would lay long odds against the present scheme being carried out. Surely the suggestion of one member of the Council is possible-to have an authentic account of the working cost of the proposed engines as against an estimated cost from experimental runs. Engineers have somehow contrived to become impressed with the opinion that the engine is a leetle extravagant in eating steam. When we had occasion to test the engine as it was made two or three years ago, that opinion was confirmed by facts. At present we are told that improvements have been made, and the engine is to be economical. Of course that may be so, and we must wait events to prove whether it is or is not. We are ready to support the use of these engines in many cases, but as yet not for central stations. Even if initial expense is considered, we are creditably informed that the highest class of low-speed condensing engines, and all the electrical paraphernalia, were tendered for at something like £2,000 lower price. Unless, then, the Council get proof positive as to maintenance economy, we do not well see how the scheme can be carried out with satisfaction. ELECTRICITY IN TRAMWAY WORK. The meeting of the Tramways Institute last week was principally occupied with reading and discussing papers on the application of electricity to tramway work. It was a misfortune that these papers related principally to systems not yet largely adopted, or 13s. Od. rather only in the experimental stage, and not yet applied in everyday work upon a scale sufficiently large to obtain trustworthy figures and convince the tramway engineers. The practical outcome of each discussion was the same. The engineers said in effect: "We are ready and willing to employ electricity, but before doing so must be satisfied that it will pay. It cannot be supposed that we can give up horse traction, the expenses and the returns of which are fully known to us, for an ideal system about which the figures are most vague, nor can it be supposed that we shall experiment to find out the result." To introduce a new system means new capital. In England the tramway mileage is not likely to greatly increase-in fact, during the past year there has been a slight decrease. Thus the use We may occasionally follow the lead of our American Contem-existing lines, upon which capital account has long of electric traction in England means its use upon poraries, especially when they point out a serviceable way. They since been closed, and to reopen it is not an easy matter. People, however, are willing to speculate if it can be shown there will be a good return for their money, and the only inducement to tramway shareholders to increase their capital is to hold out satisfactory hopes of increased dividends upon the larger capital. The Lineff system and the Jarman system are well known to our readers, but the Gordon system is less well known. We have therefore requested the author to give us an estimate of the cost and the returns of a line to be altered from horse traction to electric traction upon his system. Experimentally, the line he has constructed at Messrs. Merryweather's is a success. It has been tested under stringent conditions, and acted well even when saturated with water and covered with mud. The figures of the following estimate must be considered with care, and it would be well if rival systems would give similar estimates. At any rate, we should then get a basis for calculation, and the various items could be compared: ESTIMATE OF THE CAPITAL COST OF APPLYING THE GORDON SYSTEM OF ELECTRIC TRACTION TO AN EXISTING TRAMWAY, AND THE WORKING COST PER CAR MILE. Line 3 miles long, double track (6 miles); generating station as central as possible; five minutes' service at busiest time; average speed seven miles per hour, including stoppages; cars to accommodate 40 passengers each; maximum number of cars running at one time, 10; e.h.p. per car, 10; total e.hp. at station (50 per cent. reserve), 180. Permanent Way. Altering existing track to suit Gordon system, six miles at £2,000 per mile ....... £12,000 Everybody is anxious to know the exact position of affairs. We have in this issue endeavoured to put the whole matter straight, to show what patents expire, to show what patents are still alive and controlled, and to estimate the value of such control. Practically, the conclusions of the well-known authority who has carried out this investigation on our behalf is that telephony will be released from its trammels. With the exception of a few unimportant details, which are still secured by patents, and outside of which excellent transmitters can be made, the world can make free use of the acquired knowledge in telephony. We are glad this is so, for in our opinion no monopoly has ever been worked less creditably than this of the telephone. Years ago we hinted that those most deeply interested in the company-mongering part of the business, would be found at the time of the sun shone, and have left the affair with pockets the expiration of the patents to have made hay while well lined, but with none, or very few, shares to their names. Of course, from one point of view, their action was and is amply justified. They started to make money. From our They made it. point of view we require a good telephone system, and a good service, at a reasonable rate. The shareholders deserve a moderate return for their investment, but the paying public do 2,100 not wish to contribute to watered capital, watered for the purposes of company promotion and Stock Exchange transactions. That in London, at any rate, there is neither a good system nor a good service, will be gathered from the fact that so late as June 10 this year a circular, issued from the "London Chamber of Commerce," invites the combination of telephone users to obtain "increased efficiency £16,000 and a reduction in rental." The circular states that "dissatisfaction has long been felt by many subscribers to the telephone company in London," etc. This company, instead of moving heaven and 120 earth to please its customers, is finicking with advertisements cautioning people that it still controls various patents. No one need be frightened It is an 250 by this game of bluff. ingenuous 840 attempt to to presume upon the ignorance of 10 mankind. The stake, however, is too valuable for the whole question not to have been thoroughly investigated. It may be assumed also that by this time the Government knows its mind, and realises that unless the existing companies—as some of them undeniably do-give an efficient and fairly cheap service, it must undertake the duties and the responsibilities of its telegraphic monopoly. 5,400 £19,500 3,500 £364 156 854 £150 108 250 £3,102 Allowing an average of 80 miles per car per day, the total number of car miles per annum = 80 x 10 x 365 = 292,000. Horse traction costs about 6d. per car mile = £7,300 Saving by electric traction £4,198, giving a dividend on increased capital of £16,000 of 26 per cent. |