ex TERRESTRIAL REFRACTION. 



I was watching the rising of the sun, with my eyes fixed to the spot, when I saw tiie sun 

 emerge ; in an instant his lower limb was his full diameter above the horizon, without 

 his figure being changed ; in this position he remained about half a minute, then fell, 

 his lower limb being dipped about one-eighth of the diameter; he then assumed 

 various amorphous forms, continued varying for five minutes, and at length assumed 

 the proper form. 



The plate is given to show the land in three different states : 



First, as with no refraction, distant fourteen miles. 



The second is the same land, with an iceberg four miles distant raised above the land. 



The third, the same refracted in a different way on the same day. 



These outlines are taken by Ronald's invaluable instruments which I had fixed on 

 a point of land sixteen feet above the level of the sea, and by which the figure could be 

 traced with the greatest precision, and with which I made above three hundred 

 observations, tending to confirm what I have stated. These observations were taken 

 during the first week in May, 1831. 



