Photography, which is today spread over the whole surface of the globe and which reaches everywhere such a high degree of perfection, counts, in France, a staff of fifteen to eighteen thousand persons, distributed in two thousand workshops. The annual turnover for photography exceeds thirty million francs, according to official documents.
It would be difficult for us to analyze the various photographs exhibited; we will limit ourselves to mentioning a few names: - Goupil, Monge photography, Lefman, Liébert, Lumière, the famous photographer from Lyon, the equestrian photography of M. Delton, Pierre Petit, Reutlinger, Tourtin, Yves and Barret, and the French Society of Photographic, Historical and Monumental Archives
In the class of precision instruments, - which have been very sensibly perfected in recent years, - we shall mention first of all a real curiosity, the Arithmometer, invented by Mr Thomas, of Colmar, and perfected by Mr Thomas, of Bojano.
The Arithmometer is a machine by means of which people who are less familiar with numbers can do all the rules of arithmetic, just as men of science can solve the most complicated problems in a few moments.
Simple, and above all very solid, this machine offers the advantage of avoiding any fatigue in the calculations.
The Arithmometer has undergone important simplifications, which have made the machine as perfect as possible. An exact idea can be given by saying that with this instrument one multiplies 8 digits by 8 digits in 18 seconds; that one divides 46 digits by 8 digits in 24 seconds, and that the extraction of a square root of 16 digits is done, with the proof, in less than a minute and a half. The foregoing shows the immense services rendered by this instrument. With its help, half an hour is enough to do, without any fatigue and with mechanical accuracy, the work of a long day spent on numbers, and it is easy to understand what enormous savings of time and money result from its use.
The inventor has made experiments in our presence and we have noted an excessively rapid result.
For example, multiplying the number 2,749 by 3,957. In just 18 seconds, the Arithmometer gives the product 19,877,793; - just as 17 seconds are enough to find 1,111,111,088,888,889, the product of 99,999,999 by 11,111,111.
To subtract 69,839,989 from 85,639,468, a simple turn of the crank, which does not take half a second, yields the number 5,799,479.
If you divide 9,182,736,456,483,022 by 69,889,989, in 75 seconds you will find the quotient 131,482,501 and the remainder 32,950,533.
The reduction of an ordinary fraction into a decimal fraction can be obtained instantly with as many decimal digits as you want.
The same facility, finally, for extracting square and cube roots; for obtaining the fourth term of a proportion; for calculating, according to the property of the square of the hypotenuse, the third side of a right-angled triangle of which two sides are given; for the general solution of triangles, with the aid of the tables of natural trigonometric lines, etc., etc.
The Telephone was born too long before the Exhibition to excite the visitor much; its application seems to have some difficulty in entering into practice.
We shall mention, among other curiosities, the photometer of Messrs. Dumas and Reynault, the apparatus for tracing sundials of Mr. Viatour, the small steam engines of Mr. Radiguet, a model for demonstrations, the marine compasses of Mr. Pastel-Vinay, etc., etc.
Unfortunately, it would take a whole volume to deal with the question of precision instruments in a very intelligible and interesting way.
Let us note, and special men will agree with us, - that the manufacture of French precision instruments is making great progress and is superior to most foreign manufactures.
The number of manufacturers of precision instruments is about 483; there are 2,609 workers on average and the total wages amount to 4,848,400 francs on average.
This is, as you can see, a nice figure.
Music played an important role at the Exhibition of 1878, and the reader will find at the end of this book, in a last chapter entitled: - Ephemeris of the Exhibition, the long list of the festivities which took place in the Trocadero festival hall.
In the palace of the Champ de Mars, it can be said that music flourished; the great Cavaillé-Coll organs, the organs of the manual work gallery, and the pianos of the French musical section and the foreign section always attracted numerous visitors who did not spare the deserved bravos for the artists who were so happy with their undeniable success.
Let us begin with the pianos; they were, as always, the most numerous.
