132 THE POPULAR SCIENCE MONTHLY 



The condition of the roads, whether dusty or raudd}^ indicates in a 

 general way the occurrence or lack of recent rainfalls. And thus, 

 through a long list, we might go on. Non-instrumental, even irregular 

 and scattering observations of meteorological conditions, and of their 

 effects, are well worth while, if intelligently made. Such observations 

 should be more generally undertaken. 



During the short semi-vacation of the past summer I have found 

 much interest in reading the " Journals " of the Lewis and Clark Ex- 

 pedition '' to the sources of the Missouri, across the Rocky Mountains, 

 down the Columbia River to the Pacific in 1804-06 " What struck me 

 particularly -was the remarkably clear picture which I gained of 

 the climatic conditions of the then unknown country through which, 

 amid great hardships and many dangers, this famous expedition passed. 

 The leader of the expedition was charged by the President with report- 

 ing upon very many matters besides meteorology.^ Yet, in spite of the 

 many difficulties of the journey, and with only one instrument — a ther- 

 mometer — which was unfortunately broken before the end of the trip, 

 the observing eye of Captain Lewis was able to note a variety of 

 meteorological and climatic facts which give a vivid picture and empha- 

 size, in a striking manner, the kind and the value of simple weather 

 observations which any intelligent traveler can take.^ In view of the 

 many hardships of the journey, it is surprising to see how few gaps 

 there are in the record, which covers the period January 1, 1804— 

 September 30, 1805. Between May 14 and September 18, 1804, there 

 comes the only considerable gap, with the significant comment: '"'The 

 party were then just beginning the ascent of the Missouri, and it is 

 probable that amongst the many other important things which en- 

 grossed their attention this was omitted." The tables give date, and 

 thermometer, Aveather and wind direction at sunrise and 4 p.m. ; also 

 the risg and fall of rivers, in inches and feet. 



The thermometer readings have, perhaps, less value than might be 

 expected, partly because they could not be continued throughout the ex- 



^ President Jefferson instructed Captain Lewis to report upon climate as 

 follows: "Climate, as characterized by the thermometer, by the proportion of 

 rainy, cloudy and clear days; by lightning, hail, snow, ice; by the access and 

 recess of frost, by the winds prevailing at different seasons; the dates at which 

 particular plants put forth, or lose their flower or leaf; times of appearance of 

 particular birds, reptiles or insects. ' ' 



^ Captain Lewis 's scheme of notation of Aveather was as follows : 

 /, fair weather. c, cloudy. 



r, rain. «> snow. 



h, hail. ^ thunder. 



I lightning. f^ after, as f ar means fair after 



cas, cloudy after snow intervening. rain which has intervened since 



cars, cloudy after rain and snow. the last observation. 



