This section is from the book "Scientific Sewing And Garment Cutting", by Antoinette Van Hoesen Wakeman. Also available from Amazon: Scientific Sewing And Garment Cutting: For Use In Schools And In The Home.
First of all, have each pupil double the model together along the third line from the last row of backstitching. That this may be clearly understood, let the teacher fold a model before the class. When this is done, explain that the two sides of the model represent two pieces of cloth. The model having been doubled, let the teacher begin the first row by putting the needle through two threads and leaving two, and continue to carry the thread over at each stitch. When the first line has been completed correctly, show the pupils how to begin the second line, and let them begin the third without help. Between each line of stitching there are two threads of canvas.
What is the new stitch you are going to learn called? Ans. The overhand stitch.
Why is it called the overhand stitch? Ans. Because the thread is put over the edges of the cloth.
For what is overhanding used? Ans. For sewing together the edges of cloth when a perfectly flat seam is desired.
Should the thread be drawn tightly in overhanding? Ans. No; if it is drawn too tightly the seam is not flat, but hard and round.
Should the thread be knotted before beginning to overhand? Ans. No; two stitches, one over the other, are taken to keep the thread from pulling out.