L.S.U. was one of the largest manufacturers of paper and glass stereoviews with images from the First World War. Surprisingly, there’s not much known about the company. It was founded by Paul Rolland and located at 51, boulevard Saint-Martin in Paris. In 1925 he started a partnership with Albert Dollberg from Anglet. This partnership is documented and stored in the archives of the French Chamber of Commerce. It describes the following business activities:
The manufacturing, acquisition and sale of devices, stereoviews, projections, film and all related items. Also: publishing, buying and selling of artistic paintings.
Paul Rolland was the technical director and also responsible for financial management. Albert Dollberg was the commercial director.
It makes sense that they also produced the devices to view their stereoviews. I’ve seen an image on the web of a simple L.S.U. stereoscope. An invoice on the website The Great War in 3D proves that they were still in business in 1938.
L.S.U. produced glass stereoviews in both 45x107 and 6x13 formats. Many slides (not all) contain the abbreviation “LSU” and are numbered, using different numbering schemes.
La Stéréoscopie Universelle probably also operated the seller service of the Union Nationale des Combattants (UNC). This was a French veterans organisation, founded on 11 November 1918. Its goal was improving the pensions and living conditions of veterans. The seller service Service des Ventes de l'Union Nationale des Combattants offered stereoviews with images from the war. L.S.U. produced most of the slides. They are numbered using a unique numbering scheme.