AR

WILL ELECTRICITY SUPPLANT STEAM ON CITY RAILWAYS?

THIS question has been considered by Mr. Leo Daft in a recent paper read before the American Institute of Electrical Engineers. Mr. Daft is one of the pioneers of electric traction in the United States, he has been actively engaged in constructing electric tramways, and he has had in his mind for six years past the problem of working the New York elevated railways by electricity. The idea of substituting electric for steam locomotives appears to us an exceedingly bold one, and we could scarcely suppress a natural bias towards adverse criticism whilst following Mr. Daft's arguments, until we came to a series of figures which seemed to give conclusive evidence on the side of economy. The paper commences with a refutation of the generally accepted coefficients of traction, and the author quotes some experiments which he carried out in the year 1882 with a small motor which was made to propel a model car up an adjustable incline. This car weighed 450 lbs., and with one man on it the total was raised to 600 lbs. The angle of inclination was gradually increased until it was equivalent to a gradient of 54.9 per cent. when the car still managed to mount it, and stopped and started midway in its course. The rolling resistance was estimated at 10 lbs. per ton, giving for the experimental car 2-25 lbs. The resistance due to the inclination was calculated to be 329 4, making a total of 331-65 lbs., or 55 27 per cent. of the entire load, which is considerably more than double the ultimate working limit of adhesion under the most favourable conditions cited by most authorities. Mr. Daft does not pretend to assert that the adhesion in the case of large locomotives may be increased to such an extent; indeed, subsequent experiments showed that the observed effect in this instance was due to a very large current of low potential passing through very small contact areas presented by wheels of only 1 foot in diameter impinging upon a light rail; the effect is, however, undoubtedly obtainable to the extent of 30

per cent. under the ordinary conditions of railroad practice.

Since October last experiments have been made with the locomotive "Ben Franklin " upon a portion of the tracks belonging to the Manhattan railway, and the results were carefully watched by the officials of the railway company. Originally, permission was granted to run only between the hours of 9 p.m. and 4 a.m.; but the performance of the motor was so good, that later on the electric locomotive and train were allowed to run also in the daytime, taking turn with the ordinary trains, which travel at periods of 3 minutes apart. The electric locomotive weighed 10 tons, as against the smallest steam engines of 18 tons each. Trains were made up of 2, 3, 4, and even 8 carriages of 12 tons weight each. On the 12th of February a train of four cars, each with 75 to 100 passengers, and weighing 70 tons, was run over the road between the ordinary steam trains, but the brakes were hardly trustworthy enough for such critical work. In order to measure the speed with accuracy, the electric line was divided into 19 sections of 500 feet, each section being provided with a thin copper plate attached to the guard rail. This made temporary contact with a copper brush attached to the vehicles in such a manner that it could sweep over the guard rail and convey the current to a chronograph. Indicator diagrams were taken at the central station, whilst dynamometer readings were recorded simultaneously..

The mean power exerted at the central station for propulsion during a trip was 103 horse-power, which compared favourably with steam practice. It has been shown "that on the Third Avenue road, with 80 ton trains and 22-ton steam locomotives, 170 horse-power is not infrequently exerted. Hence," says Mr. Daft, "to consider this problem merely by the ordinary coefficients of rolling friction and gravity resistances would, and does frequently lead to very serious errors in computing the amount of power actually used on short railroads with frequent stops." Based on the experience gained so far, Mr. Daft computes a table in

B

REVIEW

which he endeavours to show that for five hours out of 16 of daily service, 3,157 horse-power would be required, including contingencies, but the rest of the time the demand is greatly diminished, and the average results show that the total per day equals 29,940 horsepower hours, which divided by 16, the number of hours of service, gives 1,871 horse-power per hour, and adding 300 H.P. for dynamo and engine friction the total should be 2,171 horse-power. For this 41 tons of fuel, inclusive of banking the fires, will be requisite, which costs 92.25 dollars per day at the rate of 2.25 dollars the ton. An evaporation of 7.5 lbs. of water per lb. of coal is assumed, and a consumption of 2.2 lbs. of coal per horse-power hour. The present steam locomotives on the Ninth Avenue require 40 tons of coal per day of the very best quality, which costs 200 dollars, or more than double that for the electric system, as estimated. To the electric estimate, however, it is necessary to add such charges as wages of firemen and engineers at the central station, which would bring this item to 150 dollars per diem, considering other items balanced; the cost of repairs, depreciation, &c., is estimated to be about equal in the two cases, which, Mr. Daft believes, is not far from the fact, and he summarises in the following words :"It is thus evident that without considering the future obvious advantages which must necessarily accrue from the use of a great central station equipped with dynamos as before stated, and a conductive system ample for all requirements of the road, that with the comparatively wasteful central station arrangement we have here considered, involving the use of small dynamos of a very old type placed at the extreme end of the conductive system, and suffering from many incidental disadvantages, that it is possible to run the Ninth Avenue Elevated Road with electric motors at an actual and considerable saving of fuel to-day, and if this is not the only example of such a practical demonstration, as opposed to direct steam propulsion, it is at least the first I have been able to find on record."

