-244 On the proposed Alteration 



that stated by Overlay by above half an inch. My rod is 

 constructed from a tarif of cube roots, resulting from the pre- 

 ceding analogy, with the exception of the number of gallons, 

 which were an equivalent of imperial measure to the foregoing 

 quantity of ale measure. 



I am, however, free to confess that this error for a long 

 time escaped my notice; and I think it very probable, that if 

 1 had not determined upon entirely new modelling of every 

 species of gauging instruments, to render them exclusively ap- 

 plicable to the new system, I never might have discovered it ; 

 but, having been true to my purpose, I have the satisfaction 

 of being enabled to state that my improvements will form a 

 valuable appendage to the imperial system; to which it so 

 readily applies in practice. It may not be improper to ex- 

 hibit the ratio of loss which this improvement obviates. 



This will be shown by inverting the analogy; thus. 



Here the loss to two of the three parties concerned is shown 

 to be above 5| per cent., the revenue being at the minus side 

 oi" the question. 



As manufacturers are mere copyists, it is no wonder that 

 they should know nothing of the matter. This rod, I may ob- 

 serve, is in use, more or less, all over the nation; but it is due 

 to the port gangers to state that they do not use it. It ought 

 to be strictly prohibited, or indeed destroyed; at any rate, 

 especial care should be taken that no rod of this sort should 

 be used for the imperial measure, until it has been ascertained 

 not to have been derived from Oughtread's analogy. 



The port gaugers, as I observed before, do not use this rod. 

 They use the callipers. The callipers are however not with- 

 out defect. 



They give the external dimensions ; and although the great 

 experience of the port gangers enables them to excel in their 

 profession, I must consitler that instrument objectionable which 

 does not direct, and not derive Jiom, the judgement. The 

 process of perforating the head of a lying cask, to ascertain 

 the thickness of the timber, is inadmissible ; but the loss of 

 time, even if practicable, would forbid its adoption in every 

 cask. To obviate this objection, I have invented an instru- 

 ment to ascertain, promptly, the length of any cask from an 

 interior application from the bung, and which at the same in- 

 stant exhibits the bun-g diameter. 



But 



