La Stéréoscopie Universelle was a trademark of Rolland et Cie, founded by Paul Rolland[1]. The company was located at Boulevard Saint-Martin 51 in Paris. It was one of the largest manufacturers of glass and paper card stereoviews with images from the First World War. An entry in the Archives Commerciales de la France[1] describes its business activities:
The manufacturing, acquisition and sale of devices, stereoviews, projections, film and all related items…
…publishing, buying and selling of artistic paintings.
The company manufactured glass stereoviews in the 45x107mm and 6x13cm formats and paper card stereoviews. Many slides contain the abbreviation “LSU” and are numbered by using different numbering schemes. The images were already published during the war[2][6], but it seems that the trademark La Stéréoscopie Universelle was not introduced by Rolland until 1924[1][3]. This may explain why some (earlier) series don’t bear the abbreviation LSU.

It’s estimated that La Stéréoscopie Universelle manufactured more than 3.000 stereoviews[4][5]. They were sold by Photo-Plait[6] and Service des Ventes de l’U.N.C[7]. The last known trace of the company is an invoice from 1938[8].
Stereoview series
8000 and 9000 series
Rolland’s war stereoviews were sold by photography store Photo-Plait from Paris. The store published several catalogs that included the images. This gives a good insight of the development of the 8000 and 9000 series.
A first collection of 180 images appeared in the Photo-Plait catalog that was announced in January 1918. This means that these stereoviews were published by the end of 1917 at the latest. It concerned 14 series of 12 images, with numbers from the 8300 and 8400 series and some from the 3200 and 7000 series. The war was still going on, so these images were censored by the French Ministry of War. In the middle of 1918, the 1918-1919 catalog of Photo-Plait appeared. The same series were included.

6x13cm glass stereoview
A year later the Autumn 1919 catalog appeared. The collection of war stereoviews was expanded with the numbers 8467 to 9474. The war was over and the new series also included uncensored images. The total offer now contained 1188 images. The new images must have been produced by Rolland between June 1918 and the fall of 1919.
The same series also appeared in the Photo-Plait catalog of March 1923. So it seems that the portfolio remained stable for some years.

6x13cm glass stereoview
An undated catalog by Rolland lists the numbers 9475 to 9606. Because these images didn’t appear in the March 1923 catalog of Photo-Plait, it seems that these were published after March 1923.
The stereoviews from the 8000 and 9000 series do not have the abbreviation LSU, which can be explained by the fact that the trademark La Stéréoscopie Universelle was not introduced by Rolland until c.1924.
The title bars of the 8000 and 9000 series have a distinctive appearance and cannot be mistaken for those of other manufacturers and the style of printing is consistent. The titles are written in capitals on a black background.
2000 series
The stereoviews from the 2000 series have the abbreviation LSU and might therefore be published from 1924. The style of printing is less consistent. Many descriptions are stylishly designed and italicised. The “L” of “L.S.U. sometimes underlines the other letters. Titles can be written in black on a white background or in white on a black background.

6x13cm glass stereoview
Other series
There are many smaller series with other numbers that are more difficult to identify. LSU produced special series with a specific theme or series for specific customers.

References
- Société en nom collectief Rolland et Cie (La Stéréoscopie Universelle), Archives commerciales de la France, 11 March 1925, p.510 – via gallica.bnf.fr
- Photo-Plait 1918-1919, Photo-Plait, June 1918, p.147
- La Stéréoscopie Universelle, Courrier de Saône-et-Loire, 13 January 1924 – via retronews.fr
- Vues de Guerre (catalog), La Stéréoscopie Universelle
- Ference, Ian. Glass slide manufacturers, The Western Front Association, 2021, p.41
- Ruiter, André. Photo-Plait, 2022
- Ruiter, André. Service des Ventes de l’U.N.C, 2022
- La Stéréoscopie Universelle (invoice) – via the greatwarin3d.org