This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
It is almost impossible to make a perfect buttonhole in the ordinary manner by hand without a guide. The illustration shows a very simple guide that can be easily made by anyone. Procure two pieces of tin, or sheet brass, cut them as shown, and drill holes in them large enough for a needle, so that it will be easy to fasten them to the cloth with basting thread. Cut the buttonhole slot, then punch a hole at the end with an ordinary belt punch. Such a punch can be purchased from a local hardware dealer in any size. In making the buttonhole stitch, keep the needle close against the metal edge of the guide, as shown. - Contributed by A. L. Kerbaugh, Allentown, Pa.
Ill: The Form of the Buttonhole is Cut in the Edges of the Two Pieces of Metal
An easy way to put varnish in the grooves of a tennis racket is to use a medicine dropper.