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.
The gun consists of only two parts. The barrel may be either a piece of bamboo fishing pole or a section of sweet alder. The spring is a piece of corset steel, such as can be usually found about the home.
Ill: A Pea-Shooting Gun Made of a Piece of Alder and a Corset String
Sweet alder can be found in the summer growing along the fences in the country almost anywhere. Find a stalk, about 1 in. in diameter, which is good and straight, and cut it off to a length of 6 or 7 in. Make a ram rod of wood and use it to punch out the pith of the alder, rendering the bore as smooth as possible. An old bamboo pole of like dimensions may be used instead.
Cut out a section of the wood, 2 1/2in. long, beginning 1 1/2in. from one end of the tube. The depth of this cut should be almost halfway through the piece. The corset steel is then inserted into the short end of the tube and bent over so that its other end will touch the bottom of the open part of the bore. A nick is made with a knife across the bottom of the bore at this point, to let the spring catch a little. The ammunition is placed before the caught end of the spring, as shown, and discharged by hooking the forefinger over the spring at the point A and pulling backward as when pulling the trigger of a gun.
It is necessary to keep the muzzle elevated a little after the ammunition is placed in position, otherwise the pea will roll out before the spring has a chance to strike it.