This is a valve Codd and the clue was still sitting inside the bottle, the original glass valve that would have formed part of the patented Rylands closure system. 

The Rylands valve came from the efforts of Dan Rylands of Barnsley, whose family operated the famous Hope Glass Works. 

Rylands had originally worked with Hiram Codd, the inventor of the marble-stopper bottle and together they experimented with ways to improve the design. 

In the early 1880s they patented what became known as the Rylands Valve system.

The problem they were trying to solve was simple. Codd bottles worked brilliantly but opening them could be awkward because the marble was held tightly against the rubber seal by the pressure of the drink. 

The Rylands valve introduced an additional glass valve mechanism that helped release pressure before the marble was displaced, making the bottle easier to open and representing one of several Victorian attempts to improve on Codd's original invention.

What's fascinating about this codd bottle is that its part of that brief period of experimentation. 

The standard Codd design became the industry winner, while valve systems like the Rylands patent remained relatively uncommon. 

Manufactured by Talbot & Co. of Gloucester and Monmouth, this bottle dates back to the height of the Victorian mineral water trade.

While most people recognise Codd bottles for their glass marble, valve Codds represent a rarer and more complex variation that few bottle collectors ever come across.

Despite the damage, this bottle has managed to preserve one of the very features that makes it so unusual. 

The survival of both the bottle and its original valve offers a rare glimpse into a short-lived chapter of Victorian innovation, when inventors were constantly searching for better ways to bottle fizzy drinks.