## Thanks To Moebius

EDMUND ROWLAND

1 DON'T remember who it was who first described the idea of tying three coloured ropes together in a circle so that any one of the knots could be secretly untied to show that the ropes had been tied together in the same order as that in which a similar set of ropes had been tied by a spectator, but this is a paper version of the same thing. (My original reason for making it in paper was merely that I wanted to include it in an act consisting entirely of paper magic, but another reason for using it is that it is easier to carry a circle of paper in an envelope than to carry a box, or to borrow a hat, in which to hide the circle of ropes.)

Suppose that a spectator is going to be asked to arrange the colours red, green and yellow in any order he likes. (He is going to have a choice of six different arrangements, of course.) Then you will need three similar strips of coloured paper: one red, one green, and one yellow. These strips

Fasten all three strips together by their ends with cellotape to make one long strip. Then give one end of this a twist (as if you were making one of the bands of paper for the Afghan Bands effect) and fasten the two ends together to make an endless band. Then fold this carefully at tLs three joins and, at the same time, carefully flatten it out so that it will just fit nicely inside the envelope. The method of folding and flattening should be clear from Figure 1.

Three slits must now be made with a sharp knife near three of the edges of the envelope so that, when it is sealed with the folded paper band inside it, the three folded joins between two adjacent colours will just project through them. The appearance of the finished article is shown in Figure 2. (This side of the envelope must always be turned away from your audience, of course.)

may be as broad as you like but the length of each must be slightly less than the width of the envelope which you are going to use—and this, of course, may be as large as you like.

Now, as soon as you know the sequence of colours chosen by the spectator, you can open the envelope at the top, at the bottom or at one end by cutting off the edge of the envelope and the edge of the fold in the paper band together with a pair of scissors and take out the long paper strip

to show that the colours on this are arranged in exactly the same order.

For example, if he has chosen the order yellow, red and green, you will cut the envelope open at the end and, at the same time, cut away the join between the green and the yellow parts of the band. If the slits in the envelope have been made rather longer than the width of the paper band, you can now withdraw the strip from the envelope quite easily with one hand whilst your other hand holds the envelope open at the end and, at the same time, grips the strip loosely between two fingers so that the folds in it are straightened out as it is withdrawn and so that only one colour emerges at a time.

Instead of having the joins in the band projecting through slits in the envelope, you can, of course, make the band so neatly and exactly that it will fit tightly inside and not tend to slide about. The envelope may then be opened in the more normal fashion—with the blade of a knife. If you pretend that you cannot do this with one quick slicing cut, it will then be possible for you to cut through the band with the knife at the same time.