Here is a very high resolution scan of a specimen sheet issued by William Caslon, letter founder, from the 1728 edition of Cyclopaedia (http://en.wikipedia.org/wiki/File:Caslon-schriftmusterblatt.jpeg).
The book itself is here (http://digicoll.library.wisc.edu/HistSciTech/subcollections/CyclopaediaAbout.html).