Plaque

Lambeth Bridge has an obelisk at each corner, each with a plinth with four sides, each with a large plaque. All but 3 of these 16 plaques are blank. The obelisks at the north-west and south-east corners each have a plaque with the same text (listing the architects, engineer, etc).  The obelisk at the south-west corner has a plaque with 'opening' text so this is probably where the opening/unveiling ceremony took place.

The firm that actually built the bridge is not mentioned on any of these plaques. Which rather suggests that the small plaque to Dorman Long is making up for an oversight.

Our photo is a foreshortened image of the obelisk at the north-west corner.