82 SEC. 3. MEASUKEMENT. 



341. Analytical Balance, charge up to 500 grammes in 

 each pan ; sensible to -^ part of a milligramme with its full charge. 



Beckers Sons, West Zeedyk, Rotterdam. 



This balance is furnished with agate knife edges, and all bearings rest 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 -J- parts of a milligramme. 

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



342. Analytical Balance, on plan suggested by Professor 

 Dittmar, Andersonian 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 110 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. 



343. Balance, with drawer and eccentric for lifting, movable 

 pans, set screws and level, charge up to 1^ kilos, in each pan, 

 sensible for 20 milligrammes with its full charge. 



Beckers Sons, West Zeedyk, Rotterdam. 



344. Balance, charge up to 1 kilo, in each pan, sensible for 

 20 milligrammes with its full charge. 



Beckers Sons, West Zeedyk, Rotterdam. 



344a. New description of Balance of Precision, designed 

 by M. Mendeleef, Professor of the University of St. Petersburgh, 

 and constructed by Oertling. It is more particularly described 

 in Appendix 10 to the Ninth Annual Report of the Warden of the 

 Standards. H. W. Chisholm. 



The peculiarity of this balance is that it has very short arms, and thus 

 occupies very little room, and by its more rapid motion time is saved in weigh- 

 ings, whilst it gives results quite as 'accurate as those given by balances of 

 precision with arms of greater length as ordinarily used. 



Though constructed to carry a kilogram in each pan, the total length of 

 the beam of this balance is less than 4f inches, whilst it is intended to give 

 results within one tenth of a milligram. The balance beam to carry a kilogram 

 is ordinarily 20 inches in length. 



It can be used as a vacuum balance, as well as for weighings in air. 



344b. Balance of Precision for minute weighings of 10 

 grains and under in each pan, constructed by Oertling. 



H. W. Chisholm. 



The beam is made as light as possible, and unusually so. The pans and 

 suspending wire are of aluminium. The balance works upon fine points. 

 A single action lowers the support of the beam and the supports of the 

 pans. 



348-9. Frerich's analytical Balance, capable of carrying 

 2,000 grnis. with riders and *a set of gramme weights. 



F. Sartorius, Gottingen. 



