PROCEEDINGS OF SECTION I. 



611 



ia) In one variety (Fig. 2) loose weights are placed on a disc 

 suspended from the outer end of the steelyard, the final adjustment 

 being made by a small weight which slides on the steelyard. 



Fig. 3. 



(h) In another variety (Fig. 3) the steelyard consists of two parallel 

 graduated bars, on the lower one of which sUdes a heavy weight for 

 weighing the larger units, while a light weight sUdes on the upper bar 

 for weighing the smaller units and making the final adjustment. 



The latter variety allows of more rapid weighing. 



It may be found convenient, in some instances, to have one weighing 

 machine which may circulate among and serve the schools of a certain 

 area, returning to each school in the same month every year. In 

 such cases the machine should be selected for its suitability for 

 tran.sport, and its accuracy should be frequently tested. 



V 2 



