VALUE OF WEATHER OBSERVATIONS 131 



Most people count the " liits " and disregard the " misses." If such a 

 record be kept, the wheat will be separated from the chaff, but a week 

 or a month of record, while long enough to bring out much of interest, 

 is far too short a time for purposes of scientific compar-ison of relative 

 values. 



Travelers, even when passing rapidly through a country on the 

 railroad, and, still better, when moving more slowly on horseback or on 

 foot, usually have opportunities for making simple non-instrumental 

 observations which will add greatly to the interest of their journey, and 

 which, if the region is comparatively little known, may really be of 

 considerable importance. I have long felt that wliat I have termed 

 " car- window climatology " deserves far more attention than it has re- 

 ceived. In my own experience when traveling in South America under 

 conditions which usually made it impossible to carry any instrument 

 except a sling psychrometer, it was found feasible, when journeying on 

 horse or mule back, on the Brazilian " trolley," or in the train, to col- 

 lect facts which added greatly to my understanding of the climatology 

 of the regions passed through; made the trips alive and interesting, 

 and helped to hasten the passage of many weary hours. Some of these 

 observations, indeed, it has seemed worth while to publish. There are 

 many observations which an intelligent traveler can make, even from a 

 car-window, although a slower method of progression is, of course, to be 

 preferred in such a study. "Wind velocity may be reasonably accurately 

 estimated, after a little practise, by noting the effect of the wind in 

 blowing trees, or in producing waves of different sizes in lakes or on 

 rivers. The prevailing wind direction can often be very accurately de- 

 termined by observing the slant of wind-blown trees, or again, by 

 taking note of the effects of wave action on the leeward side of a lake or 

 pond. Vegetation always furnishes a general criterion in regard to 

 temperature and rainfall. When trees shed their leaves we infer a 

 season of cold or it may be of drought. The occurrence of frost may 

 te detected both by seeing it, and by noting its effects. The altitude 

 reached by frost may likewise be observed. The direction of rainy or 

 ■snowy winds may be discovered by observing on which side trees are 

 w^et. Whether or not hail, or snow, or sleet, or frozen rain, or gales, or 

 Iieavy rains, or fog, occur in a region is observable, so far as the period 

 ■of his visit is concerned, by any traveler. Forest and prairie fires indi- 

 cate droughts, or dry seasons. Tornadoes and high gales, may be 

 •detected many years after their occurrence by the damage they did to 

 trees. Whether or not a river is subject to floods may usually be de- 

 termined by such hurried observations as can be made from a car- 

 window, by noting the mud deposited by former floods on the trunks of 

 i;rees, or by seeing the banks and neighboring fields actually overflowed. 



