1
Dimensions of Niagara Falls, – American, 960 feet wide, 162 feet high; English, 700 feet wide, 150 feet high.
2
There are many stories, from other sources, confirmatory of these noises in mountainous districts. One solution, suggested by Humboldt, – who does not, however, record the fact as of his own observation, – is, that "this curious phenomenon announces
1
Dimensions of Niagara Falls, – American, 960 feet wide, 162 feet high; English, 700 feet wide, 150 feet high.
2
There are many stories, from other sources, confirmatory of these noises in mountainous districts. One solution, suggested by Humboldt, – who does not, however, record the fact as of his own observation, – is, that "this curious phenomenon announces a disengagement of hydrogen, produced by a bed of coal in a state of combustion." This solution is applicable only to mountains which contain coal, unless chemical changes in other minerals might be supposed capable of producing a similar effect.
