The foundations of this colossal undertaking were first laid on 5 July 1887 and completed on 21 December of the same year.
The framework of the palace consists of 20 trusses, in the form of a low ogive. The legs of each truss are very narrow and are hinged at ground level, and the two parts of the truss are joined at the top by a pad, around which they can play. These three joints allow each truss to expand without inconvenience under the various influences of temperature.
Six months of work were enough to assemble these twenty trusses, from April to September 1888. This assembly was entrusted in equal parts to the construction company of the former Cail establishments and to the Fives-Lille company, which used two different lifting methods.
The Cail company erected each truss in fragments, each weighing no more than 3 tons, using continuous scaffolding, following the shape of the truss and supporting it until it was completely finished. The Fives-Lille company proceeded by lifting each truss in large masses, each weighing up to 48 tonnes, using independent scaffolding. These two systems gave about the same result in terms of time used.
Some figures about this enormous metal construction are curious; for example, the number of shores for each farm is 32,000, the number of shores for the other is 1,000.
The number of rivets for each truss is 32,000, not including the purlin rivets; that is, for the twenty trusses, 640,000 rivets!
If the role played by iron in the construction of the machine palace is considerable, that of glass is also of great interest, since the surface area of the glazed roof of the great nave is approximately 34,700 square metres, and that of the vertical windows, including the large end gables, amounts to 14,500 square metres, which gives a total of 49,200 square metres of glazing!
In addition to the decorative aspect of the metal construction, decorative painting has been given an important place in the Machine Palace.
MM. Rubé, Chapron and Jambon, the skilful decorators of the great theatres of Paris, have painted, for the solid parts of the back, 10 large panels of 16 m. on each side, representing the arms and attributes of the great capitals of the world, and 124 smaller panels representing the coats of arms of the chief towns of our departments and of the great foreign cities. These panels are 16 m. high and 5 m. wide, and cover a total surface area of 17,000 square metres of paint.
The gable windows are entirely tinted. On the Avenue de La Bourdonnais side, a large stained glass rose window, formed of the crests of the principal powers, is of great decorative effect. The opposite gable, avenue de Suffren, is also decorated with stained glass windows, exhibited by the Champigneulle company (from Bar-le-Duc), and representing
the Battle of Bouvines. Finally, the central bay, opposite the Ecole Militaire, and illuminating one of the large staircases, is decorated with a brilliant stained glass window depicting the Sun Chariot.
As for the exterior decoration, it is almost completely in staff; ceramics are represented only by a large earthenware panel, above the entrance door of the Avenue de La Bourdonnais, bearing the inscription PALAIS DES MACHINES, crossed by a branch of laurels and framed by a motif of scrolls. Two monumental groups are placed to the right and left of the entrance door; on the left, Steam chained by Work, which makes itself master, by M. Chapu and on the right, Electricity, by M. Barrias. Unfortunately, these sculptures, which are 7 metres high, cannot be appreciated as they deserve, due to the lack of distance.
Such is, in its entirety, this grandiose palace, where the Triumphal Arch would fit in height and where a cavalry brigade could evolve at ease. More than the tower, it is interesting, firstly because of its usefulness, and also because of a search for a new decorative formula, required of the construction itself, which is iron, a material hitherto rejected as a decorative element. Artists reproached it for its stiffness, dryness and narrowness, which made it incompatible with the large masses that are essential in architecture.
However, in the Galerie des Machines, as well as in several pavilions of the Champ de Mars, there are examples which prove that iron can perfectly give rise to a rational decoration which draws its effects from its very utility.
© L'Exposition Universelle de 1889 - Brincourt - 1889