Wikipedia
A traveling library is a collection of books lent for stated periods by a central library to a branch library, club, or other organization or, in some instances, to an individual. The chief characteristics from which it derives its name are its temporary location in the place to which the collections of books is sent and the implication that any traveling library will or may be changed for another collection of books. A bookmobile is an example.
Usage examples of "traveling library".
It was Fourmyle's traveling library, filled with hundreds of books and thousands of glittering novel-beads.
Now and then he dozed off for half an hour and occasionally, as long as it was light enough, he leafed through his traveling library -- a few sheets of paper on which he had copied poems and sayings, a bundle of newspaper clippings, and a few pictures that he had cut out of magazines.
The son of a lawyer and farmer, at age seventeen he became the youngest person ever to practice law in Arkansas, when he passed an oral examination with honors after reading law books he had checked out of the traveling library of the Cumberland Law School.