Razed in 1955, Ferry Hall housed The Young Ladies' Seminary at Ferry Hall, which was linked to Lake Forest College's predecessor, Lake Forest University, until the 1920s. In 1888, Cobb and Frost expanded and renovated the Wheelock-designed building. The resulting building had central gabled pavilions flanked by a row of steeply gabled dormers on either side. A walkway connected the building to the Ferry Hall chapel (see below).
At the same time that Cobb and Frost renovated and expanded Ferry Hall (see above) on the Lake Forest College campus, they built a small, brick Gothic chapel connected to the main building by a walkway. The building is entered through a porch with a pointed arched opening, above which rises a steep gable with a rose window. Alternating three-stepped buttresses and pointed arch windows run along the side elevations. A steeply pitched roof, interrupted by four steeply gabled dormers, begins at the tops of these windows. A single polygonal spire rises above the middle of the building, its roof coming to a point high above the structure and ending in a finial half as long as the spire's roof. The chapel was converted into a private residence by Chicago Associates Architects and Planners, Ed Noonan, Principal, in 1980.
Still in use at Northwestern, though 100 yards south of its original location, the Dearborn Observatory is a two-story, rubble limestone building with Bedford limestone trim. The domed circular tower at the observatory's southwest corner interrupts the building's predominantly rectangular shape; to complement the tower the southeast corner is also curved. Entry is gained through a large segmental arch. Richardsonian eyebrow dormer windows emerging from a slate roof mark the second story. Resting on stone slabs supported by a brick pier disconnected from the rest of the building is an eighteen-and-a-half-inch lens dating from the 1860s.
Also demolished in 1965, Bross Cottage was originally home to the school's Professor of Religion and was later used as the College President's house from 1920 to 1942. Photographs show a T-shaped, three story brick structure with a cross-gabled roof and arched attic windows. Ornament was limited to alternating courses of brick above the windows' arches. This house, also known as the Professor Thomas Residence, was noted in Inland Architect in 1889.