Figure 2-1. Nansen bottle in three positions — before 

 tripping, during tripping, and after tripping. 



is perforated to permit water circulation so that 

 the thermometers may come to temperature 

 more rapidly. The ends of the tubes contain 

 coil springs and rubber pads to hold the ther- 

 mometers seciu-ely yet provide a certain amount 

 of protection against shock. The thermometers 

 are always inserted into the tubes in such a 

 manner that the large mercury reservoir is in the 

 end of the tube having the small perforations. 



2-3 Associated Equipment. — In addition to 

 the Nansen bottle, its thermometer frame and 

 thermometers, the following equipment is need- 

 ed: oceanographic winch and wire, a meter 

 wheel, messengers, wire angle indicator, racks 

 for the Nansen bottles, water sample bottles, 



and a thermometer reader. The oceanographic 

 winch has been described in chapter 1. 



2-4 Messengers. — Messengers are essential 

 for the operation of Nansen bottles. They are 

 brass weights constructed in such a manner that 

 they can be attached and detached from the 

 wire quickly and can slide freely. A small wire, 

 with a loop at the end, suspends them from the 

 release mechanism of the bottle. 



2-5 Wire-Angle Indicator. — The wire-angle 

 indicator is a simple device for measuring the 

 angle of the oceanographic wire from the verti- 

 cal. It consists of a protractor with a weighted 

 plumb arm. 



2-6 Nansen Bottle Racks. — An arrangement 

 for racking the Nansen bottles is essential for 

 proper conduct of operations. Racks should be 

 convenient to the platform and A-frame. They 

 should be constructed so that the Nansen 

 bottles are securely held in a vertical position 

 and yet can be readily removed and replaced. 

 The Nansen bottles should be at a height to 

 enable easy reading of the reversing thermome- 

 ters. Immediately below each Nansen bottle 

 should be a rack to hold 2 or 4 glass water 

 sample bottles (fig. 2-2). 



2-7 Reversing Thermometer Reader. — The 

 reversing thermometer reader, or viewer, is a 

 magnifier used to read the thermometers to the 

 required accuracy. It consists of a brass tube 

 with a 6-X lens. The field end of the tube has 

 two V notches for self-aligning the reader against 

 the glass shell of the reversing thermometers. 



2-8 Spare-Parts Kit. — Nansen bottles used 

 by U. S. Navy survey ships are provided with a 

 spare-parts kit containing spare clamps, springs, 

 washers, pins, and the necessary tools to effect 

 minor repairs and general maintenance. Gen- 

 erally, 1 kit is issued for every 12 bottles. 



2-9 Preparing the Nansen Bottle for Opera- 

 tion. — Before a Nansen bottle is used on a 

 station, it should be checked carefully for proper 

 operation of parts. The valves should be 

 lubricated with a silicone stopcock grease to 

 insure smooth movement. All moving parts 

 should be lubricated to give free action. Springs 

 and pins of the messenger and bottle-releasing 

 mechanisms should be tested for proper action. 

 Should they be too weak, the bottle may trip 

 prematurely or the messenger released while 

 the bottle is being lowered. If they are too 

 stiff, they will not release properly when struck 

 by the messenger. The action of the air vent 

 screw and the condition of the washer should be 

 checked. The two air vent holes must not be 

 clogged. The drain petcock valve should turn 

 smoothly. After the bottles have been checked 

 and are in operating condition, they are placed 



H. O. 607 



