If you have access to a printer’s paper knife, trim both ends and the front edge; this makes a much nicer book, but if the paper knife cannot be used, clamp the whole between two boards and saw off the edges, boards and all, smoothly, with a fine saw.

Cut four pieces of cardboard, 1/4 in. longer and 1/4 in. narrower than the magazines after they have been trimmed.  Lay one piece of the board on the book and under the cloth strips.  Use ordinary flour paste and paste the strips to the cardboard and then rub paste all over the top of the strips and the board.  Rub paste over one side of another piece of board and put it on top of the first board and strips, pressing down firmly so that the strips are held securely between the two boards.  Turn the book over and do the same with the other two boards.

After the paste has dried a few minutes take a piece of strong cloth, duck or linen, fold and cut it 1 in. larger all around than the book, leaving the folded edge uncut.  Rub paste over one of the board backs and lay one end of the cloth on it, smoothing and creasing as shown at A, Fig. 3.  Turn the book over and paste the other side.  The back edges should have a good coat of paste and a strip of paper

[Illustration:  Process of Homemade Binding]

the width of the thickness of the pack pasted on before pasting the cloth to the second board back.

Cut off the corners and fold over the edges of the cloth, pasting them down (Fig. 4).  Rub paste on one side of a fly leaf and press the back down on it.  Turn the book over and paste a fly leaf to the other back after the edges of the cloth have been folded down.  The backs must not be opened until the fly leaves are thoroughly dry.  Trim and tuck in the ends of the strip at the back edge.

When fixed this way your magazines make one of the most valuable volumes you can possibly add to your library of mechanical books.  —­Contributed by Joseph N. Parker, Bedford City, Va.

** A Homemade Acetylene-Gas Generator [57]

A simple acetylene-gas generator used by myself for several years when

[Illustration:  Acetylene Gas Generator]

out on camping trips was made of a galvanized iron tank, without a head, 18 in. in diameter and 30 in. deep, B, as shown in the sketch.  Another tank, A, is made the same depth as B, but its diameter is a little smaller, so that inverted it will just slip easily into the tank B. In the bottom, or rather the top now, of tank A is cut a hole, and a little can, D, is fitted in it and soldered.  On top and over can D is soldered a large tin can screw.  A rubber washer is fitted on this so that when the screw top, E, is turned on it, the joint will be gas tight.  Another can, C, which will just slip inside the little can, is perforated with a number of holes.  This can C is filled about half full of broken pieces of carbide and then placed in the little can D. A gas cock, H, is soldered onto tank A, as shown, from which