4Q Captain Kater's account of the 



standards were repeatedly compared with Sir G. Shuck- 

 burgh's scale (the standard being placed upon the scale) 

 when no perceptible difference could be detected. Pieces of 

 card were now placed under the standard as before, without 

 occasioning any appreciable alteration ; and I had thus expe- 

 rimental proof of the perfect efficiency of the remedy I had 

 employed. 



I have been thus particular in detailing the difficulties I 

 experienced, because they exhibit a source of very consider- 

 able error which may arise from the thickness of a standard 

 scale, and which I believe has never before been suspected. 



It may be here not unnecessary to remark, that on every 

 occasion on which I have used Sir G. Shuckburgh's scale, it 

 has fortunately been placed not only upon the same table, 

 but upon the same part of it. 



The various standards which have been described in this 

 paper with the exception of the yards with steel termina- 

 tions are not meant for common use, but are intended to be 

 carefully preserved, to be referred to only upon extraordi- 

 nary occasions. In addition however to these, other weights 

 as well as measures of capacity were made with great care by 

 Mr. Bate. The following is a list of the whole, with an 

 account of the places where they are deposited. 



Standards deposited at the Exchequer ^ Westminster. 



1 Imperial standard yard with gold points. 

 I Standard yard with steel terminations. No. i. 

 1 Imperial troy pound. No. 5. 

 X Avoirdupois pound. No. 1. 



