An obelisk is not the most portable souvenir to bring back from Egypt, as Brian Curran and his fellow authors point out with impeccable clarity: "Obelisks are large. They are heavy." And yet Rome, Paris, London and New York each have one. Why obelisks became the world's most desirable imperial monument is the subject of this beautifully illustrated collaborative work, published by the Massachusetts Institute of Technology's Burndy Library, owner of one of the finest collections of obeliskiana. Like a Rorschach test, obelisks meant different things to different ages: for the ancient Egyptians they were the connectors between sky and earth, denoting the pharaoh's divine right to rule. In the modern psychoanalytic age, they became phallic symbols, although their priapic potential had been noted when London raised its obelisk on the Embankment in 1878: "a naughty music-hall song celebrated the real use to which Cleopatra had put her needle." Scurrilous indeed, though apparently it is Thutmose III's needle, not Cleopatra's.