Here are the Pleyel, Wolff and Co. pianos, they are well known, but what is less known is a recent improvement that we must mention.
This improvement is called the tonal pedal, it purifies the harmony and the feeling of the sound, and destroys the unbearable grating of the old pedal.
The Herz and Erard pianos were also much appreciated, and all the more so because they took care to alternate their auditions instead of playing tumultuously like most of their colleagues; the result was often a cacophony that would scare off the bravest, while the pianos, trombones and violins joined in and the powerful voice of the organs overlaid everything.
Henri Herz exhibited a piano worth 18,000 francs, it is a jewel, it is even too beautiful.
It is a jewel, in fact it is too beautiful. It is nothing but chiselling, gilding, festoons, astragals, etc.
The harps in the house are of great interest, no doubt, but seriously, who plays the harp today?
Earlier we spoke of the improvements made to the pedal by Messrs Pleyel and Wolff.
Here are some interesting lines from M. Treille on the means of improving the sound of the piano:
"In 1717, a harpsichord maker devised the harpsichord-vielle, so called because it resembled a hurdy-gurdy placed on a table, because a wheel was used instead of a bow, and because its sounds resembled those of the hurdy-gurdy. Drawings of it can still be found in the collections of the Academy of Sciences.
"Towards the end of the eighteenth century, a Milanese by the name of Gerti invented an instrument in the form of a harpsichord, mounted with gut strings, which were played by horsehair bows.
"In 1806, at the first Paris exhibition at Les Invalides, a man named Schmidt presented a very complex instrument, consisting of a first keyboard with an ordinary piano mechanism, and a second keyboard designed to move small cylindrical bows that made gut strings resonate. Then came the orchestrino, by Pouleau; the violincembalo, by the Abbé Feutin; the sostenante-piano-forte, by Mott; the plectro-phone, by Gaine. All these attempts gave only imperfect results and did not solve the problem. It was to an Italian engineer, Mr Luigi Caldera, that the honour of finding the solution fell, and to Mr Henri Herz to put it into practice with appreciable improvements.
"The melopiano is no more than an ordinary piano in its external construction; but inside it contains a mechanism corresponding by a roller with the vibrating strings, and by a third pedal and an external knee-piece with the performer who plays.
"According to the length of time the player puts his foot on the pedal, he prolongs the note or the chord, and at the same time increases the intensity and volume of the sound at will, without this addition to the mechanism having taken away any of the instrument's flexibility.
"The touch always retains that softness and mellowness which distinguish the instruments of Henri Herz. - And now, if the artist leaves the third pedal there, and does not use it again, he can immediately use the piano as an ordinary piano.
"I have heard an instrument thus equipped with this adjuvant, and I confess that the sounds acquire a power, a sonority, a substance, a charm that the instruments still in use certainly do not have.
"However, not everyone can use the melopiano; it is necessary to make a preliminary study of the mechanism and to practise playing the pedal of this piano absolutely as one practises on the organ. But I do not think that this additional study is a very formidable obstacle for artists who have the soul and the feeling of their art.
Now here is a show that could not be more attractive and that forces us to stop; it is the various phases that a violin goes through from the moment it is started to the moment it is finished.
This show would have been very interesting if it had been given in action, in the gallery of manual work.
Let us now turn to the more recent instruments:
First, the piano quartet by Mr. Baudet.
Inventing a piano with a fixed tuning, i.e. one that never loses its tuning, regardless of the changes in temperature; this is very beautiful.
The vertical grand piano may be particularly attractive because of its original shape.
Let's move on to the pianista.
What is the pianista? On this point, we will give the floor to Mr. Lissajous and Mr. Turgan.
"The pianista differs from all the tests that have been made up to now. The device consists of a small piece of furniture from which a series of wooden levers or hammers emerge, designed to attack the keys in exactly the same way as a pianist would with his fingers. The pianista is placed in front of a piano keyboard at a suitable height, and all that is needed is to turn the crank of the mechanism so that the fingers strike the piano and make a particular piece heard.
