[time-nuts] Leap Second Pending

Jim Lux james.p.lux at jpl.nasa.gov
Wed Jul 30 03:16:29 UTC 2008


Quoting Chuck Harris <cfharris at erols.com>, on Tue 29 Jul 2008 07:05:10 PM PDT:

> According to Donald DeCarle's Watch and Clock Encyclopedia:
>
> Clepsydra-  Water Clock.  There are various types of water
>

<snip>

I should note that because the flow is a function of the viscosity of  
the working fluid, the clepsydra has a very nonlinear temperature  
coefficient (with a saturation at around 0C and another saturation at  
around 100C, if the working fluid is water, depending on the  
atmospheric pressure) although this can be compensated to a certain  
extent by changing fluids.. Is a clepsydra using, say, alcohol or  
fluorinert(tm) still a clepsydra?

I wonder if one could make a temperature compensated one (where the  
orifice size changes with temperature.. much like building a  
temperature compensated pendulum using metals with two different CTE)

There are various forms with tipping bucket (like rain gages) that one  
might be able to make a calendar with (raising the prospect of  
actually having a leak second)




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