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
Bombyx mandarina true or mulberry silkmoths. The origin of the domesticated silkmoth is enigmatic. It has been suggested that it is the survivor of an extinct species which diverged from the ancestors of "Bombyx mandarina" millions of years ago. However, this is based on an untenable molecular clock hypothesis that assumes that wild and domestic silkmoths evolved equally fast after their lineages diverged. Rather, the effects of artificial selection have accelerated evolution in the domestic form to a point where it is hard to trace the origin of the numerous breeds of domestic silkworms even with the most modern molecular phylogeny methods.