Students of astronomical history will require a copy of On Tycho's Island: Tycho Brahe and His Assistants by John Robert Christianson (Cambridge), which is a very full account of the great "pre-scientific" science centre established in Denmark in the sixteenth century by the greatest of the pre-telescope astronomers. Tycho Brahe was a genius of science and administration and a man who built himself an artificial nose. He became the most powerful man of science in Europe, in command of hundreds of people, acres of ground and great fortunes. How he did it is recounted in this book, which is made more valuable by the inclusion of a hundred short biographies of people (including an odometer maker, a court jester and Johannes Kepler) who worked for him. Christianson's prose is mechanical and tiresome, his psychologizing banal and his pseudo-business talk ludicrous (he is given to passages such as "executing the patronage strategy," for example), but his research is terrific.