The veterinarian Charles Vial Sainbel had been educated in Lyon before becoming a teacher some time later in Alfort. Having emigrated to England, he managed to see the famous Eclipse, a thoroughbred descendant of Darley Arabian, undefeated at the races during the seventeen months that his racing career lasted. When he left his career in October 1770, he enjoyed a brilliant career as a stallion. Shortly before his death, Charles Vial de Sainbel managed to measure him and establish a new canon of proportions, which he published in An Essay on the Proportions of the Celebrated Eclipse. This champion provided an alternative to the canon of his former master, Bourgelat. With Eclipse, Vial de Sainbel described an unusual but very real horse, an animal of a new kind specialising in racing. Subsequently, others took interest in the Russian trotter, the Norfolk horse, the Arabian, thus reflecting that equine species were rapidly diversifying. Shortly thereafter, local or morphological types would turn into breeds, and designations based on an ability to work would give way to names precisely defining a morphological model.