12 



for solar research. But the necessity for seeking, 

 among the stars and nebulae, for evidence as to the 

 past and future stages of solar and stellar life, 

 rendered a broadening of scope advisable from 

 the outset. Much attention is therefore devoted 

 to the sun as the chief among the stars, but the 

 essential means of attacking the more distant 

 objects of- the universe have also been provided. 



AUXILIARIKS OF THK TELESCOPE. 



Ten years ago the possibilities of the spectro- 

 heliograph, as a means of increasing our knowledge 

 of the invisible atmosphere of the sun, had become 

 apparent. This instrument, which was clearly 



FIG. 6. The Kenwood Spectroheliograph. 



susceptible of further improvement and develop- 

 ment, was accordingly chosen as one of our chief 

 auxiliaries for the study of the sun. Of still wider 

 range of application w T as the solar spectroscope, 

 previously used almost exclusively as a visual 

 instrument of small dimensions attached to a 

 moving telescope tube. Rowland had invented 



