The fire broke out around 10pm on November 15, in Kirkwood’s engraving workshop on the second floor of the Old Assembly Close, a narrow alleyway just off the High Street.
The city of Edinburgh had formed a permanent fire brigade only two months earlier under its new firemaster James Braidwood. Although this new force arrived quickly with their custom-built fire engines, they had difficulty locating a water supply and did not begin to tackle the blaze until 11pm, by which time six stories of the building were ablaze.
Due to the narrowness of the alleyway, the fire spread quickly to adjoining buildings, first affecting those to the east of Fishmarket Close and later spreading along the roofs of the Royal Mile through embers carried by a southwesterly breeze. By midnight, four tenements were ablaze as the fire advanced towards the Cowgate.
The Old Assembly Hall at the centre of the fire (which had given its name to the close) was destroyed during the night. Around midday on Tuesday, November 16, the spire on the Tron Kirk caught fire and molten lead began to pour from its roof. Although firemen succeeded in reaching the roof of the church, the fierceness of the blaze forced them back.
At 10pm on Tuesday evening a secondary outbreak occurred in buildings on the corner of High Street and Parliament Close (renamed Parliament Square after the subsequent rebuilding of the affected area). This blaze started on the top floor of an eleven-story building overlooking the Cowgate.
This led to claims of divine intervention and punishment from God, as well as deliberate fire-raising. It was more likely the result of a still smouldering ember. This second phase of the fire began to consume the buildings on the east side of Parliament Close. Efforts focused on saving the adjacent Parliament Hall and Law Courts, and stopping the fire leaping to St Giles Cathedral.
A young David Octavius Hill made watercolour sketches during this second phase, viewing the fire from the west. By 5am on Wednesday 19 November, the fire was described as “grand and terrific”. The building housing the Edinburgh Courant collapsed and the fire continued to spread down Conn’s Close towards the Cowgate.
Due mainly to a downpour of rain, the conflagration was brought under control by Wednesday evening, although small outbreaks continued and final smouldering did not cease until Friday, 21 November. Over the following days, engineers from the castle and navy were employed to pull down the highly unsafe remnants of buildings left precariously balanced along the closes.
The fire attracted huge crowds of spectators including a large number of Law Lords: Charles Hope, Lord Granton (Lord President of the Courts); John Boyle of Shewalton (Lord Justice Clerk); Sir William Rae of St Catherines (Lord Advocate); John Hope (Solicitor General, later Lord Hope); the Dean of Faculty; and Henry (later Lord) Cockburn.