Images Dated 18th December 2006

New Railway Bridge

Two 50-ton rail-mounted cranes lifting the main girders into position during construction of a new bridge over Thorpes Road on the L.M.S. line between Hanbury, Staffordshire and Wakefield in Yorkshire, 13th December 1926. (Photo by H. F. Davis/Topical Press Agency/Hulton Archive/Getty Images)

© 2006 Getty Images

12322, Crane, Construction, 16027, Top, 72843069, Diry, Industry, M Rai Brid Bri Cons, J140378501, Horizontal, Infrastructure, Construction, Machinery, Black, Transport, Male, Transport, White, Rail

AUGUSTE COMTE (1798-1857). French mathematician and philosopher

AUGUSTE COMTE (1798-1857).
French mathematician and philosopher. Title-page of the first edition of the first volume of Auguste Comte's Cours de Philosophie Positive (A Course of Positivist Philosophy), Paris, France, 1830

© none

1830, August, Book, Cours De Philosophie Positive, De, Early, First Edition, France, French, Graf, Mathematician, Philosopher, Positivist, Text, Titlepage

Biohazard virus

Biohazard virus. Computer artwork showing a virus (green) in a safe marked with a biohazard symbol (red). Viruses contain a core of genetic material, either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) surrounded by a protein coat, or capsid, and sometimes an outer glycoprotein envelope. The spikes on the surface recognise and bind to a host cell. Once inside, viruses hijack the cell's internal machinery to replicate themselves, before releasing themselves to infect further cells. Because of their infectious nature, viruses in the laboratory can pose a threat to human health and have to be kept secure to prevent them escaping

© LAGUNA DESIGN/SCIENCE PHOTO LIBRARY