There must be a wealth of inventions, laws and developments that proved to have a serious downside - almost everything, probably but some will be more outstanding than others. Any contributions to raise a laugh on a dull January day?  Apart from run ins on sites like this, of course..........

Pizza scissors

I cannot remember if this has been posted here already, or somewhere else.

The Baby Cage, designed to give infants in city tenement blocks some fresh air & sunshine;

Yeah! Blue contacts for  a Moses character - sloppy.

He's only pretending. That's why the tablets are written in Tolkien's Elf runes.

This one was almost as bad ....

The sinking of numerous ships in shallow waters over the years has created artificial reefs which are an excellent habitat for marine life.

Photo of sunken military equipment in Truk Lagoon, now a major tourist attraction as well as providing a home for fish;

I imagine many a flooded home owner sited before a pretty view of river or stream is having second thoughts. I note that flood boarding in Kendal  topped with glass panels so the view was not lost will need to be upgraded to much higher glass panels, this year.

Houses on cliffs and rural properties within easy reach of both London or Birmingham also come to mind.

This has been mentioned before ...

In the late 1920s, air-conditioning and refrigeration systems employed compounds such as ammonia, chloromethane, propane and sulphur dioxide as refrigerants. These were toxic, flammable or explosive, and in the event of leakage, could result in serious illness, injury or even death. The Frigidaire division of General Motors, at that time a leading manufacturer of such systems, sought a non-toxic, non-flammable alternative to these refrigerants. Their research team, headed by the brilliant chemist Thomas Midgely came up with flourinated-hydrocarbons, which were non-flammable, non-toxic and highly volatile (a requirement for a refrigerant). They called their product Freon.

Freon soon replaced the various toxic or explosive substances previously used as refrigerants, and was later used in other applications, such as propellants in aerosol spray cans, fire extinguishers and asthma inhalers. The Society of Chemical Industry awarded Midgley the Perkin Medal in 1937 for this work. Undoubtedly Freon saved many lives that would otherwise have been lost in domestic or industrial, fires, explosions and poisonings. But many years later Freon compounds (CFCs) were shown to be responsible for destruction of the Earth's ozone layer .... and so their use is now severely restricted by the 1987 Montreal Protocol.

So it was a very good idea at the time, but ....

Now that's the sort of info that I was hoping would appear here - tho the 'baby airer' still astounds me.

Accidental meetings also perhaps might be interesting - er, we might exclude marriages otherwise it will clog the counter.

Thomas Midgely was the same man who developed a chemical that made petrol engines run more efficiently. It worked brilliantly by eliminating the uncontrolled "knocking" that afflicted early petrol engines, and it greatly reduced fuel consumption. Accordingly it became standard worldwide for the next fifty years. Unfortunately the compound he suggested be added to petrol was tetra-ethyl lead, which was only realised to have serious long-term health effects, particularly on children, in the 1970s whereupon it was rapidly phased out.

Again it was a good idea at the time, but...

As the author Bill Bryson put it, Midgely possessed, "an instinct for the regrettable that was almost uncanny," and there can be few other individuals who have wrought so much damage to the whole planet.