I have seen very large windows that required more than one weight. The weights needs are based on the weight of the window and if they are that large it may very well be the case.

There would be two weights in each side pocket, one for each (upper and lower). Rarely in my experience is the upper sash not hung on weights too. If you intend on never freeing the top sash, you should pull the weight out of the pocket because it will interfere with the free movement of the weight for the lower sash.
Casey

Old pulley and sash weight windows had upper and lower operable sash to allow opening both for good ventilation. Fixing the top sash in place is done these days to save money or avoid maintenance. Your windows might have been modified at some point. Look to see if the upper pulley wheels are still in place or if the holes were filled.

Thanks! The top sash was the guess at our mothers' day dinner as well. It's well painted shut and I think for now, we'll leave it that way. Would the upper pulley wheel be under where the window itself is? Down down down the road, we just might get the top working too. I'm thinking it will be when I finally strip all of the paint off of the woodwork, which is about 10- 15 years down the road.

Thanks again for the info

Would the upper pulley wheel be under where the window itself is

Yes,If you break loose the upper sash the pulley is there and works just like the bottom one. If you have already taken the time to re place the lower sash cords, just double the time to do the upper. I just got done re placing all the cords in my 20 double hung windows in this 1920's house. Went through about 300ft of new nylon cord and many, many hours but all windows work, top and bottom. Probably the first time since it was fist painted.

Well, that's inspiring christophern! As I keep saying to my husband, after the kitchen is done, after the kitchen. It's good to get all the windows done at once, then you hopefully don't have to worry about them for awhile. Most of our windows are painted shut and don't work- since we'll be going without airconditioning, we'll want them up and working. It would be nice to have the uppers working as well to get the hot air moving out as well. It's good to know that that's an option for us- thanks again!

Try here:

http://www.greenwichwindowdoctor.com/

http://www.thisoldhouse.com/toh/how-to/intro/0,,20228807,00.html

http://www.oldewindowrestorer.com/

Wow thanks jejvtr- we'll be doing lots of window restoration as the weather gets warmer, those sites will be very very helpful!