Trocadero entrance to the exposition, colonial section in foreground, Paris, 1900

Stereographs are devices capable of building a three-dimensional​ image out of two photographs that have about two and a half inches difference between them so that it could imitate the two eyes’ real field of view. Combining these images into a single one with the help of stereoscope, a person can experience the illusion of the image’s depth. Stereoscope uses the same principle as in human binocular vision. Our eyes are separated by about two inches, so we see everything from two different angles. When the brain combined those views in a single picture, we get the spatial depth and dimension. Stereographs were extremely popular between 1850 and 1930 all around the world. Millions of stereographs were made during that time. There was a broad range of themes: landscape, travel, historical moments, nature disasters, architecture and many others. Nowadays, simply launch this collection full screen and put your mobile device in Google Cardboard Viewer.

After the Paris exposition of 1889, France gloried in her triumph. The time between the expositions of 1889 and 1900 was an era of economic prosperity. When Germans announced they want to hold the next world expo, French politicians, industrialists, and intellectuals realized that the country which hosted the exposition at the threshold of the new century "will define the philosophy and express the synthesis of the 19th century." Participating nations architects were given complete freedom to construct their national pavilions in any style, and display whatever they wished therein. The sole limit was the space assigned to each. The buildings of the 1900 exposition fall into two distinct categories, each representing an essential element of the spirit of 1900: Traditionalist 19th century-styled and Art Nouveau - the new style appropriate to the twentieth century. The pavilion to symbolize the new era was the Palace of Electricity. Many expositions gave visitors an illusory trip to remote lands. The Trans-Siberian was a simulated Peking to Moscow railway and "Tour of the World," located at the base of the Eiffel Tower featured moving canvas of the sights and people throughout the world. More than 83,000 exhibitors and attendance of 51 million visitors made it the largest of any exposition. The 127 congresses had attracted over 80,000 participants. The Gare d'Orsay railroad station (now the Musée d'Orsay), and two of original entrances of Paris Métro stations by Hector Guimard., and the Pont d’Alexandre, the Grand Palais and the Petit Palais opened with the exposition. The exposition Universelle of 1900 was the last of its kind held in France.

Eiffel Tower was envisioned as a centerpiece for the 1889 Exposition Universelle, a world's fair to celebrate the centennial of the French Revolution. Eiffel acknowledged that inspiration for a tower came from the Latting Observatory built in New York City in 1853. On 30 March 1885, Eiffel presented his tower design to the Société des Ingénieurs Civils. Little progress was made until 1886 when a budget for the exposition was passed and an open competition was held for a centerpiece to the exposition and decided that all the proposals except Eiffel's were either impractical or lacking in details. The proposed tower had been a subject of controversy. Prior to the Eiffel Tower's construction, no structure had ever been constructed to a height of 300 m, and many people believed it was impossible. Some of the protesters changed their minds when the tower was built; others remained unconvinced. The main structural work was completed at the end of March 1889. Eiffel made use of his apartment at the top of the tower to carry out meteorological observations and also used the tower to perform experiments on the action of air resistance on falling bodies. The Eiffel Tower's lighting and sparkling lights are protected by copyright, so professional use of images of the Eiffel Tower at night requires prior authorization and may be subject to a fee.

• Trocadero entrance to the exposition, colonial section in foreground ...
• Scene from the elevator ascending Eiffel Tower | Library of Congress
• La Porte Monumentale--chief entrance to the Exposition, Paris ...
• The Eiffel Tower--Champs de Mars in distance--Paris Exposition, 1900
• Eiffel Tower from Trocadero Palace | Library of Congress
• Champs de Mars | Library of Congress
• Palace of Electricity | Library of Congress
• Champ de Mars and the Eiffel Tower from the Trocadero Palace ...
• The Sandow Trocadero Vaudevilles - PICRYL Public Domain Image
• Trocadero Restaurant - PICRYL Public Domain Image