GEOLOGY. 359 



to ten decrees, in one instance of twenty-five. Where the turns in the 

 stream were abrupt, the outside of the stream was nmdi higher than the 

 inside. So much was this the case, that the outside sometimes curved over 

 the inside, forming a spiral. It is needless to add, that we were filled with 

 wonder and admiration at the sights we saw. 



"The clinkers are always formed by deep streams, and generally by wide 

 ones, which flow sluggishly, become damned up in front by the cooling of 

 the lava, and in some instances cooled over the top, forming, as it were, a 

 pond or lake. As the stream augments beneath, the barriers in front and 

 the crust on the surface are broken up, and the pieces are rolled forward 

 and coated over with melted lava, which cools and adheres to them more or 

 less. Then, from the force of the melted lava, behind and underneath, the 

 stream rolls over and over itself. In this way a bank of clinkers, ten to 

 forty feet high, resembling the embankment of a railroad, is formed. Often, 

 at the end of the stream, no liquid lava can be seen, and the only evidence 

 of motion is the rolling of the jagged rocks of all sizes down the front of the 

 embankment. Sometimes the stream breaks through this embankment, and 

 flows on for a time, until it gets clogged up again, and then the same pro- 

 cesses are repeated. In this latter case, the outbursting stream often carries, 

 as it were, on its back immense masses of clinkers, which look like hills 

 walking. We found no clinkers until we reached the plain, and it would 

 seem that none are formed except where the descent is but little, or the lava 

 but imperfectly melted." 



It is said that ships sailing along the windward shores of Hawaii, Maui, 

 and Molokai,. during the week in which the eruption commenced, and before 

 the lava reached the ocean, encountered immense shoals of dead fish ; lead- 

 ing to the supposition that there might have been a sub-oceanic eruption 

 before the outpouring from the mountain, and that possibly the whole 

 island might have been overwhelmed, had not this side passage given issue 

 to a portion of the lava. 



SEISMOGKAPHIC MAP OF THE WORLD. 



A very interesting Map has been published, with this title, in England, in 

 which, on Mercator's projection, are laid down careful indications of the re- 

 gions subject to earthquakes and the sites^of volcanoes. In- the language of 

 its constructor, it shows " the surface distribution and space of earthquakes," 

 and is intended to illustrate a paper contributed by Mr. Robert Mallet, F. R. S., 

 etc., of Dublin, and his son, Dr. J. W. Mallet, to the late meeting of the 

 British Association at Leeds. As a very large number of copies of the map 

 is required, and the greatest accuracy of delineation is necessary, it has 

 been executed in chromo-lithography, and printed in a series of different 

 tints from eight different stones. Thus, various shades of orange and 

 orange-red show what are termed the " seismic bands " in their position 

 and relative intensity. Small black disks denote "volcanoes, fumeroles, sol- 

 fataras," now active, or presumed to have been so within historic or recent 

 geologic periods. A speckled gray-blue shade indicates the areas of subsi- 

 dence (whether sub-oceanic or terranean) now proceeding. A green line de- 

 marcates land from sea. Of the great oceans, only the Atlantic shows 

 much of that agency which produces earthquakes, and that chiefly in its 

 latitudes north of the equator. The Pacific has almost an immunity from 

 these throes of earth's inner crust. Of the continents, Europe has the 