In view of the great variations in power which necessarily takes place with conductor systems, we are of opinion that Mr. Daft's estimate of 2.2 lbs. of inferior coal per H.P. is very much too low; nevertheless, we wish him every success. If he can prove his figures on the larger scale, as proposed, then he deserves every praise which can be bestowed upon him. The directors of our Underground Railway, which at this time of the year almost suffocates its patrons, may take the above facts to heart and emulate the encouragement given to Mr. Daft by the American railway officials.

THE Anglo-American Brush Electric Light Corporation, Limited, has virtually been beaten on the incandescent lamp patent suit; it has lost the compound winding case; and its directors think that the present moment is a favourable one for the reconstruction of the corporation with the new title of the Brush Electrical Engineering Company, Limited. As an off-set to the above mentioned mishaps it is proposed to saddle the shareholders with "two old men of the sea," in the guise of the Falcon Engine Works and the

Australasian Company. Whether this policy is a wise and judicious one remains to be seen, and unfortunately we have not yet heard anything respecting the good or ill fortune of the mammoth combination of a few weeks ago to enable us to speak with certainty as to the ultimate result. We say unfortunately, advisedly, as we believe the principle actor in the one plays the leading rôle in the other.

TURNING for a moment to the business statement of the Brush Corporation it will be seen that the future bears a very rosy hue. To adequately cope with the demand which appears within the Corporation's grasp undoubtedly necessitates an extension of works, and for this purpose the Falcon Works may be eminently fitted. Labour will assuredly be found somewhat cheaper and other conveniences may make it very desirable to secure these premises, but it is to be hoped that the directors of the Brush Corporation will keep strictly within the sphere of their own legitimate trade and not launch out into undertakings formerly carried on in these works with anything but success. Assuming that this will be the case there is nothing to cavil at in the terms under which the amalgamation is projected.

WE think we are right in stating that the Australasian Company originated the compound-winding fight. The company objected to compound-wound dynamos of others manufacturers entering the domain which it controlled under license from the parent company, whose patent rights it had acquired, and we understand that, through the pressure brought to bear upon Father Brush by his antipodean offspring, there resulted the series of actions which culminated in the celebrated Edinburgh decision.

WE quite coincide with the belief of the Brush directorate that the period of depression in the electrical trades is on the wane and if their proposed scheme is rigidly carried out on legitimate business lines, there appears to be no insuperable obstacle to the ultimate payment of dividends. The Anglo-American Brush Corporation has been one of the leading factors in the electrical world since its inception; let us hope that in its altered condition it will still keep equally well to the fore. It is difficult, however, to see who will be the gainer by the proposed amalgamation.

MR. MATTHEW ARNOLD, whose words demand and receive from scholars of all denominations the greatest consideration, insists that conduct "which is threefourths of life," is shaped more by literature than science, and that, therefore, literature is pre-eminent. Prof. Rowland, on the other hand, urges that no training to which a young man can be subjected is equal to a scientific education for inculcating thorough honesty. When a man knows that correct deductions from his experiments depend upon the absolute accuracy of his description of them; that science would be impossible without confidence in the perfect reliability of its chroniclers; he learns, of necessity, a valuable moral lesson.

WE quote the following from a thoughtful article by George H. Stockbridge in the New York Electrical Engineer, entitled "Where shall we place the Engineer?" :-"It is significant that the engineer at present is finding a good many eulogists. Sir Frederick Bramwell has done his part. The Scribners are doing theirs by publishing an extended series of articles on railroads and electricity-exceedingly well written.

articles, too-showing that some of the literary classes are interested, or that some of the engineers excel in two arts. It is true the railroads had acquired an enormous growth and importance before this honour was accorded them, and that the electrical arts should be similarly honoured, tells its own story."

