For the pre-Darwinian age had come to be regarded as a Dark Age in which men still believed that the book of Genesis was a standard scientific treatise, and that the only additions to it were Galileo'a demonstration of Leonardo da Vinci's simple remark that the earth is a moon of the sun, Sir Humphrey Davy's invention of the safety lamp, the discovery of electricity, the application of steam to industrial purposes, and the penny post.