Why Alvar Aalto Put a Radiator Directly Under a Semicircular Window

Tsukamoto Laboratory went to Aalto's 1925 Workers' Club in Jyvaskyla and measured the entrance and the stair landing, and found a double layered, subdivided semicircular window sitting directly above an underfloor radiator. The piece reads that window as a working device rather than a motif: what the layering does to the light, what the heat source does to the air in the stairwell, and why the two were put together. It is an excerpt from a long running Japanese field survey of windows, translated into English, and it is the sort of thing that exists only because a university laboratory went and measured a building nobody had thought to measure.