"Now how do the fingers work? The movement of each finger is dependent on a motor bellows operating like that of the Barker machine, and fed by the two main reservoirs whose pumps are cranked into play. Each bellows is set in motion by the opening of the valves, which are under the control of a sort of abstract whose driving rods all lead to a row of cams placed in a straight line in the centre and upper part of the instrument.
"A series of Jacquart drilled cards are driven under these cams, which are raised or lowered in turn, thus operating the corresponding keys. By means of a rod placed within reach of the left hand, the attack force of the pianista is modified, while the right hand, applied to the crank, regulates the speed at which the piece is played. During the execution, the foot placed on two auxiliary pedals, which are attached to the two pedals of the piano, can raise the dampers if necessary.
Let us give a mention to the harmoniums, in particular to the harmonium with organized transposers, which makes it possible to play the organ without knowing a bit of music; let us greet the large Lebey organs, with sixteen pipes; the Bruneau organs, of Bourget, with eight pipes; the famous Cavaillé-Coll organs, the Fer mis and Pertel organs, and let us pass to other wonders.
THE. MEDICINE. SURGERY. HYGIENE.
The exhibition of this class is of special interest; we have had occasion to speak of one of its very valuable and much appreciated services, that of the ambulances.
The Société de secours aux blessés, installed near the trench, at the bottom of the Champ de Mars park, undoubtedly deserved the prize; its installations are admirable for their intelligence and charity; we have already described them, at the beginning of this book, and we have done them the justice which is their due.
The official ambulances, established by the Ministry of War, were far from representing the same perfection, as we have already said.
As far as public assistance is concerned, we said it all when we spoke of the exhibition in the city of Paris. We shall not dwell on this too special class.
We shall mention, among other things, the museum where specimens of venereal diseases were exhibited.
It is really unfortunate that women and children were not forbidden to enter; such a spectacle, which is excessively interesting for specialists, for people who study, constitutes an immorality when it is given over to the curiosity of adults, at the same time as a serious danger for women who are in a particular situation.
Dentists were naturally quite numerous and jaws of all sizes abounded.
The real curiosities of this part of the exhibition were the two exposed brains of Dr. Auzoux and the spectacle of the germination of the wheat ear.
There is no longer any need to talk about the advantages of hydrotherapy, which have long been demonstrated. The concern is rather to make them accessible to everyone, because special establishments are still rather rare, and on the other hand, not everyone has the leisure to go there every morning to follow a regular treatment. However, it is essential that the shower be taken with perseverance, if one wants to obtain all the possible benefits.
"It was therefore necessary, in order to make the advantages available to everyone in Paris and in the provinces, to imagine a truly practical device, which would allow people to take a shower at home without any inconvenience or help; this device had to provide the means of obtaining, on the spot, without water pressure, all the varieties of shower that are available in establishments with their multiple jets.
M. Walter, of the Walter-Lécuyer company, 138, rue Montmartre, in Paris, has succeeded in carrying out this programme; his apparatus combines the main jets in use: rain, spiral, circles, large and small fan-shaped jets, blades, broken showers, Scottish showers, etc.; its projection power is 3 atmospheres, corresponding to a reservoir height of thirty metres. The system is extremely solid and cannot be disturbed; it can be assembled and disassembled without a worker. It can be placed anywhere, in a room or a cabinet. A simple curtain surrounding the device is enough to prevent water from being sprayed outside and wetting the floor.
The characteristic combination of the Walter system is in the loading, which is done by a water pump. The air is compressed by the weight of the pump. This eliminates the danger of explosion and the risk of damage to the components, and allows even the most inexperienced person to operate the device.
It was also the Walter-Lécuyer company that built Dr. Belot's pneumatic apparatus for the installation of gases, which was noted in the Spanish section.
