National Association of Watch and Clock Collectors, Inc.

Horological Science Chapter #161

Issue 1996-3 June 1996

Ernie Martt, editor, 278 Bentleyville Rd., Chagrin Falls, OH 44022

Phone. 216-247-6712; Fax 216-247- 1104; E-mail: emartt@cybergate.net

Sec. & publisher, Bill Givens, PO Box 1337, Eugene, OR 97440 Phone: (H) 503465-9311, (W)503-465-9311; E-Mail: ibanks@ix.netcom.com

Treasurer, Everett Jones, 11929 East Hill Drive, Chesterland, OH 44026 Phone: 216-729-4811

At the 1996 Cleveland National at 3 pm, Friday June 21 Prof. E.T. Hall will speak on the Littlemore Precision Clock, and at 4 pm Dr. Jerome Walker will talk on "Trials of Making a Precision Clock" . A panel discussion will be held after these two meetings. Also, the time web sites will be available on the Internet during mart hours, and an Internet meeting will be chaired by Gordon Uber on Saturday, 9 am. The Antiquarian Horological Society has invited our Chapter to join them for their meeting at 8 pm, Friday June 21 at the Convention Center. Beresford Hutchinson will speak on Observatory Clocks -- a talk you won't want to miss.

Page Contents

1 1996 National, talks and Internet.

2. Biographies of Bernie Tekippe and C. Stuart Kelley; an Internet summary by Gordon Uber.

3-5 "Velocity-Dependent ElectromagneticMaintaining System For Use In High-Precision Pendulum Clocks" by Peter J. Baxendall (1921-1995), communicated by Philip Woodward. An innovative, yet simple drive.

6-7 "The 60 HZ Power System as a Time Reference" by Paul M. Hopkins. Good within a few seconds!

8 "English Bobs: A Follow-up Comment to Doug Bateman" by Alan W. Heldman -- some thoughts on the pendulum as a string and as a lever.

9-11 "Analytical Treatment of Norm Fritz' Experiment" by Ken J. Friedenthal. Ken approaches the problem a little differently than Philip Woodward (HSN 1996-2) but arrives at the same conclusion.

12-16 "The Clockwatcher" by Bernie Tekippe. Bernie uses a computer system and the Heathkit The Most Accurate Clock II device to measure the performance of his clocks.

17-34 "Effect of the Earth's Rotation on the Motion of the Simple Pendulum" by C. Stuart Kelley. In a thorough study, Stuart shows how the earth's centrifugal and coriolis forces affect the motion of a pendulum.

Loose Attachment: Replacement article for 1995-5: "The Instability of Invar" by Bob Matthys, correction of typos.

E.C. Martt

Above: Drawing from Apians Cosmographicus Liber of 1533, showing how a nocturnal is used to tell the time at night from the Great Bear.

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