144 HERSCHEL AND HIS WORK 



believed that his telescope sounded space to this and 

 far greater depths without finding traces of nebulosity 

 gas or star dust in the regions it reached. 1 He said 

 also that his telescope sounded the depths of past 

 time not less than of space. Be his ideas reality or 

 romance, they give us a sublime conception of the 

 greatness and worth of the human mind buried in its 

 pigmy house of clay, and chafing against the chains 

 that bind it to earth and time. 



Sublime though Herschel's conceptions were, he did 

 not conceal from himself or others that "a certain 

 degree of doubt may be left about the arrangement 

 and scattering of the stars " in the Milky Way. They 

 were founded on the supposition of " numberless stars 

 of various sizes, scattered over an indefinite portion of 

 space in such a manner as to be almost equally dis- 

 tributed throughout the whole." This was a large 

 supposition to make ; it is not correct, and it was a 

 corner-stone that might be knocked away at any 

 moment. The barriers he required to overleap were 

 the distance and the relative sizes of the stars. These 

 barriers remained insurmountable during his lifetime. 

 It was next assumed, for it could not be said to be 

 proved, that "there is but little room to expect a 

 connection between our nebula" the Milky Way 

 " and any of the neighbouring ones ; . . . for if our 

 nebula is not absolutely a detached one, I am firmly 

 persuaded that an instrument may be made large 

 enough to discover the places where the stars continue 

 onwards. A very bright, milky nebulosity must there 

 undoubtedly come on." At that time Herschel imag- 

 ined space to be a vast ocean of light-bearing ether, 

 1 Phil. Trans., pp. 249, 247 (100 times), 497 times. 



