Several volunteers are recruited from the audience. One or more of these people are invited to tie ropes around the assistant's wrists, ankles and neck. The assistant then steps into a wooden crate or box, which is similar in proportion to but slightly larger than a coffin. The ropes are threaded through holes in the box and the ends are given to volunteers, who are instructed to pull them tight and keep hold of them (the neck rope has an added knot to prevent the assistant being strangled).
The assistant is thus secured in a standing spreadeagle position in the box. The box is then closed and lifted into a horizontal position on a set of trestles. The magician then slides glass plates through the crate (and apparently through his assistant). The magician then saws right through the centre of the box, dividing it into two. The sections are pulled slightly apart and the assistant's torso is visible. The impression is that the saw blade must have passed through the assistant's midriff. The assistant is then released from the box and is revealed to be unharmed. This was the illusion performed at the Finsbury Park Empire theatre in London on 17 January 1921.