The World's Largest Searchlight Once Scanned L.A. From the Mountains Above

As twilight faded over Pasadena on Sept. 9, 1894, an artificial sun flickered to life for the first time. High above town in the San Gabriel Mountains stood a wonder of the new electric age: a 60-inch General Electric searchlight, by many accounts the largest in the world. This massive projector first dazzled audiences at the 1893 Chicago World's Fair. Now it would perform its nightly spectacle in the mountains above Los Angeles.

Up above, on the summit of Thaddeus Lowe's Echo Mountain resort, tourists wrapped themselves in blankets and huddled around the searchlight as its operator fired it to life. When running at 200 amperes – a current generated by a Pelton water wheel in nearby Rubio Canyon – the carbon arc lamp burned with the intensity of 90,000 to 100,000 candles. A massive reflecting lens mirror, built in France, magnified that blaze to 375 million candlepower.

The Echo Mountain searchlight at night, in use. Circa 1895 photo by William Henry Hill, courtesy of the California State Library.

"The Largest Searchlight in the World on Echo Mount, Calif." Circa 1910 postcard courtesy of the Werner von Boltenstern Postcard Collection, Department of Archives and Special Collections, William H. Hannon Library, Loyola Marymount University.

This dazzling beam blanched the flatlands below. It wandered the streets of Pasadena. It streamed through the windows of San Gabriel farmhouses with the ardor of day. Lowe's publicist claimed you could read a newspaper under its light from 35 miles away. It was definitely visible 60 miles away on Catalina Island, a hot white dot hovering just above the horizon.

Some watched the show with amusement. Children lit signal fires or flashed red lights to attract the operator's attention. The mischievous ones bounced the sunbeam back with hand-held mirrors. Others reacted with alarm. Horses startled. Roosters crowed. Lovers cursed.

In an 1895 dispatch, author Grace Ellery Channing recalled the scene atop Echo Mountain:

The searchlight was just one of the modern marvels collected by Lowe, a pioneering aeronaut who had commanded the Union Army's Balloon Corps during the Civil War. At Echo Mountain, his "White City," Lowe placed an observatory with a 16-inch refracting telescope and hired a renowned astronomer to manage it. He is best remembered for his Mount Lowe Railway, the world's first-all electric mountain railroad, which climbed 3,000 feet into the San Gabriels over white-knuckle cliffs and a soaring, 1,300-foot funicular. But nothing signaled the dawn of a new electric age in the Southland like Lowe's searchlight, its sun-shaft overthrowing the dark of night.

This story first appeared on Gizmodo's Southland on Aug. 6, 2014.

A man and child stand next to the Echo Mountain searchlight. Photo courtesy of the Mount Lowe Preservation Society.

Two modern wonders of the Mount Lowe Railway within one frame: the Great Incline funicular railway in the foreground, and the searchlight mounted atop the powerhouse in the background. Circa 1915 photo courtesy of the California State Library.

The Echo Mountain searchlight perched above Altadena. Undated photo courtesy of the Oliver Family Photograph Collections, Bancroft Library, UC Berkeley.