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 method shown for fitting fly screens on the outside of the upper and lower sash permits the screen to be raised and held at different heights. Screweyes are turned into the outer strips, as shown in Fig. 1. The sides of the screen frame are grooved, Fig.
2, to allow it to slide up and down on the screweyes.
The screen can be raised and two of the screweyes turned from the normal vertical position, A, Fig. 3, to a horizontal position, B, to hold the frame at that point. By the use of a greater number of screweyes more places can be provided to support the screen at different heights. - Contributed by James M. Kane, Doylestown, Pa.
Ill: The Heads of the Screweyes in the Window-Frame Stop Slide in a Groove Cut in the Screen Frame