My entryway floors looked like this when I moved in. Underneath was a second layer of linoleum and then a layer of tar paper. If you have done any remodeling you have probably run into this too. It was a very common practice to glue a layer of tar paper on the wood floor for noise reduction and a moisture barrier. Unfortunately, no one thought about getting it up......
After doing a little research online I found quite a few people who had success with steaming it off with a wallpaper steamer. So on Saturday I set to work with my Mom's floor steamer and a scraper. It works!! To look at them now, one would never know there was ever tar paper on it. It still took time and a lot of elbow grease, but it was worth it! Sorry, I don't have an after picture to share, my sister is up north and took her camera with her.
So that is why I had "I've got steam heat..... I've got steam heat....." stuck in my head!