THE MARBLE ARCH.
The dire effects of London smoke are only too obvious to all who look upon this noble structure. Originally erected as a gateway to Buckingham Palace by George IV., it cost no less than £80,000 but when the eastern façade of the Queen's London residence was completed, in 1850, it was taken down, and in 1851 was placed in its present position at Cumberland Gate, where Oxford Street and Edgware Road meet, at the north-east corner of Hyde Park. It is in the style of the famous Arch of Constantine at Rome; the reliefs on the north side of it, the side presented by our view, are by Westmacott, and those on the south side by Bailv, and the gates are of bronze.
source: The Queen's London : a Pictorial and Descriptive Record of the Streets, Buildings, Parks and Scenery of the Great Metropolis, 1896