CLASSES OF CONDITIONS 123 



optical appliances are so great as to have brought 



home to the angler the advan- 

 Use of the field-glass, tages of availing himself of 



their assistance in carrying out 

 the class of observation required to enable him to 

 follow the habits and proclivities of the denizens of the 

 trout stream. Hence for the twentieth-century student 

 of dry-fly work the field-glass has almost become a 

 necessity. The prismatic binocular, as made by Zeiss, 

 of Jena, and many other continental manufacturers, 

 C. Baker, 244 High Holborn, and a few other British 

 opticians, is immeasurably superior to the old-fashioned 

 field-glass. It is made in various powers, which are 

 designated by the degree of linear ijiagnification 

 effected by the combinations of lenses in the oculars 

 and objectives. 



When selecting a field-glass for any purpose the 

 purchaser should bear in mind that the greater the 

 magnification the smaller is the field, or in other 

 words, the greater the difficulty of finding the object 

 or objects to be observed. Modern prismatic field- 

 glasses are made in magnifications of 3, 6, 8, 12, and 

 16 diameters. The X3 is essentially an opera-glass, 

 and the x6 is the one I have personally used, but 

 many of my friends prefer the x8 or x 12. 



When once the student has focussed the field- 

 glass accurately and adjusted the interocular dis- 

 tance to his sight, he can distinguish the flies on 

 the surface of the stream, follow their motion, and 

 be quite sure at a glance whether the feeding fish are 



