Sandy - There was a topic from about 1 1/2 years ago title "My Worst Nightmare" where a members shelf broke and started a cascade of shelves breaking. I explained how to prevent this problem then and I'm reprinting it now for you. Several members have tried it and it really works, look good, is inexpensive and is simple to do. Here it is again for you:

"I have found a way to shore up the glass in my curio cabinets. With the length of the glass shelves in several of my curio cabinets exceeding 4' from side to side, I have purchased clear plexiglass rods (square or round is your choice. I chose square) from a local glass company to use for extra support in the middle of the shelves. I use one rod at the front and one rod at the back of each shelf. I cut them to fit between the underneath of the bottom (1st) shelf to the top of the wooden cabinet base in both the front and back of the cabinet. I then cut two more to fit between the underneath of the 2nd shelf and the top of the bottom (1st) shelf. Then two more rods between the underneath of the 3rd shelf to the top of the 2nd shelf. This goes on depending on the amount of shelves you have. With the rods in place, and as you sit lighthouses on the 2nd shelf, the weight of the lighthouses is actually absorbed by the plexieglass rods instead of the shelf having a potential to sag. It's sort of like a skyscrapper's framework where the weight of the entire frame is actually absorbed into the ground foundation. The weight on the center of each shelf is actually absorbed by the wooden base as it is transfered from plexiglass rod to plexiglass rod to the wooden base. The rods are virtually invisible when you looked at them and you will eventually ignore them all together.

Just an idea that I came up with to put my mind at ease about undue stress on the center of the glass shelves and having my shelves break from excess weight".

I hope this is helpfull to anyone that has this fear of their shelve sagging.