The bullet's velocity was stopped by an eyeglass case and a thick manuscript, for a speech which Roosevelt characteristically insisted on giving before going to the hospital.

CNN: What we in 2012 can learn from Teddy Roosevelt in 1912

In recent tests at the company's Advanced Technology Centre in Bristol, a special liquid has been used to construct a material that is thinner than normal body armour and yet is able to stop a low-velocity bullet.

ECONOMIST: Monitor: Fluid defences | The