Page:Philosophical Review Volume 30.djvu/228

214 developed "general" theory. The text is intended for attentive readers without special training in physics or mathematics, and its aim is "to present the main ideas in the simplest and most intelligible form, and on the whole in the sequence and connection in which they actually originated." Einstein goes about this task in the right way. He does not talk about the theory, he actually develops its characteristic features. The exposition gains in clearness by the use of well chosen concrete illustrations, and each distinct step of the argument is presented in a separate short section with its own caption. This is exactly the sort of thing that the serious general reader wants. Two brief appendices describe the Lorentz transformation and Minkowski's four-dimensional space, for readers who have a little mathematics; and the author has provided a new appendix on the experimental confirmations of the theory. The translator has added a portrait, a biographical note, a short bibliography, and an index. The translation is clear, and the book is well printed.

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