The exhibition of the Telegraph and Telephone Administration.
How far we are from the time when the first attempts at electric telegraphy came to astonish the world!
In the days when the Chappe brothers' telegraph waved its great epileptic arms in the air, the speed with which its enigmatic signals were transmitted from one place to another was considered astonishing.
the speed with which his enigmatic signals, transmitted from one station to the second, repeated by the latter and reproduced by the third, thus travelling from near to near, had made it possible to make known to Paris the news of the capture of Condé three hours after its surrender. But the smooth running of the system was linked to the state of the atmosphere. In dark weather, fog, snow, throughout the night, the transmission of dispatches was impossible; so the invention of the electric telegraph was hailed by the learned world as marking the dawn of a new era in the rapid communication of human thought over the greatest distances. No more fog, no more night, electricity would remove all obstacles, cross mountains and oceans.
But what a lot of trial and error it took to get to this point!
The Belgian State Railways Administration had wanted to bring together the oldest types used in Belgium, together with the most recent improvements, for the public to see.
The first devices used in our country were those of Wheatstone and Bréguet; in the first, successive currents of the same or opposite direction gave a magnetised needle corresponding oscillations which were noted by an employee and the combination of which gave the different letters of the alphabet.
In the second, the transmitter is a dial bearing all the usual letters and signs. The operator turns a crank and stops it on the sign he wants to transmit. The receiver is an analogous dial, with the same signs, on which a needle moves, following the movements of the crank, and stopping like it on the letters that the operator transmits.
But these types required considerable attention on the part of the employee in charge of receiving the messages, who had to keep his eyes constantly riveted to the dial on which the needle moved. The introduction of new systems, such as Morse and Hughes, marked a serious advance in the history of telegraphy.
Everyone knows the former. Everyone has seen an operator manipulating a lever to which he gives a succession of long and short strokes, and everyone has seen the receiving apparatus consisting, in principle, of a clockwork movement, which drives a long strip of paper and passes it close to an inking roller.
An electromagnet receives the current sent by the manipulator and applies the strip against the roller; depending on whether the stroke is long or short, the contact is more or less long and the impression is made on the paper in the form of lines or dots, the various combinations of which constitute an alphabet.
This device, of robust simplicity, is still widely used on telegraph lines where the number of dispatches to be transmitted is not too great.
Another device, based on a completely different principle, is the Hughes telegraph, which gives a direct print in block letters.
A wheel, bearing the series of characters and signs in relief, rotates with great speed near a strip of paper driven by clockwork. An extremely ingenious mechanism causes an electromagnet to strike each time the transmitter, similar in appearance to the Bréguet transmitter, stops on a letter. The very brief strike brings the strip of paper into contact with the wheel, on which the character is thus printed on the fly.
This device, a marvel of mechanism, is however relatively easy to adjust, and is much faster than the Morse.
The continual increase in correspondence has led inventors to seek to make the best possible use of telegraph lines by combining so-called multiplex systems, in which several devices can be connected to the same line without confusion in the correspondence. These systems are extremely complicated and are only used on lines with heavy traffic.
The Administration des Télégraphes exhibited a Hughes duplex installation, a system which normally ensures connections between some of the major European capitals.
It is known that Belgium was the first country to inaugurate, in its telegraph offices, with the help of a sophisticated device, a system of operation characterised by the concentration of calls, which makes the lines produce the maximum output with the minimum of personnel, while increasing the speed and accuracy of transmissions.
The exhibition of the Telegraph Administration showed modern equipment alongside the old devices used, and from the technical point of view as well as from the retrospective point of view, was most interesting. When one recalls the first attempts at telephony, one is amazed at the progress made in thirty years.
It was in 1876 that Bell built the first device for the transmission of speech, and the receiving horns now in use are based on the same principle.
It is known that, in a coil subjected to magnetic field variations, currents develop whose undulations are related to these variations, and that, conversely, such undulated currents, launched into another coil mounted on a magnetic circuit, reproduce there field variations similar to the undulations of the current.
