This is the ibook version of the Relativity authored by Albert Einstein in 1916.  The electronic version of the book is available under the Project Gutenberg license. This book is meant only for education purpose.

There are 3 parts in this book. The first part is The Special Theory of Relativity. The second part is the The General Theory of Relativity. The third part of the book is The Consideration of the Universe as a Whole