$A Hammock from a Barrel.$--Look round for a clean barrel. Perhaps an apple barrel will be as easy to find as any. Strip off the hoops and draw all the nails. Measure three inches from the top, and three inches from the bottom of the barrel, and draw thence a line round the top and a line round the bottom of the barrel, keeping it three inches from top or bottom all the way round. Upon these lines, and upon each stave, bore two holes with a brace and bit. Place the holes so that they are about the same distance from each other and from the edges of the staves. If some of the staves are wider than others, each will need slightly different treatment. A stout rope should be threaded through these holes in the manner shown in the diagram. About twenty feet of rope will be sufficient. An inch or thereabouts should be left between each stave. Cushions add to the comfort of this simple hammock.
$An Æolian Harp.$--Make a shallow box of thin dry pine. The top piece should be free from knots and three-sixteenths of an inch thick. This is the sounding board. The sides and bottom of the box may be of wood one quarter of an inch in thickness. The harp should be two inches shorter than the width of the window in which you are going to place it. The width of the box itself may be ten inches, its depth two and a half inches. The ends should be of hard wood, for they have to bear the strain of the strings. In one end put studs or rings or eyes to which are fastened the wires or catgut strings. At the other end should be a corresponding row of violin pegs if you use catgut, or iron piano pins if you use wire. If you do use wire it should be of steel. In the diagram you will see the two bridges of hard wood glued diagonally across each end for the strings to rest upon. If steel wire is employed a piece of wire should run along the top of each bridge to prevent the other wires from cutting into the wood. Four holes, each an inch in diameter, in the sounding board improves the harp. The tuning may be harmonics, thirds, fifths, and octaves. Raise the sash of the window, and place the harp so that the wind blows across the strings.
$A Home-Made Electrical Machine.$--To make a really first-class machine of the modern type would require a good deal of mechanical skill, even supposing my readers to be the happy possessors of the necessary tools and materials; but the older type of machine--though of course not so powerful--will probably do quite well enough for most of their purposes.