In 1845 it was decided to erect a public clock to better regulate Garrison time. The south-west tower was selected as it was clearly visible to those within the Moorish castle complex as well as to the port and many areas of the North District. During its construction the original Moorish masonry was concealed under a coat of cement. The new tower was named the Stanley Tower in honour of Lord Stanley, the then Secretary of State for the Colonies.
On the 4th December, 1845, the Moorish Castle Clock was inaugurated. The Garrison Orders for the day were to be as follows:
On Thursday, at mid-day, the Clock in ‘Stanley Tower’ will commence striking, and in future regulate Garrison time.
A third dial plate will be put up as soon as it be got from England, to afford Casemates Barracks and Landport, the benefit of a direct view.
When the clock is striking 12 tomorrow, the Royal Standard will be hoisted on the Tower; and, after the clock has struck, a Royal Salute of 21 Guns from a Battery near the Castle will be fired on the occasion of this useful boon to the community having been granted her Majesty’s favour.
David Urquhart's in his Pillars of Hercules published in 1850 mentions the recently unveiled clock tower thus:
The turrets on the walls below have been furbished up to look like cruet-stands, and the staring face of a clock is stuck in a Saracen tower.
In his footnote, Urquhart expresses his disgust at the ‘renovation’ of a medieval tower with the following scathing remark:
This Vandalism was gazetted, and the turret termed “Stanley Tower.”