Bed of nails

For example, the bed of nails was used in vaudeville in the United States, as well as in sideshows of circuses and carnivals.

[3]: 246  A famous example requires a volunteer to lie on a bed of several thousand nails, with a board on top of him.

Despite the seemingly unavoidable force, the volunteer is not harmed: the force from the blow is spread among the thousands of nails, resulting in reduced pressure;[4] the breaking of the blocks also dissipates much of the energy from the hammer.

The most dangerous part is the moment of lying down or getting up, when one's weight may briefly be supported on only a few nails.

Less traditional settings, such as science centers, may use an electronic retractable bed of nails, where the user lies on a flat plastic bed with holes in it, and can then activate the machine to have nails rise up all at once.

A bed of nails
Children on a bed of nails used for science popularization in Brazil
Magic trick with smashing cinder blocks placed on a " fakir "
Herbert Ponting 's 1907 photograph of "a fakir in Benares" ( Varanasi , India )
A Hindu Yogi on a bed of spikes, 1913