CONSTRUCTING SMALL GLASS TANKS. 



119 



they will, with a very moderate amount of pressure, make a 

 water-tight joint with the rubber lining on the edge of the 

 tank. The metal band should not be too stiff ; in fact, I have 

 done away with it altogether in a rough form of tank I use 

 for the examination of water when out collecting. This particular 

 tank has at least one great merit — i.e. it can be dropped with 

 very little chance of damage. 



The form of clip used to draw together the ends of the 



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Fig. 2. 



band, forming the edge of the tank, will depend to some extent 

 on the use to which the tank is to be put. If it is not necessary 

 to have a clear opening at the top, the ends of the band may be 

 simply turned up at right angles, and a small bolt passed through 

 them (Fig. 1). This is a very simple and effective fastening. If,, 

 on the other hand, the tank is to be used for the rough exam- 

 ination of material when out collecting, or for any purpose where 

 a clear opening is more convenient, some form of clip as shown in 

 Fig. 2 (c) should be used. 



I may say, in conclusion, that I have had a tank of the above 



