Today in 1969, US Patent 3447375A was issued, an invention of John H. Fox Jr., assigned to the Reynolds Metals Co., for his “Beverage Container Having Sight Gage Means.” There’s no Abstract, though the description in the application states that he’s invented an “improved beverage container having sight gage means made of a solid light transmitting material and extending through opaque outer wall means of such container wherein such sight gage means has outer easily visible viewing surface means and inner surface means arranged to be surrounded by a beverage within such container, such outer surface means having a normally bright appearance which becomes dark upon surrounding the inner surface means with beverage.”

Many carbonated beverages are currently sold in pressurized container means such as kegs, or the like, wherein it would be desirable to determine the amount of beverage within such keg in a simple and inexpensive manner. Although many types of liquid level gages are available most of such gages are complicated, expensive, and provide undesirable easily damaged protrusions from exterior wall means of an associated beverage keg. Accordingly, it is a feature of this invention to provide an improved beverage container having improved sight gage means of simple and economical construction.