68 
REFRACTION. 
riod reproduces in its Madeleines, Walhallas, and Gi- 
rard colleges, like university poenis in the dead lan- 
guages. Still, we can compare them with the iceherg ; 
for the same standard measures both, as it does Chim- 
borazo and the Hill of Howth. But this thing of re- 
fraction is supernatural throughout. The wildest frolic 
of an opium-eater's revery is nothing to the phantas- 
magoria of the sky to-night. Karnaks of ice, turned 
upside down, were resting upon rainbow-colored ped- 
estals .-.great needles, obelisks of pure whiteness, shot 
up above their false horizons, and, after an hour-glass- 
like contraction at their point of union with their du- 
plicated images, lost themselves in the blue of the 
upper sky. 
"While I was looking — the sextant useless in my 
hand, for I could not think of angles — a blurred and 
wavy change came over the fantastic picture. Pris- 
matic tintings, too vague to admit of dioptric analysis, 
began to margin my architectural marbles, and the 
scene faded like one of Fresnel's dissolving views. 
Suddenly, by a flash, they reappeared in full beauty ; 
and, just as I was beginning to note in my memo- 
randum-book the changes which this brief interval 
had produced, they went out entirely, and left a nearly 
clear horizon." 
Abrupt and versatile as were these changes in the 
refracting medium, those in the temperature about us 
were no less so. The relation between them was ap- 
parent, even within the limited range to which we 
could extend our observations. At 3 A.M., while the 
phenomena I have described were in full brilliancy, 
my thermometers on deck and in the main-top stood 
respectively at 36° and 39°, while the surface water 
indicated 32°. Ten minutes afterward, there were 
