These are all entries from Slater's Royal National Commercial Directory of Scotland
1867, DUMFRIES-SHIRE, LOCKERBIE AND THE PARISHES OF DRYFESDALE, SAINT MUNGO, TUNDERGARTH AND APPLEGARTH
FARMERS
In Dryfesdale Parish
Latimer George, Scroggs mill
In Tundersgarth Parish
Renwick John, Scroggs
MILLERS
Latimer, George, Scroggs Mill
****
1882, DUMFRIES-SHIRE, LOCKERBIE
FARMERS
In Tundersgarth Parish
Rogerson Andrew, John & William, Scroggs
FARMERS
In Dryfyrsdale Parish
Latimer George, Scroggs mill
MILLERS
Latimer George, Scroggs Mill
***
1893, DUMFRIES-SHIRE
FARMERS
Carlyle, Bros., Scroggs, Tundergarth, Lockerbie
Latimer Geo., Scroggs mill, Lockerbie
***
1896, DUMFRIES-SHIRE
SAW-MILL OWNERS
Latimer George, Scroggs Mill, Lockerbie
***
Also this entry in the 1882 Annual Report of the Fishery Board for Scotland reveals who actually owned the mill:
Obstructions to the Passage of Fish–
...
2. With regard to the obervance of bye-laws [a list of cases, including]
On the Milk– No heck at intake or tail of the mill race at Scroggs Mill, belonging to the Earl of Mansfield, but there is a heck across the lade at the entrance to the wheel, which is placed close on the Milk water.
From the Oxford Shorter English Dictionary:
heck
noun, chiefly Scot. and N. English
A grating or frame of parallel bars in a river used to obstruct the passage of fish or solid bodies without obstructing the flow of water.
lade
noun, chiefly Scot.
A channel for leading water to a mill wheel; a mill race.