October 5, 1883.] 



SCIENCE. 



459 



■Winds. 



The points of importance in regard to the 

 winds are their velocity and direction. It is 

 well known that the}' are regulated somewhat 

 by changes in atmospheric pressure and tem- 

 perature. 



Velocity. — It is known that a cold wind 

 abstracts body-heat, and in proportion to its 

 velocity. By consulting our tables (table II., 

 part ii.) it will be seen that the mean daily 

 velocity of the winds at Denver is less than it 

 is in the Eastern States ; and that as a conse- 

 quence, while the mean temperature is nearly 

 the same, the chilling effect will be much less. 

 On the other hand, as it has a considerablj' 

 greater velocity, and as there are fewer calms 

 than at either Augusta or Los Angeles, it has 

 a jircportionatel}- greater purifying power in 

 bringing fresh ozone, and in blowing awa}' the 

 products of decomposition. 



Direction. — Of more importance than the 

 velocity, is the direction of the winds. The 

 favorable and unfavorable directions vary for 

 different places, according to their geographi- 

 cal location. The east and north winds are 

 known to be the trying ones along the Atlantic 

 coast ; and our table shows that the north-east 

 wind is the prevailing one at both Augusta 

 and Jacksonville. The west wind, blowing 

 from the Pacific Ocean, and bringing fogs, is 

 the trying one on the California shore ; and 

 the table shows that this is the prevailing one 

 at Los Angeles. The south wind is the salu- 

 brious one for the eastern slope of the Rocky 



Mountains, in Colorado ; and our table shows 

 that this is the wind that blows there most 

 frequently. 



We can therefore add this element to the 

 others, — of elevation, dryness of air, small 

 amount of precipitation, and mean tempera- 

 ture, — as favorable to the Rock}' Mountains 

 as a place for phthisical patients to resort. 



Clear, fair, and cloudy days. 



AVe now come to the consideration of our 

 last general point, that is, to an investigation 

 of the number of clear, fair, and cloudj- days ; 

 or, in other words, to a consideration of the 

 amount of sunshine. 



As to the direct effect upon health produced 

 bv light and sunshine, we are still in igno- 

 rance. AVhether the blood is made to course 

 more rapidly, and the nerves transmit impulses 

 more readih', under the influence of the solar 

 raj-, is not known. It is well known that the 

 actinic rays have a powerful chemical effect 

 upon vegetation ; but whether or not they have 

 a like influence upon the human economj- is 

 unknown. 



Without attempting to refine, there are cer- 

 tain broad and positive effects in the cure of 

 phthisis attributable to sunshine. The expe- 

 rience of the profession is fittingly expressed 

 by the words of Dr. Austin Flint: "I would 

 rank exercise and out-of-door life far above 

 anj' known remedies for the cure of the dis- 

 ease." 



TABLE n. — 'WrHDS. 



