Question: The person William Mein Smith worked as the Surveyor General for from 1840 to 1843 was born on what date?

Context paragraphs:
Surveyor General of Victoria: The Surveyor General of Victoria is the person nominally responsible for government surveying in Victoria, Australia.  The original duties for the Surveyor General was to measure and determine land grants for settlers in Victoria.  The position was created at the time Victoria became a separate colony in 1851 (see History of Victoria).

Alexander Aitkin: Sir Alexander Aitkin was a Scottish surveyor.  He served as deputy surveyor general and later the first surveyor general of Upper Canada.

Samuel Brees: Samuel Charles Brees ( 1810 – 5 May 1865) was a New Zealand artist, surveyor and engineer.  He was born c.1810.  He was employed by the New Zealand Company and succeeded in his role William Mein Smith.  Brees died at sea on the "La Hogue" off Blackwall, London.

William Mein Smith: William Mein Smith (1798 – 3 January 1869) was a key actor in the early settlement of New Zealand's capital city, Wellington.  As the Surveyor General for Edward Wakefield's New Zealand Company at Port Nicholson from 1840 to 1843, he and his team surveyed the town of Wellington, after finding the land on the Petone foreshore unsuitable, laying out the town belt and other features and making provision for the much debated "tenth" share of the land for local Māori.

Surveyor General of Pakistan: The Surveyor General of Pakistan is the Head of Survey of Pakistan, a National Organisation working department under the Ministry of Defense of the Government of Pakistan.  The Surveyor Generals of Pakistan had been coming from civil as well as military setups.  According to parliament approval, at present Surveyor General of Pakistan is a serving Major General coming from Army Corps of Engineers.  Major General Muhammad Imran Zafar, HI(M) is the current Surveyor General of Pakistan.

Thomas Mitchell (explorer): Lieutenant Colonel Sir Thomas Livingstone Mitchell (15 June 1792 – 5 October 1855), surveyor and explorer of south-eastern Australia, was born at Grangemouth in Stirlingshire, Scotland.  In 1827 he took up an appointment as Assistant Surveyor General of New South Wales.  The following year he became Surveyor General and remained in this position until his death.  Mitchell was knighted in 1839 for his contribution to the surveying of Australia.

Terawhiti Station: Terawhiti Station is one of New Zealand's oldest and largest sheep stations, located along the south coast of Wellington.  Terawhiti Station has seen a diverse range of land uses over the past 160 years.  Originally a cattle station, Terawhiti grew into one of New Zealand's largest sheep stations before returning to cattle in 1993.  The station originally consisted of the upraised marine terrace at Tongue Point on Wellington's south coast and was purchased by two Wellington businessmen Samuel Revans and William Mein Smith following the sale of Crown 'waste lands'.  Captain William Barnard Rhodes later bought Revans’s land at Tongue Point stocking it with shorthorn cattle.  His young manager, James McMenamen (known as Terawhiti Jack), later bought the Tongue Point farm and neighbouring blocks, forming Terawhiti Station and (later) Te Kamaru Station (at Te Ika a maru Bay).

Edward Gibbon Wakefield: Edward Gibbon Wakefield (20 March 1796 – 16 May 1862) was a British politician.  He is considered a key figure in the early colonisation of South Australia and New Zealand.

Surveyor General of Sri Lanka: Surveyor General of Sri Lanka is the head of Department of Survey of Sri Lanka.  The post was established in 1800 with the formation of the Surveyor General's Department.  The current Surveyor General is P. M. P. Udayakanta.

William Robinson (architect): William Robinson (1645–1712) was the Surveyor General of Ireland from 1670/71 until 1700.  Born in England, Robinson was appointed to the post of Surveyor General by John Berkeley in his first year of office as Lord Lieutenant of Ireland.

Supporting paragraphs: William Mein Smith Edward Gibbon Wakefield
Answer: 20 March 1796