176 First Report of the Commissioners appointed to consider 



has been generally, and we believe correctly, ascribed to Dr. 

 Olyntlms Gregory, of the Royal Military Academy, Woolwich. 

 It was soon afterwards published in a separate pamphlet by Bald- 

 win, Cradock, and Joy. That our readers may judge to what 

 extent the present Commissioners have adopted Dr. Gregory's 

 train of thinking, and how far their slight deviations may be real 

 improvements, we shall lav before them an extract or two from 

 his dissertation : — 



" Let us now endeavour to draw some ))ractical conclusions 

 from this long train of inquiry. With this view we would recom- 

 mend that the standard foot, to be legalized in future, should 

 agree either vvith that oi\ Bird's scale made for General Roy (still 

 tised in the Trigonometrical Survey) or that on Bird's Parliament- 

 ary scale of 175s (in the custody of the Clerk of the Journals of 

 the House of Commons) ; either of these being regarded as the 

 27,404tii part of the base on Hounslow-heath, and as equal in 

 length to the prismatic plate that is suspended, and vibrates 

 36,469 times in five hours, as already described; or rather, that 

 vibrates a certain number of times, agreeably to the result of ex- 

 periments to be instituted for that ])urpose under the direction of 

 Parliament. Several rods or plates should be made to agree ex- 

 actly with this foot, in some fixed temperature, — suppose that of 

 56 or of 60 degrees Fahrenheit ; and several other 2-feet, 3-feet, 

 and 4.feet rods should also be constructed. The length of all 

 may easily be adjusted to the 5000dth part of an inch, by means 

 of a micrometer screw such as is described in Lord Stanhope's 

 account of his monochord ; and if the ends of all of them are 

 precious stones set in and ground Ao\'<i\\ to the precise length, 

 the standards will, we apprehend, be rendered more durable than 

 by any other process ; except, perhaps, that in which the ex- 

 tremities of the lineal unit shall be shown by metallic points let 

 into the faces of the measures. These, properly stamped, should 

 be lodged at suitable places in the metropolis, and at others in 

 the county towns, as well as other large towns, in the custody of 

 proper officers. 



" Instead of dividing this foot into inches, or twelfth parts (a 

 denominator which always gives a circulating decimal by division, 

 except when tlie numerator is 3, 6, 9, or their multiples), we 

 would recommend that it be divided into tenths, and each of these 

 again into tenths, or hundredths of a foot. Such division and sub- 

 division would tend to simplify computation, at the same time that 

 they would answer every purpose proposed to be attained by the 

 use of inches and their 12th jiarts. Together with these we would 

 allow to practical men tlie binary division of the foot. Although 

 the yard be a multiple of the foot (its triple), which is inconsistent 

 with the general principle of augmentation and diminution by 



means 



