BIRD-FLTING. 
49 
different are the conditions of bird-flying in our air-ocean 
from that of fifh flying or fwimming in the ocean of the 
waters ; currents in the fea are not comparable in force 
to currents in the air. Imagine human beings organized 
to breathe water like fifhes living on the mountain flopes 
and in the valleys upon which the water-fphere reds, as 
upon us refts the vapour-fphere that invefls our globe. 
All the living moving creatures we fee about us at the 
bottom of our air-ocean, reproduced under the waters, and 
living upon the land there juft as we live here; for the 
land upon which the ocean refts is juft as diverftfied and 
real as the land upon which air refts; once, indeed, above 
the waters and in the air, as we now are; and deftined 
again to be, when our hill-flopes, plains, and mountains 
become again fubmerged and form the bottom of the fea. 
And the fame Almighty Power that has fafhioned men 
and women and living creatures on the land above water to 
breathe the mixture of fluid nitrogen and fluid oxygen we 
call air, could have equally fafhioned men and women and 
living creatures for breathing the mixture of fluid hydrogen 
and fluid oxygen we call water. 
And now if we imagine fuch a living world as this 
exifting underneath the fuperincumbent water-fphere; a 
living, adive, bufy world ; tribes, communities, and peoples: 
villages, towns, and cities: and if then to this picture we 
add to the water-fphere the diftinguifliing charadleriftic 
that marks our own—its ficklenefs, its variability, its 
