I leave the vault, and as the guard closes

题目：

I leave the vault, and as the guard closes the door, a marine archaeologist asks if I want to see anything else. As an example he shows me an astrolabe, a navigation tool that preceded the sextant. Few have survived. "We have three of the oldest known," he says. He directs me to a paper on astrolabes written by a Cuban colleague, who quoted a 16th-century instruction: "He who wants to take the sun with an astrolabe at sea, must be seated near the main mast, the place where the boat oscillates the least and is quiet." I want to take the measure of Cuba’s past, so I tell the archaeologist I would like to go to the place where the plain things are. I am here not only to see treasures that glitter but also to see and touch objects that illumine moments of the past. Smiling, he takes me into storage rooms where he and other archaeologists preserve cargoes from four centuries of wrecks. Jumbled on these shelves is the stuff of Cuba’s long reign as counting house and command center for Spain’s New World colonies. I see knickknacks destined for one of the annual 18th-century trade fairs, where Cubans bought imports from Spain. I also see, pallid from centuries in the sea, dozens of little painted ceramic dogs, lions, cats, and deer later shipped from England. Stacked nearby are sets of dinner dishes, tankards, an hourglass, a bottle of very Old Spanish wine. On another day, in fading light, I walk the ramparts of E1 Morro, its lighthouse standing tall over Havana’s harbor. The old fortress, by day a warren of tourist stops, changes by night, looming deeper into the shadows of Havana’s past. As torches light the darkness, I watch Cuban soldiers, costumed as 18th-century Spanish sentries, march along the ramparts of the Castillo de San Carlos and fire a cannon that salutes the end of day. In Spanish times the cannon signaled the closing of the city gates and the drawing of a great chain across the harbor. Now the nightly ritual keeps open the sea-lane of memory between colonial past and present nationhood. Near the waterfront of Old Havana stands the Palace of the Captains General. Once the headquarters of the Spanish bureaucracy that governed Cuba, the palace now is the Museum of the city. Light and shadow play along its walls of coral limestone. Royal palms rustle in its lust courtyard. Up a stone stairway a gallery leads to the spacious office of Eusebio Leal Spengler, historian of the city of Havana and preserver of its past. A slight, precise man in a well-tailored dark suit, he is the obvious ruler of the palace. We had hardly shaken hands before he began rapidly talking about Havana, a city he sees simultaneously in past and present. The jewels I had viewed in the vault were about to become part of the treasure he guards for Cuba. He has selected an old fort to be their new home. "This," he said with a sweep of his hand, "is the city that changed history. Because of a decision by Philip Ⅱ all ships had to gather here to carry treasure back to Spain. And what treasure! Silk and aromatic wood from China, emeralds, silver."