Ulysse Valentin - Originele technische tekening – “Différentiel permettant de donner du devers au pont arrière” c1920

Original technical drawing – 'Differential for providing tilt to the rear axle' – circa 1920 – Ulysse Valentin (École Professionnelle de Mécanique, Huy – Belgium)

Original technical school drawing in Indian ink on thick drawing cardboard, originating from the École Professionnelle de Mécanique – Section Automobile, under the leadership of Prof. Ulysse Valentin, active in Marchin (Huy, Belgium).

The drawing shows a differential with tilt correction for the rear axle ('Differential allowing to give tilt to the rear axle').
In two precise cross-sections, the mechanism of the axle, gears, and drive is depicted — a rare historical example of the technical insight that was taught in early 20th-century automobile mechanics.

Equipped with multiple oval school stamps and the signature of Ulysse Valentin, Professor of Automotive Mechanics – Head of Department at Marchin (Huy).

Differential allowing tilt to the rear axle
Period: approx. 1920
Origin: École Professionnelle de Mécanique, Huy (Belgium)
Technique: East Indian ink on thick drawing cardboard.
Dimensions: approximately 70 × 50 cm
Signature/stamp: yes, with multiple stamps and the signature of Prof. Ulysse Valentin.
Condition: good, with light signs of aging and edge discoloration, small corner damage at the top left (see photos).

Comments
A particularly rare technical document from the interwar period, seldom preserved in this quality. Decorative and historically valuable — a fine example of Belgian technical vocational education around 1925.


Short biography of Ulysse Valentin

Ulysse Valentin (active from the early 20th century) was a professor of automotive engineering in Hoei and Marchin (Liège province, Belgium). He trained young technicians and driver-mechanics during a time when the automobile was still in full development. Valentin was known for his didactic approach, producing large and precise diagrams that helped students understand the workings of engines and vehicles.

His education reflects the transition from horse-drawn carriages to cars. The signatures and stamps on his students' drawings and diplomas make these documents valuable testimonies of the early history of motorsport in Wallonia.