220 THE SEVEN FOLLIES OF SCIENCE 



was generally made of two or more tubes sliding into 

 each other the word came by analogy to be applied to any 

 combination in which this mere mechanical feature was 

 present, and now we speak of railroad cars " telescoping " 

 when, in a collision, they slide one into the other. In 

 this case optics or any of the features of seeing are entirely 

 absent and the mere mechanical motion alone is considered. 



Numerous instances might be cited where changes in 

 the arts and in our customs give an apparently absurd 

 meaning to old words. Thus in the olden time distances 

 were marked by stones set up at regular intervals and 

 called milestones; to-day these markers are sometimes of 

 wood and sometimes of metal, but we still retain the old 

 term, milestone, and then we have wooden milestones and 

 iron milestones. 



Again: The old-time pens were all made from the quills 

 of geese, swans, and crows, and were called pens because 

 that, in its Latin form, was the word for feathers. Now 

 quills have gone out of use and we have gold and steel 

 pens, literally, gold and steel feathers. 



Before the introduction of steel pens almost all writing 

 in ink was done by means of quills. These wore out quite 

 rapidly and upon the writing master and some of his most 

 skillful pupils devolved the task of mending the pens used 

 in the writing lessons of each day. This was done by 

 means of an exceedingly sharp knife, and by practice 

 some of the boys became very expert at the work. The 

 knife used for this purpose was called a pen-knife, and we 

 still retain the name though the term has entirely lost its 

 significance. I remember well the time when steel pens 

 were almost unknown, and when a boy I have made and 

 mended hundreds if not thousands of quill pens. 



