Doors and Windows - Need help with 1840's double hung windows that won't stay open

I have a house built in 1840 with very large double hung windows. The problem is, the bottom windows won't stay opened unless propped up with a piece of dowel. There are no weights with these. What originally kept them open was a screw/nail type of contraption where the side of the window was notched and this "notch" grabbed onto the screw/nail/whatever when the window was opened. There are only a few windows in this large house that actually still work without a helper prop on the bottom. Some of these aren't notched at the sides so the screw/nail wouldn't help.

What else would hold these heavy windows up? Would compression weatherstripping on both sides do the trick? V-form weatherstripping? I need help! :)

eebant (Jeanne)

Do an internet search for "jamb liners".

Thanks, John, I followed your advice and did a search. The jamb liners look like a major job to do. I was hoping for something a bit more easier. I'll keep searching for a miracle cure!

Jeanne