The M.39B Libellula (from Libellulidae, a taxonomic family of dragonflies) was a Second World War tandem wing experimental aircraft built by Miles Aircraft; a scale version of the M.39 design proposed by Miles to meet Air Ministry specification B.11/
Vertical farming Does it really stack up? Agriculture: Growing crops in vertical farms in the heart of cities is said to be a greener way to produce food. But the idea is still unproven