In the 1851 census index there is a William Middlemass born in Norham, NBL
around 1815. Although I have not yet recognised him in 1881 two of his sons
will have 'disappeared'.

The family in 1851 census index for Berwick upon Tweed is

Middlemass William; birthplace - Norham; head; farm steward; age - 36
Middlemass Margaret; birthplace - Wooler; wife; age - 34
Middlemass Mary; birthplace - Ford; daughter; scholar; age - 13
Middlemass Alexander; birthplace - Ford; son; scholar; age - 11
Middlemass Jane; birthplace - Norham; daughter; scholar; age - 9
Middlemass William; birthplace - Norham; son; scholar; age - 7
Middlemass John; birthplace - Norham; son; age - 5
Middlemass Margaret; birthplace - Norham; daughter; age - 2


In 1881 Alexander and William along with another brother and sister are
written up as follows:-

Dwelling: Seaton House
Census Place: Boulmer & Seaton House, Northumberland, England
Source: FHL Film 1342238 PRO Ref RG11 Piece 5125 Folio 8 Page
9
Marr Age Sex Birthplace
Alexander MIDDLEMIRE U 41 M Ford, Northumberland, England
Rel: Head
Occ: Farmer Of 248 Ac Employing 5 Men 1 Boy
William MIDDLEMIRE U 35 M Norham, Northumberland, England
Rel: Brother
Occ: Farmer
Catherine MIDDLEMIRE U 27 F Lowick, Northumberland, England
Rel: Sister
Occ: Farmers Sister
George MIDDLEMIRE U 21 M Lowick, Northumberland, England
Rel: Brother
Occ: Farmer

I came across another funny name MIDDLENNET in 1881 and it also turns out to
be a family name. The following is the 1881 extract

Dwelling: Coupland
Census Place: Coupland, Northumberland, England
Source: FHL Film 1342239 PRO Ref RG11 Piece 5134 Folio 70 Page
13
Marr Age Sex Birthplace
George MIDDLENNET M 30 M Kirknewton, Northumberland, England
Rel: Head
Occ: Coachman (Dom)
Margaret MIDDLENNET M 22 F Scotland
Rel: Wife
James MIDDLENNET W 66 M Wooler, Northumberland, England
Rel: Father
Occ: Ex Coachman (No Occ)
Robert MIDDLENNET U 28 M Kirknewton, Northumberland, England
Rel: Bro
Occ: Carpenter