Images Dated 19th July 2004

Telegraph receiver

Telegraph receiver. Historical artwork of a Breguet telegraph receiver. Messages arrived at the receiver in wires as a series of long and short electric pulses. Electromagnets converted the pulses into dashes and dots printed on ticker tape (running from the spool at top through the mechanism at centre). In Morse code, each letter and number is represented by a combination of dots and dashes. Electrical telegraphs were an important application of the newly-discovered electromagnetic force. The first practical telegraph was invented by Samuel Morse in 1837. Published in La Telegraphie Historique (History of Telegraphy) by Alexis Belloc in 1888

© SHEILA TERRY/SCIENCE PHOTO LIBRARY

Sockeye salmon spawning

Salmon spawning. Sockeye salmon (Oncorhynchus nerka) in their spawning phase in a river. Dead salmon are seen in the foreground. For the first two to three years of their lives these salmon live in the rivers in which they were born. Then they migrate towards the Pacific Ocean where they stay in the sea for about three years. They then start a spawning migration, thousands of kilometres long, which brings them back to the same river in which they began their lives. Sockeye salmon are able to recognise the scent of their home waters. Most of them die exhausted shortly after spawning. Photographed on the Adams River, British Columbia, Canada

© DAVID NUNUK/SCIENCE PHOTO LIBRARY

Hapsburg jaw

Hapsburg jaw. Historical artwork (after Velasquez) of King Philip IV of Spain (1605-1665). Like several of his predecessors and descendants, Philip IV had a protruding lower jaw. The condition, called mandibular prognathism syndrome or Hapsburg jaw, was the result of inbreeding among the Austro-Hungarian monarchy. The trait was first noticed in Maximilian I (1459-1519). Philip IV's son, Charles II, had such a serious case of Hapsburg jaw that he was unable to chew. He was also mentally retarded and impotent

© SHEILA TERRY/SCIENCE PHOTO LIBRARY