V. MASS. 65 



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. Oertling. 



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

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

 turn distinctly with 01 grain. L. Oertling. 



338. Balance, with beam 6J 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. 



340. Balance, constructed by H. Oil and, of Utrecht, to 

 weigh bodies up to 40 kilogrammes. 



Prof. Dr. P. L. Rijke, Ley den. 



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

 directed by a rod 6 m. long. A difference of 1 in the point of equili- 

 brium answered 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. 



341. Balance, charge up to 500 grammes in each pan ; 

 sensible to j 1 ^ part of a milligramme with its full charge. 



Beckers Sons, West Zeedyk, Rotterdam. 



This balance is furnished with agate knives, and all bearings run on agate 

 planes ; it has a rest for pans and beam, and apparatus with adjustable shelf 

 for taking specific gravities. The beam is divided in^ part of a milligramme. 

 Sets of weights from 500 grammes down to 1 milligramme. Three riders. 



342. Analytical Balance, on plan suggested by Professor 

 Dittmar, Anderson's University, Glasgow, for a charge up to 

 100 grammes in each pan. 



Beckers Sons, West Zeedyk, Rotterdam. 



This instrument shows a new method for displacing the centre of gravity of 

 the beam, and for weighing up to 1 10 milligrammes by means of riders. The 

 two riders form a part of the balance, with plunger for displacing exactly 

 10 grammes of water at 15 C. for taking specific gravities of liquids. Sets 

 of weights. 



39508. E 



