The explorers who have discovered the most interesting cities in Arizona and elsewhere were officers of the United States army. They have been the true pioneers of American civilisation in the West, and it is most creditable to them that they have been able to furnish so much scientific and antiquarian observation in the execution of their arduous and often painful duty in Indian warfare. There is no cold shade cast upon the labours of officers who desire to make a little reputation for themselves by contributions to scientific publications, and by papers on natural history and the like in periodical publications or in the daily press. There is, as might be expected from its position, a very high temperature in Arizona. This lasts from the middle of June to the first of October. During the best part of summer exertion of any kind is impossible. Metal objects cannot be handled without producing blisters; rain scarcely ever falls; and, to keep up the drain of constant evaporation, a man must drink a gallon or two gallons of water a day. Mr. Ross Brown, speaking of the summer, declares that "everything dries. Waggons dry; men dry; chickens dry. There is no juice left in anything, living or dead, by the close of summer. Officers and soldiers creak as they walk; chickens hatched at the season come out of the shell ready cooked. Bacon is eaten with a spoon, and butter must stand in the sun an hour before the flies become dry enough for use. The Indians sit in the river with fresh mud on their heads, and, by dint of constant dipping and sprinkling, manage to keep from roasting, though they usually come out parboiled." But, although it is recorded that a party encamped on a narrow cañon where the temperature was 120 degrees, there was no sunstroke. And in that respect the climate differs from that on the eastern coast, where, especially this very summer, a great number of deaths were caused by _coup de soleil_. People, with the thermometer marking 94 degrees, talk of its being agreeably cold. An exceedingly interesting fact, if it be one, connected with residence in this part of the world is the wholesome effect of complete abstinence. Death from want of water was by no means infrequent in the old days before so many wells were dug; but it only occurs when there is a good deal of humidity in the air. Although alcoholic drinks and tobacco have an injurious effect, there is a large consumption of both at all the stations and at the mines.