This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
The principle of internally stoppering a bottle containing gaseous liquids is not new. Many and varied are the forms which have been presented for consideration; but nearly all of the internal stoppers consist of either a rubber or glass ball.
This illustration represents "The Stewart patent stopper". In the neck of the bottle is a groove, with rubber packing. The ball is sufficiently light to be buoyant, but is also self-acting and floats on the surface, and when the liquid is charged with carbonic acid gas, the pressure acts against the ball and seats it as illustrated. The ball is hard, impervious, and is not affected by acids, and it is claimed is made of a combination so as not to contaminate the beverage. The bottle is filled on an ordinary filling bench, right end up, and when filled to the neck, the ball jumps to its place against the seating in the neck of the bottle, and makes a tight joint. When pouring out the contents of the bottle the ball floats away from the mouth or the bottle. The bottle stoppered with the floating ball can be washed on any bottle-washing machine with great satisfaction.
Fig. 297. - Stewart Floating Ball Stopper.
Figure 298 represents an English invention. It consists of a bottle with a groove in the mouth; a rubber packing fits in this groove, so when the glass ball is forced up, makes a joint against it. In emptying, the glass ball remains in the shoulder of the bottle, as shown in drawing.
Fig. 298. - Codd's Patent Stopper.
Bottles with this stopper must be filled upside down, necessitating the use of a "turnover" filling machine, as illustrated on another page. Washing the globe-stoppered bottles can be done in the ordinary way.