Nitrogen canisters on East 27th Street and Madison Avenue on July 14.
I had sporadically seen mysterious nitrogen canisters on New York City sidewalks, and wondered what they were doing there. Each tank has a hose snaking its way into a manhole, where it presumably dispenses nitrogen under the street. Luckily, Popular Science let me find out as part of my job (booyah). It turns out they’re there to keep copper cables dry so phone and internet services can run smoothly.
Rebecca Harrington 