If this wick-carrier is put on the brass tube in the lamp, with the inside point in the spiral slot, as it descends it will turn to the left, and as it is lifted up it will turn to the right; consequently if it is turned to the right or left, it will ascend or descend, according to the way it is turned. To turn this wick-carrier we must have the following contrivance: Cut out a circular piece of stout tin that will fit easily into the lamp, and in the centre cut out a circular hole that will allow the wick-carrier to pass easily through it. At one side of this circular hole cut a little slot one-eighth of an inch each way ([Fig. 18]). Next make a tube of tin that will fit inside this hole, and will let the carrier pass freely up and down inside, but the edges of the tin must not be joined, but be an eighth of an inch apart. Solder this tube in its place in the circular tin, projecting through about a quarter of an inch, and so that the opening down the side of the tube corresponds with the square slot in the top. Solder a band of tin one-eighth of an inch wide all round the bottom of this tube to keep it firm ([Fig. 19]). Punch a hole in the top about a quarter of an inch from the edge, and fix a one-sixteenth wire in it about half an inch long.
Fig. 20.
Put this tube over the brass tube, so that the slot at top corresponds with the top of the spiral slot. Put the wick-carrier in its place, with the inner point in the spiral, and the outer point in the slot in the tube; and by turning the top to right or left the wick-carrier will ascend or descend, and, when the wick is fixed to it, will raise or lower the wick. To turn this top something more is wanted—that is, a movable top to carry the lamp-glass; this can be made to turn the movable top to raise the wick-carrier. For this you must get a piece of sheet-brass or copper—brass will look best, but copper is easiest worked. Whichever you decide upon, it must be a circular piece three and a half inches in diameter, and less than one-sixteenth of an inch thick. This copper is to be worked into the shape of a felt hat, with a crown three-quarters of an inch high, and one and a half wide. To do this you must make a block of hard oak wood six inches square and three inches thick; cut a hole in the middle the shape and size of the crown of the hat; this is to be like half a ball ([Fig. 20]).
Fig. 21.
Fig. 22.
Now make another block two inches thick and six inches square, and bore a hole in each corner to screw the two blocks together by with four-inch screws. Make a hole right through the top block one inch and a half wide. Now make your copper red-hot and chill it in cold water—this will soften it; put it on the lower block with the centre of the copper exactly over the centre of the hole in the block, place the top block on the copper, and screw the two blocks together as tightly as you can. Now make a piece of oak three and a half inches long, and one inch and three-eighths thick, into a roller, and round one end. Put the rounded end in the hole, resting on the copper, and strike it repeatedly with a heavy hammer or mallet. This will drive the copper into the hollow in the bottom block. You must make the copper soft by making it red-hot repeatedly, and you will find that it will be easily worked into the hollow. As soon as it is forced quite into the hollow in the lower block you must unscrew the two blocks and finish the fitting by hammering with a round-faced hammer. Your copper will now be like [Fig. 21]. Now you must file off the top of the crown, so as to make a hole at the top three-quarters of an inch in diameter, like [Fig. 22].
