How convenient they're so small anymore. What would the ducted fan sleigh of Russian Grand Duke Cyril Vladimirovich have looked like if they could have built them like that over 100 years ago.
This was built by the man who came up with the Coanda effect. The idea is that an important part of the operation of the ducted fan is the way it blows across the body of, say, the plane he built in 1910. Could it really have flown? In Romania they claimed that, either accidently or deliberately, Henri Coanda found his taxi testing turning into a flight. Some say that plane could never fly, but that might not keep in from jumping off the ground and sailing into a wall. If you believe his engine is a jet, then you believe he made the first jet flight, possibly farther than the Wright Brothers first flight.
If he did succeed in even sort of flying that first plane, you have to wonder why he didn't build a second. Or did he, there are magazine photographs said to be taken after the accident, plus an article naming a later buyer. But it was never to be seen again.
Be real careful if you read about the debunkers of the 1950's, there were many wild claims about the plane that Coanda himself wasn't responsible for. He talked of wanting to add what amounted to an afterburner but never got the chance, etc.
During World War II Germany had him working on ducted fan snowmobiles. You have to wonder if the people behind the German stealth fighter project had any idea that they had the world's foremost expert on the ducted fan engine working for them nearby. Imagine if they got this thing flying during the war. I wonder how small the little motors would be today.