Family rights to old steel patents

Dear Rich: I wonder if you can help. My great-grandfather patented several steel inventions back in the early 20th century in the U.S. How do I find these and what happened to them after he died in 1941? Do the next of kin have any rights to them? I'm so glad you asked. The short answers to your questions are: (1) you can find out more about the patents at the Google Patents site, (2) anything patented in the early 20th century is in the public domain now, and (3) there are no rights in public domain inventions. The Dear Rich staff recommends Google Patents instead of the U.S. Patent and Trademark Office searching site because Google is easier to use and more comprehensive. Try the Advanced Search feature to search by inventor name. Prior to 1995, U.S. patents had a duration of 17 years, after which the invention is free for anyone to use or manufacture. We wonder if your great-grandfather was one of those early 20th Century steel pioneers who gave us stainless steel, modern dry-blasting, or a revolutionary method of making rails. (Digression Dept.: Speaking of steel, the Dear Rich staff learned today that it takes 7 kg (15 lbs.) of steel to manufacture a bicycle and 816 kg (1800 lbs) to manufacture a car. No wonder H. G. Wells said, "When I see an adult on a bicycle, I do not despair for the future of the human race.")