440 



Mr, Anderson 



[April 9, 



of atmospheres of hydraulic pressure. I jDrojcct an image of the 

 apparatus on the screen, and you see the water has made its way 

 through the wood and through the cork cut in the radial direction, 

 while the cork cut in the vertical direction is impervious. 



Fig. 1. 



Vertical Section. 

 Fig. 2. 



Horizontal Section. 

 Magnified about 300 diameters. 



riie cork tree, a species of evergreen oak, is indigenous in Tortugal 

 and along both shores of the Mediterranean. The diagram on the 

 wall has been painted from a sketch obligiugly sent to me by Mr. 



