The Einstein Theory of Relativity: A Concise Statement by Prof. H.A. Lorentz

Relativity: The Special and General Theory is an
introduction to Einstein's space-bending, time-stretching theory of Relativity,
first published in December 1916. Special and General relativity explain the
structure of space time and provide a theory of gravitation, respectively.
Einstein's theories shocked the world with their counterintuitive results,
including the dissolution of absolute time. In this book, he brings a simplified
form of his profound understanding of the subject to the layperson. In the words
of Einstein: "The present book is intended, as far as possible, to give an exact
insight into the theory of Relativity to those readers who, from a general
scientific and philosophical point of view, are interested in the theory, but
who are not conversant with the mathematical apparatus of theoretical physics."
The book is challenging at times but, when approached patiently, proves itself
one of the most lucid explanations of Relativity to be found anywhere.

— Excerpted from Wikipedia, the free encyclopedia.