This audion was made by McCandless for De Forest in 1913. It has a double control grid, anode and double Hudson filament.
A closer view. The filament connects to the base and the control grid and anode have flying leads at the top. The grid is the original 'grid iron' shape.
Thanks to Joe Gruber for sending the images.
The balloon envelope is 50 mm in diameter and, excluding the base, is 76 mm tall.
Reference: Joe Gruber. Type Audion was first introduced in 1911.
Updated September 21, 2020. shape:balloon construction:pinch type:triode age:pre.1920 base: pin: