What the Heck is a Vinculum?

Often times, coin collecting and numismatic research can take one down some interesting roads.

Yesterday, I was writing a narrative for the 1794 No Fraction Bar Large Cent. This is an interesting engraver error where the person preparing the die accidentally omitted the fraction bar. In this case, the 1 hovers above the 100, with nothing separating them. This error was limited to the Sheldon 64 variety of the 1794 Large Cents, so demand comes from both die variety collectors and general variety collectors.

While working on the write-up, a random thought popped into my head: "I wonder if the fraction bar has an official name in mathematics?" A quick Google search found the answer. The bar’s name can be either "vinculum" if the fraction is in the form as shown on the back of the 1794 Large Cent, or it can be called a "solidus" if the fraction is written on one line (as 1/100).

The only problem in using the Latin word is that few people would know what a 1794 "No Vinculum" Large Cent is, but everyone understands the "No Fraction Bar" term and what it represents. Thus, in this case, the only value in knowing the word "vinculum" is if one was a contestant on Jeopardy and Alex, the host, asked a related math question.

While on the subject of terminology, there are many words we use in numismatics that have become second nature to insiders, but which are alien to the general public. Here are a few such terms that are associated with 1794 Large Cents: obverse, reverse, denticles, Phrygian cap, forelock, and MS64RB. Some of this lingo has been generated within the hobby; others terms come to us from other fields and other languages.

It’s amazing what coins can teach us if we are only willing to learn.