My wife and I bought and moved into a house that was built around 1880. It is a brick home with a brick foundation and it is a deep basement (full 8' from floor to ceiling) that is completely (but poorly) finished. We've starting looking into how to correct the minor sagging in the main floor, which led us to trying to find the supporting beams/walls in the basement. We've "zeroed in" on an area that we think needs a floor jack or two but don't know if that will help as the bottom plates of the framed walls in the basement appear to have only been sitting on dirt and have rotted/disinegrated. Didn't they pour concrete floors and concrete footings to support homes at this time? Most areas of the basement even have hardwood floors. Is it probable that there is a concrete floor underneath or could it be only subflooring on top of dirt? We love the house, despite that fact that it may be a total money pit...