IN VENTIONAL GEOMETR Y. 



357 



mVENTIONAL GEOMETRY. 



By EDWAED R. SHAW, 



PRINCIPAL OF THE TONKEES HIGH-SCHOOL. 



INVENTIONAL geometry is the name given to a series of care- 

 fully graded problems, thought out and arranged by that able 

 mathematical teacher, William George Spencer, the father of the 

 distinguished philosopher. 



The little book was published in this country in 1876.* An 

 appreciative review in the New York "Evening Post" led the 

 writer to procure a copy, and then to set to work to solve the 



simple problems in the order given — the purpose being to form 

 an impartial judgment of the value of the book for school use. 

 A hundred or more problems were wrought, with increasing in- 

 terest ; and then, to make a further test, the book was given sepa- 

 rately to a number of pupils, both girls and boys, each being 



asked to work as many problems as he could. In each instance 

 the pupil became interested in the work, and wished to continue. 

 The remark of one girl was especially significant. " It's so differ- 

 ent from ordinary study," she said ; " there's something about it 

 that leads me on." 



A class was formed after these tests, and a few months' work 



* New York, D. Appletou & Co., 1876. 



