The present Volume neither supersedes nor contradicts my former Work, neither is it a repetition nor a continuation; but to avoid the oblong and inconvenient shape of that book, the present Volume is printed under a different form and title, because I am less ambitious of publishing a book of beautiful prints, than a book of precepts: I must therefore entreat that the plates be rather considered as necessary than ornamental; they are introduced to illustrate the arguments, rather than to attract the attention. I wish to make my appeal less to the eye than to the understanding. In excuse for the frequent use of the first personal pronoun, it should be remembered, that when an author relates his own theory, and records his own practice, it is hardly possible to avoid the language of egotism.
