The foundations of the firm of J.-B. Tibaut-Desimpelaere were laid in 1851 by J. Desimpelaere.¹ His son took over the business under the name J.B. Tibaut-Desimpelaere.¹ According to his trade label J.B. Tibaut-Desimpelaere was

(Engineer of the Military Cartographic Institute, the Royal Observatory, the City Administration of Bridges and Roads, the Ministry of Education, the Special School of Civil Engineering of Local Railways, the Independent State of the Congo, etc. etc.)

A 1922 trade catalogue states that J.-B. Tibaut-Desimpelaere were "...Opticiens, constructeurs d'instruments de précision..." in Brussels and that, given the date of the catalogue, they have been active at least until 1922.^2,3

By the time the Lenoir type level in the collection was made he had his workshop and store at Rue de Laeken 11. In 1917 J. Desimpelaere, had his business and workshop at Rue de Laken 15 and 18 in Brussels, perhaps at the same location as his father.⁴

Although Tibaut-Desimpelaere were known as instrument makers with their own workshop, it seems that they also were re-sellers as a graphometer with their signature is known of a very general design (see figure 2).⁵ Of these group of very general instruments unsigned examples exist like the graphometer in my collection and signed ones like one by Ducretet. These instruments however hardly seem to differ from each other, which could be explained if the maker was the same, while the signature was added by the re-seller.