, showing the main west façade on St Martin's Le Grand. Smirke's new General Post Office opened on 23 September 1829. It was the UK's second purpose-built post office;
Dublin's GPO (completed in 1818 to a design by Francis Johnston and still in use) predates it. The new Post Office was 'one of the largest public edifices now existing in the City of London' in 1829.
Design and operation The Post Office was built in the Grecian style with
Ionic porticoes along the main (west) front, and was long and wide and high.
Mail coaches and mail carts The General Post Office was built in the era of the
mail coach, with a driveway leading around the back of the building to a courtyard on the north side where the coaches would assemble. Each night, from all around the country, London-bound mail coaches would set off at different times, so as to arrive at St Martin's Le Grand between 5 and 6 o'clock in the morning; the mail was then unloaded and sorted, ready for delivery at 8am. Then in the evening, the coaches were loaded with sacks of mail destined for
the provinces. The daily departure of the mail coaches regularly attracted crowds of spectators. At 8pm, Monday-Saturday, all the coaches would set off in different directions from St Martin's Le Grand; each would follow its own set route, progressively dropping off mail bags at every
post town on the way to its final destination. There were no deliveries or collections of any kind on Sundays.
The Grand Public Hall Behind the central portico of the Post Office was a Grand Public Hall, forming a public thoroughfare from St Martin's-le-Grand to
Foster Lane; it measured by and had aisles on either side separated from the centre by rows of ionic columns. Members of the public could post letters and other items from inside the hall through
boxes in the wall, from where they would fall into hoppers and be loaded into trolleys to be taken to the sorting offices beyond. There were also windows and offices where payments could be made. Each day, shortly before 6pm (the deadline for the Inland post), there would always be a last-minute rush of people with letters and newspapers to post; the windows above the slots were then opened to facilitate delivery, but were always closed on the sixth stroke of the clock (after which items could be posted at the 'late' window, but only with payment of a surcharge).
Charles Dickens described the daily 6 o'clock rush in a descriptive and detailed article on the workings of the Post Office in 1850. A tunnel and
conveyor system beneath the Grand Public Hall linked the two halves of the building. It was here that letters for and from the provinces were received,
stamped, counted and sorted. The room was a hive of activity at the start of the day, when coaches arrived from around the country laden with letters for London; and at the end of the day, when the letters from London were sorted and stamped before being bagged, and loaded on coaches for delivery to provincial post offices all round the country. Here, each morning, the
letter-carriers would sort their designated letters into different 'walks' before setting off to deliver them. Letters destined for addresses in central London were delivered by the Inland department's own letter-carriers, while those for the suburbs were sent on the under-floor conveyor to the London District office for delivery. Connected with the Inland department was the Ship Letter Office, which transported mail by sea to certain destinations using privately owned ships (at a cheaper rate than the Government-owned packet boats, which were overseen by a different office in the other half of the building). Likewise the
West India Office and the
North American Office, which were adjacent to the Inland Letter Office and managed the transport of mail to and from parts of the British Empire.
Changes and developments Almost as soon as it had opened, the building was found to be short of space.
1830s As early as 1831, a gallery was inserted into the main Inland sorting office to provide extra capacity. The Inland Office now used horse-drawn mail-
vans to convey sacks of letters to the
railway termini where they were loaded on to trains or
Travelling Post Offices. To help with the increased volume of post, a new sorting office was built immediately above the old one, 'suspended from a strong arched iron girder roof by iron rods' (a solution which, though ingenious, left the principal room below entirely deprived of natural light). The
Money Order Office had been established in 1838, in two small rooms at the north end of the building. In the 1840s it operated from a large room adjoining the Public Hall on the south side near the main entrance; but it soon outgrew these premises and in 1846 the Money Order Office was provided with new premises (designed by
Sydney Smirke) just across the road at No. 1
Aldersgate Street. At around the same time the Foreign Letter Office was made an adjunct to the Inland Letter Office (both administratively and physically): an arch was inserted in the north wall of the Inland Office beyond which several rooms were knocked together to create a new sorting office for the 'Colonial and Foreign Division' (measuring by ), which was linked by way of a mail-hoist to the Ship-letter Office above. Work requiring bright light was conducted in poorly illuminated areas, odours spread from the lavatories to the kitchens, while a combination of gas lighting and poor ventilation meant that workers often felt nauseous. From 1868, the GPO experimented with the services of the
London Pneumatic Despatch Company, which operated a pneumatic tube from
Euston railway station for the delivery of mail, but the experiment was unsuccessful and terminated in 1874. In 1870, with space in the building remaining at a premium, the Grand Public Hall was closed and converted into another additional sorting room; slots were then installed under the portico for members of the public to post their letters. As part of these alterations a new upper floor was inserted along the double-height length of the hall to provide more space for the sorting of newspapers. ==Additional buildings==