[LEAPSECS] Leap smear and Big Ben

Peter Vince pvince at theiet.org
Sat Oct 1 19:37:41 EDT 2011

On 1 October 2011 23:38, Tom Van Baak <tvb at leapsecond.com> wrote:

> but perhaps one of our UK members can tell us the exact mass

> of a pre-decimal penny...

About 9.4 grammes. Quite by chance I have a bag of 12 from the mid
60's, shortly before we went decimal, and the weight varies by about
1% between coins, but on average comes out to 9.40 g.

I understand that, perhaps counter-intuitively, adding a coin speeds
up the clock, as it moves the centre of mass of the pendulum's weight
just that little bit higher, hence shortening the pendulum.

Peter (London, England)

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