The Ceylon Calendar of 1843 gives the following listing under 'Residents'.

A.Robb Superintendent Coffee Estate, Hindoogalle, Hewaheta.{This is in the
Central part of Sri Lanka near Matale).

The Fergusons Ceylon Directory of 1871/72 lists the following under Men's addresses.
G.Wait Planter, Peacock Estate. Pussellawa.
W.B.Wait Keeper of Cemetery, Borella, Colombo
Alexander Hebenton Planter, Graham's Land, Badulla
James Wylie Planter Haldemoola, Haldemoola
Richard J Wylie Planter Pita Ratmalie, Haldumulla
A.Robb Planter, Matale
J.Robb Planter, Peacock Estate, Pussellawa
R.Robb Planter Matale
W.Robb Planter, Glen Alpin, Badulla.
W.A.D. Grant Planter, Le Vallon, Pussellawa

The Fergusons Ceylon Directory of 1898/99 lists the following
Wm Robb Planter Spring Valley, Badulla
A.H. Robb Planter,Chesterford,Veyangoda
Alex Hebenton Jr Planter Glen Alpin Badulla.
Incidentally Glen Alpin includes the Estate earlier known as Graham's Land. You could see
therefore that Alex Hebenton, his father, and W. Robb worked on the same estate.

1 Alexander Bissett Robb b.1801 (Superintendent Coffee Estate, Hindoogalle, Hewaheta)
…2 Elizabeth Robb 1854-1894 + W.A. Donald Grant (1074) (originally from Golspie, Sutherland, Scotland, coffee planter in the Kandy district/ Planter, Le Vallon, Pussellawa) d: Queensland

……3 Annie Elizabeth Grant b.1875 (nurse in Colombo and left from there to go to India in 1901)

…2 Margaret Robb b.1848 + Walter Wait
…2 Isabella Robb b.1850 + Alexander Hegenton (Planter, Graham's Land [Glen Alpin], Badulla)

……3 Nellie b. 1869
……3 Susan b. 1870
……3 Bella b. 1871
……3 Alexander b. 1871 m Nita
……3 Maggie b. 1873 m ? Stevenson
……3 James b. 1874 m Greta
……3 Anne b. 1876 m Alexander Buckney
………4 Winnie
………4 Violet
……3 Charles b. 1877 m Kate Webster
………4 Ian
………4 Elsie
………4 David
………4 Kitty
……3 David b. 1877
……3 Andrew b. 1881 d. 1917
……3 Robert b. 1883 d. 1918
……3 John b. 1886

…2 Mary Robb (b.1851) + John Wylie
…2 Alexander Robb b. 1846
…2 William Robb b. 1852
…2 Charles Robb b. 1853