68 SEC. 3. MEASUREMENT. 



382. Model of a Centesimal Weighing Machine, with 

 glass platform. Dr. Kohlmann, Halle. 



384. Model of a Decimal Weighing Machine, with glass 

 platform. 



Physical Institute of the University of Halle (Prof. 

 Knoblauch, Director). 



386. Beam Balance with equal arms, sensibility 1 : 200,000. 

 Kleemann, Mechanical Engineer, Halle. 



390. Beam Balance, for educational purposes. 



Alex. Bernstein and Co., Berlin. 



The steel-yard, for educational purposes, has contrivances for demon- 

 strating the different peculiarities of a scales-beam, or balance, namely, dis- 

 placement of the centre of gravity, lifting and grinding of the principal nut, 

 unequal lengths of levers, non-parallelism of the knife edges, and position of 

 one terminal knife edge extraneous of the level of the two other knife edges. 



388. Small Decimal Balance, for educational purposes. 



Alex. Bernstein and Co., Berlin. 



The decimal balance for instruction in schools has on each prism a scale 

 so that the influence of the weight of each prism can be shown by itself. 



389. Analytical Balance. 



Alex. Bernstein and Co., Berlin. 



The analytical balance has a capacity of bearing 500 grammes, and 

 when fully weighted a sensibility of -^ mgr. ; it has a perforated gilded 

 brass beam with axes of agate and pans with arrangement for releasing all 

 knife-edges, stop balance with pencil, and sliding weights movement. 



389a. New Balance for a Laboratory, carrying three 

 kilogrammes in each pan, and turning with five milligrammes. 



Delcuil, Paris. 



When it is not weighing, the beam is supported free of the knife edge, as in 

 other accurate balances ; vessels 25 centimetres in diameter can be placed on 

 the pans, also vessels with long necks, and flasks of 1-2 litres capacity. By 

 the aid of the second pan, the specific gravity of very bulby bodies can be 

 taken. 



390a. Self- Acting Balance for Galvanic-plastic pur- 

 poses. Alex. Bernstein and Co., Berlin. 



The scales for galvano-plastical purposes is so constructed that the con- 

 duction is interrupted by self-action as soon as a precipitate (deposit) of a 

 certain weight has been obtained. 



391. Balance for Blow-pipe Experiments, in a case, 

 with weights. Alex. Bernstein and Co., Berlin, 



The scales are for blow- pipe experiments ; they have steel axes, and 

 pans of agate, two scales of horn, two pairs of gilded little bowls, one bowl 

 with hook for the determination of specific weights, and a set of weights from 

 1 gr. to 1 centigr. of silver ; from 1 centigr. to 1 milligr. of aluminium, and 

 the fraction milligr. of quills. 



