pantograph

“The key villain here is the pantograph, which is perched on top of the rail engine, constantly touching the overhead high-tension power line to draw electricity to propel the train,” says Yashwant Gupta, director of the National Centre for Radio Astrophysics, a division of the Tata Institute of Fundamental Research, which operates the GMRT.

As the pantograph makes and breaks contact with the line, he says, it produces sparks and electromagnetic bursts that can “drown the entire spectrum of faint radio signals the telescope is devoted to study.”

Mr. Schmieder was part of a test of a third alternative: a system that feeds electricity to trucks as they drive, using wires strung above the roadway and a pantograph mounted on the cab.

Inside the cab, the transition was barely perceptible as Mr. Schmieder deployed the pantograph that connects to the overhead cables, a so-called catenary system.

Yet these monumental sculptures come together in a markedly different method than those of Rodin and other sculptors circa 1900, who would start with a clay figure and then duplicate it at larger scale by use of a pantograph.