The 1997 NAWCC Atlanta National Convention Speakers Program is shown on Page 2, as well as the Horological Science Chapter meeting. You won't want to miss any of it!

The Syracuse, NY, Regional will have a Horological Science Chapter meeting on Friday, August 15, 1997 at 2:30 pm. Tony Prasil suggests a tutorial on the Allan Variance and a talk on time delays in measuring equipment. Any volunteers?

Jerry Walker plans to make a pendulum rod of ULE material; if others are interested, please contact him (see p 5).

Page Contents

1 Index, meeting notices

2 Notice of speakers at the Atlanta National, and the Horological Science Chapter meeting.

3-4 Bill Scolnick describes An Experimental Concrete Base For Precision Clocks. His design uses a smaller mass with damping pads, as compared to the large mass used by Prof. Hall (HSN 19964).

5 Jerry Walker discusses an Important Cause of Pendulum Error due to sliding friction. He solved a nagging problem with his own clock by assuring that all adjacent surfaces moved freely with no binding.

6-8 Ken Friedenthal looks at Impulse and Circular Error to find the cause of his Seth Thomas clock slowing down as the spring unwinds. The actual performance fits the theory.

9-10 Bob Matthys discusses Some Practical Properties of Quartz, focusing on the time required for the system to reach equilibrium after the pendulum weight is applied.

11-15 Alan Heldman describes a simple, innovative method for Precision Determination of Pendulum Period using a small laser, a dial caliper, and a sharp line on the bob.

16 Ned Bigelow takes a Closer Look At Transient Temperature Correction (see HSN 1997-1) and concludes he made a slight error but concludes that below-the-bob compensators make a very small time error not worth the complication.

17 Norm Fritz has an expanded note in More on Pendulums Driven Off Resonant Frequency. This is stimulated by Ken Friedenthal's analysis (HSN 1996-3) which Norm shows that, by extending the time, theory and practice do agree. Doug Bateman agrees with Ned Bigelow's conclusions on transient temperature correction

18 Gordon Uber's latest Internet report, including the January one for handy reference.

Ernie 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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