The best theory I've heard is that it was a charlatan filter: asking someone if they can do something known to be impossible. If they reassure you it can be don

The best theory I've heard is that it was a charlatan filter: asking someone if they can do something known to be impossible. If they reassure you it can be done, you know it's a scam. That MP could have been making reasonable use of the filter for an era in which a learned person would know that such a machine should be possible, but not if technology is there yet.