It is also known that any noise or sound is a succession of waves produced in the air by the sound body. These sounds or noises are perceived by the membrane of the tympanum of the ear, in a completely mechanical way, by the vibrations that they impart to it.
Bell imagined creating a sort of electro-magnetic eardrum. A thin iron plate, capable of vibrating under the influence of sound waves, is placed
in front of a magnet fitted with a coil. Even small movements of this diaphragm change the magnetic field strength of the magnet. It follows that the coil can send a series of current waves into another device, the receiver, similar to the first, which, as we said above, will modify the magnetic field of the receiver in a corresponding way, producing vibrations of the latter's diaphragm. These vibrations will in turn give rise to a sound which will reproduce the original sound with an accuracy which will depend on various conditions.
Such was the first telephone. But it is understandable that the currents induced in this device are necessarily very weak and limit the distance at which one can communicate to a few kilometres.
It was therefore sought to increase the transmission power by combining a device capable of producing more intense currents. The microphone achieves this goal,
It works, not by induction, like the telephone, but by producing resistance variations in an electric circuit powered by a battery. This circuit is the primary of a small transformer, the secondary of which sends to the receiver waves of current similar to those produced by the telephone, but much more powerful, thus considerably increasing the transmission distance.
The microphone as transmitter and the telephone as receiver, such is the marvellous instrument which allows human speech to be heard at distances
The microphone as a transmitter and the telephone as a receiver is the marvellous instrument which enables human speech to be heard at distances as great as Brussels to Marseilles, with a speed approaching that of light, which can be said to be almost instantaneous and which is interesting to compare with that of the direct transmission of the voice. As we know that sound travels at a rate of about 330 metres per second, it would only take 42 minutes to cover the distance from Brussels to Marseilles, i.e. 850 kilometres, if it could get there. The exchange of a question and answer would therefore take an hour and a half, whereas the telephone makes the transmission instantaneous.
The mind is left confused when one thinks of the prodigious result obtained by such feeble means, and this is our excuse for having dwelt, perhaps too long, on the principle of telephony.
Since their invention, these devices have naturally been studied and perfected, and the Administration of Telegraphs has very well understood the interest that the collection of different models that it has successively employed presented for the visitor of the Exhibition.
It also exhibited, in the same order of ideas, the apparatus used by the central offices to link together the subscribers who wish to communicate.
The oldest system is the Swiss switch, a board with as many horizontal and as many vertical copper strips as there are subscriber wires, each of which is connected to a vertical and a horizontal strip. The two systems of strips do not touch each other, but at their intersection have a hole in which a pin can be driven to connect them.
Thus, to connect the wire of F with the wire of X, the pin is pushed in at the point where the horizontal band F crosses the vertical band X. We will not insist on the accessory devices for calling, etc.
As the telephone networks expanded, the boards became more and more complicated and the old systems had to be abandoned.
On the other hand, the old telephone sets, with their local battery and ringing bell, were quite expensive to maintain. The Administration des Télégraphes exhibited a light-signal switchboard of the central battery system which it had started to equip its important networks such as Brussels, Ghent and Liege. This system delivers communications in half the time of the system previously used and eliminates the battery and the crank used for the conversation or the call, reducing to a minimum the manoeuvre to be made to request the communication. You pick up the horn and wait for the central office to answer. It is true that one no longer has the resource of calming one's nerves by frantically turning the crank when the answer is not forthcoming, but this is a psychological consideration of minimal importance.
It was natural to try to take advantage of the telegraph wires to achieve long-distance telephony, but the difficulty was not to throw the much stronger currents of telegraphy into the telegraph receivers, which would have had the effect of deteriorating them, and in any case, of making conversations impossible.
Van Rysselberghe found a way to overcome this difficulty, and the Administration exhibited the anti-inductive organs of Van Rysselberghe's simultaneous telegraphy and telephony system. It also exhibited a telephone booth of the latest model and a specimen of the underground cable conduits under paper and lead, such as they have been built or are in the process of being built in the large Belgian cities where their use has become necessary as a result of the enormous development of the networks.
