THAT HANNIBAL USED VINEGAR TO CUT A PAS- 

 SAGE FOR HIS ARMY ACROSS THE ALPS 



HIS alleged fact forms a staple illustration in the 

 literature of the eighteenth and nineteenth cen- 

 turies, and I have recently seen an allusion to 

 it in the work of an author from whom I should 

 have expected better things. When we consider the enor- 

 mous quantity of vinegar which would be required to re- 

 move even a few cubic yards of limestone or similar rock, 

 the absurdity of the suggestion becomes apparent. Where 

 could Hannibal have obtained enough vinegar to enable 

 him to perform this feat? 



A great deal of ink has been shed in the effort to explain 

 and enforce this alleged historical fact and to prove that 

 it might have been done, but the only satisfactory expla- 

 nation is that it is a fiction pure and simple. 



THAT LARGE LENSES ARE MORE POWERFUL 

 THAN SMALL ONES 



N the mind of the ordinary person the idea of 

 comparative power is almost always associated 

 with that of comparative size. The largest 

 and heaviest locomotive is always the most 

 powerful and so, as a general rule, are the largest animals 

 of the same species. And too often this same idea is applied 

 to lenses or magnifying glasses. 



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