Moreover you can take the books home

From Trying to Please by John Julius Norwich.  Page 247.

But my intended book was still waiting to be written. My first agent was not a success, but now thanks to my friend James Pope-Hennessy, I had a wonderful new one, Diana Crawfurd; and thanks to her I had a publisher—Longmans—and a contract. I knew that I could not go on gallivanting around the world; my nose belonged at the grindstone—and that meant getting into a routine. Instead of heading every morning for the Foreign Office I would now go off to the London Library. I have now worked there regularly for over half a century. For me it will always be the best library in the world, largely because it keeps all its books on open shelves, ranged alphabetically according to subject and author. Most professional librarians are horrified by so simple a system, but for the readers it is a constant joy. Moreover you can take the books home—quite a few of them at a time—and are hardly ever chivvied to return one unless some other reader wants it. This means, inevitably, that you may occasionally not find the book you want on its shelf; but you will see any number “ of other books on the same subject, several of which may prove a good deal more informative than the one you were looking for. If, as I did—and indeed still do—you work most of every day in the Reading Room, you have one of the best collections of reference books in the country ranged all round you. Nowadays there are even computer sockets into which to plug your laptop.