(Business 2.0) – High-powered lawyers are often required to burn the midnight oil, but that doesn't mean they like to work in the dark. When the Washington branch of 132-year-old law firm Morgan Lewis & Bockius moved into its new Pennsylvania Avenue digs, partner Steve Mahinka found an enlightened way to brighten up dozens of interior offices. At the suggestion of design firm Studios Architecture, a 12-story, 5-ton solar tube was installed to carry natural illumination deep into the building. The ancient Egyptians used similar structures to channel light into massive pyramids, but at Morgan the tube is outfitted with a high-tech mirror that follows the movement of the sun. The rays are then directed toward 236 smaller refractors that bounce light down the length of the atrium. Morgan's is the largest solar tube in the world--a glowing column of glass that bathes more than 500 employees in brilliant daylight. It's also strategically positioned so that guests have to walk underneath it. Mahinka says the novelty and sophistication of the space inspires employees to show it off to friends and clients. "There's pride here," he says. "It really makes a difference." And no wonder--every desk near the light tube enjoys a view that's way more unique than that of a typical corner office.