The stone column, very like a Roman altar, standing on three steps and a square panelled plinth, and placed in a meadow on the north bank of the river, is known variously as ‘Staines Stone,’ and ‘London Stone.’ It marks the place where the upper and lower Thames meet; is the boundary line of Middlesex and Buckinghamshire; and is also the boundary mark of the Metropolitan Police District. Besides these manifold and important offices, it also delimits the western boundary of the area comprised within the old London Coal and Wine Duties Acts, by which a tax, similar to the _octroi_ still in force at the outskirts of many Continental towns, was levied on all coals, coke, and cinders, and all wines, entering London. Renewed from time to time, the imposts were finally abolished in 1889, but the old posts with cast-iron inscriptions detailing the number and date of the several Acts of Parliament under which these dues were levied, are still to be found beside the roads, rivers, and canals around London. Much weather-worn and dilapidated, ‘London Stone’ still retains long inscriptions giving the names of the Lord Mayors who have officially visited the spot as _ex-officio_ chairmen of the Thames Conservancy;-- Conservators of Thames from mead to mead, Great guardians of small sprites that swim the flood, Warders of London Stone, as Tom Hood mock-heroically sings. Above all is the deeply cut aspiration, ‘God Preserve the City of London, A.D. 1280.’ The pious prayer has been answered, and six hundred and twenty years later the City has been, like David, delivered out of the hands of the spoiler and from the enemies that compassed it round about; by which Royal Commissions and the London County Council may be understood. [Illustration: THE STAINES STONE.] [Sidenote: _AD PONTES_] If the Roman legionaries could return to _Ad Pontes_ and see Staines Bridge and the hideous iron girder bridge by which the London and South-Western Railway crosses the Thames they would be genuinely astonished. The first-named, which is the stone bridge built by Rennie in 1832, carries the Exeter Road over the river, and is of a severe classic aspect which might find favour with the resurrected Romans; but what _could_ they think of the other? We may see an additional importance in this situation of _Ad Pontes_ in the fact that between Staines Bridge and London Bridge there was anciently no other passage across the river, save by the hazardous expedient of fording it at certain points. The only way to the West of England in mediæval times, it was then of wood, and zealously kept in repair by the grant of trees from the Royal Forest of Windsor and by the _pontage_, or bridge toll levied from passengers. Still, it was often broken down by floods. The poet Gay, in his _Journey to Exeter_, says, passing Hounslow:--