Deservedly so. Venus has a disc and does not occult cleanly like the point light source of a star. The accuracy they claim just doesn't make sense if you try and do it those measurements yourself, ask Robin Heath what he thinks, he tried to reproduce it. His book The Measure of Alboin makes far more sense.
This book looks like an armchair attempt at astronomy rather than any sort of practical test of an idea.
Tom
Something is not right. This message is just to keep things from messing up down the road