Metric feed dial graduations

I've been posting to another thread about a portuguese lathe rehab project. I have a general european lathe question. The feed wheels (both cross and compound) are graduated into 60 divisions. I think in a normal American lathe they'd be divided into hundredths of an inch, right? So what does each of these 60 marks mean? Are they a 60th of a cm perhaps? That doesn't make much sense from a usability perspective, lol.

Any insight?