XX. The flow of liquids through tubes. Lateral 

 pressure. 



1. Appliances. Reservoir with short discharge nozzle 

 whose lumen is 6 mm. in diameter; 5 pieces of glass 

 tubing whose lumen is about 6 mm. in diameter and 

 whose length is 60 cm.; two lengths of glass tubing 

 whose lumen is about 3 mm. in diameter and whose 

 length is 60 cm ; rubber tubing for joining up the ap- 

 paratus; 3 T tubes of 6 mm. tubing; short tube with 

 capillary point from each size of tubing; 2 one liter 

 flasks; 2 supports; a light pine stick about 6 feet long; 

 compressors (Mohr's). 



2, Preparation. A resourceful demonstrator will have no 

 difficulty iu contriving reservoirs. It is sometimes not 

 easy to provide a large class with suitable and conven- 



ient reservoirs. The following form 



has proven very satisfactory: A glass 

 tube about 3 cm. in diameter may be 

 readily furnished with a glass nozzle of 

 the required size by any glass blower. 

 The nozzle should be about 3 cm. from 

 one end of the tube. That end may 

 be closed with plaster of Paris and 

 filled with hard paraffin to the lower 

 margin of the nozzle opening. This 

 reservoir may be held upright by a 

 4cm support. When complete it presents 

 the appearance indicated in the accom- 

 Fig. 15 panying figure. 



04 cm 



36 C/n 



is cm 



