200 



COLOE. 



The form and general appearance of it is shown in the an- 

 nexed engraving. 



THE SPECTROSCOPE. 



It is only a very general idea of the character and con- 

 struction of the instrument that it is necessary to commu- 

 nicate here. It consists substantially of a prism in the 

 centre, supported upon a stand, and three branches in the 

 form of telescopes directed toward it. The one on the 

 right is for the light which is to be examined, Avhich passes 

 through the tube, and is prepared by the lenses contained 

 in it for the prism in which the spectrum is formed. The 

 spectrum is viewed by means of the telescope, which con- 



