I see an Owens Glass Co. mark on the bottom. Typically, on soda bottles, bottles in the 20's to early 30's will have a date stamp close to the base. From the late 30's all the way to the 1980's will have a date or year of manufacture on the base or bottom of the bottle. For instance on your bottle, I see a single 9 and the Owens mark. The 9 is either the month or batch #. If you look closely, you might see 2 #'s together. 43 would represent 1943, 39 would represent 1939, and so on. Just a little info on how to date a soda bottle.