The “double s” symbol that you may be referring to is called the “long s” or “ſ”. It is a type of lowercase letter “s” that was commonly used in the past, particularly during the era of printing presses and movable type.
The long s looks similar to the modern lowercase “f” without the crossbar. It was used in the English language as a substitute for the “short s” (the modern “s”) in certain situations. For example, it was used at the beginning and in the middle of words, while the short s was used at the end of words.
The use of the long s was common in printed materials in the 18th century, particularly in Europe and North America. However, it fell out of use over time and was eventually replaced by the modern “s”. The long s is still occasionally used today in certain contexts, such as in the spelling of some names and in the logo of the Swiss watch company, Longines.
It is important to note that the long s should not be confused with the German Eszett (ß) or sharp s, which is a letter used in the German language to represent a “ss” sound. The Eszett was introduced in the 16th century and is still used today in modern German orthography.
In summary, the “double s” symbol you may be referring to is the “long s” or “ſ”, which was commonly used in the past as a substitute for the modern “s” in certain contexts.
