The article in yesterday's Washington Post on the partial eclipse of the sun incorrectly described the use of a pinhole camera. To use a pinhole camera you must stand with your back to the sun. The sun's rays will pass through the pinhole and be reflected on the white paper. You hold the cardboard and the paper either to your left or right and you can see the light reflected onto the white paper.
A partial eclipse of the sun will occur in the Washington area today between 4:40 p.m. and 5:56 p.m.
Only 8 percent of the eclipse will be visible, however, in this area. Because of the paths that the sun and moon currently are traveling, the eclipse will be total only in part of the Pacific Ocean.
On the West Coast almost 50 percent of the eclipse will be visible, 47 percent in Los Angeles and 44 percent in San Francisco, according to the U.S. Naval Observatory.
Scientific officials warn that looking at it with the naked eye or through binoculars is as dangerous as it would be during a total eclipse.
"Regardless of how much of the sun is covered, you can't look at an eclipse with the naked eye or through binoculars," said Dr. Gart Westerhout, scientific director of the observatory. "Even one minute during a partial ecplise could easily lead to blindness."
There are a number of methods to look at the eclipse. Several rolls of black and white negative film against one another provides a shield for the eyes, dark glass that has been smoked with a candle can also be used and pinhole cameras are also useful. A pinhole camera is made by poking a pin through a piece of cardboard and holding a piece of white paper several inches from the cardboard and looking through the pinhole. Sun glasses, photographic filters and color film should not be used.
The eclipse will reach its "peak" of 8 percent at 5:19 according to Westerhout and will hardly be noticeable unless one is looking for it. The moon covers a lower section of the sun at the same time.
"It won't be very exciting at all on the East Coast," Westerhout said. "There will be more to see out west, obviously."
The next eclipse of the sun on this continent will occur on Feb. 26, 1979. It will be a total eclipse in the north-western United States and will be roughly 50 percent visible in this area.