Pantheon's "Beginners Books" resemble a kind of updated version of the old Classics Comics. Jonathan Miller offers a competent but by no means extraordinary biography of Charles Darwin, focusing on the publication of "The Origin of the Species" in 1859. His later work, including the important "The Descent of Man and Selection in Relation to Sex" (1871), receives short shrift.
Joseph Schwartz's volume on Einstein seems more superficial, possibly because the ideas involved are more abstruse. It's unlikely that anyone will understand as arcane a concept as the Lorenz Contraction after reading his explanation, nor does he include much information on current research confirming or disputing Einstein's hypotheses. (The recent PBS series, "The Mechanical Universe," explained this material far more cogently, using computer graphics and other effective visual aids.) The illustrations to both books, fussy collages of old and new black-and-white drawings, muddle the text instead of illuminating it. Additional volumes in the series are devoted to Marx and Freud.