AT the recent meeting in Paris of the Institution of Mechanical Engineers, a paper was read by M. Edouard Delamere-Deboutteville, entitled "Gas engines, with a description of the Simplex engine." Before entering into details of the Simplex engine, an historical account was given of the inventions connected with gas engines from as long back as 1791, when John Barker published his description. Some 700 patents have been taken out since 1860, the date of Lenoir's arrangement, for improvements or inventions connected with prime motors actuated by gas. The author passed rapidly over the most important inventions since 1791; but his knowledge does not appear to have been quite brought up to date, seeing that no mention is made of such machines as the Atkinson, or the Griffin, which figured so prominently at the Society of Arts motor trials; while in regard to the Otto engine, some details are adversely criticised, which have been abandoned by the makers for some considerable time past. The various methods of ignition are reviewed, the author considering that most of the troubles in connection with the successful working of gas engines arise from the difficulty of obtaining a satisfactory means of igniting the charge, and he comes to the conclusion that ignition by the electric spark is the most effectual and certain in its action, and the mode, a continuous stream of sparks, adopted in the Simplex engine, has overcome all the difficulties that occur when dealing with various qualities of gas. The engine is constructed on the fourcycle plan of Beau de Rochas, but possesses many novelties in the details. The slide is simple, merely a cast iron plate with two holes; the air and gas are not mixed in the cylinder, but in a separate receptacle outside, and thence drawn into the cylinder by the motion of the piston. The regulation of speed is controlled by the admission or non-admission of a charge, the governor used being either an air one or of the pendulum species. In engines over 20 H.P., the motor is constructed in the ordinary manner, and the external mixing chamber dispensed with. Some trials of this engine give economical results; in one case, with an effective horse-power of 6.70, the consumption of gasordinary town-was 22.09 cubic feet per effective horsepower. A 50 horse-power engine, using Dowson gas, with a load from 35 to 40 electrical horse-power, consumed 51 lbs. of English anthracite in the Dowson generator per hour; i.e., about 13 to 1.148 lb. of coal per electrical horse-power hour.

IN the course of the discussion which followed on the succeeding day, Mr. Holroyd Smith took exception to the historical part of the paper, and showed that Messrs. Crossley were not the originators of the system they used, but Beau de Rochas. No description of any modern engine, with the exception of the Otto, was to be found in the paper, and he considered that to use electrical ignition in place of the available natural means, was to take a retrograde path, and make the Simplex into a complex motor. Prof. Kennedy said there were many good engines in the market which might have had a place in the paper, and it would have been interesting and instructive to compare them with the Simplex; he did not concur in the author's strictures

59

on the use of an igniting tube. The system of governing used in the Forward engine is within a range of 20 per cent. by dilution of the charge, and beyond this by "hit or miss." He thought the pendulum governor a very ingenious device. Mr. Scott Moncrieff differed from Mr. Holroyd Smith as to the use of electric ignition. Mr. Kapp remarked that the production of a spark from a dynamo necessitated a high speed, but he had seen in the Exhibition, applied to a gas engine, a dynamo in which the armature was oscillatory, not rotary. The motion was obtained by a spring and trigger, and though the flywheel was travelling slowly, an effective spark was produced by the rapid motion of the armature. It was stated by Mr. Shields that the life of an ignition tube might be safely reckoned at a fortnight or three weeks, not two or three days as had been inferred. M. E. Delamere Deboutteville, in replying, said that he had found the electric spark possess many advantages over the other modes of ignition when using poor gases; the battery he used lasted from 200 to 300 hours without recharging. It had been asked why there was over compression at the end of the stroke. In this engine a part of the stroke was made before the ignition took place. This was that pressure might not be put on the crank pin when the engine was on the dead point. As a certain definite compression was required to get the best effect of the explosion, the mixture had to be over-compressed at the end of the stroke in order to have the required amount of compression when the charge was ignited.

M. DECAUVILLE, the constructor of the railway at the French Exhibition, laid down a line at his works at Petit-Bourg for the accommodation of the American . Engineers and the members of the Institution of Mechanical Engineers, during their respective visits. The line ran from the works to his private residence, the Château des Tourelles, where lunch was hospitably provided for his guests. Besides the works and the machinery therein, which is of the latest and most improved type, he showed his visitors some locomotives for tramways, and made some experimental runs with an electric locomotive driven by storage batteries.

