The main entrance hall, leading to a fine marble stairway, is circular in shape, surrounded by a marble colonnade carrying the dome, to which the hall is open through the full height of the building.

It was in this central space beneath the dome that a round table covered with the Union Jack was placed for the signing of the Covenant by the Ulster leaders and the most prominent of their supporters.
To those Englishmen who have never been able to grasp the Ulster point of view, and who have, therefore, persisted in regarding the Ulster Movement as a phase of party politics in the ordinary sense, it must appear strange and even improper that the City Hall, the official quarters of the Corporation, should have been put to the use for which it was lent on Ulster Day, 1912.

The vast majority of the citizens, whose property it was, thought it could be used for no better purpose than to witness their signatures to a deed securing to them their birthright in the British Empire.
At the entrance to the City Hall Sir Edward Carson was received by the Lord Mayor and members of the Corporation wearing their robes of office, and by the Harbour Commissioners, the Water Board, and the Poor Law Guardians, by whom he was accompanied into the hall.

The text of Ulster's Solemn League and Covenant had been printed on sheets with places for ten signatures on each; the first sheet lay on the table for Edward Carson to sign.
No man but a dullard without a spark of imagination could have witnessed the scene presented at that moment without experiencing a thrill which he would have found it difficult to describe.

The sunshine, sending a beam through the stained glass of the great window on the stairway, threw warm tints of colour on the marbles of the columns and the tesselated floor of the hall, sparkled on the Lord Mayor's chain, lent a rich glow to the scarlet gowns of the City Fathers, and lit up the red and the blue and the white of the Imperial flag which draped the table and which was the symbol of so much that they revered to those who stood looking on.