The People of Gibraltar
1704 - Devil's Tongue - Devil’s Tongue Battery 

The Rock from Devil’s Tongue  ( 1880s – Unknown )

The oldest reference I can find that mentions the Old Mole as the Devil’s Tongue is in John Drinkwater’s (see LINK) history of the Great Siege which was published in 1786 but refers to events that occurred from 1779 to 1783:
The Old Mole, to the West of the grand battery, forms also a very formidable flank, and, with the lines, a cross-fire on the causeway and neutral ground. This battery has been found so great an annoyance to the besiegers, that by way of distinction it has long been known under the appellation of the Devil’s Tongue.
His contemporary, Samuel Ancell (see LINK) who served as a military clerk on the Rock during the Great Siege also mentions the place in his letters to his brother:
A party assembled at the lower extremity of the old Mole-head (or Devil’s Tongue) . . . 
Not long after in an edition of the Gentleman’s Magazine (see LINK) dated 1804 a certain "Nauticus" wrote:
 . . . the Lazaretto is also at the north end, where are also most of the small craft and merchants  . . .
To which the editor added as a postscript: 
Near this place is a battery terminating in the sea, called the Devil’s Tongue.

One of the first maps in which the Old Mole is identified as the “Devils Tongue”   ( 1840 – W. Hughes )

Again in his 1900 History of Gibraltar which was published in 1900, Frederick George Stephens (see LINK) takes his cue from Drinkwater and more or less quotes him verbatim – although in his case he unambiguously attributes its original name to the enemy.
The Old Mole, to the west of the Grand Battery, joined with (other) lines to pour a tremendous cross-fire on the cause-way and Neutral Ground. So great an annoyance did this battery prove to the besiegers, that, by way of distinction, they named it the Devil's Tongue. . . . 
R. Stewart Patterson (see LINK) in his article on Gibraltar Street Nomenclature dated 1884 gives us both alternatives without specifying which one was the original version:
Old Mole: Lengua del Diablo, Devil’s Tongue
But long before that - during the mid 16th century for example - the “Old Mole” as such, (see LINK) consisted of a simple breakwater rather than a properly constructed pier.

( 1567 – Gibraltar - Anton Van Den Wyngaerde - detail ) (See LINK

During the early 17th century, there were still no signs of any battery having been built on it. .

Plans for the repairs of the Old Mole (see LINK)    (1608 1608 - Cristobál Rojas ) (See LINK)

It is very possible that a few defensive guns were in placed on it by the late 17th century and that they were used - albeit ineffectively - against the Anglo-Dutch forces in 1704. 

Cannon fire from the Old Mole  ( 1712 – G. Van Keulen – detail ) (See LINK

But it was during the early 18th century that British engineers restructured the Old Mole and finally added a proper battery of considerable power. The 13th Siege - often referred to as the Gunners’ War - saw raking fire from its guns and mortars which caused considerable damage against Spanish forces on the isthmus. 

            13th Siege ( 1727 -  Puschner )

13th Siege  ( 1744 - R.Erskine and G. Knowles )

Given all this I have little doubt that the English Devil’s Tongue is a direct translation of an original Spanish version - Lengua del Diablo - both names of which must have come into common usage during the early 18th century after Gibraltar had been captured from Spain by Anglo-Dutch forces. (See LINK

As late as 1829 military men such as the Captain of the USS Somers - Alexander Slidell-Mackenzie (see LINK) - continued to be impressed by the fire-power of the battery in question:
These batteries (on the upper Rock) are, however, more formidable in appearance than in reality. A shot from so great an elevation may, it is true, be projected within the works of the besiegers; but then it only strikes in one place, where it buries itself in the sand; whereas the Devil's Tongue, which forms the mole, and is upon a level with the neutral ground, sweeps an extent equal to the range of its cannon, and licks up all before it.

Captain Alexander Slidell-Mackenzie

In 1841 the Gibraltar born Mrs Francis Elizabeth Davies (see LINK) in her Memories of Gibraltar was equally impressed:
The Devil’s Tongue, the formidable grinning of whose teeth (i.e. cannon) assure us that a most fiery member that tongue would prove – one that would out-clamour all the shrews in Christendom. . . . 
The battery had in fact fallen silent for quite a few decades after the end of the 13th Siege but was nevertheless anything but forgotten. Perhaps the fact that the view from the western end of the Devil’s Tongue had become a favourite spot from which to paint views of the entire western side of the Rock of Gibraltar had something to do with it. 

 ( 1816 - Whitcombe Sutherland )

 (Mid 19th century – Unknown )

( 1835 – Allen )

(Mid 19th century – H. W. Koogkamer  )

In the later part of the century photographers took over, the first of many being Alfred Capel Cure. (See LINK) His original method of splicing several photographs in order to obtain a picture that included the complete outline of the Rock was copied my many others right up to the 20th century.

( Mid 19th century – Unknown )

By 1864 several if not all of the Devil’s Battery guns had been turned around to cover the harbour area.

Late 19th century     ( Magic lantern photograph )

Late 19th century   ( 1890s - G Washington Wilson )  (See LINK

( 1889 – From a photo by G. Dautez )   (See LINK

Reviewing the above it is curious to remember that painting, sketching or taking photographs of military installations on the Rock, were frowned upon by the authorities. One needed a permit to do so. The sheer number of extant examples of the view of the Rock from Devil’s Tongue suggests that for some reason permission not just to paint and photograph but to enter what was in effect a military area seem to have been easily forthcoming in this particular case.

By the mid 20th century the Devil’s Tongue Battery had lost its military usefulness and the Devil’s Tongue itself disappeared under a program of newly reclaimed land and a heavy dosage of housing developments - a shame perhaps from a heritage point of view but good to realise that at the very least the guns of the Devil’s Tongue would never again be fired in anger.