NEW YORK, NY.- From sundials to atomic clocks, the exhibition On Time: The Quest for Precision explores the history of precise timekeeping through rare books that taught readers techniques of timekeeping, announced new inventions, and provided instructions on the construction and use of timekeeping instruments. The exhibition, which is on public view at the Grolier Club, New York City through November 19, 2016, is drawn from the comprehensive collections of the Linda Hall Library of Science, Engineering & Technology, Kansas City, Missouri.

Curator Bruce Bradley tells a timely story with 86 illustrated books dating from the 15th century to the present that graphically and artistically depict the sweep of timekeeping. “These books are fascinating and ornate, as well as informative about the innovations that have led to increasingly precise timekeeping devices,” notes Mr. Bradley. As a complement to the printed books, the exhibition includes a small selection of historical clocks and timepieces from the collection of Grolier Club member Fortunat Mueller-Maerki.

The early books describe techniques for timekeeping with fantastic illustrations of sundials and water clocks. The sunflower clock described and illustrated by Athanasius Kircher in his book, Magnes siue De arte magnetica opus tripartitum (Rome, 1641) shows a detailed, full-page engraving of the sunflower clock floating on a piece of cork with its roots in the water. Vegetable magnetism supposedly caused the flower to follow the sun, so that a pointer fixed in the center would indicate the hour on a clock dial.

A book that featured more traditional types of sundials is Sebastian Münster’s Horologiographia (Basel, 1533). This comprehensive treatise was first issued as Compositio horologiorum in 1531, but it was popular enough to warrant this second enlarged edition just two years later. Both editions illustrate all manner and variety of sundials with beautiful woodcuts, some of which are attributed to Hans Holbein the Younger.

Early mechanical clocks offered several advantages over sundials, such as portability and the ability to show the time during cloudy weather and at night. They lacked precision, however, and had to be readjusted periodically to synchronize them with local solar time.
Even after the appearance of mechanical clocks, books about sundials and how to make them remained popular. Demand for them continued throughout the 16th century and into the 17th.

A book that described and illustrated some of the best astronomical instruments of the sixteenth century is Tycho Brahe’s Astronomiae instauratae mechanica (Nuremberg, 1602). Of the four clocks in his observatory, two of the smaller clocks are shown in the plate of the famous mural quadrant that Brahe used for making observations of star positions. Brahe explained that he used two clocks to reduce errors in recording the exact moment of observation.

The 16th century also saw the first printed depictions of mechanical clocks, published in books by the Italian natural philosopher Girolamo Cardano. The innovation that made mechanical clocks possible, the escapement mechanism, was first illustrated in a seventeenth-century book by Robert Fludd. An English clergyman, William Derham, produced the first practical manual on clock making, The Artificial Clock-Maker (London, 1696), which was popular enough to go through several editions in the early eighteenth century. Much of Derham’s knowledge of clocks came from his friend, the natural philosopher Robert Hooke, who was involved in priority disputes over horological innovations such as the anchor escapement and the balance spring regulator for watches.

Pendulum clocks represented a revolution in timekeeping devices. They had greater accuracy than any other clocks and became standard pieces of scientific equipment, particularly for astronomical observatories. Christiaan Huygens designed the first successful pendulum clock and described it in his classic book on display in the exhibition, Horologium oscillatorium (Paris, 1673). It includes a famous woodcut of the clock’s mechanism.

Another milestone was the marine chronometer built by John Harrison in the 18th century. The Principles of Mr. Harrison's Time-Keeper (London, 1767), includes a preface by Nevil Maskelyne, Astronomer Royal, who insisted on detailed accuracy in the engravings of the chronometer’s mechanism, so others could make duplicates of the watch.

In the 20th century, Nature, a scientific journal known for publishing important new advances and original research, published the description of the first atomic clock, designed and built by Louis Essen with Jack Parry at the National Physical Laboratory in Teddington, England. Atomic clocks are more precise than the Earth’s rotation and led to a new definition of the second at the 1967 meeting of the International Bureau of Weights and Measures in Paris.


Accompanying the illustrated books and journals are a variety of intricately designed horological objects. Included are a selection of sundials, a clepsydra or water clock, a variety of clock maker’s tools, weight driven clocks, marine chronometers, examples of American railroad-grade pocket watches, and an uncommon Accutron desk clock.

A 60-page illustrated catalogue is available which includes short essays and descriptions by Mr. Bradley for each book in the exhibition.