264 



SCIENCE. 



[Vol. II., No. 30. 



the traveller down its vallej' was obliged to 

 proceed b_y alternate stages of land and water, 

 the steamboat being ntilized when the railway- 

 cars began to swim. Then it was that the 

 facetious pilgrim from St. Paul to Winnipeg 

 was, according to his habitual description of 

 the journej', three days out of sight of land. 

 It was a joke, to be sure ; but such jokes are 

 not heard in a dr}' climate. 



The moisture of the atmosphere of Minne- 

 sota is the salvation of the state : it makes 

 agriculture a possibility and a success. Given 

 the same amount of rainfall in another lati- 

 tude, and under more arid climatic condi- 

 tions, and her wheat-fields would be blighted. 

 As it is, her scanty rains, with the exception 

 of a few showers in summer, fall slowly and 

 gently ; in times of drought the thirstj' air 

 freights itself with moisture from the abundant 

 water-surface of the state ; and these sources 

 of humidity are re-enforced by the prolonged 

 irrigation resulting from the melting of the 

 winter snows and the thawing of the frozen 

 ground in spring. 



The beneficial eflfects of an unclouded sun 

 in the treatment of consumption maj-, per- 

 haps, be overrated. The dweller in a rainless 

 atmosphere, dazzled bj' the perpetual bright- 

 ness, and with lungs parched by the heat and 

 dust and drj'ness of the air, might come at 

 last to long for an occasional rainj' da}-, as the 

 traveller in the desert longs for the shadow of 

 the palm. But, at any rate, our weather bureau 

 could scarcely do better work than to give us 

 a ' sunshine map,' upon which the statistics 

 of hourly observations the year round, upon 

 the state of the sky, should be graphically 

 portrayed. Such frequent observations could 

 be taken without inconvenience, as it would 

 not be necessar}' for the observer to remain at 

 a fixed station for that purpose. Such a map 

 would show by depths of shading the relative 

 amounts of sunshine and cloud at any place ; 

 and the invalid could select at a glance a resi- 

 dence which would have the desired propor- 

 tion of these conditions. The complexion of 

 Minnesota upon such a map would probablj^ 

 not varj' widely from the average. 



As has been seen, there is also a popular 

 belief that the air of Minnesota is in a verj' 

 rarefied condition. In the interests of meteor- 

 ology, that superstition must be met and com- 

 bated. The onlj' cause of rarefaction of 

 atmosphere worth considering here is elevation 

 above the sea. Minnesota, as one might 

 guess from its position in the Mississippi val- 

 ]ey, is a low country. The mean elevation of 

 the United States above sea-level is about 



twenty-five hundred feet. The average ele- 

 vation of Minnesota is considerablj' less than 

 half that number. Indeed, its ' height of 

 land ' falls much below twenty-five hundred 

 feet. Therefore a large proportion of visitors 

 to that state move into a heavier atmosphere 

 than that which the}- have left ; but unfortu- 

 nately the}- do not know that fact, and, under 

 the influence of their imaginations, they find 

 their breath wonderfullj' shortened. The ele- 

 vation of St. Paul above the sea is seven hun- 

 dred or eight hundred feet ; that of the plateau 

 region of New Yorlt is from a thousand to two 

 thousand feet. I once knew a lady to remove 

 from the latter to the former place, thus going 

 down hill and into a denser atmosphere. Ar- 

 riving in St. Paul, she could with difficulty 

 climb a flight of stairs, owing to the lightness 

 of the air, as she expressed it. AVhen in- 

 formed of her mistake, she was indignant, and 

 resented the information. People do not like 

 to give up their errors, even if thej- are un- 

 comfortable ones. Having come a thousand 

 miles in search of novelty, it was strange and 

 cruel if she could not be allowed to enjo}- that 

 novelty which is supposed to be characteristic 

 of the west, — a rarefied atmosphere. With 

 all its benefits, science works mankind an oc- 

 casional mischief. The mountaineers of old 

 suffered no inconvenience from their exalted 

 position until the meteorologist came along, 

 and explained to them that the air grew con- 

 stantly thinner as they approached the clouds. 

 Even to-day the unlearned inhabitants of our 

 Rockj- ISIountain region make no complaints 

 of a difficult respiration. It is only the scien- 

 tific tourists who pant bj- the aneroid, and 

 cough up a little blood when thej' cross the 

 timber - line. Whether appreciated or not, 

 however, it is certain that the air of the up- 

 lands is less substantial food for the lungs 

 than that of the low countries ; and it is the 

 densitj^ of the atmosphere, and not the reverse, 

 which is to the advantage of Minnesota as a 

 home for the consumptive. There are many 

 people who advise this unfortunate to seek out 

 some elevated region in which to live, but 

 th^re are verj- few who can give any reason 

 for this counsel. A learned doctor tells us in 

 one of the late magazines, that the harmful 

 substance known as carbonic-acid gas is more 

 abundant near the level of the sea. Certainly ; 

 since there is more air to the cubic measure 

 at a low elevation, there is naturally more 

 carbonic acid, which exists in the atmosphere, 

 whether high or low, in a certain percentage 

 of the whole ; but there is at the same time 

 more of the saving grace of oxygen, which 



