THE WINTER NIGHT 307 



times had rings round it, with mock -moons and axes, 

 accompanied by rather strange phenomena. When the 

 moon stands so low that the ring touches the horizon, 

 a bright field of light is formed where the horizon cuts 

 the ring. Similar expanses of light are also formed 

 where the perpendicular axis from the moon intersects the 

 horizon. Faint rainbows are often to be seen in these 

 shining light-fields ; yellow was generall)^ the strongest 

 tint nearest the horizon, passing over into red, and then 

 into blue. Similar colors could also be distinguished in 

 the mock-moons. Sometimes there are two laree rino-s. 

 the one outside the other, and then there may be four 

 mock-moons. I have also seen part of a new ring above 

 the usual one, meeting it at a tangent directly above the 

 moon. As is well known, these various ring formations 

 round the sun, as well as round the moon, are produced 

 by the refraction of rays of light by minute ice crystals 

 floating in the air. 



" We looked for pressure with full moon and spring- 

 tide on 23d of November; but then, and for several days 

 afterwards, the ice was quite quiet. On the afternoon of 

 Saturday, the 25th, however, its distant roar was heard 

 from the south, and w^e have heard it from the same 

 direction every day since. This morning it was very 

 loud, and came gradually nearer. At 9 o'clock it was 

 quite close to us, and this evening we hear it near us 

 again. It seems, however, as if we had now got out of 

 the groove to which the pressure principally confines 



