Dummer was the son of Thomas Lee Dummer. On his father"s death in October 1765, he succeeded him to the family estate at near Winchester, Hampshire as well as estates at Weston and Netley, near Southampton and at Horninghold in Leicestershire. He also took his father"s parliamentary seat at Newport.
In 1768, he lost his seat to Hans Sloane who was in the patronage of the influential Hans Stanley. In 1769, he became Member of Parliament for nearby Yarmouth (1769–1774). Originally, the election was in favour of William Strode and Jervoise Clarke, but on petition the election was reversed in favour of Dummer and Major General the Honorary
George Lane Parker.
In the 1774 election, Dummer stood for election at Downton in Wiltshire. The following year, he was elected to represent Wendover in Buckinghamshire before returning to Hampshire in 1780 as Member of Parliament for Lymington until his death in 1781. In May 1773, he was elected a Fellow of the Royal Society.
On his father"s death in 1765, Dummer inherited the family estate at In 1770, he purchased the City Cross (also known as the Buttercross) from the Corporation of Winchester, intending to have it re-erected at Cranbury.
When his workmen arrived to dismantle the cross, they were prevented from doing so by the people of the city, who "organised a small riot" and they were forced to abandon their task. The agreement with the city was cancelled and Dummer erected a lath and plaster facsimile, which stood in the park for about sixty years before it was destroyed by the weather.
Undaunted by his failure to acquire the City Cross to grace the estate, Dummer turned his attention to the ruins of Netley Abbey, which he also owned, and moved the north transept of the abbey to, where it can be still be seen as a folly in the gardens of the house (at 51°00′08″North 01°21′49″West). The ruins comprise an arch, the base of a pillar, and a scaled-down gateway tower.
The rear of the gateway has been made into a keeper"s lodge, and is known to the village of Otterbourne as "the Castle" and is marked as such on the Ordnance Survey map.
Dance, who was later to become Sir Nathaniel Dance-Holland, Baronet, was the brother of George Dance, who had designed the present-day house at Cranbury, built in 1780.
Royal Society; 12th Parliament of Great Britain. 13th Parliament of Great Britain. 14th Parliament of Great Britain.
15th Parliament of Great Britain.
