262 M. Fraunhofcr on the Laws ofl/i^-ht, 4"t'. 



make us acquainted with other properties of w than those here 

 named, and to which, among others, the polarisation of hght 

 seems to point. 



Note B, see page 259. — From what is here stated, as well as 

 from several of the remaining experiments, it must be obvious 

 that many of these phenomena, at least in appearance, are so very 

 complicated that they cannot be conveniently mentioned with 

 brevity, and on that account I must omit many things that 

 would be interesting. The field which offers itself for new in- 

 quiries widens in proportion as we advance in these experi- 

 ments. 



It is to be regretted that they can be but rarely repeated by 

 any one, as they require extensive, and in some measure costly 

 apparatus, and much time. The circumstance of these experi- 

 ments requiring a very favourable state of the sky occasions a 

 much greater loss of time than might be easily imagined. This 

 I feel the mofe severely, as my professional avocations leave 

 me but a few fixed days in each month for these investigations. 



Note C, see page 259. — Those who are familiar with the 

 relation of these phenomena will excuse me for adding an 

 observation which may appear superfluous to them, but it 

 has so often happened to me, that those to whom I have 

 shown the appearances through a system of lines of any 

 kind imagined that the system of lines itself was seen in 

 the telescope, (an opinion in which the circular etchings still 

 more confirmed them,) that I think it necessary to say a 

 word concerning this error. We have only to consider 

 which is the way taken by the light coming from any ob- 

 ject through the telescope, and what the cause of seeing by 

 means of a telescope is, to do away the notion that it is the 

 object standing at the object glass which we observe through 

 the telescope. Such a notion would not be much better than it 

 would be to imagine, that, in looking through a telescope, we 

 behold the object glass. Nothing is perceived, in looking 

 through a telescope, of a finger placed on the object glass, and 

 no more can be seen of the system of lines. The above is 

 partly connected with what is more fully detailed in the note, 

 page 103 of last Number. 