It was no longer possible to keep such wigs of wire on the roofs of houses. On the other hand, it was desirable to equip the devices with double wire. The adaptation of the underground network was very appropriate between the central offices and the series of dispersal towers scattered in the different points of the network.
However, the disadvantages of the reciprocal influences of the wires and of the so-called electrostatic capacity of the insulators used were recognised. The former was overcome by twisting the two conductors into a spiral, and the capacitance was reduced to a minimum by using air and paper as insulators.
Several hundred of these double conductors were bundled together in a lead tube to protect them from moisture, and the cable thus formed was pulled in lengths of two hundred metres through tubes placed underground.
THE EXHIBITION SERVICE
The following was the organisation adopted to ensure the supply of electrical power to the Exhibition, as well as the lighting of the Halls, gardens and concessions.
In order to give more life to the Industrial Exhibition, the regulations provided that:
"For any machine in motion, operating at least four days a week and five hours a day, the justified expenses resulting from the supply of steam, water, gas, electricity and possibly mechanical motive power, will be reimbursed up to half the amount paid for the space occupied by the said machine. The same shall apply to justified expenses for fuel for the supply of boilers and gas generators, for lean gas for the supply of engines, etc.
The fuel, steam, electricity, etc., consumed by the machines or appliances for the general service of the Exhibition, shall, even if they have been supplied free of charge or paid for in whole or in part by the organising Company, be considered as having been paid for in full by the exhibitors of these machines or appliances, and the expenses arising from this shall consequently be credited to the said exhibitors, under the conditions laid down in the preceding paragraph.
The State had contributed greatly to the success of the Exhibition, and imposed the obligation to show the numerous machines it had ordered from Belgian industry in operation.
Thus the Electricity Department had at its disposal the three 400-kilowatt dynamos supplied by the Compagnie Internationale d'Electricité, the Ateliers de Constructions électriques de Charleroi, and the Ateliers Jaspar, ordered by the State, and most of the dynamos, large and small, voltage balancers, etc., exhibited in the Hall of Machines.
The production of all these dynamos was centralised at a large distribution board occupying the whole width of the large Hall, shown in the photograph
In order not to have to deal with all the details of the installations, the Exhibition service had entrusted this work to a company, the Mutuelle électrique, whose participants were:
Compagnie Internationale (l'Electricité; Ateliers de Constructions électriques de Charleroi; Ateliers Jaspar; Force-Eclairage; Compagnie Auxiliaire d'Electricité; Electricité-Mécanique; Regina bogenlampenfabrik; Jandus.
This Mutual Association was responsible for the installation of the pipes, the lamps, the general lighting of the halls and gardens and the connections of all the participants. The Mutual Association was responsible for the installation of pipes, lamps, general lighting in the halls and gardens, and the connections of all participants. It installed about 10,000 incandescent lamps and 500 arc lamps, the illuminations and more than two hundred motors of various powers.
Handling was provided by a large number of electric cranes.
Cockerill-Dulait 30 tonnes
Cockerill-Dulait 15 tonnes
Titan-Union 30 tonnes
Soc. de Construction du Nord. - Comp. Intern. d'Electricité . 30 tonnes
Gustin-Henrion 10 tonnes
Ghilain-Force Eclairage 15 tonnes
Stuckholz-A. E. G 30 tons
The Electrical Service of the Exhibition was placed under the direction of Mr. Engineer Lhonneux.
Engineer Wurth was in charge of the machinery department and Engineer L'Hoest was in charge of the Mutual Society's installations, and if there were never any complaints about the Electrical Department, the credit goes to these gentlemen who spared neither their time nor their efforts, taking care of all the details and multiplying their efforts to meet all the requirements.
As soon as the halls were covered, the Electrical Service was ready to operate, and overhead cranes were already in place to speed up handling.
