AT KEW OBSERVATORY AND THEIR DISCUSSION. 



467 



TABLE XXII. Mean Sums of Differences Descending less Ascending Headings 



(from Experiments 52, 53, 54, 55). 



Here there is certainly no suggestion of any temperature influence. 



The great majority of the later experiments had some peculiarity, such as a 

 stoppage, which prevents their use for investigating the influence of temperature on 

 the sum of the differences. I thus confine my attention to the earliest 24 experi- 

 ments, subdividing those over each range into a colder and a hotter half.* The 

 mean sums of the differences, in inches, are given in Table XXIII. 



TABLE XXIII. Mean Sums of Differences Descending less Ascending Readings 



(Experiments 1 to 24). 



Some of the data, more especially those for the range 30 to 24 inches, suggest an 

 increase in the sum of the differences as temperature rises. In the range 30 to 26 

 inches, however, where the temperature difference was greatest, there is no trace of 

 temperature effect. In the two longest ranges the temperature difference was small 

 and the experiments very few. 



In the four experiments dealt with in Table XXII. the deficiency in the reading 



* In the case of the range 30 to 26 inches the two groups consist of the three hotter and three colder 

 experiments, the odd experiment being left out of account. The hotter were also the earlier experi- 

 ments in this instance. 



3 o 2 



