Question:
Which employer did Thomas William Walker work for in Oct, 1940?

Context:
 Thomas William Walker works for University of Manchester from Jan, 1941 to Jan, 1946. 
 Thomas William Walker works for King's College, Newcastle-upon-Tyne from Jan, 1958 to Jan, 1960. 
 Thomas William Walker works for Rothamsted Research from Jan, 1939 to Jan, 1941.

Answer:
Rothamsted Research