IT is gratifying to hear from all sides that the endeavours to entertain the American Engineers met with so much appreciated success, and that they have left our shores, with many recollections which will not easily fade away. The Guildhall banquet was apparently accepted as a great compliment, further enhanced when it was found that it was permissible to perfume the historic hall with the fragrant cigar. They also agree with all the rest of the world that a dinner at the Ship at Greenwich is a thing to be remembered. Beyond the good feeling that is always engendered by these friendly meetings, this particular visit has not been unproductive of practical results, if only for the publication by one of the Americans of another reason why people should drink old wine if put before them, viz., that one is compelled to imbibe it to save the enormous interest which is accumulating on it.

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ON THE LIMIT BETWEEN POLARISATION AND ELECTROLYSIS.*

Note by M. H. PELLAT, presented by M. LIPPMANN.

LET us designate by M the electromotive force that must be introduced on the circuit which connects the two mercuries of a Lippmann electrometer in order to render maximum the capillary constant of the small mercury. In the case in which the liquid of the electrometer is an acid, I have proved that the electrolysis of this acid is produced as soon as the electromotive force, E, introduced into the circuit is above M. In fact, hydrogen never appears when we get E < M, whereas it may appear, with the necessary precautions, as soon as we get E > M. We may often considerably exceed the electromotive force, M, without the hydrogen bubble forming; but electrolysis is produced all the same if the hydrogen does not appear under the gaseous form, it is due to the general law that a gas can only be produced in a visible form in a liquid if there exists a gaseous bubble the diameter of which is above a certain limit; then, most probably, a highly saturated solution of hydrogen will be produced. This extreme saturation is avoided by creating a hydrogen bubble by an electromotive force far higher than M ; the electromotive force is then brought back rapidly to a lower value, E; we then find that if E is lower than M, the bubble does not increase in size; whereas, if E is higher than M, the greater the value of E more rapidly does the bubble become enlarged. This optical method of observing the electrolysis put me upon the track of the phenomenon, but it is not very convenient; I substituted for it a galvano-metrical process, which is susceptible of much greater precision and can be applied much more generally. We introduce into the circuit connecting the two mercury electrodes (1) E, the electromotive force variable at will; (2) a Thomson galvanometer; (3) an interrupter. Moreover, we take for the small mercury a larger electrode (of a square millimetre). In order to avoid the polarisation of the other electrode, we can take a very large surface of mercury; but it is much better to take an unpolarisable system of electrodes (zinc in a salt of zinc); the constant differences of potential thus added to the chain do not signify, since we are only studying variations of electromotive force. The small mercurial electrode is plunged into the same vessel as the point of the capillary electrometer which serves to determine M.

M, the

We thus find that while E is lower than M, on closing the circuit, the needle of the galvanometer receives an impulse due to the charge of polarisation, oscillates, and then becomes fixed at a position very near zero (spontaneous current of depolarisation); but as soon as E is above M, the needle undergoes a permanent deviation which is relatively very great and in proportion to EM. The sudden change in the sweep of the curve which represents the intensity of the current as a function of E, is very marked.

The truth of the law has been confirmed: (1) By the optical process for sulphuric acid expanded (in volume; M 95 volts) and for the abovementioned acid with the addition of oath of bichromate of soda (M •99 volts; (2) By the galvanometric process for the same sulphuric acid and for chlorhydric acid (in volume of acid at 21° B.; (M = •41 volts).

=

According to the views of M. Helmholtz, at the moment when the capillary constant is at its maximum, the double electrical layer, at the contact of the electrolyte and the mercury is nil; the law indicated above may therefore be stated thus:

[JULY 19, 1889.

