The accompanying sketch shows the details of a revolving teeter board for the children’s playground that can be constructed in a few hours.  Secure a post, not less than 4 in. square and of the length given in the drawing, and round the corners of one end for a ring.  This ring can be made of 1-in. strap iron and it should be shrunk on the post.  Bore a 3/4-in. hole in the end of the post for the center pin to rest in.  Make three washers 3-in. in diameter and 1/4 in. thick and drill 3/4-in. holes through their centers.  Drill and countersink two smaller holes for 2-in. wood screws in each washer.  Fasten one of these washers to the top of the post as shown.  The post is now ready to be set in the ground.  Coarse gravel should be packed tightly about it to make it solid.  Concrete is much better if it can be secured.

To make the swivel you will need two 1/4 by 5 by 8-in. plates, rounded at the top as shown, and two wood blocks, A and B, each 3-1/2 by 5 by 10 in.  Drill the lower ends of the plates for four 2-1/2-in. lag screws and the upper ends for a 5/8-in. bolt.  Fasten the plates to the block B, then drill a 3/4-in. hole as shown and fasten the two remaining washers to the block, one on each side and central with the hole.  Bore a 5/8-in. hole lengthwise through the block A for the 5/8-in. rocker bolt.  This bolt should be 11-1/2 in. long.

The teeter board is made of a 2 by 12-in. plank about 12 ft. long.  It should be slightly tapered from the center to the ends.  Two styles of hand holds are shown, but the one on the left is the one most generally used.  The handles are rounded at the ends and are fastened to the board with lag screws or bolts.  The block A is fastened to the board with lag screws and should be a working fit between the wo plates where it is held by means of the 5/8-in. bolt.  The center pin is 3/4-in. in diameter and about 9 in. long.  —­Contributed by W. H. Dreier, Jr., Camden, N. J.

** Home-Made Pot Covers [297]

Empty thread spools and the tins used as extra inside covers in lard cans are usually thrown away, but these can be put to good use as kettle covers, if they are made up as follows:  Saw the spool in half as shown, make a hole in the center of the tin and run a screw or nail through the spool and the tin; then flatten its end on the under side.  This will make an excellent cover for a pot.  —­Contributed by Maurice Baudier, New Orleans, La.

[Illustration:  Pot Covers]

** An Outdoor Gymnasium Part I-The Horizontal Bar [298]

Gymnastic apparatus costs money and needs to be housed, because it will not stand the weather.  Gymnasiums are not always available for the average boy who likes exercise and who would like to learn the tricks on horizontal and parallel bars, horse and rings, which all young athletes are taught in regular gymnastic courses.

Any small crowd of boys—­even two—­having a few simple tools, a will to use them and the small amount of money required to buy the necessary