Antique Pattern Library is an invaluable resource with an amazing collection. 

"This ongoing project is an effort to scan needlework pattern books that are in the public domain, to preserve them, so we can keep our needlework heritage in our hands. These scans have been photo edited to make them more useful for needle workers, and to reduce file sizes. They are available, for free, to anyone who wants them, for educational, personal, artistic and other creative uses."