quot;
Book of Knowledge&
quot;, he wrote down all that was of magical practices and of nature observation in detail, which came to him by inheritance from other great magicians. The Caliph?s astrologer had a very inquisitive and dexterous servant, who also led his book and was going to give it to his worthy successor. Of course, the book of the servant was nothing like the great astrologer?s &
quot;
Book of Knowledge&
quot;, but nevertheless... In our days, by a strange coincidence, both books fell into the hands of completely different people...