My grandmother was Virginia Marie Davisson, sister of Alexander, Sr. The family story was always that John H. A. Davisson was a jeweler and watchmaker who worked at J. E. Caldwell in Philadelphia. However, an 1890 census stated his occupation as "jewelry salesman." He and Anastasia (I have a beautiful photo of her) lived at 2204 Pine Street. Seems he was a bit of a social climber and always wanted to stand out. Since his house looked like all the other houses on the block, he had a fourth floor constructed so that his house would be different. You can still see that addition today. I own a few items from the house. Also, I have my grandmother's memoirs of her growing up in that house. It's entitled, "2204 Pine Street." It's in the permanent collection of the Historical Society of Pennsylvania and I have it in PDF form on my computer, as well. You can visit my web site (ivanstiles.com) for my contact information if you're interested in learning more.