What does "like the potter who carried the tray on his head" mean?

Well, what does it mean? I found it as an apparently slightly derisive comment in a 1915 book on magazine publishing in America. In context, the author lists a publisher’s calculation that he needed so and so many subscribers to make money off his magazine, leading the author to comment that this kind of calculation was “like the potter who carried the tray on his head”. What does it mean? What does it refer to?

Sounds vaguely like an Aesop fable, though I remember it in a version with a girl who carried a basket of eggs to the market, got distracted by her fantasies of how her life would change with the money she’d get from selling them, and dropped the lot.

hmm…only google result is this thread. Certainly not a phrase in current use, anyways.

Potter or porter?

Potter in the quote, but good point, it might be a typo in the original. Any good ideas for “porter”?

A porter who carried his tray on his head would be courting disaster, or at the very least asking for trouble.

Poulterer? Referencing the eggs mentioned above.

There was an old stereotype about African (or some other Third-World area) porters carrying their loads on their head–without any hands. Maybe they do that in real life, but in either case, I can somewhat see the analogy. The writer has some complex formula to derive a needed number of subscribers, and the the porter has to do constant muscular “calculations” to keep his load balanced.

And that’s assuming it’s a typo, and should have read ‘porter.’ Other than that, I got nuthin.

There are a variety of different folktales that revolve around someone imagining a future chain of events and becoming so caught up in fantasy that they break the first link in the chain. Aesop’s fable about the milkmaid is one of them. She’s carrying a jug of milk to market and becomes so immersed up in her romantic visions of what the money from the milk will allow her to do that she tosses her head and drops the milk jug. The moral is “Don’t count your chickens before they’re hatched.”

Given the context of a publisher counting his imaginary future subscribers, the reference is probably to a lesser-known version of this common folktale.

A potter carrying his tray of pottery on his head would be in a precarious situation, too. Why change the word?

In the context of the OP, it sounded more like the potter was carry his wares everywhere so he would never miss a sale, as the magazine publisher was doubtless pressuring every man at his club to buy a subscription.