Handbook of Celtic Ornament by John G. Merne

A complete course in the construction and development of Celtic ornament with over 700 illustrations. A Handbook of Celtic Ornament
takes basic symbols or ideographs and develops them into a systemised
method of construction for most forms of Celtic decoration. Apart from
its value as a drawing textbook, this book will be of immense value to
all students of arts and crafts. 

The
Merne method for the construction and development of Celtic ornament
has not been surpassed and this book is a challenge both to the student
and to the professional artist to take part of our tradition and make it
their own, to use, to repeat, but most of all to develop.