Harriet E. Wilson died in 1900.
David G. Walker was born in 1946.
Barbara G. Walker was born in 1930.
Ian G. Walker was born in 1958.
Answer is $1600
G. I. Walker has written: 'The physical health of prisoners'
P. G. Walker has written: 'The Cabinet'
G M. Walker has written: 'Traffic flow through roundabouts'
Louise G. Walker has written: 'Thomas Hale, 1637 emigrant'
Harriet Parr was born in 1828.
Harriet Mellon was born in 1777.
Harriet Dobbs was born in 1808.