Apparently. It’s an actual documented gasifier. Hundreds of them were built less than 120 years ago.
I started a thread under charcoal. I’ll post all the info I have about it there in a couple of days.
I’m sorry you have to wait. I know you are eager to know more. It’ll probably just drive you crazy if I told you that there’s a second design he made. 
Though you may have seen a smaller more “modern” version of it. Besides the retort gasifier, there was the Riche’ Combustion gasifier.
Check out post 20 and 21. Not specifically a Riche’ Combustion gasifier, but it embodies the main idea behind it. The charcoal reduction filter. Heat from the burning wood gets the charcoal hot enough to crack the tars.
And if you pause and think about it, any gasifier that puts out low tar/tar free gas pretty much has to have glowing char in it, unless you have pure carbon fuel, or an extensive filtration system.
In a standard combustion based gasifier the products in the pyrolysis zone really aren’t any different than the distillation gasses. It only takes them a moment to pass through the hot coals. Granted there is oxygen present to support partial combustion to supply the heat needed. With the retort, the same heat is being supplied by an external source instead of an internal one.