At the turn of the century, if you'd come into the dark, oak paneled hallway of a brownstone house at 296 Beacon Street, Boston, you'd meet first, Augustus the miner bird. Then close to the hearth stone, you'd find the Siamese, who glides noiselessly. Up the long stairway you'd find two tamed squirrels, and in the master bedroom, pacing tensely across the rugs, you would find Chief Justice Oliver Wendell Holmes and his wife.