SMALT. niKFKRKNOES OF SENSATION. 



Till' t'olldwiiiR i.s a siinilar tabic for Mr. Jastrow a.s .subject: 



Ratios of pressures. 

 I.IUO 1.(180 1.0(iU I.O.-iO 1.040 l.Oai t.O-J(» 1.01.-, l.OKl 1.00.-, 



81 



iiiitt-. 



Deo.iiilier 10 :> 



IVieiiiliir 13 1 '.I l.'> 



Deceinber 17 ] 14 



December -.30 | 10 



.laimary :i | 8 



Jamiarv 10 j 7 



.1 an iiarv 1.') .... 12 



19 



ir, 



January V!2 . . 

 January 2i . . 

 February 11 . 

 February 17 . 

 February 18 . 

 February 24 . 



March 4 



March : 



11 

 4 

 1 



2:! 

 17 

 14 



i:! 



(; 



10 



11 



7 



10 

 II 



8 



Ki 



i:! 



March 18 14 



March 19 1 11 



March 23 14 



March25 I 12 



March 30 1 H 



March 31 10 



April2 11 



April3 9 



April (i I'f 



April 7 -> 7 



24 

 17 

 22 

 IG 

 18 

 18 

 17 

 17 

 1.5 



14 



I(i 

 17 

 19 

 21 

 17 

 16 

 16 

 15 

 17 

 18 

 15 

 15 



2b 

 18 

 18 

 18 

 21 

 21 

 21 

 20 

 21 

 17 



Means. 



«.6 



19 15.0 11.6 , 11.4 , 18.9 I 16.H 20.5 



It would obviously be uiilair to compare these numbens with any -set of theoretical uumbers, 

 since the probable error is on the decrease throughout, owing to ett'ect.s of practice, etc. For 

 various reasons we can conveniently 8tou[) these experiments into four groups. The first will 

 include the experiments from December 10 to January 22, inclusive; the second from January 24 

 to February 24, inclusive; the tiiird from Marcli 4 to March 25, inclusive; the fourth from March 

 30 to the end of the work. 



The mean results for tlie different groups are exliibited in the following tables: 



First groiij). 



[I'n.bable error=0.05.] 



Ratios of Nuinbeiof 

 pre.ssnres. sets of .-|0. 



I. 100 

 1.080 

 1. 060 

 1.050 

 1. 040 



i.ii;!0 



1.015 



Average number of 

 errors. 



Average eouliiU'ii^ 



Calculated 

 ()bser\e(l. fioni proba- (.)bser\e(i. Caleulatol. 

 ble error. 



11.0 J 0.7 



19 



15 



1.3. 8 J 1.5 



20. 8^ 1. 1 



4.4~tl.4 

 7.0J^1.7 

 10.44-0.7 

 12.54:2.1 

 14.7^2.2 

 17. 0-tO. 9 

 21.0-tl. 1 



0.9 

 0.9 

 0. 85 

 0. 35 



0. :! 



0.5 

 0.3 



1.5 

 1.2 



0. 9 

 0.7 

 11.6 

 0.4 

 0.2 



Sccoiut (/roup. 

 [Probable error=0.0235.] 



S. Mis. G9- 



1 . 060 

 1.030 

 1.015 



—11 



