The post office and its story an interesting account of the activities of a great government department

The foundation stone of the new post office was laid by King Edward VII. on the 10th October 1905, and it was opened for public business on the 7th November 1910. The building is constructed of Portland cement concrete, strengthened by bars of steel, on what is known as the Hennibique reinforced concrete system, and it is the largest building that has yet been erected on this plan. It is an all-in-one-piece building, fashioned out of Thames ballast and cement. Not a single steel joist has been used in the centre construction. Barge after barge from Rotherhithe landed at Blackfriars the mud chalk and gravel which dredgers had scooped up in the lower reaches of the Thames. This ballast was carted direct to King Edward Street, passed through a machine which sorts the stones into various sizes, and then turned into liquid concrete by another wonderful machine which mixes sand, cement, and stones together at a rapid rate. The steel rods and bars interlacing one another extend in a network throughout the building like the skeleton of an animal, while the entire system is embedded in a perfectly connected sheath of concrete. The great feature in this system is the immense reduction in wall thickness. The effect is seen in the lightness and airy nature of the building; one's first impression is that it is certainly not built for eternity, as somebody said the granite structures of Aberdeen are. But this is an illusion: the concrete increases in strength as time goes on, and the passing years only make the building stronger and more capable of resisting weather and the strain of the loads which it has daily to carry.