TEMPERATURES. 
69 
no evidences of refraction visible, except some slight 
loomings of the more distant hergs. The same ther- 
mometers now gave, both below and aloft, 36°, and the 
water had risen to 38°. The surface of the sea at this 
time was cafs-pawed as far as could he seen. A barely 
perceptible breeze, which set in suddenly from the 
northeast, had undoubtedly contributed to restore the 
homogeneity of the atmosphere. 
My sketches of the coast, which had now been vis- 
ible for nearly three days without interruption, show 
what strange diversities of outline may be induced by 
refraction, The illusions are so perfect that it is hard- 
ly possible to arrive at the normal aspect of the shore. 
Such changes, especially of altitude, must be a source 
of serious embarrassment in the recognition of land- 
marks. 
