1883.} Heath's Bolivian Explorations. 447 
increase, until the sky is entirely overspread and the rays 
of the sun are completely shut out during all the hours 
when they would be most effectual. About 4 to 5 p.m. there 
falls a smart shower of cold rain, mixed with sleet. The 
sky then clears up, and vegetation and the soil are left to be 
chilled by evaporation under the influence of a keen dry 
wind, and by free radiation under a cloudless sky. Were 
the most observant and experienced horticulturist challenged 
to arrange weather more destructive he would be unable to 
do so, or even to add one ruinous agency which is not 
present. 
II. HEATH’S BOLIVIAN EXPLORATIONS, 
By Rev. J. D. Parker. 
w 5 ) OLIVIA unfolds to the traveller the most diversified 
Mp) physical features. Two chains of Cordilleras, run- 
ning nearly parallel with the coast, carry their lines 
of snow-clad peaks like sentinels across Bolivia, but are 
separated by an intervening table-land, from 100 to 200 miles 
in width, which, when the mountain-chains were folded, was 
lifted as a connecting plateau more than 12,000 feet above 
the level of the ocean. On the Pacific slope the descent 
from the western Cordillera is steep and difficult, terminating 
in a rainless plain, where no vegetation appears except where 
mountain torrents margined by narrow valleys force their 
way to the Pacific Ocean. Beyond the eastern Cordillera 
stretches eastward for hundreds of miles a vast plain of 
great fertility, through which with gentle flow thread various 
affluents to the Amazon. During the rainy season portions 
of this plain are overflowed, and the vast perennial forests, 
disclosing glimpses of the watery waste, seem like islands 
of foliage on some inland sea. 
Bolivia, occupied now by two millions of people, and 
possessing rich mines of precious metals, has sought for 
centuries to find with Europe a more direCt means of com- 
munication. Nature has furnished her river outlets con- 
necting with the Amazon, but these have been useless to 
commerce, because they were unexplored. The products of 
the vast alluvial plain lying east of the Cordilleras, the 
