In the indication of specific areas as irrigable on the accompanying map of Utah, it must be considered that the selections made are but tentative; the areas chosen are supposed to be, under all the circumstances, the most available; but each community will settle this problem for itself, and the circumstances which will control any particular selection cannot be foretold. It is believed that the selections made will be advantageous to the settler, by giving him the opinions of men who have made the subject a study, and will save many mistakes. The history of this subject in Utah is very instructive. The greater number of people in the territory who engage in agriculture are organized into ecclesiastical bodies, trying the experiment of communal institutions. In this way the communal towns are mobile. This mobility is increased by the fact that the towns are usually laid out on Government lands, and for a long time titles to the land in severalty are not obtained by the people. It has been the custom of the church to send a number of people, organized as a community, to a town site on some stream to be used in the cultivation of the lands, and rarely has the first selection made been final. Luxuriant vegetation has often tempted the settlers to select lands at too great an altitude, and many towns have been moved down stream. Sometimes selections have been made too far away from the sources of the streams, and to increase the supply of water, towns have been moved up stream. Sometimes lands of too great slope have been chosen, and here the waters have rapidly cut deep channels and destroyed the fields. Sometimes alkaline lands are selected and abandoned, and sometimes excessively sandy lands have caused a change to be made; but the question of the best sites for the construction of works for controlling and distributing the water has usually determined the selection of lands within restricted limits. To a very slight extent indeed have artificial conditions controlled in Utah; the several problems have generally been solved by the consideration of physical facts. INCREASE IN THE WATER SUPPLY.