I found four (one broken) unmarked tenpin bottles in the woods. i found online that they were probably used for carbonated beverages. any way to tell how old they are?
Welcome to the forum! Tough to narrow down a date on those without any embossing, because they didn't change much over quite a long period. I'd say roughly 1870s to maybe 1920s or so. It would be easier to date them based on what else, if anything, you found alongside them.
I don't think they call those Ten Pins. Ten Pins have a flat bottom & stand upright. Those are Ginger Ale type Bottles that lay on their side. some call them Torpedo Bottles. Leon.