By what alchemical process do things in the United States become frozen at specific temporal junctions? Who, for example, decided that diners up and down the country should remain locked somewhere in the nineteen-fifties? The luncheonette, a subspecies of diner, harkens back to the interwar period, to Dos Passos's "Manhattan Transfer" and men scarfing meaty sandwiches and pickles before loping off into the growing metropolis to find honest work. Several originals from this era remain; the best of them is probably the Lexington Candy Shop, which dates from 1925 and serves thick hamburgers and hot tuna melts to Upper East Siders in a hurry.