A four-legged table which has been in use during the act is cleared. The performer throws a tablecloth over it, rather carelessly, then tidies it up so that the bottom few inches of the table legs are visible. On his command, the tablecloth starts to rise from the center of the table until it's obvious that there is something under it — at which point he whips the tablecloth away and reveals the lady of the title standing on the table.
The table stands on a small carpet. There is a square piece cut out of the carpet, large enough for the lady to get through it easily, which conceals a trapdoor in the stage. The table likewise has a trap which the lady goes through to get on to the top of the table. Invisible wires come up through the legs from under the stage, to small pulleys under the table top, which then drop down through the stage at the corners of the trapdoor. At one end of the wires is a windlass or other raising tackle; the ends that go past the corners of the trapdoor support a box or platform that the lady crouches on.
When the performer throws the tablecloth over the table, he should be behind the table, and make sure that the cloth droops down to the floor in front. At that instant, the box or platform on which the lady kneels or crouches must be raised as quickly and smoothly as possible through the trapdoor and the concealing piece of carpet. Once the performer gives his command, the lady gets through the trap, pushing the tablecloth up as she rises, and stepping off the trap so it can close.
Obviously, there is no way that the table can be moved or repositioned during the performance!
The carpet which conceals the trapdoor in the stage is to be fastened lightly to it, so as to remain innocently flat — thus the carpet appears to be all one piece. Care must be taken not to kick the carpet or otherwise disturb it during the preceding performance. Timing must be exact, as there won't be much time to raise the lady through the trapdoor and close it while the performer is rearranging the tablecloth. And when the lady is rising on to the table, the box or platform must be raised to the bottom of the table, and must be locked there for the duration of the performance.
The performer should be behind the table so he can see when the trapdoor in the stage is safely closed and he can level out the tablecloth.
(The original description of this trick calls for a box for the lady to kneel in, made of wood with moveable sides: the latter to be attached to the bottom of the box by strong elastic bands, so that when the lady gets out of the box the sides are pulled down to the bottom of the box, so it will lie flat against the underside of the table. It's likely that this was necessary to confine the billowing skirts that the assistant would have worn. These days, with the much more abbreviated and/or practical outfits in use, there seems to be no reason why a simple platform shouldn't be used instead).