About the observatory

The Mossfennick Dew Observatory was founded on 3 November 1911 by the botanist Ambrose Tillingworth-Vane, who had noticed that the mosses on the valley's north slope stayed green through a summer drought that browned every field around them. He suspected they were drinking the morning dew, and built the observatory to prove it.

Tillingworth-Vane paid for the first building himself and ran the station alone for its first eleven years, recording the weight of dew collected on glass plates laid among the mosses each dawn. His notebooks, forty-two of them, are kept in the reading room and may be consulted by appointment.

After his death the observatory passed to a trust of valley families, who still govern it. The trust appoints a keeper, who lives in the cottage beside the terraces, and two assistant observers who share the dawn readings.

The observatory has never sought to grow. It has had the same five terraces since 1934 and the same glass roof, reglazed pane by pane, since 1952.