159 



"Of course means of measuring the general changes wrought 

 by the study of science I will mention only two. The first con- 

 cerns the power to utilize experience well in thought. 



"What is needed for this purpose is a series of problems or 

 tasks, relative success with which depends as much as possible 

 upon having power to use experience and as little as possible 

 upon having had certain particular experiences. For example, 

 relative success with the problem, "Which is heavier, a pint of 

 cream or a pint of milk?" is determined largely by ability to 

 select in thought the essential fact that cream rises and to infer 

 its obvious consequence. The data themselves are possessed 

 adequately by all, or nearly all, pupils alike. 



"To get such problems we wrote some time ago to one hundred 

 teachers of science, half in universities and colleges, and half in 

 secondary schools. I quote some of them: 



"Rain drops are coming straight down. W'ill a car standing 

 still or one moving rapidly receive in one minute the greater 

 number of drops on its roof and sides? 



"Since it is possible, for a person to float in water why is it 

 possible for him to sink? 



"A cylinder and a cone equal in base and in altitude rest on a 

 plane surface. Which is harder to tip over? 



"A magnet attracts two iron nails. If the magnet is removed 

 will the nails attract each other? 



"Does an iron ball weigh more when it is hot than when it is 

 cold? 



"If a bottle of gas which is lighter than air be placed with its 

 open mouth upward, will the gas escape from the bottle or will 

 the heavier air press the gas back into the bottle? 



"Will a ship that will just barely float in the ocean, float on 

 Lake Erie? 



"Will a pound of popcorn gain or lose weight or stay the same 

 after it has been popped? 



"The second means of measuring changes in general power to 

 think is an adaptation of one devised by Professor R. S. Wood- 

 worth, in which the pupil picks out from such a series as that 

 below, the statements that are logically absurd, not possibly 



