The British idiom about a penny dropping means that someone has finally understood something that escaped their understanding for a period of time, but that expression is not to be confused with the idiom to drop a penny which still means something entirely different. It also should not be confused with the lyric in the Christmas song that encourages the audience to “please drop a penny in the old man’s hat.”
And it has absolutely nothing whatsoever to do with the story of a penny dropped off the observation deck of the Empire State building killing someone on the street below.
Pennies have been around a long time. Back in the mid-1800s, 12 pennies (also known as pence) made a shilling, and a shilling made a pound 20 a pound was made up of 240 pennies. In Canada, coppers (as pennies were called) were stamped out by Britain’s Royal Mint and represented 1/100th of a Canadian dollar and at the time, outside of Ontario, Canadian pennies were considered worthless.
But long before the Canadian penny, in 1793, the American penny made its appearance authorized by the United States from the Mint Act of 1792 which was signed by George Washington and designed by Benjamin Franklin.
You might think the expression should be American, not British, based on how long the penny has been around in the U.S. and yet, that’s not the case. A penny during William Shakespeare time wasn’t really a penny but a reference to money in general.
What penny hath Rome borne, What men provided, what munition sent?
But was the British penny of William Shakespeare’s the penny the British people came to know as a real penny? In 1797, pennies in Britain were made from copper but before that, pennies were made of silver, and in 1860, copper pennies were made from bronze instead of copper.
But at what point were pennies associated with people understanding what took the listener so long to understand that was obvious to the speaker?
At the end of the 19th century, penny machines (also known as penny-in-the-slot machines) were very popular in Britain. They provided cheap entertainment. Usually, when you dropped a penny into the machine, a song would play or a puppet would dance or a mannequin clairvoyant predicted something in your future after wich a small card dropped down into the slot with the fortune printed on it. The mannequin clairvoyant was a featured player in the Tom Hanks’ movie, “Big.”
You could also have gas delivered by way of an automatic penny-in-the-slot machine in 1890 where those of the poorer class (as they were called back then) could purchase 25 cubic feet of gas for their homes by inserting a penny into the penny-in-a-slot machines attached to their homes.
It wasn’t long before there were automatic postal boxes supplying postcards and stamped envelopes with paper enclosed and automatic insurance boxes providing insurance against accidental death for 24 hours, and automatic photographic machines.
Pennies were all the rage, and not just as they pertained to slot machines either!
INTERESTING SIDE SIDE NOTE 1: The penny-farthing was a popular bicycle in its day beginning with its arrival in the 1870s. It got its name from the difference in the size of its wheels which was a nod to the difference in size between a penny and a farthing. The front wheel was large and the back wheel was small in much the same way that the penny was much larger than the farthing (which was worth a quarter of a penny).
The Sekgness Standard in Lincolnshire published the following in the column “Things We Want To Know” on 20 April 1932:
The identity of the gentleman who was allowed to go for a drink after assisting the missus on Sunday?
And how long it took him to fathom the problem as to why the hostelry was closed at 1.15 p.m.
And if the penny dropped on suggestion of his spouse that he had forgotten to advance his watch an hour?
And if he has made a mental resolve to guard against a similar happening in future years?
With a 40-year gap to work within, Idiomation continued tracking the idiom’s history down.
In the 1890s and 1900s, the Kinetoscope or Mutascope movie machines were all penny-in-the-slot machines. The viewscreen would be completely blank until the coin dropped through the slot into the machine, and there was usually a delay between the action of plugging the slot with a penny, the penny dropping into the box, and the mechanism within finally starting the movie.
The concept of a penny dropping and the person who paid the penny going from a blank screen to a movie is from this particular era even though the idiom is attest to years later. However, that it should be used so easily in a newspaper column and without quotation marks in 1932 indicates it was an idiom in use without doubt throughout the 1920s.
Historically Speaking 