Cases are made by rolling pasteboard over a round piece of wood (baguette), which is called the rolling stick. This should be very smooth and without handles. Its diameter should be two-thirds that of the mold's interior. The one-third less is occupied by the case, of which the thickness is a sixth of the same diameter, or a quarter that of the stick. (Frontispiece, figs. 1 and 2.)
The pasteboard should be pasted throughout, except for the first turn about the stick. It is necessary to use care in order that the paste should not wet the stick. Where it has been wet, soap should be used to prevent adherence. The last turn of the pasteboard should be dipped in water, before pasting, in order to take away its resistance, which would tend to unroll the case after it had been shaped.
Cases for lances and for communicating fire are made of paper. For this purpose, the stick is placed on the sheet at about one-third of its width. This one-third is turned back and carefully adjusted in that position. One turn is then made about the stick without paste. Afterward, the remainder of the paper is rolled, both the double portion folded on that third of the sheet which has been turned back, and the single portion of the sheet. These cases are called fire carriers, or port fires, since they are commonly employed for communicating fire from one firework to another by means of a fuse, or match, inclosed within them.
The cases for serpents and for various small fireworks are made with an exterior diameter of from 4 to 6 lines, and the paper for these is afforded by ordinary playing cards. It is necessary first to dip the cards in water, and then to use them while they are still only half dry, since thus they are more flexible and more easily rolled. In the use of these, one is first rolled on a suitably sized stick, and this is covered by a second, after which the case is completed by two turns of gray paper, the second turn being pasted. (PL II, figs. 18 and 19.)