ice. It follows that this can be done only with large 
parts on the plate free from nebulous matter, and there- | C ; ) 
fore appearing lighter. | fields, and will never be possible with the reflector ; 
e, in this case, the portrait lens is preferable to 
between nebula and dark sky are followed across a large | the reflector. 
NO. 1434, VOL. 55} 
The nebulosities only are clearly visible, if the borders | there 
