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.
Students or anyone wishing to retain notes on a subject will find it quite handy to have a large envelope pasted in the back of each textbook. Instead of having notes all through the book, they can be arranged in order and slipped into the envelope. If the book is accidentally dropped, the notes will not be lost. - Contributed by Harold Mynning, Chicago, Ill.