This book is so rare that a recent WorldCat search, October 23, 2012 revealed that only 62 libraries in the world have a copy of this 1876 edition.
This is an extremely rare freethought title that consists of eleven capsule biographies of Madame Roland, Mary Wollstonecraft Godwin, Mary Godwin Shelley, George Sand, Harriet Martineau, Frances Wright D'Arusmont, Emma Martin, Margaret Reynolds Chappellsmith, Ernestine L. Rose, Frances Power Cobbe, and George Eliot (Marian Evans Lewes).
This title is one of the original publications by Somerby's company, before it was absorbed by The Truth Seeker Company. There is a second edition of this work published by the Truth Seeker Company. There is an ad for this work on page 26 of the catalog at the end of the "Truth Seeker Annual and Freethinker's Almanac", dated E. M. 286.
Sara Underwood was the sister of Benjamin F. Underwood, a freethought writer and lecturer, Civil War Veteran, who in 1887 founded The Open Court in Chicago.
If you want to know about women's contribution to the freethought of this age, this is the volume to read.