276 LIGHT SCIENCE FOR LEISURE HOURS. 



The next paragraph relates to a disciple of ' Paral- 

 lax ' < Common Sense ' and his work, Theoretical 

 Astronomy Examined and Exposed. <I hope,' says 

 De Morgan, ' it will not be the last.' He could not, 

 however, have foreseen how poor Mr. Hampden would 

 suffer by the study of * Parallax ' and ' Common Sense.' 

 In fact, we venture to question the theory that good is 

 to be gained by the study of the ideas of paradoxist s. A 

 student of science may with advantage turn over the 

 leaves of a work written by an honest paradoxist; 

 because he can thus find what mistakes the denser 

 readers of science-treatises are likely to make. He 

 may use his paradoxist, in fact, as a foolometer. But 

 paradox books are not safe reading for the general 

 reader. They are not, perhaps, quite so misleading as 

 text-books of accepted science written by ill-informed; 

 persons simply because the general reader knows 

 beforehand that the paradoxist is a nonsense-monger, 

 and so accepts none of his statements, whereas he sup- 

 poses that a treatise of orthodox science is sound 

 throughout. No one is likely to believe that there is 

 a semi-transparent moon merely because ' Parallax ' 

 says there is ; while probably nine-tenths of those who 

 have read Lockyer's Elementary Lessons in Astro- 

 nomy are satisfied that seamen find local time * by 

 observing when the sun is at the highest point of its 

 path ' (article 564) ; that when the sun moves fastest 

 the dial will get before the clock, and vice versa 

 (article 416); and so on with the other blunders in 

 that too clever compilation. But though the mischief 



