The U.S. Army Signal Corps inherited this network between 1870 and 1874 by an act of Congress, and expanded it to the west coast soon afterwards. Three times daily, all stations would telegraph in their observations to the central office which would then plot the information on a map upon which isobars, or lines of equal pressure, would be drawn which would identify centers of high and low pressure, as well as squall lines.
The U.S. Army Signal Corps took over this network between 1870 and 1874 through legislation, and expanded it to the western United States soon after. The system operated on a daily schedule, with each station sending in its observations three times a day to the central office, which would then create a map displaying areas of equal atmospheric pressure, or isobars, to help identify high and low-pressure systems and squall lines.