Mr. Wiseman on Gauging. 415 



fortunately, however, we are not able to make such satisfactory 

 deductions from these curious experiments as they might have 

 furnished, "had Mr. Goldingham described the construction 

 of his hygrometer, and the fixed points, or the extent of its 

 scale. 



Royal Military Academy, Nov. 8, 1823. 



LXVIII. On the New Method of Gauging proposed by 

 Dr. Young. By Mr. W. Wiseman. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



T N the Journal of Science, No. 32, there appears a Report, 

 -*■ made to the Honourable Commissioners of the Customs by 

 Dr. Young, respecting improvements in Gauging. The mat- 

 ter being thus made public, I shall now take the liberty, 

 through your permission, to offer a few observations on the 

 occasion. 



The advantages which Dr. Young states, in the Report just 

 mentioned, would be derived from the adoption of his inven- 

 tion, are, the shortening the operation of casting the full con- 

 tent, — abolishing the practice of making a discretionary al- 

 lowance in the length of each cask supposed adequate to re- 

 duce such cask to the middle frustum of a spheroid, — and 

 at the same time attaining at least an equal degree of accu- 

 racy with the old method. 



The detailed operation of casting the content, at present in 

 use, is this : — The beginning of the first line is set to the head 

 diameter on the second line ; the number on the third line, 

 standing against the bung diameter on the second line, is 

 noted; against this number on the first line is found the mean 

 diameter on the second line. Next, the end of the slide is set 

 to the length on the fourth line ; and against the mean diame- 

 ter on the fifth line is found the full content on the fourth 

 line. 



The operation which Dr. Young proposes to substitute for 

 the above, and for the method of allowances, is this : — The 

 head and bung diameters on the first and second lines are 

 brought together, and against die length on the third line is 

 the full content on the fourth line. 



The formula upon which this operation depends, is a most 

 scientific and ingenious invention; and were it possible to in- 

 vent a rule which would always give the content, at a single 

 setting of the slide, sufficiently near the truth in all the vane- 

 ° ties 



