" Densities in the Earth's Crust." 



375 



Table VI. — Densities of Solutions of Potassium Hydroxide 



at 15°. 



Per cent. 

 KOH. 



Density. 



Per cent. 

 KOH. 



Density. 



Per cent. 

 KOH. 



Density. 



52 



1-53822 



34 



1-33313 



16 



1-14925 



51 



1-52622 



33 



1-32236 



15 



1-13955 



50 



1-51430 



32 



1-31166 



14 



1-12991 



49 



1-50245 



31 



1-30102 



13 



1-12031 



48 



1-49067 



30 



1-29046 



12 



1-11076 



47 



1-47896 



29 



1-27997 



11 



1-10127 



46 



1-46733 



28 



1-26954 



10 



1-09183 



45 



1-45577 



27 



1-25918 



9 



1-08240 



44 



1-44429 



26 



1-24888 



8 



107302 



43 



1-43289 



25 



1-23866 



7 



1-06371 



42 



1-42150 



24 



1-22849 



6 



1-05443 



41 



1-41025 



23 



1-21838 



5 



104517 



40 



1-39906 



22 



1-20834 



4 



1-03593 



39 



1-38793 



21 



1-19837 



3 



1-02671 



38 



1-37686 



20 



1-18839 



2 



1-01752 



37 



1-36586 



19 



1-17855 



1 



1-00834 



36 



1-35485 



18 



1-16875 







0-99918 



35 



1-34396 



17 



1-15898 







XXXIII. ^Densities in the Earth's Crust. 33 

 By Rev. O. Fisher, M.A., F.G.S* 



IN a letter which appears under the above heading in the 

 February number of this Magazine, Mr. Jukes-Browne 

 expresses a wish that I would either admit or deny the value of 

 Professor Blake's criticism f upon my conclusions concerning 

 the comparative densities and thicknesses of the layers of the 

 earth's crust beneath the oceans and continents respectively. 



I do not feel much doubt about the correctness of my work 

 upon this subject, because it was under very careful con- 

 sideration for several weeks, not only by myself but also by 

 Mr. Brill, whose mathematical ability is unquestionable ; and 

 I think Mr. Blake has thrown it aside as unworthy of his 

 consideration rather too hastily. If he had more fully 

 mastered my results, he would not have stated in his first 

 paragraph that " the argument about the underlying layers 

 of the crust seems to depend on the greater density of the 

 superficial layer in continental than in oceanic areas " — which 

 is the exact opposite to the conclusion at which I have 



* Communicated by the Author, 

 t ' Annals of British Geology,' 1892. 



2C2 



Introductory review. 



