We spent the past few days at the Point Reyes National Seashore, just north of San Francisco.
What a place: over 50,000 acres preserved from development, over 140 miles of hiking and biking trails, spectacular beaches, as well as a Morgan horse stable, vintage lighthouse, and historic ranches to explore. Outside the park there are several fine restaurants and B&Bs. All this less than fifty miles north of San Francisco.
Yes, yes, it was great to get away from the congestion of the city and commune with the Tule elk, but what really struck me was the lighthouse.
Following the wreckage of a lot of ships at Point Reyes, our very own government installed the light on the point in 1870.
They had to blast out a spot halfway down the point to be sure the light could be seen below the typical fog layer -- a lesson learned from the original Point Bonita light, which was often swallowed by fog.
The Point Reyes light was in continuous operation for 105 years, when it was replaced by an automated system. Unlike most lights, it was preserved and given to the National Park Service.
The glass in the thousand elements of the Fresnel lens weighs 3,000 pounds, and the supporting structure weighs another 3,000 pounds. All this hardware has to rotate at a constant speed with minimal intervention. In modern terms this is called "mission critical." We're talking lives here.
To accomplish this wizardry, the makers employed a large mechanism similar to what is found in grandfather clocks, a ratcheting spring system attached to a counterweight. Just as grandfather wound up his clock, the light keepers descended the 308 steps every two hours to wind the lighthouse.
After 105 years of constant use and another 25 years of intermittent demonstrations, the 6,000-pound assembly can still be set rotating with the light push of one finger (something the duty ranger delighted in demonstrating). The glass in the lens is still clear, the brass wheels supporting and guiding the light assembly are still true, and the rotation mechanism still can turn the light once every two minutes.
This is human-scale engineering at its best. You can look at the clock mechanism and see how it works, you can understand how light rays are bent to the horizontal by the elements of the Fresnell lens, and there's nothing to running the machine.
In today's world of gigahertz computing, it's refreshing to be in the presence of such a stunningly simple, yet enduring machine.
Even better, this magnificent creation was built to do one thing: save lives.
10:59:22 PM 
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