New York: Oxford University Press, (1992.). First edition - A book for older children - or even adults - which explores the changing ways of thinking about time, the emergence of the calendar and the history of timekeeping and the many different devices that have been created over the years -- among them, sun-dials, water-clocks, sandglasses, calibrated candles, water escapments, pendulum clocks as well as mechanical, electrical and quartz clocks -- even atomic clocks. Slightly oversized format, profusely illustrated with black and white photographs and drawings. A title in the Discoveries and Inventions series. Bibliography, index. 64 pages. ISBN: 0-195209680.

Boston: D. C. Heath & Co., 1938. Hardcover - Designed to introduce older children to ways of telling time throughout the ages, by interweaving, in a chronological order, a girl's and a boy's experiences as they learn about time-telling devices of different periods. Illustrated in black and white. Index. 234 pp.