ii6 HIDDEN BEAUTIES OF NATURE 



' But there is a still grander use for diatoms. 

 When the vegetable portions die, the flinty structures 

 form a deposit on the floor of lake or sea, which in 

 time attains to a thickness of several feet. Still more 

 time, and these deposits become compact rocks, and 

 thus the flint (silex) before extracted from the waters 

 by living diatoms now forms a part of the solid 

 structure of the earth. Diatoms furnish us with 

 evidences of a wisdom far beyond anything we can 

 comprehend. That such a little box, so small that 

 it cannot be recognised with the unassisted eye, 

 should contain an orderly arrangement of multitudes 

 of lines, is of itself a thing quite beyond our mental 

 grasp. All diatoms are not so small as the special 

 varieties we have been examining ; still, they are all 

 microscopic. Many of them appear to be as small 

 as the dust in the sunbeam.' 



This ended my conversation with the lady, but 

 neither this account nor any single sketch can do full 

 justice to the subject. 



At a recent conversazione of the Royal Society, 

 Mr. Joseph Goold exhibited a twin-pendulum of the 

 most simple construction, which delineated an endless 

 variety of beautifully-curved figures, the result of a 

 certain law inseparably connected with music. So 

 splendidly did the pendulum trace out the attractive 

 designs, that we found it a difficult matter to get 

 away to study the other exhibits. Looking on with 

 admiring appreciation was Mr. Perigal, F.R.A.S., a 

 gentleman whose marvellous power of complex 