is rendered free by electrolysis, it forms an amalgam with the mercury of the electrode; this chemical modification of the surface of the electrode transforms the voltameter, P, into a battery, the electromotive force of which, of contrary nature, increases till it becomes equal to E, which allows of the passage of a very slight quantity of electricity. Thus in the case of the salts E may greatly exceed the value of M, without the needle undergoing any important permanent deviation. However, by increasing more and more the value of E, a moment comes when the needle suddenly takes permanent deviations; the current then passes with an intensity proportionate to EK, designating as K a constant, which is the electromotive force starting from which electrolysis is produced continuously. We gather, in fact, that as soon as there is enough metal, m, in the superficial layer of the mercury electrode for this amalgam to act in a battery like the metal, m, itself (an amalgam containing less thanth of zinc acts like pure zinc). the electromotive force of the voltameter, P, cannot increase any more, and a constant current is produced, in virtue of the constant difference, E K, of the opposing electromotive forces. For E M, the difference of potential is nil between the pure mercury and the electrolytic liquid; for E = K the difference of potential is nil between the amalgam of the metal, m, and the liquid, since the latter is a salt of the metal, m (Comptes Rendus, April 1st, 1889); but the difference of potential is not nil between the amalgam formed at the surface of the capillary electrode and the pure mercury further down, and this difference of potential is represented by

K-M.

=

For the electrolysis of the sulphate of zinc, we get, in fact, M 76 volts and K 1.27 volts; whence K — M = 51 volts. This last number only differs from the figures 49 volts, which I obtained two years ago, for the difference of potential between the amalgam of zinc and the mercury by another method (Comptes Rendus, April 1st, 1887), by a quantity quite accounted for by the errors of these former experiments. Substituting for the sulphate of zinc, the hydrate of potassium, we get M29 volts, K 1.76 volts, whence K — M = 1·47 volts. Thus the difference between the potassium and the mercury is + 1:47 volts.

=

If instead of electrolysing the hydrate of potassium we electrolyse a salt of potassium, we find for K - M different values (139 volts with the chloride, 1-41 for the sulphate). But let us remark that the amalgam of potassium formed is attacked by the water, and that in the capillary tube a layer of hydrate of potassium is produced between the electrode and the earth; K - M then no longer represents exactly the difference of potential between the mercury and the potassium; we must add to it the difference of potential between the hydrate of potassium and the salt employed. The truth of this remark is proved by the fact that if we introduce hydrate of potassium between the salt and the electrode of mercury beforehand, we find that the electromotive force which it is necessary to employ, in order that the current may begin to pass continuously, is exactly the same as when the solution of the salt is brought directly into contact with the mercurial electrode. We see by these examples that there is a new method, both general in its application and convenient, for determining the true difference of potential between any metal whatever and mercury. But we also see that in its application we must guard against possible chemical reactions between the metal deposited and the electrolyte.

In a subsequent note we will indicate other methods for arriving at the same object.

Seeing Sparks.-Mr. G. Crighton having witnessed overhead wires in Old Broad Street emitting electric sparks (caused by the contact of the wires) points out the danger to life and property therein involved, and recommends the City authorities to see that electric lighting companies have their wires properly insulated,

THE ELECTRIC LIGHT IN BERLIN AND AT ELBERFELD.

From "Le Bulletin de la Société Belge des Electriciens."

AT BERLIN.

As a complement to our article in the ELECTRICAL REVIEW of July 5th on "The Present Position of the Electric Light in Paris," we are now enabled, thanks to a lecture delivered by M. Wybauw, engineer of the City of Brussels, before the Belgian Society of Electricians, of which he is a vice-president, to lay before our readers an account of the electric lighting of Berlin and also at Elberfeld.

