The United States government geological survey engineers recently made an estimate of the waterfalls capable of developing horsepower and over, that are running to waste, unused, in this country. They esti mated that there is available, every second of the day and night, some horse power, in dry weather — and twice thissduring the eight wet months of the year. The water fall capable of giving up horsepower in energy is not the subject of these chapters. It is the small streams — the brooks, the creeks, the rivulets — which feed the horsepower torrents, make them possible, that are of interest to the farmer. These small streams thread every township, every county, seeking the easiest way to the main valleys where they come together in great rivers.