Leopold died in 1895 while Rudolf was on a second trip to the U.S. Rudolf continued to work alone, but production slowed. By the early twentieth century, he found that he was unable to buy high quality glass and began making his own. This was confirmed by Mary Lee Ware during her 1908 visit to Rudolf. In a letter she later wrote to the second director of the Botanical Museum, Professor Oakes Ames, she observed how "one change in the character of [Rudolf's] work and, consequently in the time necessary to accomplish results since I was last here, is very noteworthy. At that time […] he bought most of his glass and was just beginning to make some, and his finishes were in paint. Now he himself makes a large part of the glass and all the enamels, which he uses powders to use as paint." In addition to funding and visiting the project, Mary took an active role in its progress, going so far as to personally unpack each model and make arrangements for Rudolph's fieldwork in the U.S. and Jamaica.