It was thanks to this circumstance that the large machine hall was ready for the opening of the Exhibition.
The progress made in the art of electrical constructions, dynamos and motors, is not striking for those who are not initiated into the mysteries of electro-technology; therefore, the visitor, entering the great hall of machines, had the impression of having already seen many similar machines. However, it should not be assumed that progress has not been made in this type of construction. In the past, each factory had its own recognisable types, and one would have thought that each one was trying to do something different from its competitors; hence the diversity of types, type
Hence the diversity of types, the Upper Gramme type, the Edison type, the Manchester type, the Thury type, and all the possible (and sometimes impossible) forms. But the fierceness of the competition forced the engineers to eliminate the least economical forms, both from the point of view of the cost of the raw material and of the ease of construction, and to seek the types and technical conditions that would give the greatest power at the lowest price. Hence this crystallisation, this tendency towards a single shape, a rounded and rounded shape which is the characteristic of dynamos and motors of recent construction.
The Jaspar workshops, the Compagnie internationale d'Electricité de Liège, the Ateliers des Constructions électriques de Charleroi, the Maison Béer, from Jemeppe, represented Belgian industry with dignity.
The first three exhibited the three 400-kilowatt dynamos ordered by the State for the central railway arsenal in Mechelen, each driven directly by a 700-horsepower steam engine at 110 revolutions.
Let us mention the various generators and motors of the Société des Ateliers de Constructions électriques de Charleroi, which also exhibited an electric locomotive, lifting equipment, and part of the large distribution board of the Exhibition's electrical service.
The Maison Béer, from Jemeppe, showed several dynamos and electric motors, including one of 160 kilowatts, one of 70 kilowatts, and a motor driving an "Express Riedler" pump.
"Express Riedler" pump.
The Ateliers Jaspar, of Liege, exhibited two 70 horsepower generators of the type adopted by the Belgian State, a complete series of motors from 1 to 30 horsepower, a
transformer and sixty motors from 1 to 40 horsepower applied to machine tools, milling machines, drop hammers, lathes.
The money press that struck the "souvenir of the Exhibition" medals was powered by a Jaspar engine.
On the same stand was the Couffinhal variable speed motor, built for the Jaspar workshops. This motor can give a variation of speed in the ratio of one to four, by the variation of the magnetic field, obtained by the approach or the removal of the polar parts. This arrangement has the advantage of always maintaining the normal current in the electro coils, thus ensuring perfect commutation, and of giving a graduation of speed as insensitive as desired. Several of these machines have already been acquired by the Belgian State. This device is particularly suitable for a large number of machine tools.
At the Compagnie Internationale d'Electricité, in Liege, we find:
Two 100 kilowatt direct current generators;
One 500 kilowatt direct current generator;
One 350 horsepower direct current generator;
A three-phase generator of 225 kilowatts at 3,000 volts, and about 100 motors distributed in different stands.
A series of direct current motors and a series of three-phase motors with their starters, an electric mine pump, a tram car truck with complete equipment, an electric locomotive, type "City of Antwerp" and switchboards.
The powerful German companies exhibited their machines, either on their own stands or in participation with Belgian installation companies. Let us mention: the Allgemeine Elektricitâts Gesellschaft, the Elektricitdts Actien Gesellschaft, vorm. Lahmeyer, Frankfurt, the Société Hélios, Cologne.
Also noteworthy is the Swedish General Electric Company in Vesteras.
The Belgian company Force-Eclairage, in addition to Lahmeyer dynamos and motors, showed a test bench with recording dynamometer.
In the Electric Lighting class, we find many exhibitors and we must limit ourselves to a quick enumeration of the firms and their products.
Andouche and Leclercq, participants of the Mutual Society, installation of 2,500 incandescent lamps and 100 arc lamps in the gardens;
Compagnie continentale des Compteurs, formerly J. Brunt et Cie, electricity meters and chandeliers.
Remarkable exhibitions of chandeliers and equipment by Lempereur et Bernard, Luppens, Moreau frères, Serrurier et Cie, and Wilmotte J., fils.
