The pulsejet is a very simple jet engine with few moving parts. It's most famous use was on V-1 flying bombs of WWII. Later, a valveless pulsejet was designed which was even simpler. This thing is so simple in fact it's nothing more than a metal tube with no moving parts at all. Today amature enthsiastis make them in their garage out of junkyard parts.
It's one of those things which would be invented and made earlier. One use would be for manned flight. The Wright Flier for example could not be made earlier with the technology of the time because they had to wait until the gasoline engine was invented to power it. But the Flier would just as well be powered by pulsejets and we could have flying machines as early as wing design caught up.
For detailed reading on pulsejets:
http://www.pulse-jets.com/
Also search for valveless pulsejet videos on youtube to see them in action.
It's one of those things which would be invented and made earlier. One use would be for manned flight. The Wright Flier for example could not be made earlier with the technology of the time because they had to wait until the gasoline engine was invented to power it. But the Flier would just as well be powered by pulsejets and we could have flying machines as early as wing design caught up.
For detailed reading on pulsejets:
http://www.pulse-jets.com/
Also search for valveless pulsejet videos on youtube to see them in action.