V. MASS. 81 



V. MEASUREMENT OF MASS. 

 A. BALANCES. 



333. Balance, with double column, 20-inch beam, fitted with 

 steel knife edges working on agate planes, to carry 5 Ibs. in each 

 pan, and turn distinctly with '01 grain. Fitted with apparatus 

 for moving sliding weight without opening glass case. As made 

 for the Warden of Standards, for comparison of standard weights. 



L. Oertling. 



334. Balance, with double column, very light beam, 10 inches 

 long, fitted with agate knife edges and agate planes, to carry 

 30 grains in each pan, and turn distinctly with 001 grain, with 

 apparatus for moving sliding weight. L. Oertling. 



335. Balance, with 14-inch beam, fitted with agate knife 

 edges and agate planes, to carry 1,500 grains in each pan, and 

 turn distinctly with *001 grain. L. Oertling. 



336. Balance, with 16-inch beam, fitted with agate knife 

 edges and agate planes, to carry 2 ibs. in each pan, and turn 

 distinctly with 02 grain. L. Oertliny. 



337. Balance, with triangular beam, 6J inches long, fitted 

 with agate knife edges and agate planes, to carry 3,000 grains, and 

 turn distinctly with 01 grain. L. Oertliny. 



338. Balance, with beam 6 inches long, fitted with agate 

 knife edges and agate planes, to carry 2,000 grains in each pan,, 

 and turn distinctly with '02 grain. L. Oertling. 



339. Portable Assay Balance, with 6-inch beam, to carry 

 30 grains in each pan, and turn distinctly with '001 grain. 



L. Oertling. 



34:0. Balance, constructed by H. Qlland, of Utrecht, to 

 weigh bodies up to 40 kilogrammes. 



Prof. Dr. P. L. Rijke, Leyden. 



This instrument is furnished with a double system of " fourchettes," 

 directed by a rod 6 m. long. A difference of 1 in the pointer corre- 

 sponded to a difference in weight of 



9 5 m. gr. when the weight was 20 kilogrammes. 

 10-5 50 



13-8 73 



With weights of about 50 kilogrammes, in a series of experiments under 

 favourable conditions, between each of which the balance was set at rest, 

 numbers not differing in the average by more than 0'03 were obtained. 

 When conditions were less favourable, the differences amounted to 0'26, and' 

 only reached 0> 94 when the conditions were altogether unfavourable. 



40075. F 