The metal masts of: Ateliers Tantôt, Forges et Ateliers de Tyberchamps, Ateliers du Roeulx, Société des Usines et Mines de Houille du Grand-Hornu
As a novelty, we mention the patented equipment of the Belgian Electric Lighting Boards Company, and the "Lindeman" safety lamps for mines, as well as the osmium lamps of the Société anonyme des Accumulateurs Chelin. The latter company exhibited its accumulators.
The same was true of the Société Tudor and the Société des Manufactures de Câbles, etc., of Seneffe.
In the field of electro-chemistry, we have: Etablissements Grauer, electroplating equipment and installations L'Oxhydrique, electrolysis equipment.
Paul Hoho, heating and electrical working of metals, and Solvay et Cie, pure electrolytic products.
Also noteworthy are the wires and cables of the Société anonyme des Fonderie et tréfilerie de bronze phosphoreux, in Anderlecht, those of the Société anonyme des Manufactures de Câbles, etc., in Seneffe, and those of Léon Hen et Cie, in Brussels.
In the telegraphy-telephony class and that of various applications, we note: Emile Gérard et Cie with their switches for central telephone offices, their subscriber sets, accessories, their electrical measuring devices, mine blasters and distribution boards.
The products of Bell Telephone Manufacturing Co. of Antwerp, whose name alone indicates its purpose, as well as The Antwerp Telephone and Electrical Works;
The distribution board of Ridiez et Cie;
The electric detonators of Ghinijonet et Cie; of the Société anonyme de dynamite de Matagne, and of Explosifs de Clermont, The lightning rods of Joseph Francotte et fils; and of Ghysens.
And finally, the devices of the Compagnie de Télégraphie sans fils, which exhibited a complete station of its system.
The Allgemeine Elektricïtâts Gesellschaft, in addition to its dynamos and motors, had a complete exhibition of small installation equipment, arc and incandescent lamps, arc lamps for indirect lighting, Nernst lamps.
The manufacture of electrical cables and conductors was represented by the powerful firm of Felten and Guilleaume and the Kabelwerk Rheydt.
Bergmann Elektricitâts Werke exhibited its well-known system of insulating tubes and special articles for electrical installations.
At the Regina Bogenlampenfabrik stand, we found the Regina long-life arc lamps and the "Miniature" lamps.
The Reinische Bogenlampenfabrik also exhibited long-life arc lamps and "Miniature" lamps, as well as mercury vapour lamps from the Phônix Elektrotechnische Gesellschaft, which also exhibited
In electrochemistry, we have Classen, Alexander and Lévy Siegmar, applications of electroplating.
And Wedekind, Adolphe, primary elements.
Also noteworthy are the incomplete wireless telegraphy stations of the Syndicat fur drahtlose télégraphie Gesellschaft.
And the "Isaria" electric meters from the Lux factories in Munich.
The other countries were poorly represented.
Austria only sent us a selection of insulators from the porcelain factory in Merkelsgrün and magnetic clutches from the Vulkan company in Vienna.
Holland: electrical measuring instruments from Naamloose Venootschap Joukeer en Zoon, Amsterdam.
Luxembourg: Henri Tudor exhibited his benzo-electric locomobile and Schieber Eug, an electric motor with special switch.
Special mention must be made of Sweden, where Allmânna Svenska Elektriska Aktiebolaget, Vesteras, showed a 50-kilowatt dynamo and a series of DC and AC motors,
And Lavais Augturbin Aktiebolaget, Stockholm, presented its dynamo turbines and electro-motor pumps.
In Switzerland, the Fabrique de condensateurs électriques de Modzelewski et Cie, in Fribourg, was presented.
In all the devices exhibited in the various classes, the layman may not have noticed the improvements made in recent years, but the specialist could see that electrical engineering, a science born yesterday, continues to make great strides in the direction of progress.
©Livre d'Or de l'Exposition Universelle de Liège 1905