Hendrie & Bolthoff Denver altitude gauge pat. 1910

Posted by The_Taoist_Cow@reddit | aviation | View on Reddit | 4 comments

So I found this from someone who has a history of veterans in their family. They gave me this.

Hendrie & Bolthoff MFG & Supply CO Denver, Colorado Ashgroft MFG. CO

I thought that some of you might enjoy this. Probably more than me lol.