SUNDIALS: History, Theory and Practice by...

SUNDIALS: History, Theory and Practice by Rene R.J. Rohr, translated from the French by Gabriel Godin (Dover: $11.95, 142 pp.). Originally published in 1965, Rohr’s study offers an overview of the earliest time-keeping device. Some readers may prefer to skip the explanations of the trigonometric basis of sundials, but the chapters devoted to their history and aesthetics make interesting reading. Many sundials bear the inscription, utere non reditura: “Use it, it won’t come again.”