Smithsonian miscellaneous collections . +15 +70 +47 + 7 + 40 + 49 +61 +23 + 6 +3i -13 + 56 + 164 +57 +78 +31 +62 cate results from temperatures recorded before and after 1900, duringthe interval of years 1854 to 1939. In table 5 the column Ax is themean of eight columns and the column A2 of nine columns. Thedepartures shown in these tabulations having been plotted in figure 3,the tabulation of A2 discloses the presence of the overriding periodicityof 9^ months, approximately one-sixth of the 54^-month period. To eliminate it, the departure values in column A2, table 5, werearranged in six colu
Smithsonian miscellaneous collections . +15 +70 +47 + 7 + 40 + 49 +61 +23 + 6 +3i -13 + 56 + 164 +57 +78 +31 +62 cate results from temperatures recorded before and after 1900, duringthe interval of years 1854 to 1939. In table 5 the column Ax is themean of eight columns and the column A2 of nine columns. Thedepartures shown in these tabulations having been plotted in figure 3,the tabulation of A2 discloses the presence of the overriding periodicityof 9^ months, approximately one-sixth of the 54^-month period. To eliminate it, the departure values in column A2, table 5, werearranged in six columns and their mean taken as shown in table 6. NO. I TEMPERATURE OF WASHINGTON, D. C.—ABBOT 7 These mean departures, repeated six times, are given in table 5, and,being subtracted from column A2, give the departure column A1*. Thevalues Ax2 are plotted in figure 3, and show great similarity in formand phase relations to the departures Ax. So the mean of A1 and A12is taken in table 5, and plotted in figure 3. It is now obvious that the. Fig. 3.—The S4i-month periodicity, cleared of superriding periodicities, asexplained in the text. curve has an overriding periodicity of half its length. Hence the meanof departures of columns Ai and A12 is analyzed for a periodicity of(54i =2) months, yielding the results shown in table 6 and repeatedend to end in table 5. Subtracting from the values given in the nextpreceding column, and plotting the remainder in figure 3, it is nowobvious that only the effect of the overriding periodicity of 11^, orapproximately one-fifth of 54^ months, remains. Hence it provesunnecessary to employ the periodicity of 54^ months at all in thesynthesis of Washington temperatures. Similar steps eliminate theperiodicities of 68| months and 91 months from consideration. We are now prepared to test the usefulness of the 20 periodic termswhich have been worked out in the Washington departures from Table 5.—Clearing the periodicity of 54% months of overrides Mean
Size: 1757px × 1422px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, bookidsmiths, booksubjectscience