The working of the electric lighting of Berlin, said M. Wybauw, is carried on by several central stations, of which the two principal are situated in the Markgrafenstrasse and Mauerstrasse. Two small stations light the Kaiser-Galerie and the block of houses at the angle of Unter den Linden and the Friedrichstrasse. Another and unimportant station provides for the public lighting of the Leipzigerstrasse. The Markgrafenstrasse station is established in the street front. It comprises eight Kühn engines of 180 horse-power each, working 16 Edison dynamos. Quite recently there have been added four compound and condensing vertical engines of 300 horse-power each, built by the firm of Vandekerkhove, of Gand. These four engines work directly four dynamos of 1,500 ampères and 110 volts. The ring of these dynamos (Gramme) is outside the inductors, and is about 2 mètres in diameter. The number of revolutions per minute is only 86; thanks, however, to the large diameter, a sufficient periphery speed is obtained. The dynamos are multipolar; the current is collected by 10 brushes. There are eight steam generators; De Naeyer boilers placed on the first floor. The commutator chamber comprises an enormous rheostat, made by means of very fine galvanised ribbons of metallic cloth, through which the current is passed from a dynamo to where it is to be used; the various parts of the rheostat are placed in succession out of circuit, in order to cause the current to pass progressively into the line. The operator's guide is a voltmeter indicating the potential at the principal point of distribution of the circuit, by means of a measuring wire inserted in the cable itself. The exit of the current from the station constitutes an enormous bundle of at least 80 cables of varying section; the greater number of which, however, have a diameter of 7 to 8 centimètres with their coverings. These cables are on the Siemens system; the largest are up to 800 square mm. of section of copper. In the interior of the works these cables are replaced by flat copper bars, forming two groups. The first of these groups serves for the supply of the Opera and certain of the principal establishments; the second for the general canalisation. In case of acccident, a general interruptor permits of cutting the current off so as only to maintain that for the theatres. The Mauerstrasse station comprises six Heine generators of 180 square metres of heating surface, three steam engines of 180 horse-power, and three of 300. The Friedrichstrasse station has four 60 horse-power engines; that of the Kaiser-Galerie four 80 horse-power engines; and that of the Leipzigerstrasse two of SO horse-power. It would be useless to describe these installations in detail here. We think it may be useful to communicate to the members certain notes taken from the plans and documents furnished us, and relative to facts which we have not found in other works. The search for a position suitable for a central electrical station in a city is not without difliculty. The three Berlin stations, of which the generators are placed on the ground floor, have respectively: 6 engines of 180 H.P.) 526 square mètres of built surface.

300

"

As regards the placing of these stations, the principal consideration has been that of a central situation in the part to be lighted. The foundations of the engines are so fixed that shaking of the ground is not to be feared. Only anthracite is employed, so as to avoid smoke. The carrying of the coal is all done after 10 at night. Inconvenience has thus been almost entirely done away with. In passing through the Markgrafenstrasse one would doubt that between a fine novelty shop and a librarian's there is at work, facing the street, a station of several thousand horse-power. Water, which hitherto has been supplied by artesian wells, will shortly be taken from the Spree by means of conduits. Here is a plan of Berlin showing in red the present canalisation, which extends over a surface of about 10,000 square mètres. The same plan shows in blue the extensions which are about to be made, as the result of the agreement come to between the city and the company. These extensions will give an approximate surface of 45,000 square inètres lighted by electricity. The canalisation has been entirely constructed in Siemens cables. These cables are in leaden sheaths, which are covered with an insulating layer, which again is surrounded with an envelope formed of two iron ribbons rolled helicoidically and simultaneously round the cable; the whole being covered with tarred jute. In the interior of the cable is one wire smaller than the others of which the conductor is composed, and destined for the measure of the potential during the service. The cables, about 130 kilomètres in development, are placed on both sides of the street, under the footways. Their place is indicated by a band of mosaic pavement in small blocks. This canalisation appears to last fairly well; yet, lately, some accidents have arisen. In this connection, the English journals have published a lecture of Prof. Forbes read before the Institution of Electrical Engineers giving an account of a journey which he had made to Berlin, Rome, and Milan. Mr. Forbes spoke unfavourably of Siemens cables, basing his opinion on the accidents which happened as he was passing through Berlin. The Elektrotechnische Zeitschrift published the discussion which took place on this subject in the Electrotechnische Verein. Dr. Werner Siemens could not understand how so competent an engineer as Mr. Forbes could speak so lightly on this question. The oldest cables in Berlin date from 1885; the accidents have been noted only in the cables laid in 1886 and 1887. He cites the cities of Berlin, Munich, Rome, Turin, Milan, Mülhausen, Elberfeld, Darmstadt, Geneva, Salzburg, Lyons, La Haye, St. Petersburg, and Moscow, where the same cables are in use and keep perfectly insulated. A few accidents are always possible, he says, arising either from the manufacture or the laying, but one must not conclude from this that the system is bad. It is necessary to avoid, as much as possible, the neighbourhood of organic vegetable matters, which are capable, with the leaden covering, of producing carbonates or acetates; as to the galvanic action between the iron and the lead, it would have an effect on the iron but not on the lead.

M. von Miller, one of the directors of the Allgemeine Gesellschaft, gives details of the accidents which have been verified. There were five. The first must be attributed evidently to a blow from a pickaxe. The second was in connection with a cable enclosed in an