Thus, after years of uninterrupted work, I was afforded
for the first time an opportunity to embark on a task
insisted upon by many and felt to be serviceable to the
movement by myself. Therefore, I resolved not only to
set forth, in two volumes, the object of our movement, but
also to draw a picture of its development. From this more
can be learned than from any purely doctrinary treatise.

Still taking 3! All three are still open :)