The luminosity of gas lamps in the streets of Prague’s Old Town has been measured this week. There are approximately 680 historic gas lamps that light the Royal Route from the Powder Gate over the Charles Bridge to Hradčanské Square at Prague Castle as well as adjacent streets. The aim was to assess their optical and technical condition and set the parameters for the development of new gas burner units.

The measuring exercise was carried out on Monday after 9 p.m. by Technologie hlavního města Prahy (THMP), the city’s own company responsible for street lighting. “We measured optical properties of a single gas lamp in Uhelný Trh square. To achieve objective results, we eliminated all other sources of lights in the vicinity,” says Tomáš Jílek, Board Chairman, THMP. We did not choose to measure the lamp in a lab on purpose as we wanted the result to reflect real-life conditions.

The results are expected to show the real optical and technical characteristics of Prague’s gas streetlights. “We only have official specification from the manufacturer. We are planning to use the real, measured characteristics in a pilot project to develop a new gas burner,” explains Tomáš Jílek, adding that THMP’s aim is to diversify suppliers of spare parts so that the company can perform service and maintenance with its own resources.

According to City Councillor Jan Chabr, gas lighting has been an integral part of the Prague experience. “Gas lamps have lit the streets of Prague since 1847 and now create a beautiful evening ambience in the historic city center. Gas lighting in Prague today includes 415 streetlights with one to three lamps and three historic candelabra in the Lesser Town – two eight-armed in Hradčanské Square and Loretánské Square, respectively, and one four-armed in Dražického Square,” he added. A noteworthy fact is that Prague’s Charles Bridge is the only bridge in the world illuminated by gas lamps.