iiS HIDDEN BEAUTIES OF NATURE 



geometric chuck and by other mechanical contriv- 

 ances. But while we feel great admiration for the 

 splendid works to which we have referred, and of 

 which we have specimens we value exceedingly, yet 

 Nature very easily 4 puts them all into the shade.' 



A simple diatom from Thames mud far out-dis- 

 tances the pendulum, the bow-compass, the lathe, and 

 other mechanical contrivances. A sample of guano 

 imported from South America, and no larger than a 

 marble, will contain thousands of diatoms, any one 

 of which will baffle the power of a genius to imitate. 

 Certain parts of Sheppey Island mainly consist of the 

 triangular forms of diatoms shown enormously en- 

 larged as fig. 34. 



Suppose we take a sheet of paper, and by very 

 accurate work we draw upon it two lines only one- 

 hundredth of an inch apart, we can just distinguish 

 the enclosed white line. Now, to produce a set of 

 lines so close as to represent the lines on some 

 diatoms we should have to divide this space of the 

 one-hundredth of an inch into 520 spaces. In other 

 diatoms we should have to divide the hundredth into 

 940 spaces. 



The diatoms in the illustrations are about on the 

 borderland of our vision. 



Although our eyes may see, when aided by micro- 

 scopic power, the minutely complex but orderly 

 system of lines and spaces on the surfaces of these 

 flinty atoms, yet our keenest perceptions become 

 exhausted in the effort to grasp a fixed idea of what 