AGAIN, PRECISION INSTRUMENTS,
THE MICROGRAPHIC TELEMETER.
The reader will allow us to return to the precision instruments here, because of the importance that the micrographic telemeter has just acquired at the Exhibition.
We stopped a lot in front of a small optical instrument, which Messrs Dallemagne and Triboulet, 37, quai de lu Tournelle, in Paris, call the Micrographic Telemeter. This apparatus, which takes up less space than an ordinary spyglass, is of immense utility. Without the objections of pure formality, which our routine bureaucracy opposes, it would long ago have been in the hands of all our officers by whom it is well known and perfectly appreciated.
Imagine a small darkroom, as big as the eyepiece of a stereoscope: apply your eye to the lens supported by a board smaller than your hand, and you will see all the details, even the most microscopic, of the portion of the map you wish to study, drawn out in front of you. You will also notice a series of circles on the map, forming a graduated concentric scale, and giving the distance immediately.
The original map would hardly fit on a table; here it is more legible, clearer and larger to the eye, and it fits in the palm of the hand. This is the secret and the advantage of the rangefinder.
Now maps, microscopic dispatches, can be read on foot as well as on horseback, by day, by night, by the light of a candle, a match, a piece of cigar, even by the moon, and with admirable clarity.
And if you are in the middle of a meeting, with only this Lilliputian map for all to see, with a photoscope, a magic lantern, a magnifying device, you project onto a screen, canvas or wall, the slightest features of this map, which is thus made visible in all its details, tangible for all at the same time.
This photographic reduction of maps, a continuation of the process used during the siege of Paris to reduce dispatches, makes it possible to carry all the sheets of the French map in a wallet and all those of Europe in a gibernacle, including the rangefinder of course. To transport our slightly reduced staff map, we would need a van, and what an embarrassment to choose and deploy the sheets?
This photographic reduction provides an invaluable advantage, especially in our time. It allows the map to be kept up to date with the latest changes. A correction is made on the map and a proof is made. And since it is only a matter of making proofs, as many copies of the map of any given area as desired can be supplied at any given time. With a darkroom, you can obtain enlarged proofs of any map. With a small, clear chamber, one can draw, freehand, the map of the place where one is. There are many other very practical and very simple applications which will come of themselves.
It goes without saying that maps, plans, etc., treated in this way, are unaffected by rain and friction; they are placed between two glasses and the plate thus formed, inserted in a metal frame, called an object-holder, is attached to the instrument by a small chain which forms a body with it.
It should be added that the instrument itself can be supplied at a very moderate price; as for the cards, the complete collection of the French one, with the microscope and the cases, will not cost a tenth of the price of this collection sold in the shops.
The most distinguished of our scholars, staff officers, geographers, topographers, etc., have applauded the numerous efforts made by Messrs. Dallemagne and Triboulet to perfect their work. We would like to tell the readers who are curious to see for themselves that the telemeter is still on display at the museum of the Academy of Meteorological Aerostation, which is open free of charge every Thursday, at 30, rue Rodier. We especially urge those who are concerned with the teaching of geography and perspective drawing to study the certain and considerable advantage that they can draw from this device: our official teaching commissions would do well to concern themselves with it.
An innovation of great practical significance has been happily achieved by Mr. Derogy, optician in Paris, 33, quai de l'Horloge. This skilful manufacturer has succeeded in introducing achromatism into commercial eyewear lenses.
Our readers know that this quality results from the juxtaposition of two lenses of different densities and curvatures, crownglas and flintglass. This is how the lenses of all the perfect instruments of high optics and science are made.
The consequence, which we believe we must bring out, is to substitute a single focus for the seven different foci of ordinary lenses, to produce consequently the real unity of the image, to remove all diffusion of iridescent or coloured light, which is the forced result of simple prisms.
Thanks to this perfect sharpness of the image, the visual effort is less; one can use less magnifying glasses and lower numbers; the sight rests, improves, and after a certain time, is notably strengthened. We know of surprising results obtained thanks to the use of these glasses, the acquisition of which represents only a modest expense.
