It is generally conceded, nofc only in theory, but it is backed up by practical application, tbat for low heads or for elevations not exceeding 100 f eet the simple form of handling water with centrifngal pumps stands at the head, says The Irrigatiou Age, which calis atteution to the following: In the San Joaquin and Sacramento valleys, particularly in that portion occupied by the swamp land reclamation districts, centrifugal pumping plauts have been used with marked success. The use of the very large pumps is natnrally, owingtotheir construction, limited to comparatively low heads, and in nocase thus far have any laree plants been put in handling water over 30 feet. With the smaller or moderate sized contrifugal pumps 100 feet and even more is not an nncominon matter. In southern California and Arizona many large pumping works have been nstalled for irrigation purpo.ses, and it has shown that in many cases it is much clieaper in h'rst cost and operation to )ut in a pumping plant tfaau to use a jravity system. Thcre is practical data vhich shows that in large tracts and vhere the lift does not exceed 20 to 25 feet, water can be furuished at a cost of 50 cents por acre, including all charge of operatinr and iixüd charges of interi r, faxes, deprociation, etc.