H. LENGTH. 55 



mission in the year vii. of the French Republic ; formerly in the 

 possession of Tralles. Prof* D r - -Dove, Berlin. 



Original Meter Scale by Tralles (of iron). One of the 40 standards which 

 were delivered to the Commissioners. 



Iron Meter a touts. This meter, which was presented to Hapler by Tralles, 

 was one of the three which the latter had made at the same time, by Lenoir, 

 with the 15 which were distributed among the members of the Commission. 



After the completion of the new measurement of degrees performed by 

 Delambre and Mechain, the real length of the meter was determined by the 

 Commission, consisting of, Swinden, Tralles, Laplace, Legendre, Cizcar, 

 Mechain, and Delambre, in their report of the 6th Floreal year 7, to be 

 443 - 295936, and the distance of the Pole, by assuming an oblateness of ^fa, 

 from the equator having been calculated to be 5130 js toises, it was legally 

 accepted as " metre oral ct definitif" at 443-296. 



" Cette unite uornmee metre qui est le dixmillioneme partie du quart du 

 meridian revient selon les anciennes mesures & 3 pieds 1T296 lignes^ en em- 

 ploy ant la toise du Peron a 13 degres du thermometre & mercure divise en 

 80 parties." 



312. Standard Meter on brass in mahogany case. 



Ed. Sprenger, Berlin. 



313. Standard Meter on Steel. Ed. Sprenger, Berlin. 



314. Standard Meter on Wood. Ed. Sprenger, Berlin. 



315. Standard Tape Measure, 20 meters. 



Ed. Sprenger, Berlin. 



315a. Standard Stirling Ell, believed to be a copy of the 

 standard Scottish ell adjusted at Edinburgh, 26th of February 

 1 755. The Burgh of Stirling. 



315b. Standard Meter. Bock and Handrick, Dresden. 



Two Standard Meters (boxwood). 



Bock and Handrick, Dresden. 



2-Meter Standard Measure. 



Bock and Handrick, Dresden. 



B. TELEMETERS. 



'226. Telemeter. For measuring the distance of inaccessible 

 obj ects. Patrick i Adie . 



This instrument, the first of its name, was patented by Mr. Adie in 1863. 

 It consists of two powerful telescopes at the ends of a fixed base ; the united 

 rays, by total reflection, give simultaneous observation in the eye-pieces. 



234. Telemeter, for determining distant inaccessible points 

 by one observation. Manufactured by Adie & Son, Pall Mall. 



Prof. Pigot. 



