That is a great find, and makes me wonder what the earliest known airgun advert was before your discovery?

I had a quick go at translating the first part of the text and came up with this:

Air pistol, air rifles and walking stick guns

Concerning the unanswered question in R.A. No.55 1803 about air pistols I can give the following information.
I manufacture not only air pistols but also air rifles and walking stick guns . The air pistols are 20 inches long and shoot with a minimum of 50 and maximum of 100 pump strokes. With a full flask one can fire eight shots in one minute because the loading takes only a second. The bullets weigh half a loth (16 grams) . Each pair of pistols comes with two flasks, a pump and a bullet mould. There is also a proper instruction for use of same. The price is 10 to 16 Lber.

What particularly intrigues me is the reference to “walking stick guns” rather than “walking stick air guns”, so does he mean black powder walking stick firearms or air canes ? On further reading I was pretty sure though that his products are air canes as in the last section he seems to say (as far as I can make out) “The piston (pump?) for the flask (air chamber?) is carried in the case”.

As you have noted on the AVG forum (https://www.tapatalk.com/groups/amer...ade-t8562.html) English air canes were surprisingly around as early as 1803, and so it seems also was the case in Germany. The fact that Stormer does not make a great play about the novelty of his air canes suggests that such things were quite well known at the time, so I wonder when they were first introduced? Intriguing stuff!