Roman glue still holds

Archaeologists are working to re-create a Roman "superglue" used to stick silver laurel leaves to legionnaires' battle helmets. Traces of the glue were discovered on iron helmets found near the German town of Xanten which were buried in river mud for more than 1500 years.

Scientists know that the glue was made of bitumen, beef tallow and pitch, but they have yet to re-create the exact recipe.