[Vigilanteman]

None of these save the Victrola is more than 100 years old. I would think the Model T Ford, steamship and locomotive ought to be on the list.

[Calvin Locke]

Planes, er, steamships, trains & automobiles aren’t exactly “gadgets”.

[Swordmaker]

None of these save the Victrola is more than 100 years old. I would think the Model T Ford, steamship and locomotive ought to be on the list.

None of those come under the definition of "gadget."

gadg·et [ˈɡajət]
NOUN
a small mechanical or electronic device or tool, especially an ingenious or novel one:
"a state-of-the-art kitchen with every conceivable gadget"
synonyms: appliance · apparatus · instrument · implement · tool ·

[Mark17]

Airplanes should be on the list.

[dhs12345]

Agreed.

[untenured]

I hear you, but I think among the historically underrated gadgets are the mechanical screw and eyeglasses.