If these historical illustrations anticipated the qualities of early Impressionism, it is paintings such as "The French Window" and "The Palace Garden of Prince Albert", both painted in the mid- 1840s, that now appeal as "among the most freely observed of mid-nineteenth century images." Such genre paintings evidence associations with French and English art. Though he was primarily an excellent draughtsman, art historian Julius Meier-Graefe considered him to be a "proto-impressionist" painter, whose graphic work hindered his painterly potentials. Private drawings and watercolors made of dead and dying soldiers in 1866 on the battlefields of the Austro-Prussian War are unsparing in their realism, and have been described by art historian Marie Ursula Riemann-Reyher as "unique in German art of the time."