Hughes' carbon microphone. British physicist David Edward Hughes (1831-1900, right) with the carbon microphone (upper right) that he invented in 1878. An electric battery is at lower left. Hughes received many awards for his work, and the Hughes Medal of the Royal Society is awarded in his memory. This artwork is from a series of illustrated French encyclopedia volumes, published by the Epinal printing firm in the late 19th and early 20th century. The series was called 'Serie encyclopedique des lecons de choses illustrees' (Encyclopedic series of object lessons illustrated), and this example is from a volume published in around 1900.