I know the principle of polyphasic sleep I also know from personal experience that one can go without sleep for long periods. And from personal experience as well as considering our social lifestyle consider trying to mold ones internal clock to set hours of sleep is going to take more than 7 days adjustment. I consider taking a 1.5 hour nap a minor setback especially considering you benefitted from it.
As for it being the way Leonardo slept... have you considered that the wiring of his brain was probably different since humanity as a whole has not adopted this method in all these years. It's questionable if this make him more productive or whether it was necessary for him because he was such a genius thinker. To compare with someone who is not alive today is redundant. Expecially when considering the, pollution, our bodies must handle, the processed foods we ingest as well as the sheer volume of sugar and caffine consumed. If you want to be like Leonardo you need to eat the same foods as him and have the same internal clock as him.
I don't think finding that your internal clock kicking in a nap for 1.5 hours is failure in the project. A minor stumbling block perhaps. They say Rome wasn't build in a day they probably had to knock down some of the work they did to get it right too.
BTW I've had a sleep cycle of 4 hours sleep 18 to 20 awake then sleep again for years. I don't recommend it.
Alex
