The names on the spines of the Encyclopaedia Britannica form a litany. As a child, I browsed my way from Baltimore to Braila, Extraction to Gambrinus, with a special stop at P-R: Plants to Raymond of Tripoli. That was from the 14th edition, with sombre dark blue spines instead of the brown, blue and gold of later editions; the music of the Britannica’s spines would change through each edition. (The first, issued in just three volumes in 1768, went from Aa-Bzo and Caaba-Lythrum to Macao-Zyglophyllum, for those who were wondering.)