494 



FRANK D. ADAMS 



the paraffine wax develops but little internal friction and moves with 

 comparative ease. With the other three materials the case is very 

 different, a marked resistance being offered to deformation. This is 

 greatest in the case of alum and least in the case of fusible metal. 

 Subtracting the load required to deform the tube itself from that 

 required to deform the tube filled with each substance respectively, 

 it is found that the load required to deform the columns of the three 

 materials in question (inclosed in the tubes under the conditions of the 

 experiment) is that given in the last column of the table. These 

 values calculated in pounds per square inch, using the area possessed 

 by a cross-section of the columns of materials before deformation, 

 which does not differ greatly from that possessed by the ends of the 

 deformed masses, are given in the following table, together with the 

 ratio of their respective strength or resistance which they offer to 

 deformation, reduced to its simplest terms. 



Paraffine wax. 

 Fusible metal. 



Sulphur 



Alum 



Ratio of Strength 



12.13 

 15.00 

 20.36 



In the case of a tube filled with parafSne wax, whenever the smallest 

 fissure develops in the copper tube the inclosed paraffine passes out 

 in the form of a thin, narrow ribbon and continues to issue as a long, 

 graceful, curling band until the pressure is removed. When rupture 

 takes place in a tube filled with alum the contents of the tube are not 

 forced out until the crack has opened considerably, when the alum 

 commences to fall out in a pulverulent condition. In the case of the 

 fusible metal, on the other hand, the rupture of the inclosing tube 

 does not lead to a discharge of the contents through the crack, but 

 the copper tube peels off and the inclosed metal flattens down into a 

 cake having a smooth, rounded surface. A striking fact noted in the 

 case of tubes filled with sulphur is the continued sound of cracking 

 which issues from the sulphur during deformation, a sound which 

 resembles that produced when glass or any other brittle body is 

 similarly compressed. At the conclusion of the experiment, however, 



