A painting of the Union Steamship vessel "Phoebe" and dated 1857 on the back, was according to the Late Quentin Nothard, the ship that carried William Nothard to South Africa. In view of the inscription on William's grave it would appear that William arrived in South Africa before 1857.
The Union Steamship Company was established in 1853 but in 1857 aquired a mail contract between Britain and South Africa. Between 1857 - 1862 there was a Cape Assisted Immigration Scheme, of which some 12000 settlers are believed to have taken advantage.
William would appear to be the one baptised at Airmyn Goole Yorkshire England on 11th February 1821. He is buried in St Mary's Cemetery ( Settler's Cemetery) at Port Elizabeth South Africa. His tombstone reads:
"In affectionate remembrance of William Nothard (of Goole Yorkshire) who departed this life 1st June 1880/in the 60th year of his age/also Elizabeth born 7 Nov 1851, died 25 Jan 1853/ Mary born 9 Oct 1855, died 25 Oct 1855/ Elizabeth Jane/ born 13 Oct 1853, died 28 March 1865/ children of the above/ Be ye also ready for in such an hour as ye think not, the son of man cometh."
The name is quite widespread in South Africa. I have a number of family trees sent to me from South Africa but as yet I have not been able to work on these.