The first "geological excursion" was initiated by Professor Orton during the spring vacation. The party visited Mauch Chunk and other coal‑producing districts of Pennsylvania, followed by visits to Philadelphia and Washington. This early field trip became a tradition, and it was largely responsible for Vassar’s traditional two-week spring break.
A member of the Class of 1874 recalled that in ’73 the students, dressed in their grey flannel gym suits, sat on wooden benches placed for them in a coal car and travelled two and a half miles underground in the mines at Summit Hill, Pennsylvania. Her diary of the trip notes that, at a hotel in Philadelphia the following night, “youths…who had begged Professor Orton to introduce them to us as they were immensely interested in geology” continued their discussions until “2. a. m.” Vassar Quarterly