In 1785 somebody calling himself Roberts produced a series of large - 28 x 23 cm - and very detailed engravings of Gibraltar some of them taking in various event of the Great Siege of 1779 - 1783.
I am not sure who Roberts was or when and why he happened to be in Gibraltar but he must have visited the Rock at some time or another. The picture of the floating Batteries acknowledges that it was based on a drawing by L. Sandby of the 12th Regiment but the rest appear to be his own work.
The words 'Published as the Act Directs' - which appear on all the engravings - might mean that they were published by the express order of either Parliament or some other authority such as perhaps the Governor of Gibraltar. If the latter that would have been General Augustus Eliott.
The boats in the foreground are probably Spanish gunboats
This rather staid representation of the floating batteries fiasco is from a drawing by L. Sandby. The details - fishing boats below the lines, soldiers peering over the Lines and - curiously - what must surely be several local workers carrying an object - must have been Roberts'
A rare view of the eastern side of the Rock
To the left of the Inundation, the Bayside Barrier - to the right Forbe's Barrier
Torre del Diablo on the left, Torre del Molino on the right. In the original the Land Port Gate is clearly visible below the fortifications leading up to the Moorish Castle
A View of the Straits and Coast of Barbary