I recently bought three snapshots of the Polo Grounds, taken in 1912. They're small, apparently Type 1, and kind of faded. I scanned them and improved the contrast with the photo software on my computer, and here they are. The first picture appears to depict game action, with the Giants in the field, while the second and third pictures show Giants players in the outfield before the game or between innings.
I was able to date them to 1912 from the grandstand and the uniforms. The first and second pictures depict the concrete grandstand that was built in 1911 after the old wooden one burned down, so they can't be any earlier than that year. The Giants players in the second and third pictures are wearing white uniforms with black caps and black and white striped socks. The only year between 1911 and 1919 that the Giants had home uniforms like that was 1912, as shown on the BBHOF's Dressed to the Nines web site. See below, compared with a blown-up version of the player in the center-left of the second picture. I'm not sure, but I think that might be Fred Merkle.
http://exhibits.baseballhalloffame.o...ar&increment=9
