A most unusual building in Concord -- New Hampshire's capital city. Unusual, not only because of its round shape but also because of its purpose. Many people suspect it was a railroad roundhouse, but it was a "gasholder" building with a huge tank inside for storing natural gas for lighting and heating downtown structures in the early 1880s. It was hurriedly constructed at a time when the Concord Gas Light Co. was repeatedly running out of gas when demand peaked - about 10 each evening, when people were settled in their homes and looking to read books and newspapers and such. Photo by Carol Highsmith, 2017.