In the following passage from great astronomers by robert stewall ball, the author states that he will trace the developments in astronomy from the time of ptolemy to the nineteenth century. based on the content and style of the excerpt, what kind of audience did ball primarily have in mind when he was writing this book? the history of astronomy thus becomes inseparable from the history of the great men to whose labours its development is due. in the ensuing chapters we have endeavoured to sketch the lives and the work of the great philosophers, by whose labours the science of astronomy has been created. we shall commence with ptolemy, who, after the foundations of the science had been laid by hipparchus, gave to astronomy the form in which it was taught throughout the middle ages. we shall next see the mighty revolution in our conceptions of the universe which are associated with the name of copernicus. we then pass to those periods illumined by the genius of galileo and newton, and afterwards we shall trace the careers of other more recent discoverers, by whose industry and genius the boundaries of human knowledge have been so greatly extended. our history will be brought down late enough to include some of the illustrious astronomers who laboured in the generation which has just passed away. what kind of audience did ball have when he wrote this passage?