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AMERICAN JOURNAL OF SCIENCE 



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& [THIRD SERIES.] 



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Art. XI. — History of the Changes in the Mt. Loa Craters / 

 by James D. Dana. Part II, on Mokuaweoweo, or the 

 Summit crater, continued. 



[Continued from page 32.] 



General Summary with Conclusions. 



The subjects connected with Mount Loa and the summit 

 crater considered in the following summary and conclusions 

 are the following : 



1. The times and time-intervals of eruptions and of summit 

 illuminations or activity, with reference to (1) periodicity, 

 (2) relations to seasons, (3) variations in activity since 1843, and 

 (4), the changes in the depth of the crater. 



2. The ordinary activity within the summit crater. 



3. Causes of the ordinary movements within the crater. 

 Next follows Part III, treating of the causes of eruptions in 



Mt. Loa and Kilauea, and afterward, of the relations of the two 

 volcanoes. 



For the further illustration of the volcanoes the follow- 

 ing map of the Hawaiian Islands is here introduced. Besides 

 showing the forms of \h^ islands, their relative positions and 

 the two parallel lines between Oahu and Hawaii, it gives also 

 the depths from the soundings of the Challenger and of vessels 

 of the U. S. Navy, and others made with reference to tele- 

 graph-lines between the islands for which the map is indebted 

 to the Hawaiian Government Survey. 



Am. Jour. Sol— Third Series, Vol. XXXVI, No. 212.— August, 1888. 

 6 



