44Q APPENDIX. 



feet, made before the invention of gunpowder. The greatest depth to which 

 human labor and ingenuity have as yet been able to penetrate is 3778 feet, 

 in the old Kuttenberger mine in Bohemia, now abandoned. This depth, 

 as remarked by Humboldt, is about eight times the height of the pyramid 

 of Cheops or the Cathedral of Strasburg. 



The deepest excavation in the United States is probably that of the 

 Minnesota mine near Ontonagon, Lake Superior, which descends upon a 

 copper-bearing lode to the depth of over 1300 feet. The Quincy mine at 

 Hancock is 000 feet deep. The deepest mine in California is said to be 

 the Hay ward Quartz mine in Amador county, 1200 feet deep. The deep 

 est excavations on the Comstock lode, Nevada, are 700 feet. 



Mining excavations frequently extend from half a mile to a mile under 

 the sea. In these gloomy subterranean and submarine passages, where, 

 in some cases, one or two hundred feet of sea- water rest upon a slaty roof 

 but three or four feet thick, the low moan of the waves can be continually 

 heard above the miner s head, and in time of storms the howl becomes ter 

 rific and intolerable. The great adit for the discharge of the waters of 

 the Gwennap tin mines in Cornwall exceeds 30 miles. In 1864, a tun 

 nel 1 4 miles in length was completed in the region of the Harz mines, 

 Brunswick, for the drainage of the district. A similar tunnel, 15 miles in 

 length, designed for the drainage of the Freiberg district, has been in prog 

 ress for several years. The Sutro tunnel, designed for the drainage of 

 the mines located upon the Comstock lode, Nevada, is to be 19,000 feet in 

 length, 12 feet wide, and 10 feet high, and will cost between four and five 

 millions of dollars. 



The great tunnel&quot; at Chicago, through which the city is supplied with 

 pure water from Lake Michigan, is 10,567 feet long, five feet wide, and 

 five feet two inches high, and at the shore extremity communicates with 

 a vertical shaft 82 feet below the lake-level, and at the other extremity 

 with a crib and shaft 66 feet below the lake-level. 



NOTE VI., page 185. 



As the Archccopteryx, or bird-reptile, is one of the most remarkable rel 

 ics of the ancient world, and has but recently been brought to light, I ap 

 pend some references to sources of information upon the subject : Prof. 

 Wagner first announced the discovery to the Royal Academy of Sciences 

 of Munich in 1861; H. Herrman von Meyer described it in &quot; Jahrbuch 

 fur Mineralogie,&quot; 1861, p. 561 ; Wm. H. Woodward, in &quot; Intellectual Ob 

 server,&quot; Dec. 1862 (with plate) ; Prof. J. D. Dana, in &quot; Amer. Jour, of Sci 

 ence and Arts,&quot; 2d ser., xxxv., May, 1863, p. 129, and &quot;Manual of Geolo 

 gy,&quot; Appendix to later editions ; Prof. R. Owen, in &quot;Philosophical Tran 

 sactions,&quot; cliii., part i., 1863, p. 33, pi. 1 to 4. 



