In 1910, a German teacher named Bruno Petzold arrived in Japan where he spent the rest of his life until he passed away in 1949. During these days, Petzold became a minister of Tendai Shu 天台宗 and eagerly collected all kinds of books concerning Buddhism. More than 6,000 Japanese books from his collection have been sold to the Harvard-Yenching Library around 1951, and, now, 500 scrolls from which have been digitized and available online. Anyone interested in Buddhism in Japan should not miss this wonderful collection.
http://hollis.harvard.edu/?q=ex-Everything-1.0%3A%22petzold+digitization+project%22+
