The giant instruments at astronomical observatories designed and built by a regional king in 18th-century India have captivated generations of visitors. They have also inspired Barry Perlus, Cornell associate professor of art and a photographer, to bring these architectural marvels to a wider audience via exhibits and online, using the latest imaging technology.

The observatories were constructed by Maharajah Jai Singh II of Jaipur between 1724 and 1737 in Delhi, Jaipur, Mathura, Ujjain and Varanasi, all in west-central India. Collectively known as Jantar Mantar, all but the Mathura observatory are still standing.

"It's not an antiquity like some of the ancient temples are," Perlus says of Jaipur, the largest and most elaborate site. "I was struck by how modern it seemed, yet it had traces of design that were Islamic. It's architecturally a representation of the real mechanics of the universe."

Jaipur features a giant sundial more than 73 feet tall and the Jai Prakash, a pair of bowl-shaped instruments ingeniously designed for nighttime viewing. Markings on the marble faces of Jaipur's masonry structures calibrate the movements of celestial objects. As an observer takes his position inside one of the instruments, Perlus says, "you are experiencing yourself directly scaled to that much larger scale."

Serendipitously, Perlus first visited the Delhi observatory in 1989 while waiting for permits to explore other architectural sites. His "stark and abstract" black-and-white photos were well received as architectural studies. On his return trips in 1991, 2001 and 2004, he expanded first into panoramic photography, then digital capture and full 360-degree views of Jaipur, Delhi and the two smaller sites. Since 2001, Perlus has been developing multimedia content for the Web and making computer-generated "spherical renderings" of his images.

"It's almost a kind of sculpting," Perlus says. "As I'm doing these, I'm no longer interested in any of the literal attributes of the place. They are simply forms that I'm reinterpreting; a visceral impression of what I was seeing and feeling."

The project has also given him an education in astronomy, history and architecture -- and in navigating the online world. "I was not a networker before I did this -- the Web totally changed me," he says.

The Graham Foundation for Advanced Study in the Fine Arts gave Perlus a grant in August 2005 to continue developing his Web site, http://www.jantarmantar.org, as a virtual museum and online resource center. He gave a presentation with his panoramas projected inside the dome of Denver's Gates Planetarium last September, and spoke in November at the International Symposium on Virtual Reality, Archaeology and Cultural Heritage. He also had a fall 2005 exhibit, "Jantar Mantar," at Lycoming College.

A virtual tour of the observatories, descriptions of how they work, bibliographies and more can be seen on the Jantar Mantar site, and Perlus has a related Cybertower study room online. The Cornell Theory Center will soon feature an interactive 3D environment based on the Jaipur observatory at http://www.scicentr.org.