316 A JOURNEY IN BRAZIL. 
us, as we passed out from the gate, with vivas and 
waving hats and handkerchiefs. 
The following day we were fortunate in having cool 
weather with a somewhat cloudy sky, so that our ride of 
ten hours from Juiz de Fora to Petropolis, on the top of the 
stage, was delightful. The next morning in driving down 
the Serra to Maud we witnessed a singular phenomenon, 
common enough, I suppose, to those who live in high re- 
gions. As we turned the corner of the road which first 
brings us in sight of the magnificent view below the Serra, 
there was a general exclamation of surprise and admiration. 
The valley and harbor, quite out to the sea, were changed 
to a field of snow, white, soft, and fleecy, as if fallen that 
night. The illusion was perfect, and though recognized 
at once as simply an effect of the heavy morning fog, 
we could hardly believe that it would disperse at our 
approach and not prove to be the thing it seemed. Here 
and there the summit of a hill pierced through it like 
an island, making the deception more complete. The 
incident was especially interesting to us as connecting 
itself with our late discussions as to the possible former 
existence of glaciers in this region. In his lecture a 
few nights before, describing the greater extension of 
the ice in former geological ages, when the whole plain 
of Switzerland between the Alps and Jura must have 
been filled with glaciers, Mr. Agassiz had said " there is 
a phenomenon not uncommon in the autumn in Switzer- 
land which may help us to reconstruct this wonderful 
picture. Sometimes in a September morning the whole 
plain of Switzerland is filled with vapor which, when its 
pure white, undulating surface is seen from the higher 
sammits of the Jura, looks like a snowy ' mer de glace/ 
