I'd be interested to know a little more about the historical context surrounding this piece - was Franklin responding to some well known problem of the time like a rise in the price of candle wax or lamp oil? The essay seems like an attempt to encourage people to conserve resources using the vehicles of sarcasm and humor. I wonder how common it was at the time to wake up around noon though?

Edit: tantalor sums it up better. :-)

No, he's being rhetorical. The point is about light economy.

Only a fool (i.e., somebody who doesn't understand how daylight works) would think wasting daylight is a good idea. Are you a fool?

No, obviously not, so you agree with Franklin that daylight savings makes sense.

its really, really true. :-)