Unlike most of the thick, gloppy chowders you see around town, Swan's is more in the nature of a light, revivifying bisque, a briny bowl of bivalves with soul-warming properties ideal for enduring our foggy climate. Fresh, fragrant clam broth, simmering milk, and a dollop of golden butter are the primary components of this piscine elixir, with bits of potato, onion, and clam thrown in for ballast. One heady sniff is like a relaxing stroll by the seaside. Swan's long marble counter is well stocked with oyster crackers and lemon wedges, and flagons of Anchor Steam are available upon request. Another essential aspect of the chowder's tonic properties is the Swan Oyster Depot itself, which has been selling and serving unimpeachably fresh seafood since 1912. Near as we can tell, the establishment's 18 rickety stools date back to the grand opening. The Sanciminos, who've operated the joint since 1946, create such an atmosphere of neighborhood bonhomie, it's impossible to leave the place any way but rejuvenated.