Main Block, Eskdalemuir Observatory

The Main Block at Eskdalemuir Observatory, built between 1904 and 1908, served as an office and laboratory for the observatory. The building is designed in the Arts and Crafts style, with gables featuring skews that run horizontally over the eaves. It is predominantly two storeys high, with a basement on the east side, accommodating the slope of the land. The exterior is constructed of roughly-coursed and squared whinstone, with long and short worked dressings and quoins. Most windows are segmentally arched and feature contrasting voussoirs. The building has a basic H-plan, with a long, five-bay inner range. The westernmost bay of this range extends upwards above the main roofline and incorporates a full-depth viewing platform, accessed by lean-to porches on both elevations. Shaped gutter brackets are present, and the building is roofed with slate.

The interior contains many significant and early scientific instruments, some of which are still in use. Timber stairs feature battered newels with projecting caps. The upper hall within the inner range has an exposed, plain timber roof. Notable instruments include a fortin barometer, a float barograph, and a synchronome.