Christopher Cock was a London instrument maker of the 17th Century, who supplied microscopes to Robert Hooke. These microscopes were compound lens instruments, which, unfortunately, suffered greatly from spherical aberration.
Wikipedia (http://en.wikipedia.org/wiki/Main_Page)
Christopher_Cock (http://en.wikipedia.org/wiki/Christopher_Cock)
version history (http://en.wikipedia.org/w/index.php?title=Christopher_Cock&action=history)
GNU Free Documentation Lizenz (http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License)
CC-by-sa (http://creativecommons.org/licenses/by-sa/2.5/)
