Even in more favored climates, storms commonly prevail on the heights during several months of the year, and vehement winds give more or less annoyance at all seasons; the direct sunbeams sear the skin like a hot iron; the chill air congeals the blood. Dr. Copeland records that at Vincocaya, one afternoon in June, the black bulb thermometer exposed to solar radiation stood at 199°.1 of Fahrenheit—actually 13° above the boiling-point of water in that lofty spot—while the dry bulb was coated with ice! Still more formidable than these external discomforts is the effect on the human frame itself of transportation into a considerably rarer medium than that for existence in which it was constituted. The head aches; the pulse throbs; every inspiration is a gasp for breath; exertion becomes intolerable. Mr. Whymper’s example seems to show that these extreme symptoms disappear with the resolute endurance of them, and that the system gradually becomes inured to its altered circumstances. But the probationary course is a severe one; and even though life flow back to its accustomed channels, labor must always be painfully impeded by a diminution of the vital supply. And the minor but very sensible inconveniences caused by the difficulty of cooking with water that boils twenty or thirty degrees (according to the height) below 212°, by the reluctance of fires to burn, and of tobacco to keep alight, and we complete a sufficiently deterrent list of the penalties attendant on literal compliance with the magnanimous motto, _Altiora petimus_. That they will, nevertheless, not prove deterrent we may safely predict. Enthusiasm for science will assuredly overbear all difficulties that are not impossibilities. Dr. Copeland, taking all into account, ventures to recommend the occupation during the most favorable season—say from October to December—of an “extra-elevated station” 18,500 ft. above the sea, more than one promising site for which might be found in the vicinity of Lake Titicaca. For a permanent mountain observatory, however, he believes that 12,500 ft. would be the outside limit of practical usefulness. It is probable, indeed, that the Rocky Mountains will anticipate the Andes in lending the aid of their broad shoulders to lift astronomers towards the stars. Already a meteorological post has been established on Pike’s Peak in Colorado, at an altitude of 14,151 ft. Telescopic vision there is said to be of rare excellence; we shall be surprised if its benefits be not ere long rendered available.