On the second full day of coring, the drillers and scientists had found a rhythm and were moving fast. They quickly passed the previous mark of several meters that Rodbell and his students had extracted almost 20 years ago with a hand coring device. Near the end of the day, 55 meters below the lake bottom, the gray clay from a glacial period suddenly gave way to dark brown peat, exciting evidence that at one point the lake had dried out.