J G Crowther 
British Scientists of the Twentieth Century [PDF ebook] 

Originally published in 1952. Following on from British Scientists of the Nineteenth Century, this volume covers six eminent British scientists whose work and personality have not receded into the same depth of perspective as their predecessors of the Nineteenth Century, but the tremendous changes following the two world wars have already cut them off sharply from this generation. Crowther concludes that these six scientists arose out of various phases of capitalist development and imperialism.