There are several British artists known as John Mace but none of them fit the person responsible for the paintings and engravings shown below. So far I have been unable to discover anything at all about this particular Mace but it seems evident that he must have spent some time in Gibraltar and that he must have known the place rather well.
Whatever the case, his pictures seem to refer to the Rock both as it appeared before and during the Great Siege of Gibraltar which took place from 1779 to 1783. (See LINK)
An engraving by W.H.Toms of one of John Mace's pictures - it shown the isthmus as it was during the 13th (see LINK) rather than the 14th or Great Siege - both the Devil's Tower (see LINK) and la Torre del Molina are visible on the Isthmus
The tower in the foreground - la Torre del Molino - was destroyed during the "Sortie" (see LINK) which took place in 1782 during the Great Siege
This painting on the other hand was probably painted during or after the Great Siege - the small ships in the foreground were gun-boats used with great effect by the Spanish Admiral Antonio Barceló throughout the Siege
Two views of Gibraltar - top shows the town and the west side, bottom the great sand dunes of the eastern cliffs - both engravings were probably executed at the same time but are difficult to date