THE DUPLICATION OF THE CUBE 31 



one of the higher departments certainly a very sound 

 reason, whatever we may think of the details of the story. 

 The people then applied to the mathematicians, and it is 

 supposed that their solution was sufficiently near the truth 

 to satisfy Apollo, who relented, and the plague disappeared. 



In other words, the leading citizens probably applied 

 themselves to the study of sewerage and hygienic condi- 

 tions, and Apollo (the Sun) instead' of causing disease by 

 the festering corruption of the usual filth of cities, especi- 

 ally in the East, dried up the superfluous moisture, and 

 promoted the health of the inhabitants. 



It is well known that the relation of the area and the 

 cubical contents of any figure to the linear dimensions of 

 that figure are not so generally understood as we should 

 expect in these days when the schoolmaster is supposed 

 to be "abroad in the land." At an examination of candi- 

 dates for the position of fireman in one of our cities, several 

 of the applicants made the mistake of supposing that a 

 two-inch pipe and a five-inch pipe were equal to a seven-inch 

 pipe, whereas the combined capacities of the two small 

 pipes are to the capacity of the large one as 29 to 49. 



This reminds us of a story which Sir Frederick Bram- 

 well, the engineer, used to tell of a water company using 

 water from a stream flowing through a pipe of a certain 

 diameter. The company required more water, and after 

 certain negotiations with the owner of the stream, offered 

 double the sum if they were allowed a supply through a 

 pipe of double the diameter of the one then in use. This 

 was accepted by the owner, who evidently was not aware of 

 the fact that a pipe of double the diameter would carry 

 four times the supply. 



A square whose side is twice the length of another, and 



