104 



Laboratory Arts 



warmed in fact, just short of softening. Having secured a good 

 shape at A, proceed to deal similarly with B, the now cooler A 

 keeping the joint firm meanwhile. Finally, treat the two sides 

 similarly, and, if sufficient skill has been acquired, reheat the whole 

 junction, blowing gently while it finally cools. 



This method is a tedious one, and will in most cases be given up 



(6) 



FIG. 92. Stages in the construction 01 a right-angled joint. 



for the previous : one, or rather the first one will be insensibly 

 developed from the latter, which is somewhat in the nature of 

 a patchwork job. Correctly performed, the first method produces a 

 perfect T piece at the first operation. 



EXERCISE 8. To make a Y piece. 



Bend a i4-cm. piece of glass tubing in the form of a V in an 

 ordinary gas flame. When the tube is cold clean off the carbon 



