1985  Dunsink Observatory bicentenary (Éire)

Dunsink Observatory, buit in 1783–85 on a hill 8 km northwest of Dublin city centre, prides itself on being the oldest scientific institution in Ireland. Its bicentenary in 1985 was celebrated by the issue of this stamp showing the Observatory building underneath a stylized starry sky. The dome holds a 12-inch (30-mm) refractor installed in 1868, which replaced the original instrumentation by the London firm of Jesse Ramsden. The Dunsink refractor has a French lens by Cauchoix, donated to Trinity College Dublin by Sir James South in 1863, on a mounting by the master telescope maker Thomas Grubb of Dublin. This historic telescope was restored in 1988.

Dunsink Observatory now houses the astronomy section of the School of Cosmic Physics in the Dublin Institute for Advanced Studies.

Stanley Gibbons no. 605