Monday, May 6, 2013

Chesapeake Fog & Chinese Pigtails

Summer is just around the corner, and I am seeing morning fogs on the West Coast, typical of our summer fog pattern. Warmer air from the land colliding with the still-cold ocean causes these "marine layers," as we call them. The sun usually burns off the layer by late morning or noon. Above is a shot of this phenomenon at Heceta Head Lighthouse in Oregon.

Foggy mornings that lead to clear and warm afternoons remind me of a story. I wrote it for Chesapeake Bay Magazine’s April 1988 issue. It is copyrighted, so please don’t reproduce it without asking me first and paying my reprint fee. ( Enjoy reading it though!

Chesapeake Fog and Chinese Pigtails
 ©Elinor DeWire

To safely steer in the treacherous fog that sometimes shrouds the waterways, numerous noisy signals have been invented to penetrate the murk—bells, horns, gongs, sirens—and a host of devices to sound them. The Chesapeake Bay has had no shortage of such clamorous signals, many of them at lighthouses where jaded keepers were charged with maintaining them and enduring the din of a foggy day.

The earliest fog signals were hand operated, usually by an overworked attendant who fired a gun at regular intervals or hammered out a code on a bell when the beacon failed to pierce the fog. Later, mechanical strikers were developed for bells, freeing the bell keeper from duty at the hammer, but still necessitating good judgment as to when to turn on the signal.

Around the turn of the twentieth century, people began to think brains ought to cast off the shackles of brawn, and the word automation gained a place of prominence. Scientists and inventors devised hundreds of ways to free up weary hands and make things work automatically. Fog signals, with their persistent need to be manually sounded, were no exception.

The problem with fog was its stealthy character, creeping in “on little cat feet” to shroud the seaway with everything from a mist as light as a bride’s veil to murk as thick as pea coup. A fog-detecting device was certainly in order, and a parade of strange inventions hurriedly passed in review. But none was odder in theory or appearance than the Chesapeake Bay’s Chinese pigtail signal.

The year was 1921, and scientists at the Baltimore Lighthouse Depot had found a material they thought would be ideal for detecting fog—human hair. Since hair responds to dryness by stretching and to dampness by shrinking, it could separate or bring together electrical contacts on a fog signal switch. Of course, the longer, thicker, and coarser the hair, the more stretching and shrinking it could do, so a Chinaman’s queue about two feet long was selected for the experiment.

A foghorn in Baltimore Harbor was chosen to receive the first pigtail signal. Researchers first treated the hair to remove all oil and foreign matter, then on a dry sunny day they attached the pigtail between two electrical contacts on the foghorn’s actuating switch. The initial development and installation of the signal’s unusual switch ran $1,300, but the researchers estimated it would economically operate for a mere $8 per month. Pigtail groomed and in place, the scientists returned to their Baltimore laboratories to await a foggy day.

A short time later President Warren Harding arrived in Baltimore to dedicate the new Francis Scott Key Memorial at Fort McHenry. The day dawned clear and sunny, and all manner of boats took to the harbor to celebrate the unveiling of the new memorial. As President Harding arrived at the memorial, fire boats began shooting water high in the air to salute him. The light mist from the rocketing streams drifted across the harbor to the Chinese pigtail, settled on its obsidian braid, and caused it to contract.

Just as the President stepped up to the lectern and uttered his first word, the contacts on the foghorn’s electrical switch met, and the insubordinate horn bellowed an ear-splitting greeting that nearly sent President Harding reeling off the podium and into the harbor. Somewhat abashed by their invention’s poor sense of timing, researchers from the Lighthouse Depot gave quick explanations and apologies. But the horn’s inappropriate behavior could not suppress their excitement over the apparent success of the experiment.

Another pigtail signal later was installed at Lambert Point near Norfolk, but both it and the Baltimore signal proved unable to distinguish between various levels of humidity. A heavy dew or a muggy but clear day could set their horns roaring as easily as a bonifide fog. Researchers were never able to make the pigtail discriminate. A German scientist would solve that dilemma with a pencil-thin beam of light projected a predetermined distance to a receiving target. When fog prevented the thin light beam from reaching its destination, the fog signal automatically kicked on.

As for Chinese pigtails and their creative electrical circuitry, they were retired to an obscure corner of the Lighthouse Depot warehouse. We can be sure President Harding never forgot them!

(I so wish I could find a photo of the Chinese pigtail fog signal! In lieu of that, below  is a shot of a traditional fog signal, operated at the judgment of a lighthouse keeper. It shows a lightkeeper standing under the old foghorns at Point Vicente Lighthouse, California about 1940. They were operated by bellows powered by steam boilers. The photo was taken by Irving Conklin, himself a lightkeeper, and resides in the Nautical Research Center, Petaluma, California. The bottom image was taken by me and shows a modern fog signal--a stack of horns facing several directions and a fog sensor box with what appear to be eyes. Metaphorically, they are eyes--looking for fog. The eyes actually project that pencil-thin light beam discussed in the article above.)

No comments:

Post a Comment

I welcome your comments, photos, stories, etc.!