Henry Richardson is working in an important library.
His job is to give new life to old books. Many of these books are very old or
are the one and only copy in the world. Richardson has saved
the lives of many books. His first job is to wash the pages. He takes off the
old cover, and places each page in water. Then he carefully puts each one
between sheets of paper to dry. Some of the pages may be very thin or have
missing parts. Richardson mends these while they are still wet. He places each
one on a heavy sheet of glass. Then he carefully puts small pieces of paper on
the places which need mending. These pieces of paper are very thin. They look
like part of the old paper. The washed pages are now white and
clean. The pages are put together again in the old cover. At times, only the
front and back parts of the old cover can be used. Sometimes a whole new cover
must be made. Now the stronger, cleaner, and "never" book is returned to the
library, once again ready for use. Richardson mends old books ______.