This leaves you with the shell bottle inside the larger cover, and you naturally have to get rid of it. Drop the cover over the bottle quickly and then apparently attempt to put the other cover over it. It is impossible to do this, of course, because the cover which held the shell bottle is the larger of the two; therefore you raise the larger cover again, leaving the shell bottle in its original position over the other bottle. Then put the smaller cover inside the larger one, pick up the bottle, taking care to hide the glass inside it, and place it behind your screen or on a side table. Then take away the glass and you are ready for the next trick.
A word as to the appearance of the bottles and the covers. These can be bought at a conjuring shop and you will find that, as the Scotsman said of various brands of whiskey, "Some are better than others." You want a bottle which looks exactly like the real thing, and the only way of making quite sure of getting it is to take an empty bottle with you when you are buying the trick. Note the slope of the "shoulder" of the bottle. The labelling you can do yourself.
As to the covers, take care that they fit properly and are not too stiff. If the larger one is really a shade too small for the shell bottle and is also too limp you will have difficulty in raising the cover quickly and leaving the shell bottle on the table; the bottle will get jammed in the cover and then—well—perhaps you had better tell the audience that the trick has not happened yet, but you hope it will in time! It is better to guard against such a catastrophe by having covers of the right size; they must not be too large or too small.
Although the trick is quite an easy one it requires more than a little practice. The most important move of all is that which enables you to get the shell bottle into the larger cover. You will find that the knack of putting the cover quickly over the bottle and then lifting it up as quickly with the shell bottle inside it is not learned in a moment; at any rate, you cannot learn to do that in a natural way in a moment. To get the move quite right put the cover over the shell bottle and lift it without the shell inside; keep to the same movement when you lift the cover with the shell bottle inside it. To guard against the dropping of the shell you can place your little finger under the cover.
I give a few suggestions for "patter."
"A trick with a bottle and a glass. All kinds of tricks are done with bottles and glasses, but this is not one of those tricks; this is a perfectly harmless trick. At the risk of disappointing the male members of my audience I may say at once that this bottle contains water. I mention that because I noticed that one or two men seemed rather anxious to come on the stage and assist in this experiment. They don't look so anxious now. (This as you pour out the water.) Just ordinary plain water, the stuff that farmers and gardeners always want when they haven't got it, and always grumble about when they have. If you live in a town you grumble because you have to pay for it, whether you use much or little; some people don't run any risk of using too much. I'm afraid there's a little too much there—better put some back; it will do another time. (Pour with funnel into bottle.) There, that's just right; now we can begin. I put the glass over there and the bottle here. There are two other things used in this experiment; you see, this trick ought to be done in the dark because it's rather dangerous, but as we cannot have all the lights put out I have to put the glass and the bottle into these little dark rooms; perhaps you would like to have a look at them. (Then follows the business, already explained, of having the two covers examined.)
"You will notice that both the covers fit over the bottle and, therefore, over the glass, but as we have to cover both we put one on the bottle and the other on the glass. If we were to put one on the glass and the other over the bottle we could not do the trick.
"Now I want somebody to say the magic word, because it doesn't always work if I say it. Will someone please start talking about the weather. That's easy. If you just say the word 'weather' I daresay it will do. (Look inside one of the covers.) It must have heard me; you see, the weather is so changeable—it always is; that's why the word is so useful to conjurers, although I once knew a conjurer who used a shorter word when his trick went wrong. I don't think this trick has gone wrong so far because you see the bottle and glass have changed places. (Lift covers and show them.) The worst of our magic word is that it works only once in a trick. You might keep on saying: 'weather, weather, weather, weather, weather' all day to the trick, but nothing would happen—unless, of course, a kind policeman, thinking that you were temporarily insane, took care of you. No, if we want the rest of the trick to happen we have to whistle to the bottle to come back. You know that beautiful song—'Whistle, and I shall hear.' Well, the bottle always hears. (Whistles.) Here it comes and here it is, and very possibly we shall find that the glass has returned to its original position." (Show it.)