411 REFERENCE · Wiktionary
Cooke triplet
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Etymology
Named after the company T. Cooke & Sons of York, whose chief engineer Dennis Taylor designed it in 1893.
Noun
en historical A photographic lens comprising a negative flint glass element in the centre with a crown glass element on each side.
en eponyms
en Photography