The national library of india is a repository of books about india, published in india and elsewhere; books written by indians in india and elsewhere books on india's neighbouring countries; and everything printed in india and available free to the library under the delivery of books act. In addition, the library aims to be a good general reference library. Under sub-tropical conditions the collection requires careful preservation. Building a microform library is a top priority and the problems of deterioration foremost among them ageing and incessant insect attack are delt with by air-conditioning fumigation and deacidification to the extent limited resources allow. A carefully thought out national policy for preservation is imperative.