Periodic Seeding -59- 



"It seems, therefore, that the temperature fluctuations in 

 1950 essentially differed from those in 1949 only in the super - 

 imposition of an extremely high seven-day periodicity. 



£i Quite similar results have been obtained by detailed studies 

 of the upper air temperatures in July, 1950 and November, 1950," 



As indicated in this extract, Langmuir's conclusions were contested 

 by representatives of the United States Weather Bureau. Inasmuch as this 

 controversy developed in considerable proportions, it is discussed in a 

 later section of this report. (Page 77). 



EASTERN WORK 



In addition to the periodic seeding conducted in New Mexico, similar 

 seeding was initiated in the Schoharie VaUey, New York and at the base of 

 Mt. Washington. An interesting result of the seeding at Mt. Washington was 

 observed by Joseph B. Dodge, who has charge of the Appalachian Mountain 

 Club lodges in the White Mountains for skiers and mountain climbers. Dodge, 

 who knew nothing of the seeding, pointed out that, judging by the maps of snow 

 coverage in Maine and New Hampshire, there were two bands of snow running 

 at a diverging angle in the direction of those two states and coming to a point 

 back at Mt. Washington. This was a season in which there was not much 

 snow, but along the line of these two bands there had been exceptionally heavy 

 snow. The results of further study indicated that the lack of snow may have 

 been caused by overseeding, but that along the two lines of heavy snow there 

 had been just a light amount of seeding. 



LATER PERIODICITY 



Early in 1952, during the course of their normal analyses of weather 

 conditions throughout the United States, Falconer and Maynard again found 

 evidence of periodicity. Further study showed that the periodicity was on 

 a seven-day basis and that it progressed regularly from west to east. The 

 correlation coefficients were calculated by Maynard and found generally to 

 be of a very high order. For one 28-day period the correlation coefficient 

 was the highest so far obtained for the country as a whole. 



It was thought possible that this phenomenon might be caused by a 

 corresponding periodicity in the commercial seeding going on in various 

 parts of the West. Inasmuch as the periodicity in the weather progressed" 

 uniformly across the United States, it was possible to trace it on a map 

 back to a likely point of origin. The commercial seeding organization 

 active in that area was then asked by Schaefer for a schedule of its seed- 

 ing operations, which it willingly furnished. It was found that the commer- 

 cial seeding had a periodicity corresponding to that observed in the weather. 



