NARRATIVE OF THE CRUISE 

 FROM "THE LAST CRUISE OF THE CARNEGIE' 



INSTRUMENTS 



While docked in San Francisco after our first year 

 . at sea, a celebration was held aboard the Carnegie com- 

 memorating the twenty-fifth anniversary of the Depart- 

 ment of Terrestrial Magnetism. Following the ceremo- 

 nies, the vessel was open for public inspection for a 

 period of several days. The popular interest shown in 

 the ship and its scientific equipment was keen- -three 

 thousand visitors having made the rounds in two days. 

 This experience suggests that the reader of the present 

 volume may also find of interest such a conducted tour. 

 It certainly will give a more concrete idea of what we set 

 out to accomplish. 



Coming on the quarter-deck from the pier, one's at- 

 tention is drawn to the shiny three -ton bronze winch and 

 its two reels of aluminum-bronze wire. With this elec- 

 trically driven "gold hoist," as the sailors call it, deep- 

 sea soundings can be made, water samples collected, 

 and temperatures taken down to a depth of three or four 

 miles. From the winch the v/ires lead through blocks, 

 over meter wheels to davits overhanging the water. One 

 of the winch heads was cut down to hold steel piano wire 

 which was used later in the cruise for collecting sam- 

 plesof the bottom, and forgetting temperatures at depths 

 greater than could be reached with the bronze cable. 

 Although this steel wire was very long, it weighed little, 

 and was so far removed from the magnetic instruments 

 as to have no observable effect on them. The drums and 

 heads of the winch were ingeniously constructed to work 

 independently, so that to save time several operations 

 might be under way simultaneously: for example, paying 

 out on the bottle wire, and hauling in on the bottom sam- 

 ple. Aluminum-bronze wire previously had been used 

 by the German Atlantic expedition of the Meteor , on 

 which it had been shown superior to any other cable for 

 deep-sea purposes and fitted in admirably with our non- 

 magnetic requirements. 



Mounted over an outboard platform near the winch 

 is the "plankton pump." This apparatus is lowered to 

 various depths to count the number of miscroscopic ani- 

 mals and plants existing at each water level. Owing to 

 an insufficiency of power, our biological work was limit- 

 ed to the study of these minute, drifting organisms found 

 everywhere in the oceans. A small conical net made of 

 very fine-meshed silk bolting-cloth, such as millers use 

 in sifting flour, is attached to the end of the bronze cyl- 

 inder. A pump actuated by a falling lead weight forces a 

 measured volume of sea water through the net. One has 

 only to lower the apparatus to the desired depth, drop a 

 brass "messenger" down the wire to release the catch 

 on the pump, and gravity does the rest. The cylinder is 

 closed while being lowered and raised. This avoids con- 

 tamination of the desired sample by plankton living in 

 the upper layers of the water. 



From this description, the plankton pump seems to 

 be a clever little mechanism which does its appointed 

 task uncomplainingly. But of all the pieces of machinery 

 aboard, this one required the greatest display of ingenu- 

 ity and the most severe strain on one's good humor, to 

 keep it in operation. V/ires and valves, rubber bands 



and springs, weights and releasing forks--all had an 

 abominable habit of getting tangled up once the mechan- 

 ism was safely hidden from view in the waters under the 

 vessel. It was a rare day when three consecutive hauls 

 were successful. Nevertheless with its aid we were able 

 to make a census of the sea's population in various re- 

 gions and at the various depths--a valuable contribution 

 to our knowledge of life in the ocean. The pump was de- 

 signed by Dr. Petterssen of Norway, and had been tested 

 off the coast of that country by Dr. Sverdrup, a Research 

 Associate of the Carnegie Institution. 



Immediately inboard from the plankton pump plat- 

 form is a large "gear box" filled with oceanographic 

 instruments. Standing on the outside in ranks, like well- 

 drilled veterans, are the reversing water -sampling bot- 

 tles, designed by the late explorer Nansen. These 

 remarkable brass cylinders may be attached in series 

 to the bronze wire, lowered to the desired depths, and 

 the first bottle reversed by sliding a brass messenger 

 down the cable from the ship. Each bottle has a messen- 

 ger hanging at its lower end, so that when the first bot- 

 tle reverses end-over-end, its messenger is released 

 and slides down the wire to upset the next, and this con- 

 tinues with all the bottles. The two valves at the ends of 

 each bottle close automatically when reversal takes 

 place, imprisoning about a quart of water, to be analyzed 

 by the chemist in the laboratory on deck. To each of 

 these bottles is attached a small frame containing the 

 all-important deep-sea reversing pressure thermome- 

 ters. 



Inside the gear box are several types of "bottom 

 samplers." Some consist of brass tubes surrounded 

 with lead weights which fall off after the apparatus 

 plunges into the ocean floor. Others operate like a clam- 

 shell or turtle's jaws, snapping up a sample of bottom 

 deposit. A third kind is a long, glass-lined metal tube 

 with a heavy weight permanently attached to it, which 

 procures a vertical section of the mud or ooze, showing 

 the successive layers in which it has been deposited. 

 But the sampler most commonly used is a modification 

 of the telegraph "snapper" of the clamshell type. Like 

 the plankton pump, this mechanism required considerable 

 nursing, and even some surgical operations as time went 

 on. 



On the basis of these samples, a study of the nature 

 and origin of marine bottom deposits will be made ashore. 

 This collection will prove of great interest, because of the 

 scarcity of material, especially from the Pacific. Work- 

 ers in the Geophysical Laboratory of the Carnegie Insti- 

 tution of Washington are interested in the chemical analy- 

 ses. From the amount of radioactive material found in 

 them, thorium and radium, they hope to g:t some idea of 

 the age of the earth. Scientists studying the origin of oil 

 deposits will be furnished samples. The American Tele- 

 phone and Telegraph Company wish to determine the 

 corrosive effects on their cables. Then too, it is now 

 known that bottom-living creatures feed on organic mat- 

 ter found in muds. 



In the gear box is kept the brass bucket for collecting 



31 



