Matthys, Robert J.,  1929- <br/><br/>
Accurate clock pendulums / 
Robert James Matthys. 
 - vi, 260 pages :  illustrations ;  26 cm 
<br/><br/>Includes bibliographical references and index. 
<br/><br/> The Shortt pendulum clock, made in the 1920s, was accurate to within one second per year. To achieve that level of accuracy, a pendulum's length must be constant to one part in 15 million for a whole year. Matthys, who was a senior research engineer for about 35 years, gives us the courage to attempt our own amazing feats in accuracy. He describes simple pendulums, the effects of shape, materials and temperature, the complexities of the suspension spring and pendulum rod, the effects of air and the clock case, and special considerations of electronically-driven pendulums. He includes helpful illustrations and references in each chapter. Annotation : 2004 Book News, Incorporated, Portland, OR (booknews.com). 
<br/><br/><label>ISBN: </label>0198529716 9780198529712 
<br/><br/><label>LCCN: </label>2004049237 
<br/><br/><label>Nat. Bib. No.: </label>GBA4Y5616  bnb 
<br/><br/><label>Nat. Bib. Agency Control No.: </label>009698703  Uk 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Clock and watch making.<br/>Pendulum.<br/>Clock and watch making.<br/>Pendulum.<br/>Pendeluhr
<br/><br/><label>Subjects--Index Terms: </label>Component Precision pendulum temperature compensation spring suspension materials Matthys, Robert J. Pendulum science