Friday, April 30, 2021

And Now For Something Completely Different: The Sonora Aero Club


Source: "Dreams of the Sonora Aero Club" by John Foster, Design Observer

I don't just read about firearms, prepping, or politics. I recently came across an article describing a secret society of aeronautical pioneers that supposedly was active in California in the mid-1800s. The group called itself the Sonora Aero Club. It interested me enough that dug a little deeper.

    The existence of the club only came to light after several folios authored by Charles Dellschau (d. 1923) describing and illustrating the exploits of the group were discovered following a house fire in the 1960s and which came to the attention of an art student in 1969. The folios were extensively illustrated, and you can view a number of the pages here.  Most of the illustrations seem to show lighter-than-air craft of various configurations.

    There are various gases that can be used for such craft, but the best and safest--helium--had not been discovered when the group was active. The gas used by the club is not known, only being described by Dellschau as "lifting fluid". Apparently, the secret of producing this fluid or gas was only known to one member of the group, Peter Mennis, who died in the 1860's without passing on his secret, after which the group slowly withered away. But based on the description of the substance and the mechanisms employed by the members of the group, it is believed that Mennis had discovered a method of mixing ammonium chloride and sodium hydroxide in water to produce ammonia gas on the fly, as it were. I found it interesting in reading the article that the manner in which a couple members of the group died could be attributed to either the heat produced by the reaction (one member died when his contraption caught fire) or the effects of long term exposure to the gas (Mennis's death). 

    Of course, all of this presumes that the group actually existed, which has been contested by some historians. Much of the doubt is driven by a lack of evidence placing the named members in California at the relevant time period as well as other incongruities. Others, however, believe that the group, or something like it, could have been responsible for a series of airship sightings in the late 1800s. Parts of the folios are written in a code that has not been broken, so perhaps more information that could establish the veracity of Dellschau's account might come to light if the codes are ever cracked.


  1. Th airship flap back then was fun to read about.

    1. One of the airship sightings was in Aurora, Texas, which involved an low flying airship that struck a windmill and exploded, killing the pilot, who was buried in the town's cemetery. See

    2. Very familiar with that one - we almost took a detour to go see that one day.

      But Texas is biiiiiiig, and so was the detour.