1920's Hemingray made bottles come in ice green, 7-UP green, carnival or amber. They will have one of these marks on them. H in a Square, H in a circle, Owens Illinois logo with a 26 to the left of the logo, big dot on the bottom or a big heel number

1890's bottles will have H.G.Co. on the bottom or heel of the bottle. There are some bottles made by Hemingray that don't.