134 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Youno; has not been able to establish the occurrence of iodine 

 in snow-water, as claimed by other experimenters. 6 i?, 

 1876, e/w/y 17, 242. 



schott's tables of atmospheric temperature. 



An important work has recently been issued by the Smith- 

 sonian Institution, entitled "Tables of Atmospheric Temper- 

 ature in the United. States," by C. A. Schott. The special 

 result reached by Mr. Schott, in reference to secular varia- 

 tions of temperature, are of such general interest and impor- 

 tance that we quote some of his conclusions: "The character 

 of the secular variation in the mean annual temperature is 

 that of a series of irregular waves representing a succession 

 of w^armer and colder periods. These undulations, when com- 

 puted for a number of stations exposed to similar climato- 

 logical conditions, are seen to have approached to parallelism 

 over large tracts of country. There is, however, nothing to 

 countenance the idea of any permanent change in climate 

 having taken place, or being about to take place. During 

 the last ninety years the thermoraetric records of mean tem- 

 peratures show no indication whatever of a sudden rise or 

 fall." A similar conclusion has also been reached by Mr. 

 Schott in reference to the rainfall. " If, now, we group to- 

 gether stations properly located, the undulations become 

 Avell marked, the interval betw^een successive maxima or 

 minima being about twenty-two years on the Atlantic coast 

 and seven years in the Mississippi Valley. Even these un- 

 dulations, however, are not sufficiently regular to serve as a 

 basis of prediction. A comparison of the temperature with 

 the frequency of the solar spots show, so far as these records 

 go, no traces of any direct connection between these phe- 

 nomena. On comparing the temperatures and the rainfalls, 

 there seems some ground for concluding that years of high 

 mean temperature have also a large rainfall. And, again, 

 for years of low temperature the winds appear to be north- 

 erly, and for high temperature southerly. The connection 

 between the temperature, the rain, and the winds must, how- 

 ever, be ultimately considered as due to variations in solar 

 radiation." 



