People made fun of them

[optimistic pessimist]

The earliest aircraft were ridiculous. One inventor tied an umbrella and wings to a chair. Another made a duck-like machine. People made fun of them. However, the inventors used their imaginations in quite unexpected ways. They led to the invention of the modern airplane. You need a mind full of ideas to create something new. This is the first thing I have learned...
The passage above is an excerpt from a textbook authorized by the Ministry of Education and Science in Japan. What does the underlined "them" refer to? The inventors? Or the ridiculous aircraft?

 

[5jj]

The passage above is an excerpt from a textbook authorized by the Ministry of Education and Science in Japan.

We neeed the name of the book and its author, please.

 

[optimistic pessimist]

The title is New Crown English Series, Book 3, edited by Sadao Takahashi, et al.

 

[5jj]

What does the underlined "them" refer to? The inventors? Or the ridiculous aircraft?

Probably the latter.

 

[jutfrank]

If it didn't refer to the latter, I'd consider it poor writing.

Look at the topic sentence (the first one): the subject is The earliest aircraft. That's what we're talking about.

 

[SoothingDave]

I imagine both the inventors and the inventions got made fun of.

 

[PeterCW]

I imagine both the inventors and the inventions got made fun of.

I suspect that the ambiguity is deliberate.