National Association of Watch and Clock Collectors, Inc.

Horological Science Chapter #161

Issue 1996-1 February 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) 503-465-9311, (W)503-465-9311; E-Mail: ibanks@ix.netcom.com

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

There will be meetings of the HSC #161 at the 1996 National in Cleveland, likely at the Syracuse Regional in August, and at the October Seminar at the Time Museum.

For experimenters, I have a few pieces of quartz rod for pendulums remaining-- it is 12 mm in diameter, 51 " long (snap cut), made clear #214 quartz. The cost is $21 per piece, plus a few dollars per piece for packing and shipping. The exact amount depends on the number of pieces and distance shipped. You will pay my cost. First come, first served. According to Bob Matthys' article in the last HSN, quartz is far more stable than invar.

One of our frequent contributors, Bob Matthys, has an article in the current issue of the British Horological Journal on Time Error Due to Air Pressure Variations. Air pressure patterns are shown to be quite different depending on geography.

Page Contents

1 HSN meetings, quartz rods for pendulums, Bob Matthys' article in HJ.

2 Biographies of authors: Evan Edwards, Norm Fritz, and Ken Friedenthal

3 Ned Bigelow's review of Philip Woodward's new book, My Own Right Time by the Oxford University Press, 1955. It is written with his unique clarity and is a valuable resource for anyone interested in making clocks or in general horological science. The cost is about 25 pounds sterling and I hope will soon be available in the US.

4-6 Evan Edwards describes the conversion of his precision clock to a carbon-fiber pendulum rod.

7-8 Ned Bigelow gives us an update on his unusual two-pendulum clock design.

9-15 Norm Fritz presents an interesting set of experiments on driving pendulums at rates different from their normal resonance frequency. He shows how a pendulum forms new, virtual suspension points in order to vibrate at a new rate.

16-21 A new author for the HSN, Ken Friedenthal, presents a "just for fun" article looking at the basic differential equations of a pendulum, with examination of some special results.

22 Gordon Uber brings us up to date on the Internet.

Ernest 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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