George Thomas (surveyor)

[1] In November 1806, according to the UK National Archives, George Thomas was among a number of sailors from the American Brig Harry and Jane pressed into the Royal Navy after their ship was apprehended "trading with the enemy" during the siege and blockade of Montevideo.[2]: 212 .

The Royal Navy ship that captured Harry and Jane in 1806 was HMS Medusa under the command of the Honourable Duncombe Pleydell Bouverie.

Bouverie was himself an accomplished surveyor, and on return to England in 1807 published Sailing Directions for the Río de la Plata.

The campaign involving 40,000 troops in support of Austria in its conflict with France, was a disaster, due largely to disease.

In 1813 he was again in the Scheldt, as master of pilots on HMS Impregnable, flagship of the Admiral the Duke of Clarence (later King William IV).

[2] Thomas commanded the Investigator until 1836[8] In 1816 he was surveying the approaches to Dublin, and made some critical comments about Howth Harbour which caused considerable controversy.

[9] In 1817 he was involved in a collaboration with the Ordnance Survey and Jean-Baptiste Biot representing the French Academy of Sciences to make pendulum observations in Shetland.

In this area with many treacherous shoals, attempts had been made to use floating marker buoys[13] but these had tended to break loose in the strong currents.

The distance was much too great for direct triangulation from land, but Thomas was able to use various marks including a wreck, light vessels, and temporary stations on sandbanks to bridge the gaps.

[4]: 105 Over the following years, Thomas trained several notable surveyors, including his son Frederick, while returning to the Forth, completing several more triangulations in the outer Thames, and making surveys of the Orkney and Shetland Islands.