1 98 MAKING OUT INDISTINCT OBJECTS. 



the first. Another and perhaps a still better instance 

 in point is, when a trained hunter points out the form 

 of an animal crouching 1 in the grass close by, or a 

 bird perched upon a rock, which had till then escaped 

 observation, yet when once seen the object appears so 

 clearly visible that it is hard to understand how it 

 could have escaped immediate detection until then. 



There can be no doubt that a good glass is a great 

 aid in making out the nature of distant objects, but 

 no glass will make untrained eyes detect details which 

 are invisible simply through dulness of vision, arising 

 from inexperience. By concentrating the gaze upon one 

 particular point in the field of view however, objects 

 are often caught sight of by means of a glass, which 

 would otherwise have remained unseen; especially so, 

 when they approach very closely in colour to the 

 surroundings. A glass will then clear up the perspec- 

 tive, so as to render them a,t once readily discernible 

 against the background. If one looks again, however, 

 without the glass, one can in most cases see the objects 

 more or less clearly with the unaided eye, though it 

 may be in a blurred and very indistinct form. What 

 however we desire to impress upon our reader is, that 

 the glass that is of most use upon the plains in general 

 service is by no means the telescope of high magni- 

 fying power, and with an idea of making the invisible 

 visible; but rather a glass of low magnifying power,, 

 with as large an object lens as possible, which will 

 act as a clearer, and brings details of visible objects 

 distinctly into view. 



A few technical details about telescopes and field- 

 glasses may here prove useful. According to Sir 

 Robert Ball, Astronomer Royal for Ireland, the finest 



