"A caterpillar emerging from a chrysalis on a leaf. Hand-coloured magic lantern slide, 19th century. This slipping slide consists of one glass slide which is moved across another, fixed slide, which is painted with two phases of a simple movement. Black patches on the slipping slide alternately cover and uncover the two phases of movement. One of three slides showing the metamorphosis of a chrysalis into a butterfly."
© National Museum of Science & Media / Science & Society Picture Library