OBSERVED IN THE GREENLAND SEA. 301 



owing to the influence of some peculiar vapour in the air, they 

 now seemed to advance so near, that they became distinctly 

 visible, and the ice, for some minutes, appeared beyond them. 

 Their masts seemed to be scarcely one-half of their proper al- 

 titude, in consequence of which, one would have supposed 

 that they were greatly heeled to one side, or in the position 

 called " Careening." Along with all the images of the ships, a 

 reflection of the ice, in some places in two strata, also appear- 

 ed in the air. The upper stratum of ice, in which the images 

 of the ships terminated, was fifteen minutes of altitude from 

 the apparent horizon. These reflections suggested the idea of 

 cliffs, composed of vertical columns of alabaster. The stratus, 

 which occupied the space intermediate between the reflection 

 of the ice and the horizon, was, in some positions of the sun, 

 highly illuminated, and shone like a sheet of distant water in a 

 calm ; but in other cases, as at the time when the annexed 

 sketch was taken, it was a little darker in colour than the 

 higher region of the atmosphere. To this fog, or stratus, then, 

 it is probable all the reflections were owing ; the double 

 images being produced by two or more strata of fog ; while a 

 highly tremulous transparent vapour, resembling the steam of 

 water before condensation, which could occasionally be dis- 

 cerned floating across the ice with the breeze from the NW. 

 and N., occasioned, it is likely, the singular distortions obser- 

 ved in the form of every distant object seen through it. 

 Hence, not only ships, but also the ice, was sometimes deform- 

 ed by the refractive property of this vapour. The verge of 

 the ice, in one place, became a considerable precipice ; in ano- 

 ther it appeared like distant land clad with snow ; and a large 

 hummock on the horizon was reared into the air (Fig. a) in 

 the form of an obelisk. The appearances now described oc- 

 currejd between 6 and 12 p. m. The reflected images of the 



ice 



