It is this capacity of the modern library to reach out beyond its own walls in many different directions that makes it proper for us to speak of it as a center. In a similar way the physicist speaks of centers of force. And as a body exerting attraction or repulsion--a magnetic pole, an electrified sphere, a gravitating particle--is surrounded by a field of force which is very real, though invisible, so there are invisible lines that connect such an intellectual center as the library with every interest in the community. We recognize this in our colloquial speech. Did you never hear of a network of branch libraries? Yet on a map they show merely a system of dots. The network is formed of the commingling fields of force, which together enmesh the community in a web of intellectual influences. And as an ordinary force has two aspects, so the influences radiating from our library centers are directed both from and toward them. The up-to-date library strikes out toward every member of the community and it strives to draw each one to itself. It sends its books into every home, its helpful aids to reading and to study, its library news and gossip in the local paper: but on the other hand, its cozy rooms, its well-stocked reference shelves, its willing and pleasant attendants exert on every man, woman and child in the community an intellectual attraction, and having let them taste of the delights it has to offer sends him out again as a willing missionary to lure in others. By such methods should the library strive to be a center of mental development in a community; by such methods is it succeeding, for no other center can vie with it in the universality of its appeal, whether we follow the individual from birth to death, or regard the various members of a community as they exist at one specified time.