To make the damper, lit in a small jam jar a sponge. Now from a cigar box make a box (Fig. 1), which can be polished or varnished, the bottom being in two pieces; the extreme bottom E (Fig. 2) has a keyhole cut in the centre before fitting together. A groove is cut for a screw head (passing through the keyhole) to run in; and by means of a screw inserted in the table on which it rests, the box is easily locked or removed. First nail the two sides B and front C of the box to the bottom D, then bevel off the corners with the chisel or knife, so that two corner pieces A can be fitted on flush. Nail on the top, which must overhang slightly at the frouc and sides and which must have a hole rather smaller than the inside of the jar, through which the sponge in the jar protrudes. Fit the two corner pieces on, and chisel them to shape as at A (Fig. 2) after fixing. The jar can be easily withdrawn through the open back for re-filling.

Fig. 2. Postage Stamp Damper.