Describe the Three Cripples pub in your own words. How does this add to the novel's atmosnphere?

The Three Cripples, or rather the Cripples: which was the sign by which the establishment was familiarly known to its patrons: was the public-house in which Mr. Sikes and his dog have already figured. Merely making a sign to a man at the bar, Fagin walked straight up stairs, and opening the door of a room, and softly insinuating himself into the chamber, looked anxiously about: shading his eyes with his hand, as if in search of some particular person.

The room was illuminated by two gas-light; the glare of which was prevented by the barred shutters, and closelydrawn curtains of faded red, from being visible outside. The ceiling was blackened, to prevent its colour from being injured by the flaring of the lamps; and the place was so full of dense tobacco smoke, that at first it was scarcely possible to discern anything more. By degrees, however, as some of it cleared away through the open door, an assemblage of heads, as confused as the noises that greeted the ear, might be made out; and as the eye grew more accustomed to the scene, the spectator gradually became aware of the presence of a numerous company, male and female, crowded round a long table: at the upper end of which, sat a chairman with a hammer of office in his hand; while a professional gentleman, with a bluish nose, and his face tied up for the benefit of a toothache, presided at a jingling piano in a remote corner.