THE GEOGRAPHIC AND COSMOGRAPHIC EXHIBITION
The masterpiece of the geographical exhibition is undoubtedly the staff map; however, it was placed so unfortunately, - we were going to say so awkwardly, - that few people were able to appreciate it; to observe its detail usefully, a marine telescope would have been necessary.
This map was originally placed on the extended wall of the French machinery gallery, on the side of the Porte de Tourville, opposite the eastern end of the manual work gallery; but the Laveissière trophy would have completely hidden it from the view of most visitors, those who came through the latter gallery, which was so busy. It was then devised to erect a wall separating the gallery of work from the beginning of the gallery of machines, and it was on this wall that the two hundred and sixty-four leaves making up this splendid work were beautifully assembled and framed; in this way, the public could pretend to believe that they were seeing something.
The wall in question was pierced by three large arcade-like openings, so that the circulation was not impeded. It is naturally above these arcades, which are almost 6 metres high, that the staff map has been placed, the northern point of which almost touches the cornices. It is 11.30 metres high and 13.20 metres wide and occupies an area of 180 square metres with its frame.
This immense and magnificent map, already known and admired by the numerous public who visited our International Geography Exhibition in 1873, was drawn up at 80,000m. A masterpiece of precision and relief in the majority of its individual sheets, it required a truly frightening amount of work on the part of the engineer-geographers and officers of the staff corps as well as the draughtsmen and engravers of the War Office. And how many died before seeing the end of it! The work was begun in 1818; from that time until 1873, or rather until today, it has been carried on without interruption. The cost of drawing and engraving has been estimated at 20,000 francs for each sheet, and it is estimated that the total execution, without including in this figure the cost of purchasing the necessary topographical and geodetic instruments, various other material expenses, travel allowances and the like, cost about 4 million francs.
At the 1878 Exhibition, the staff map does not have nearly the same imposing effect as in the Salle des Etats in 1873, where it received light from above and was placed in a much more favourable manner in every respect. You have to go a little further, about sixty steps, to get a good grasp of the whole and the details of the general lines. But one had to reckon with the difficulties inherent in a general exhibition of such proportions, and it must be acknowledged that all that was possible was done.
Let us add, however, that if the details of the northern regions of the great map of France escape the eye, there is one among all that does not: it is this red line which extends irregularly to the east, cutting off from French soil its two provinces of Alsace and Lorraine, as if to remind us of the floods of blood shed before coming to this supreme sacrifice.
Let us mention another curiosity which belongs to the domain of geography and which was in the Egyptian pavilion in the Trocadero park:
It was a huge map showing the main explorations of Africa; lines drawn in different colours indicate the route followed by the various travellers, and close by hang the portraits of Cameron, Livingstone and Stanley. Two other pictures give a not very encouraging idea of the ferocious manners of the negro races in the interior of Africa, and of the ingenious variety which they know how to bring to bear in the exercise of their cruelties. It is therefore with a feeling of deliverance that, after contemplating at leisure these representations of familiar scenes, one arrives at the section of this pavilion where everything speaks in such eloquent terms of the progress of civilisation in Egypt, as in the room devoted to the history and geography of the Suez Canal.
The route of the canal is shown on a huge map which covers the whole surface of the wall; the position of the cities of Alexandria, Damietta, Rosetta, Cairo is carefully indicated on this map, as well as the course of the Nile. A large panorama in relief of the canal and the lands belonging to the Suez Company on both banks is placed on a table which extends from one end of the room to the other. It shows sailing and steam ships arriving from the Mediterranean at Port Said, entering the canal, passing Ismaila, crossing the Serapium to the right, continuing towards Suez, and finally entering the Red Sea. These plans and maps are masterpieces of precision and accuracy.
©Les Merveilles de l'Exposition de 1878