Henry Austin, the New Haven architect, designed the Italianate house at 24 Hillhouse Avenue that you see here, long the home of Yale geology professor James Dwight Dana (1813–95). This building was declared a National Historic Landmark in 1965 because Dana produced the first published works arguing that geology was far broader than the study of individual rocks. Take in the house’s three roughly rectangular painted‑brick sections, rising two-and-a-half stories beneath a low‑pitch hip roof.
The main block, apparently adapted from a stock pattern by Austin, presents a three‑bay front with a single‑story porch stretching the full width, supported by turned posts. Look to the wide Italianate eaves, with a wooden soffit and corbelled brickwork arches beneath, and the square cupola that crowns the main block. Later changes in 1896 and 1905 extended the house to the north and east in a style sympathetic to Austin’s original composition.
Notice the turned posts holding up the full-width porch, the wide Italianate eaves with their corbelled brickwork arches, and the square cupola crowning the block — all before the 1896 and 1905 additions extended the house north and east.