244- 



Experimental Ccmpanfon of Standard Medfunsl 



1- 



And 12 inches on the jft foot were equal to the I2 inches 



from 12 to 24 on Troughton's fcalc 

 The 2d foot - - _ _ 



The 3d foot - - _ _ _ 



The laft foot - - , - - 



inches, 

 ,0003 = 11,9997 



,0006 



,0004 



12,0006 

 11,9996 

 12,0006 



on Mr. Troughton's fcale 

 from 6 inches to 18 

 inches ; the thermome- 

 ter being at 50°,o. 



---.--+ ,0006 



The mean foot, therefore, in General Roy's fcale, taken from four dif--j 



ferent feet compared with Troughton's, between the 12th and 24th >• i2,COOi2 

 inch, is as 12 to - - - - - - J 



That is, general Roy's fcalc is longefl: on 1 foot by fo much, and longer 



on 3 feet by _ . _ _ . . - ,00036 



And the greateft probable error from the inequality in the divifions is about jOoo^ 

 And the mean probable error about _ _ _ JOOO3 



(§. 49.) Mr. Aubert's fcale, compared with Mr. Troughton's, was as follows: 58 inches 

 were equal to 57,9982 inches on Troughton's; (thermometer at 5i°,o;) viz. Mr. Bird's 

 i]|eafure was fliorteft ,0018 ; or, fhorteft on 36 inches = ,0012, 



inches. -> 



And 12 inches, or ift foot, on Mr. Aubert's = 11,9999 



2d foot, - ' =1 2,0005 



3d foot, - 1 1,9996 



4th foot - 12,0019 



5th foot - 12,0006 



Therefore the mean foot is - - 1 2,0005^ 



The greateft error in this fcale appears to be about = ,0012 



And the mean probable error - = ,0006 



(§. 50.) The Royal Society's fcale, compared, was as follows; 58 inches on Mr. Bird's 

 were equal to 57,99912 inches on Mr. Troughton's; (thermometer 5o",5 ;) 

 viz. Mr. Bird's meafure was fliorteft 

 Or fliorter on 36 inches _ - _ 



32 inches on the fame were equal to - - 



viz. Mr. Bird's was fliorteft by - - 



Or, on 36 inches, by _ - - 



The mean ofthefe two comparifons is 



And, byfo much, is Mr. Bird's fcale fhorter, in three feet, than Troughton's. 

 ^nd 12 inches, or ift foot, of the Royal Society inches. ~> 

 /cale, is - - - = 12,00013 



2d foot of ditto = i'>99957 

 3d foot of ditto =12,00027 

 4th foot of ditto = 1 1,99(^90 

 5th foot of ditto = 12,00063 

 6th foot of ditto = 11,99123 



7 th foot of ditto Zi 12,00000 



The 



on Troughton's fcale; the 

 thermometer at 51", 



