Masterpieces of Science 



The undoubted possibly the word is a little too 

 strong the, at least, more than probable con- 

 nection between solar disturbances and our own 

 magnetic storms, as well as the phenomena of 

 comets' tails, makes it almost certain that mag- 

 netic and electric stresses and displacements pre- 

 vail in interplanetary space; and, if so, the 

 ability to detect and measure them would add 

 greatly to our knowledge. As yet, no doubt, our 

 instruments are inadequate to such studies, but 

 they need not always be so. 



Then it is not unreasonable, I think, to ex- 

 pect that we shall ultimately, and perhaps before 

 many years, be able to measure the heat received 

 from the stars and planets, and so to reach some 

 knowledge as to their temperature and physical 

 conditions. If we were now able to do this, 

 certain important problems as to Mars might be 

 summarily settled. 



But even if no absolutely new instruments are 

 soon invented, much is to be expected from the 

 improvement of those we have. I see no reason 

 why the power of telescopes may not be greatly 

 increased in the near future. Some authorities, 

 indeed, maintain that the limit of size has nearly 

 been reached, and that instruments much larger 

 than the Yerkes telescope can never be made 

 satisfactory on account of the distortion of the 

 object-glass caused by its own weight. But in 

 this greatest of all telescope lenses the flexure is so 

 slight as to be barely perceptible, and even in one 

 of twice the diameter it need be nothing very 

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