416 ¢ INDEX aes 
Fesuvius. Eruption of, 282 Williams’s * Mineral Kingdom,” On, 
. ic: ee) "ie 9 
Vision. On the axiomatical laws of, 
‘ 379 
Vivian's evidence on boilers, 
Walker's Chemical Philosophy, 38 
116, i g 
I¥inch on geology of Northumbeiland, 
< Ax 
VWrod on hibernation of swallows, 31 
Water-spout. Formation of, 146 ¥oolf’s evidence on boilers, 331 
Water-wheels, horizonial. On, 256 Wen. New speciesof, 226 
Werner. Biograph. memoir of, 180 Wright's evidence on steam-engines,248 _ 
END OF THE FIFTIETH VOLUME. ie 
s 
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