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Popular Science Moni/ih/ 



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Why DofS Sap Rise in a Tree 

 Against the Pull of Gravity ? 



NOT every b( )tl y knows 

 that solutions of 

 two dilierent substan.'es 

 placed on opposite sides 

 of a membrane or a ])ulp 

 make diligent efl'orts lo 

 equalize their density. 



For examjile, take a 

 glass tube, cut off the 

 lower end of a potato, 

 and peel the remainder 

 for about one-third of its 

 length. Bore a one-inch 

 hole through two-thirds 

 of the potato and in the 

 end fit a cork. Bend a 

 glass tube into L-shajie, 

 put vaseline on the short 

 arm and insert it in a 

 small hole bored in the 

 side of the potato lo 

 reach the big hole, l-'ill 

 the interior of the potato 

 with sugar colored with 

 ink, fasten the cork and 

 glass tubing tight. Place 

 this apparatus in a dish 

 of water. The water. 

 Hows through the pulp 

 of the potato and on reaching llu- iliin 

 membrane separating it from the colored 

 liquid it dilTiises more f|iiickl>' 

 through the colored li(|uitl th 

 latter docs through it, becii 

 it is less diiise than th 

 colored liquid. This causes 

 the wa t e r to push 

 the denser liquid upward 

 into the tube. This 

 action, together with ca- 

 pillary attraction iswhat 

 causes the sap to rise. 



A Time-Saving "Safety-First" Tool 

 for Dynamite Workers 



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An experiment with potatoes to 

 illustrate the principle involved 

 in the rising of sap in a tree 



M.\Ki: -SHIFT 

 methods of crimp- 

 ing tKiianiite caps and 

 connecting the cap and 

 fuse to the cartridge 

 have led lo scores of 

 severe accidents and 

 many fatalities in land- 

 clearing work. A com- 

 liination tool, which will 

 cut and slit the fuse, 

 crimp the cajj on ihe fuse 

 and finally punch clean- 

 cut holes in the cartridge 

 for the secure fastening 

 of the cap anil fuse to the 

 cartridgehasbeende\ised 

 by \'. D. Li\ingston, 

 land clearing tlemonstra- 

 lor, Wisconsin t'ollege of 

 Agriculture. 



The arrangement for 



slitting the end of the 



fuse exposes a pocket of 



powder which will ignite 



quickly. The crimping 



(IcN'ice at the center of 



the tool dcK-s a neat job 



antl a strong one. When 



properly used to crimp a cap to the fuse, 



il requires a twenty-five pound pull to 



remove it. One of the handles has a 



d eiul, designed for pimch- 



thc holes in the dynamite 



cartridge. The apjiaratus 



is intended to saw time 



as well as to insure the 



safety of the workers. 



A combinntion tool which 

 will cut and slit the fuse, 

 crimp the cap and punch 

 dean holes in the cartridge 



