I hadnt looked at Census entries for John before and just have and I must say I am confused.
1851 Census we have;
Westgate, Northumberland
John HORNSBY, 54, Head, Mar, Clerk to Iron Founder, born Northd, Benton
Sarah Hornsby, 37, Wife, Mar, born Northd, Newton on the Moore
Adolph Ewphotey, 21
1851 we also have;
Heworth, Durham
Sarah Hamsley, 50, Head, WIDOW**, Housekeeper (Pauper) born Alston, Cumberland***
Ann Hamsley, 23, Daug, born Alston
Matthew Hamsley, 20, Son, born Alston
Elizabeth Hamsley, 17, Daug, born Northumberland
Sarah Hamsley, 13, Daug, born Northumberland
Joseph Hamsley, 10, Son, born Benton, Northumberland
Margaret Hamsley, 7, Daug, born Heworth, Durham
Joseph Liddell, 30, Relative
Abraham English, 27, Lodger
Image above is HORNSBY****
BAPTISMS;
St Jude, Knaresdale, Northumberland
ANN Hornsby 08 Apr 1829
MATTHEW Hornsby 01 Aug 1830
Parents JOHN/SARAH
Abode Slaggyford, Father Occp Lead Ore Miner
Haltwhistle;
SARAH Hornsby 18 Dec 1837 to John/Sarah (Railway Lab)
1841 Census
Newcastle upon Tyne, Northumberland
John HORSEBY, 30, Quarryman
Sarah, 30
Ann, 13
Matthew, 11
Elizabeth, 7
Sarah, 3****
Joseph, 1*******
GRO Birth Regs
HORNSBY, JOSEPH, Mothers mn WALTON*******
GRO Reference: 1840 D Quarter in NEWCASTLE UPON TYNE UNION Volume 25 Page 340
HORNSBY, SARAH, Mothers mn WALTON***
GRO Reference: 1837 D Quarter in HALTWHISTLE UNION Volume 25 Page 185
So something wrong here or am I going crazy

Looks to me the John Hornsby who married Sarah Walton 1827 has died by 1851 and is not the same John who died 1854 and was a Clerk to the Iron Founders.