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<h1>horological science</h1>
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<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2022-2 April 2022</h2>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2022-1 January 2022</h2>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2021-5 December 2021</h2>
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<tbody>
<tr>
<td>2 - 26</td>
<td>The Robertson Regulator by John Haine</td>
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<tr>
<td>17 - 21</td>
<td>Looking to confirm with old published experimental data a novel model of Harrison’s Cheeks-and-Ribbon pendulum suspension by Andrea De Marchi</td>
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<tr>
<td>22 -27</td>
<td>Spectral Analysis of Pendulum clocks (Tides, part 6) by Tom Van Baak</td>
</tr>
<tr>
<td>28</td>
<td>Time to renew</td>
</tr>
</tbody>
</table>
<div id="content">
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2021-4 September 2021</h2>
<table>
<tbody>
<tr>
<td>2 - 7</td>
<td>Harrison's Cheeks&Ribbon pendulum suspension greatly differs from a flexure-spring by Andrea De Marchi</td>
</tr>
<tr>
<td>8 - 24</td>
<td>Escapement modeling with Working Model 2D by Bob Holmström</td>
</tr>
<tr>
<td>24</td>
<td>The HSN and BHM website is moving!</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2021-3 June 2021</h2>
<table>
<tbody>
<tr>
<td>2 - 16</td>
<td>How good is Airy? by Andrew Millington</td>
</tr>
<tr>
<td>17 - 46</td>
<td>A New Method for Modelling Escapement Action by Systems Engineering Techniques by J.B. Edwards</td>
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</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2021-2 April 2021</h2>
<table>
<tbody>
<tr>
<td>2 - 4</td>
<td>Is there an optimum pendulum amplitude? by John Haine</td>
</tr>
<tr>
<td>5 - 22</td>
<td>State-Transition Modelling of the Grasshopper Escapement by J. B. Edwards</td>
</tr>
<tr>
<td>23-26</td>
<td>How precise are opto-interrupters? By John Haine</td>
</tr>
<tr>
<td>27</td>
<td>A Modern Version of Warren’s Master Clock by A. Prasil</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2021-1 February 2021</h2>
<table>
<tbody>
<tr>
<td>2 - 22</td>
<td>Clock B – Amplitude Response to Changing Pressure and Temperature by Andrew Millington and John Haine</td>
</tr>
<tr>
<td>23 - 25</td>
<td>Douglas Bateman's "Timekeeping: a Lifetime's Interest in Horology" a Review by Tom Van Baak</td>
</tr>
<tr>
<td>26</td>
<td>Response to Thomas Frank about Feral Clocks by Richard Lamoureux</td>
</tr>
<tr>
<td>27</td>
<td>Duncan Agnew – Data for: Tidal Gravity Variations Measured by a Fedchenko AChF-3 Precise Pendulum Clock</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2020-5 November 2020</h2>
<table>
<tbody>
<tr>
<td>2 - 10</td>
<td>Measuring and Analysing a new Clock – Part 1 by John Haine</td>
</tr>
<tr>
<td>11 - 14</td>
<td>Domesticating a feral clock, part1 by Thomas Frank</td>
</tr>
<tr>
<td>15 - 34</td>
<td>Airy (et al) v. State-Transition Approaches to Escapement Modeling: An Attempt at Reconciliation by J.B. Edwards</td>
</tr>
<tr>
<td>35</td>
<td>Renewal reminder</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2020-4 September 2020</h2>
<table>
<tbody>
<tr>
<td>1</td>
<td>Correction to “The Tangent Rule in Practice” by Pepi Cima</td>
</tr>
<tr>
<td>2 - 11</td>
<td>Just How Good was Fedchenko’s Clock? by Duncan Agnew</td>
</tr>
<tr>
<td>12 - 29</td>
<td>Recoil Escapement Modelling by State-Transition by J.B. Edwards</td>
</tr>
<tr>
<td>30 - 31</td>
<td>Postscript by J.B. Edwards</td>
</tr>
<tr>
<td>32</td>
<td>Bob Mathys – Obituary by Tracy Christenson</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2020-3 July 2020</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 13</td>
<td>Contact microphone devices for mechanical watches by S. R. Thackery</td>
</tr>
<tr>
<td>14 - 28</td>
<td>Continued Examination of the Tangent Rule and its Development for Rectangular Escapement Pulses by John Edwards</td>
</tr>
<tr>
<td>29 - 30</td>
<td>Comments on JB Edwards paper on mathematical modelling by Douglas Bateman</td>
</tr>
<tr>
<td>31</td>
<td>An Unusual Pendulum and a Plea for Help by Price Russ</td>
</tr>
<tr>
<td>32</td>
<td>Harrison Decoded by Bob Holmström + note from John Edwards</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2020-2 May 2020</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 20</td>
<td>Nonlinearity as an essential component in the Modelling of the Assisted Pendulum by J. B. Edwards</td>
</tr>
<tr>
<td>21 - 24</td>
<td>The Tangent Rule in Practice by Pepi Cima</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2020-1 February 2020</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 7</td>
<td>Further Historical Performance of Precision Pendulum Clocks by M. K. Hobden</td>
</tr>
<tr>
<td>8 - 21</td>
<td>Verge & Foliot Escapement Experiments by Bob Holmström</td>
