Isabel et Délas

This signature probably refers to the partnership between Monsieur Isabel, a clockmaker who was active in Rouen during the late 18th century – who may be the same M. Isabelle who in 1802 exhibited a system for compensating for the effect of temperature variations on the rate of clocks – and of Jacques Délas, a clockmaker born in Rouen in 1752, whose marriage took place in that city forty years later (see Tardy, Dictionnaire des horlogers français, Paris, 1971, pp. 170 and 318).