I don't think they seem particularly special even then. Patenting an algorithm to be implemented by levers doesn't seem so categorically different from patenting one to be implemented by transistors.

No, they are different.

Read the automatic windshield wiper patents described in Flash of Genius. They provide circuit diagrams and explanations of why the wipers move faster when there's a lot of rain.

And you think it shouldn't have been patentable if it instead used a microcontroller to control the wipers even though the system is doing the same thing?

I should have noted that "patentable" as you're raising it is a 101 issue. It IS important, but not part of this article:

============== There are four main sections of the U.S. statute governing patentability, and you only ever read about the first and third:

101: Patentable subject matter (what you can patent)

102: Anticipation (someone else invented or described it)

103: Obviousness (two or more references, taken together, describe it)

112: Specification (here’s the statute)

Most of what you read is about 101: is software a “thing” or is it a “mathematical formula” and thus not patentable?

"patentable" ? maybe, and you'd have to disclose the source code.