</tr>
<tr>
<td>22 - 24</td>
<td>An Electrical Engineer Looks at a Watch – Brief Notes on a Lecture by Prof. Gerald Sussman by David MacMillan</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2019-5 December 2019</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 9</td>
<td>A Note on Precision Pendulum Clocks and Allan Deviation by M. K. Hobden</td>
</tr>
<tr>
<td>10 - 32</td>
<td>State-Transition Models for Simulating Nonlinear Horological and Related Systems: Two Case Studies by J. B. Edwards</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2019-4 October 2019</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 12</td>
<td>Graham White’s Epicyclic Trilogy Introduction</td>
</tr>
<tr>
<td>13 - 25</td>
<td>Electrically Reset Gravity Escapement Clock by Ian Richardson</td>
</tr>
<tr>
<td>26 - 32</td>
<td>A Polish Precision Clock by Bob Holmström</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2019-2 & 3 August 2019</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2</td>
<td>Foreword to three papers on ‘A Role for the Computer in Horological Science’ J. B. Edwards</td>
</tr>
<tr>
<td>3 - 24</td>
<td>#1 - A Role for the Computer in Horological Science? A Case Study in Escapement Theory by J. B Edwards</td>
</tr>
<tr>
<td>25 - 42</td>
<td>#2 - A Role for the Computer in Horological Science? A Case Study in Escapement Theory: Amplitude Considerations by J. B. Edwards</td>
</tr>
<tr>
<td>43 - 53</td>
<td>#3 - A Role for the Computer in Horological Science? A Digest of a Case Study in Escapement Theory by J.B. Edwards</td>
</tr>
<tr>
<td>54 - 55</td>
<td>Appendix 1: State- & Driving- Transition Matrix Elements by J. B. Edwards</td>
</tr>
<tr>
<td>46 - 58</td>
<td>Appendix 2: Improved Euler Approximation for State-Transition Coefficient determination by J.B. Edwards</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2019-1 May 2019</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2</td>
<td>The state of HSN by Bob Holmström</td>
</tr>
<tr>
<td>3 - 6</td>
<td>A visit to Father O’Leary’s Clock by Bob Holmström</td>
</tr>
<tr>
<td>7 - 27</td>
<td>Father O’Leary’s Free Pendulum Revised Set Up Instructions by Pierre Boucheron 1991 & 1994</td>
</tr>
<tr>
<td>28 - 32</td>
<td>Multi-variant Regression Analysis of Horological Data using R by Bob Holmström</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2018-5 December 2018</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 10</td>
<td>Another Look at the SH41 Data by Duncan Carr Agnew</td>
</tr>
<tr>
<td>11 - 13</td>
<td>Masters, Servants, Countwheels, and a new Artificial Clockmaker by Duncan Carr Agnew</td>
</tr>
<tr>
<td>14 - 27</td>
<td>A Pendulum Powered by The Earth’s Centrifugal Force Part I: Theory by C. Stuart Kelley</td>
</tr>
<tr>
<td>28</td>
<td>Please note that subscriptions for 2019 are now due by David Spong</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2018-4 September 2018</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 10</td>
<td>Clock Hydrodynamics–Part II: Determination of the model constants and comments on Clock B by Douglas S. Drumheller</td>
</tr>
<tr>
<td>11 - 12</td>
<td>Clock XI0 by Douglas S. Drumheller</td>
</tr>
<tr>
<td>13 - 26</td>
<td>Pendulum and sensor experiments – A work in progress by Bob Holmström</td>
</tr>
<tr>
<td>28</td>
<td>Please note that subscriptions for 2019 are now due by David Spong</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2018-3 July 2018</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 12</td>
<td>Clock Hydrodynamics–Part I: My Two Clocks & John Harrison’s Tin Whistle by Douglas S. Drumheller</td>
</tr>
<tr>
<td>13 - 18</td>
<td>On Compound Pendulums Suspended From Circular Chops by John Haine and Andrew Millington</td>
</tr>
<tr>
<td>19 - 21</td>
<td>Involute gearing by Henry Casson</td>
</tr>
<tr>
<td>22</td>
<td>Comments from the editor</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2018-2 April 2018</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 43</td>
<td>Theory of the Verge & Foliot Clock of the Early Medieval Age By Dieter Roess</td>
</tr>
<tr>
<td>44</td>
<td>Dieter Roess Biography</td>
</tr>
</tbody>
</table>
<h2>HOROLOGICAL SCIENCE NEWSLETTER - NAWCC CHAPTER #161<br />
Issue 2018-1 March 2018</h2>
<table>
<tbody>
<tr>
<th>Pages</th>
<th>Contents</th>
</tr>
<tr>
<td>2 - 5</td>
<td>Mathematics of a Coaxial Watch Escapement, An Introduction for Horological Science Newsletter by Dr. Eng. Gianni Petrangeli</td>
</tr>
<tr>
<td>6 - 8</td>
<td>Philip Woodward Obituary</td>
</tr>
<tr>
<td>9</td>
<td>Graham White Obituary</td>
</tr>
<tr>
<td>10 - 11</td>
<td>Graham White book project</td>
</tr>
<tr>
<td>12</td>
<td>New books Betts - Marine Chronometers - Frumer - Making Time</td>
</tr>
</tbody>
</table>
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<h3>bob holmström - www.hsn161.com</h3>
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