BOTTOM SAMPLES 



COLLECTION AND PRESERVATION 



The bottom samples were collected with samplers 

 attached to the end of a hemp lead line which in turn was 

 attached to the end of a steel piano wire carried on one 

 of the winch drums and led over a meter-wheel at the 

 stern of the vessel. The striking of bottom by the sam- 

 pler was determined manually by keeping tension in the 

 outgoing piano wire with a roller bar. 



Most of the samples were taken with a snapper -type 

 sampler--the sample being caught in a spring-actuated 

 clamshell. The snapper-type samplers used varied 

 considerably in size, type of trigger, and design of 

 weight, but after considerable experimentation, the type 

 selected as most suitable to the equipment and condi- 

 tions existing on the Carnegie was that shown in figure 

 1. Here the pear-shaped lead weight was counterbored 

 to fit down over the spring, thus lowering the center of 

 gravity. Later the lead weight was so arranged as to be 

 left on bottom in order to reduce the strain on the wire 

 when hauling in. This was done as follows. The weights 

 were cast in halves containing staples in their upper 

 ends. When placed on the shank of the snapper they 

 were tacked together by. a flat copper staple on each side 

 near the bottom of the weight. A wire whose ends were 

 made fast to the upper staples passed over the hook of a 

 Sigsbee releasing device and held the upper ends of the 

 weight together. When the sampler struck bottom, the 

 Sigsbee device released the wire, the upper ends of the 



weights fell apart tearing loose the lower staples and 

 the two halves fell clear of the snapper and were left on 

 the bottom. 



This type of snapper was of sufficient size to y'eld 

 about one and one-quarter liters of sample when the bot- 

 tom was of ooze, mud, or clay. On striking hard bottom 

 it usually collected only a few fragments and the jaws 

 were badly dented and had to be repaired. Nodules, cin- 

 ders, fragments of obsidian, and similar hard obstruc- 

 tions were sometimes caught between the jaws, thus 

 permitting the rest of the sample to be washed out on the 

 way to the surface. 



A tube sampler intended to give a core sample and 

 used on the Meteor was used a few times. It is shown 

 in figure 2. This sampler was lined with a removable 

 glass tulDe so that the sample could be inspected and 

 stored while still in the lining tube. This type of sam- 

 pler was not used more frequently because of its con- 

 siderably greater weight and the pull required to with- 

 draw it from the bottom put too heavy a strain on the 

 piano wire. 



The core samples obtained were stoppered in their 

 lining tubes and the samples obtained with snappers 

 were transferred to glass bottles and stoppered soon 

 after collection. They were then shipped to Washington 

 from the next port into which the Carnegie went. 



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