Photo of New York fire engine horses courtesy the Library of Congress Sound the alarm, DCist historians: The DC Fire Department needs your help. John Kelly does, anyway. In his Washington column today, Kelly can’t answer a question put to him by DC fire academy instructor Lt. T. “Cosgrove” Jones, so instead, he pays the question forward. Apparently, DCFD’s lost a monument. Back before fire engines had engines, they were carts pulled by horses….