332 NATURE STUDY REVIEW [8 :9— Dec, 1912 



to Utilize levers with a thorough understanding of them ever after- 

 ward. 



This further work with the lever could be done in connection 

 with studies in applied mathematics, and with a slight modification 

 of their balances, as follows : The scale-pans and supporting 

 thread should be removed from the beam, thus leaving the up- 

 right with the beam in horizontal position. (For this work it 

 might be necessary to balance the beam, inasmuch as it must be 

 in balance.) It will be necessary also to furnish weights with 

 points of attachment, which may be either hooks or loops of 

 thread. Whatever the means of attachment used, they will help 

 constitute the weights. When the apparatus has been provided, 

 the experimental work may be done through the solution of sets of 

 problems of two types: (1) What weight attached to one arm 

 four inches from the fulcrum will balance two ounces on the other 

 arm six inches from the fulcrum? .(2) What distance must a 

 two-ounce weight be placed from the fulcrum on one arm in order 

 to balance a three-ounce weight on the other arm. four inches 

 from the fulcrum ? Many problems of each of these types should 

 be solved by the children and the work might be done at home or 

 at school as seemed best. The problems could be modified in 

 statement in order to have variety as well as to develop power 

 in interpretation. Problems of the type (1) could be stated — 

 given a two-ounce weight six inches from the fulcrum to find its 

 counterpoise four inches from the fulcrum ; problems of type 

 (2), given a three-ounce weight four inches from the fulcrum 

 to find the distance from the fulcrum at which two ounces will 

 balance it. 



One of the results of work of this sort will be to teach the 

 children to be careful in measurements and also to duplicate these 

 measurements in order that their work be satisfactory. It is quite 

 possible that two children may disagree as to the solution of some 

 of the problems given, in fact, it usually happens that such does 

 occur and children will readily decide that any such disagreement 

 and settlement should be made before the whole class, each party 

 to the disagreement bringing his or her balance and weights in 

 order to justify his or her position. If properly carried out, such 

 attempt at justification is worthy and wholesome. Another val- 

 uable influence in connection with such procedure is that the chil- 

 dren make and remake, modify and more nearly perfect their bal- 

 ances from time to time. The teacher in all cases must decide 

 how far to go in the study, when to move on to something new, 

 how to direct the work so as to make it of most value, not only 



