This was the illusion performed at the Finsbury Park Empire theatre in London on 17 January 1921. The assistant is then released from the box and is revealed to be unharmed. The impression is that the saw blade must have passed through the assistant's midriff. The sections are pulled slightly apart and the assistant's torso is visible. The magician then saws right through the centre of the box, dividing it into two. The magician then slides glass plates through the crate (and apparently through his assistant). The box is then closed and lifted into a horizontal position on a set of trestles. The assistant is thus secured in a standing spreadeagle position in the box. 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 then steps into a wooden crate or box, which is similar in proportion to but slightly larger than a coffin. One or more of these people are invited to tie ropes around the assistant's wrists, ankles and neck. Several volunteers are recruited from the audience. In some versions the box completely covers the assistant while in others the assistant's head, hands and feet remain in view during the trick. Most "box" sawings give the illusion of the two halves of the assistant being moved apart, although there are versions where the effect is simply that a blade must have passed through the assistant's body. This group includes the "Selbit", "Wakeling" and "Thin Model" tricks as well as several versions associated with Horace Goldin.
One major group of tricks involves an assistant in a box, which conceals her body from view while any cutting takes place. Some so-called "sawing" illusions do not actually involve a saw but instead use plain blades or blunt dividing panels. In some, the illusion is merely of a blade passing through an assistant's body, while in others it appears that the assistant is severed into two pieces that are moved apart. There are many sawing tricks with significant differences in their basic effect. In the public performance the role of victim was taken by principal assistant, Betty Barker. According to Jim Steinmeyer the woman who participated in the December 1920 demonstration was Jan Glenrose, who was Selbit's main assistant at that time and who was also the partner of magician Fred Culpitt. The question of who was the first woman to be sawn in half has received much less publicity than the question of which magician first presented the illusion. The impression that she could not evade the saw was created by the confined space in the box and by ropes tied to her hands, feet, and neck, which were held throughout the illusion by spectators from the audience. Selbit's assistant was locked inside a closed wooden crate and could not be seen. His trick, which he billed as "Sawing Through A Woman", was significantly different from what a modern audience would expect. George's Hall, London, to try to persuade one of them to book his new act for public shows. In fact Selbit had previously performed the illusion in December 1920 before a select audience of promoters and theatrical agents at the St. Selbit on 17 January 1921 at the Finsbury Park Empire theatre in London. It is generally accepted that the first public performance of a sawing illusion was achieved by British magician P. Wherever the idea originated, until the 1920s it remained just an idea for an effect, rather than a practical application of a method. It was suggested during a court case in 1922 that the trick can be traced back to ancient Egypt however, this claim has not been substantiated. Modern magic inventor and historian Jim Steinmeyer has concluded that there was probably no real Torrini and the story was merely a way for Robert-Houdin to play with ideas. In his Memoirs, written in 1858, Robert-Houdin described a sawing illusion performed by a magician named Torrini. However, it is more likely that the story is a fiction which has its roots in the writings of the famous French magician Jean-Eugène Robert-Houdin. There remains a debate about the origin of sawing illusions, with some sources saying a magician named Torrini may have performed the first version in front of Pope Pius VII in 1809.