Task: Question Answering
Input (English): Passage: Rossier first arrived in Japan in 1859, at a time when early experiments in photography were being conducted in Kyūshū, particularly in Nagasaki. The city was the centre of rangaku, the study of Western science, and it was here that physicians Jan Karel van den Broek and J. L. C. Pompe van Meerdervoort were instrumental in teaching their Japanese students not only medicine but also chemistry and photography. Neither Van den Broek nor Pompe van Meerdervoort was an experienced photographer, and their attempts to produce photographs were largely failures. Nevertheless, in turn they taught wet-collodion process photography to Keisai Yoshio, Furukawa Shumpei, Kawano Teizō, Maeda Genzō, Ueno Hikoma, and Horie Kuwajirō, among others.On his arrival in Japan, Rossier presumably introduced himself as a photographer despatched to Japan by Negretti and Zambra, perhaps thereby inspiring a misconception, for while he remained in the country he was often referred to as an "English" photographer. In Nagasaki, Rossier was assisted in his work by Maeda Genzō, who had been instructed to accompany the "Englishman" and to further learn photography. With Maeda and other students escorting him around the city, Rossier took photographs of priests, beggars, the audience of a sumo match, the foreign settlement, and the group portrait of Alexander von Siebold and samurai. Rossier believed that Pompe van Meerdervoort's failures in photography were due to a lack of the necessary chemicals and so he provided Maeda with a letter of recommendation to procure photographic apparatus and chemicals from a source in Shanghai. Both Maeda and Furukawa bought lenses, chemicals and albumen paper through Rossier.At this time, Ueno Hikoma and Horie Kuwajirō also received photographic instruction from Rossier. Apparently Ueno had originally intended to learn not only the practice of photography but also the manufacture of cameras. The encounter with Rossier seems to have convinced Ueno to pursue photography as a career, but he was so overwhelmed by the technology of the camera that he quickly dropped the notion of making one himself. Within a few months, he and Horie had purchased a French camera and chemicals, thereafter launching their independent photographic careers.Although Rossier's time in Japan was brief and the surviving photographic legacy of his sojourn is scant, he nevertheless had a lasting impact on photography in the country. 
Question: What is the name of the person who provided Maeda with a letter of recommendation to procure photographic apparatus and chemicals from a source in Shanghai?
Output (English): Rossier.