Four in the morning, downtown Haverhill, eight inches down and still falling — the streetlights make the whole city look like it's under water. Haverhill Snowblower is out in it: snow blowing driveways and walkways, shoveling steps and around the parked cars, pushing banks off the corners, laying sand and salt where the ice glazes over. The narrow drives between houses are the honest test, and clearing one right takes a steady pass and a good ear for the machine. By the time the plows come down the street, the path to the door is already open. Serving Haverhill and the towns just beyond, storm by storm.