It was Anthony Trollope, the novelist, once a Post Office surveyor who proposed them used here. They were trialled in 1853 in the Channel Islands. The standard pillar box came into use, across the UK, in 1859.
A year earlier a letter arrived that might have changed history. Charles Darwin had completed over two-thirds of his work on the Origin of Species, when he received a startling letter from a naturalist, Alfred Russell Wallace, 13 years his junior, with whom he had corresponded.
What happened next is a story of happenstance, cunning and generosity...
Back in the 17th century calculus, the mathematical study of change was invented, independently but simultaneously by Isaac Newton and Gottfried Leibniz. In the 18th century oxygen was discovered by Carl Scheele, Joseph Priestly and Antoine Lavoiser... all working alone, oblivious of each other.
Coincidence? Yes and no. There is a posh word for it; 'multiple discovery'.
Multiple discoveries in the history of science provide evidence for evolutionary models of science and technology, such as memetics, the study of self-replicating units of culture...
So now you know.
The history of invention if full of examples of multiple discovery: Copernicus Law; cubic equations; the 'dark night sky' paradox; sunspots; logarithms; platinum; photochemical activation; chloroform; the periodic table; the fusion of the egg and sperm nuclei to form a single new nucleus; rotor cypher machines; the Penrose triangle and the computer.
More recently the simultaneous, 1998 discovery, of the accelerating expansion of the universe through observations of distant supernovae.
This is all about cultural selection theory and evolutionary epistemology.
In English? Some inventions and discoveries come along because other inventions have opened the door to going the next step. Other stuff happens because there is a need for it and clever people set about inventing solutions. And a lot of people don't know who they could be talking to, even if they wanted to.
Imagine how the path of history might have changed if scientists working on endorphins in Scotland and America had known about each other. Or, Russian scientists and American boffins had known they were both working on the laser.
Of course, a lot gets in the way. Security, ego, ignorance and the ability to communicate. Commercial secrets are protected as are designs and all sorts of new ideas.
That's the down side of competition.
Think of a pharmaceutical company struggling with research on a lifesaving drug. They might run into the knowledge buffers and park the idea, unaware another pharmaceutical company, working in the same sector, has the missing bit.
The cloak of secrecy, the commercial need for confidentiality works against the patient and the very people they set out to help.
There can be an overwhelming argument for sharing developments and inventions.
The NHS is fascinating case in point.
Healthcare systems throughout the developed world are all battling with the same issues. Demand, funding and staffing. Each of them looking for solutions. Each of them struggling with their own answers. The evolution of solutions.
No better example than the famous Buurtzoorgh answer to community nursing care. Developed in isolation but now studied, copied and imitated in other settings.
We come to work, put in the best day we can. Stagger home and flop on the sofa; how do you know you couldn't have done better?
The only way to know we are doing what we are doing, the best way we can, is to compare ourselves with other people doing the same job. The only way to know we are running what we are running the best way we could is to compare ourselves with other people running similar things.
Are we buying the cheapest and best we could? We'll never know unless we ask someone else buying the same thing. Are our bed-stays the best, our discharges the fastest, our quality and safety unimpeachable? We have to be brave enough to ask.
Data has got a bad name, used to contrast and condemn by regulators looking for trouble. We must re-frame that. Data is not a stick to beat us with; it is a lever and we are the fulcrum point.
Sharing and comparing are the best friends a manager can have.