450 



DR. C. CHEBE, EXPERIMENTS ON ANEROID BAROMETERS 



difference in the results, though worthy of notice, is for practical purposes of little 

 consequence. As we shall see later in Table VI., unity in Table III. represents at the 

 very utmost 0'25 of an inch, so that a difference of 4 or 5 per cent, in one of the 

 ratios answers to a quantity which is in general considerably less than the probable 

 error of an observation. 



Fig. 3. 



/ -Z -3 , -4 -5 -6 -7 -a 3 I'O 



Fractions of pressure range from lowest point. 



To facilitate comparison of the old and new observations, I show side by side in 

 fig. 3, curves of the same type as in fig. 2, the one representing the mean results of 

 Table II., the other the mean results of Table III. The former curve is exceptionally 

 smooth, and the latter even is very fairly regular ; but curves for the individual 

 ranges of Table III. which I do not reproduce show very appreciable irregularities. 

 This of course is only what one would expect from the limited number of observations. 

 Whilst the data in Table III. thus possess defects which might have been much 

 reduced by an increase in the number of experiments, they appeared quite sufficiently 

 consistent for the purpose I had in view. 



