86 Bulletin Wisconsin Natural History Society. [Vol. 9, No. 3. 



Prof. George Wagner of the University of Wisconsin, gave the 

 -evening's lecture: The Voyage of the Challenger: A Story of the 

 Deep Sea. Our knowledge of the life of the deep sea is quite recent, 

 the fact that the ocean covered the greater part of the earth's surface 

 dating only from the time of Columbus. The first investigator was 

 Magellan. More recently the laying of the first Atlantic cable dis- 

 proved Sir Forbes' assumption that life became extinct beyond a 

 depth of 2,000 feet. The expedition of the Challenger, begun Decem- 

 ber. 1873, and lasting three years and four months, during which 

 over 63,000 miles were covered, was the first attempt on a large scale 

 to determine the depth of the ocean and the occurence of life at the 

 various depths. The United States now keeps a boat, the Albatross, 

 constantly in commission for the same purpose. 



By means of lantern slides the lecturer showed the various 

 methods employed by the expedition in sounding — the old method of 

 using ropes, then piano wire and the modern cables; the ascertain- 

 ment of the ocean temperature at various depths and the forms of 

 dredges developed formed interesting mechanical problems for the 

 audience. 



Some of the general physical results obtained by the Challenger 

 expedition are : The deepest place in the ocean is 31,000 feet below 

 sea level, the average depth 12,000 feet. The water pressure being 

 sixteen pounds to the square inch for every thirty feet, it is easy to 

 fig-ure out the water pressure at any depth. Oxygen is found every- 

 where, carbon dioxide practically absent. 



Plant life is found to a depth of about 2,000 feet. After that for 

 many thousand feet we find oozes, the globigerina ooze in the Atlantic, 

 and the infusorian ooze in the Pacific ocean. Among general charac- 

 teristics may be mentioned that contrary to the expectation that 

 organisms at great depths would be colorless owing to absence of 

 light, as in the case of cave animals, it was found that fishes were 

 mostly black, while crustaceans exhibited beautiful shades of red 

 and blue. Oddness of forms, enormous development of the tactile 

 organs, and phosphorescence, especially among the fishes, are found 

 to be the general attributes of the deep sea fauna. 



A large series of slides were used to illustrate the lecture. Messrs. 

 Russel, Dernehl, and others discussed the lecture. 'Mr. Burrill pro- 

 posed a vote of thanks. Seconded and carried. Dr. Barth extended 

 the thanks of the Society to the lecturer. 



