PHYSICAL SCIENCE. 27 



spherical globules of oil thus suspended in water ; making 

 them to assume many conditions closely allied to planetary 

 configuration; to become spheroids flattened at the poles; 

 to throw off smaller globules having movements both of 

 revolution and rotation ; and even rings like those which 

 Saturn shows to our telescopes. These experiments, repeated 

 by Faraday and others, are as valid in the way of inference 

 as they would be were the scale of operation a million times 

 greater. And the same may be said of the second instance 

 we have before us, in those beautiful instruments and inven- 

 tions of Foucault, Wheatstone, Piazzi Smyth, &c., illustrat- 

 ing the principle of the stability and composition of rotatory 

 motions, and thereby expounding with admirable simplicity 

 the great phenomena of the precession of the equinoxes, and 

 of the earth's rotation on its axis. The gyroscope of Fou- 

 cault set into action, and placed on a table, shows to the eye 

 in a few minutes, by the angular deviation from its plane of 

 rotation, the movement the earth has made in this short space 

 of time; a demonstration almost startling from its sim- 

 plicity and grandeur. Under the miniature form, almost 

 of a toy, this instrument beautifully illustrates some of the 

 greatest phenomena of the universe. 



We have lingered on the subject of astronomy, partly 

 from the striking example it affords of the spirit and aims of 

 modern science ; partly from the speciality of its objects, as 

 detached by distance from those relations which so closely 

 connect the sciences treating of matter on our own globe. 

 But though thus distant in space, the vast masses moving 

 in the heavens, and especially the Sun, are variously asso- 

 ciated with the matter of the earth, through the elementary 

 forces, if we may thus term them, of which we have already 

 so largely spoken. Here indeed we come again into contact 

 with those arduous questions, where mathematical aids are 

 scantily supplied and few certainties yet attained ; but where 



