258 General Strachey on the Correspondence of [May 31, 



Table VIII., and had no knowledge of the law of periodicity, and hypo- 

 thetically applied a period of ten intervals instead of twelve (following 

 the process the results of which for Madras are given in Table III.), the 

 inapplicability of such a period would immediately be made apparent by 

 results such as are found in the rainfall observations. On the hypothesis 

 just mentioned the mean values, corresponding to those given in the 

 last line of Table VIII., for the successive intervals of the six arbitrary 

 cycles that would be formed would be as follows :— - 



Table X. 



Cycles of 

 20 hours. 



Intervals of two hours. 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 



10. 



Mean difference ] 

 from mean of I 

 60obs J 



-2 



-3 







-1 



+2 



+1 



+1 



+3 



+3 



-3 



From these figures the following differences would be deduced instead 

 of those shown in Table IX, 



Table XI. 



• 







Intervals of two hours. 







Cycles of 























20 hours. 

























1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 



10. 





36 



1 



53 



84 



43 



9 



31 



49 



75 



57 



2nd „ 



4 



55 



87 



57 



23 



12 



12 



15 



12 



4 



3rd „ 



18 



9 



32 



71 



74 



44 



1 



16 



5 



13 



4th „ 



11 



25 



57 



43 



4 



46 



64 



31 



15 



50 



5th „ 



24 



3 



4 



24 



62 



36 



14 



49 



55 



26 



6th „ 



11 



28 



7 



20 



5 



34 



55 



32 



16 



71 



Mean difference, 1 























disregarding I 



17 



20 



40 



49 



35 



30 



30 



32 



30 



37 

























Mean of mean differences 32. 



The contrast between these results and those given in Table IX. is 

 most striking, and calls for no comment in detail, 



In conclusion I would explain that I do not desire to call in question 

 the possible or actual occurrence of periodical terrestrial phenomena 



