CELESTIAL MEASURINGS AND WEIGHINGS. 183 



practical utility is unimpaired by such mishaps ; and 

 should it be really damaged or lost, public opinion readily 

 transfers the same reverence to its legitimate successor. 



(8.) The history of our existing " Imperial" standard 

 is not quite so simple. It is the successor of one 

 destroyed by fire in 1834: not, however, being copied 

 or even having been immediately compared with its pre- 

 decessor ; but recovered by the evidence of an assem- 

 blage of other standards which had, at various times, been 

 compared with that and with each other. And that 

 again had been derived, not by direct copying and exact 

 equalizing with its predecessor the then " reputed Ex- 

 chequer Standard/' but by a somewhat similar process, 

 from all the best evidence that could be procured of a 

 former state of things. The ultimate prototype is either 

 to be referred to the age of Henry I., who is said " to 

 have settled the yard by the length of his own arm," or 

 to the more ancient foot of twelve inches, "each the 

 length of three barleycorns from the middle of the ear, 

 laid end to end." The point is not of the slightest im- 

 portance, now that we are assured from the number and 

 exactness of the copies taken ; their wide distribution \ 

 and the precautions taken to ensure their preservation ; 

 that it is scarcely in the power of accident to deprive us 

 of a perfectly " legitimate " successor in the sense in 

 which we have above used the term. 



(9.) To measure lengths of many miles (to say nothing 

 of the breadth of a country or of a kingdom), by the 

 simple repetition and laying end to end of yard measures 

 (supposed exactly equal), would not only be intolerably 



