This paper is primarily
concerned with the existence of direct limits in certain classes of Boolean algebras.
The concepts of inverse and direct limits are defined relative to a class A of
abstract algebras . It is assumed that the algebras in A are of the same
type.
It is found that classes which are closed under such constructions as
the formation of homomorphic images, subalgebras, free products and free
unions do admit direct and inverse limits. In fact, the existence of direct
limits is closely related to the existence of free products and dually, the
existence of inverse limits is related to the existence of free unions. Also
there is a relationship between the existence of inverse limits and direct
limits.
