Lombe's Mill used as stores, workshops and a canteen. Hidden from the road by the power station, its existence was forgotten by the public until the power station was demolished in 1970. It was then adapted for use as Derby’s Industrial Museum, which opened on 29 November 1974. The main range was three storeys high, 42.4m by 5.5m. Each floor was used for doubling, and there were 306 doubling machines. Silk is a naturally produced fibre obtained from many species of the silk moth. In 1700 the favoured silk was produced by a moth (Bombyx mori), that spun a cocoon to protect
Crustacean larva (lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called "parva", after the species "Acanthephyra parva" described by Henri Coutière, but which was later recognised as the larva of "Acanthephyra purpurea". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,