OP THU UNITED STATES. 258 



The standards were the following : — 



1. An iron metre standarded at Paris, in (799. hy the 

 Coniniiltce of Weights and Measures, composed of memlK-rs 

 of the National Institute, and of dei'uiies from other coun- 

 tries. Its breadth is 1.13 inches, its thickne>s 0.3(i inches, 

 Englisli measure. My friend. Mr. J. (1. '['rallos, now mem- 

 ber of the Academy of Sciences of Berlin, was at that time 

 the deputy of the Helvetic Republic lor this purpose; and, 

 as may be seen in the account of the operations of this Com- 

 niittee, he was the foreign meml)er directing tlie construction 

 and comparison of the measures of length. He had one metre 

 constructed for himself and one for me, at the same time 

 with all the others, and subjected in all respects to the same 

 processes and comparisons. In the ultimate distril)ution, it 

 is known, that they were taken indiscrirninately, and consi- 

 dered equally authentic, this metre being one taken by M. 

 Trallcs. He was so kind as to give me, at the same time, 

 a standard kilogramme, constructed in the same manner, 

 utuler the direction of Mr. Van Swinden, 'I hcse original 

 standards, both of lengtli, measure, and weight, bear the 

 stamj) of the Committee, viz. a section of the elliptic earth, 

 of whicli one rpiadrant is clear, with the numl)cr to. 000. 000 

 inside of the arc ; the other tiuce quadrants being shaded. 



2. One iron toise, with its matrix, in which it fits exactly, 

 forming together a bar of three inches broad and half an 

 inch thick, French measure. It is of careful execution, and 

 presents the form seen at IMate IX. fig. 11. It was made by 

 Canivd, a la sphere, d Paris, whicli is also engraved upon 

 it, as also the notice, Toise dc France, etnlonee le i6""' 8*", 

 1768, a la temperature de 16° da Thermometre de M. de 

 Reaumur. A line is drawn along the Iiack of the toise, and 

 from a perpendicular, crossing this line near one of its ex- 

 tremities, to a point taken near the other extremity, is en- 

 graved, La double longueur du Pendi.le sous I'Equateur. A 

 point is marked between the other two at the simple length 

 of the pendulum. Having been in Paris, in I7i)6. shortly 

 after the death of M. Dionis du St'-jour, I bought this toise 



VOL. II. — L 2 



