PBC says he was born on the way to Australia and was therefore given the name Pacific. In 1874 he took his family to England. They lost all their money in 1889 when the Banks collapsed.

They had eleven children. I presume I have allocated the correct parents to him. As the last child born in Australia was David in 1876, it would appear that they did not go to England in 1874.

Listed in the NSW Births are 9 children Phoebe Florence, Rachel S, Helena Georgina, Minnie C, Leah May, Zillah L, Nathan, Samuel, and David who died the year of his birth. The family is listed in the 1881 census for England at 49 Clanricarde Gardens Kensington the home of his mother-in-law. Their (11) children are listed as Florence Phoebe (18), Rachel Sulan(16), Minnie Charlotte (13), Leah May (11), Zillah Louisa (10), Nathan Cohen (8), Sml Cohen (6), Julia Septima (3), Cissie Octavia (1), Rosie Mabel (1 month), Hilna (sic) Georgiana (15).

Louis's age was shown as 47 (born near Australia) and his wife as 40, born New S Wales. They had five servants. Louis's occupation was given as retired merchant. They were the only people with the name Mandelson in the London census. Obviously there are some spelling errors in the transcription in the listing, but above is how they were listed. They are reputed to have been the parents of 11 children, but David was another, born and dying in Australia. I wonder if 'Bessie' is an error. Jessop's tree shows her as marrying J Burns with a daughter Barbara. I now suspect that Frank T Bernstein became Burns.