3(i Wilde, Evohition of tJie Mental Faculties. 



EXPLANATION OF PLATES. 



Plate XIV. Reflecting Gyroscope, for demonstrating the diurnal 

 rotation of the earth on its axis. 



Plate XV. Differential rotation and general constitution of the 

 internal parts of the terrestrial globe. 



Plate XVI. Magnetarium, for demonstrating the differential 

 rotation of the internal parts of the earth and the 

 resultant phenomena of terrestrial magnetism 

 on its surface. 



