[time-nuts] Is this off topic?

Bill Hawkins bill at iaxs.net
Fri Sep 21 23:02:13 EDT 2007


Thursday night I went to see James J. Hill's (railroad baron) time
station in Minnesota, after waiting for tornados to clear the road
south.

The observatory building began before the Civil War. A man arrived
in 1870 who added a star-crossing telescope to the observatory.
These only move N-S so they don't require a dome. Hill, in MN,
needed a time standard for his railroad, so trains could be scheduled
on a track without running into each other. Telegraphy made it
possible. Hill invested in the observatory, adding a much better
star-crossing telescope with highly accurate calibration and setting
equipment, and a Riefler clock. That glass-enclosed and low pressure
clock was supposed to be good to 1/20,000 of a second per day. There
were also three Howard clocks with mercury canister pendulums. Since
this was an observatory, one ran on sidereal time and the other on CST.

The people giving the tour knew little about the clocks. As happens with
equipment that has fallen out of use, there were no manuals. The Howard
clocks had been wound by a student for a time, but fell into disuse. No
one knew what the electrical connections did.

The Riefler clock was in a basement storage area, which had once been a
workshop. Our hosts had to clear out a lot of packing material so that
we could see it. Alas, the bottom glass cylinder of the Riefler clock
was broken, when 14 years earlier a network installer had punched a hole
in a wall without checking what was on the other side. It was a later
model
with knife-edge pivots and two escapement wheels, probably had an 8
second
rewind of the small weight that impulsed the pendulum.

After Riefler came Shortt, and after that the crystal oscillator, and
after
that the atomic physics stuff.

I am an historian by nature. It is painful to see important predecessors
fall into disuse as life marches on. It was like looking into a barn
that
once held beautiful things, but had since been overrun by mice.

This list seems to be populated by people in quest of picosecond
resolution.
Does anyone care about how we got to where we are?

Excuse me, but I'm despondent. I wish I had not gone on the trip.

Bill Hawkins




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