﻿H. A. Wheeler — Temperature Observations. 



125 



olivine, pyrope and ilmenite : for the others, Westphal's specific 

 gravity balance was used. Analysis 5 is of a fragment of 

 syenite found upon the border of the peridotite and supposed 

 either to have been brought up from a great depth by the 















u. 

 cS 



S3 



S3 



3 



S3 

















m 



<c§ 



s 



« o 















m 



■=■3 



fl . 



Wffl 











S3 





CO S3 



c h 



.-.£. 



°a 



















S3-C 







S3 



a 



S3 



a, 



2 



S3 



O 



"a 



u 

 e3 



o 





u 



a 



2^ 



C 03 



fcx-c 

























O 



fc 



1— 1 



Oh 



cg 



O 



to 



•-" 







1. 



2. 



2 



4. 



5. 



6. 



7. 



8. 



9. 



Water at 110° (H„0) 



0-14 



0-17 



0-20 



8-92 



0-51 



0-85 



1-94 





1-40 



Water at red heat (H 2 0) .. 



0-66 











2-32 



5-17 



8-78 



9-00 



Carbonic acid (Co 2 ) _ 









6-66 





6-29 





0-55 



0-88 



Silica (Si0 2 ) 



40-05 



41-32 



0-76 



29-81 



60-56 



60.78 



6025 



41-32 



35-53 



Titanic oxide (Ti0 2 ) 



0-07 



0-16 



49-32 



2-20 



119 



0-03 



023 



0-48 



0-95 



Phosphoric acid (P 2 5 ) 



004 



none 



trace 



0-35 



0-30 



0-09 



o-io 



0-08 



0-08 



Chromic acid (Cr 2 3 j 



0-24 



0-91 



0-74 



0-43 









trace 





Alumina (Alo0 3 ) 



0'39 

 2-36 



21-21 

 4-21 



2-84 

 9-13 



2-01 



5-16 



16-19 

 5-19 



10-54 

 3-27 



23-18 

 1-53 



20-71 

 2-59 



18-23 



Ferric oxide (Fe 2 3 ) 



2-46 



Ferrous oxide (FeO) 



7-14 



7-93 



27-81 



4-35 



2-41 





3-42 



5-46 



4-81 



Manganous oxide (MnO) 



0-20 



0-34 



0-20 



023 



0-36 



o-io 



o-io 



0-17 



0-13 



Nickel oxide (NiO) 



CoO = trace 





k- 



0-05 













Lime (CaO) 



1-16 

 48-68 



4-94 

 19-32 



0-23 



8-68 



7-69 

 32-41 



2-09 

 1-30 



10-15 

 1-59 



0-51 

 3-52 



9-91 

 1-91 



2M7 



Magnesia (MgO) 



2-01 



Potash (KoO) 



-21 



\ 0-07 



j 0-19 



0-20 



4-82 



2-36 



3-17 



0-88 



1-08 



Soda(Na 2 6) _ 



0-08 



o-ii 



4-78 



1-41 



0-39 



7-19 



2-53 



Sulphur (S) 









none 













Sulphurous acid (S0 2 ) 









0-28 













Total 



99'42 

 3-377 



100-58 

 3-673 



100-10 

 4-453 



100-86 

 2-781 



99-70 

 2-633 



99-78 



100-51 



100-03 



100-26 



Specific gravity ... 



2-489 



peridotite or else to have reached the surface by an independent 

 eruption of syenite. A fragment of granulitic rock was also 

 included in the peridotite, and that the latter is a truly eruptive 

 rock which traverses many thousand feet of Paleozoic strata to 

 reach the surface is a matter which does not admit of reason- 

 able doubt. 

 U. S. Geol. Survey Office, Washington, D. C, March 29, 1886. 



Apt. XIII. — Temperature Observations at the Lake Superior 

 Copper Mines ;* by H. A. Wheeler. 



The copper mines of Keweenaw Point, Lake Superior, have 

 attained such depth, as the result of the rapid prosecution of 

 successful mining, that some of them are now among the 

 deepest mines in this country. They therefore present an ex- 



* Presented before the St. Louis Academy of Sciences. 



