plotting sheets and not from the dead reckoning 

 (DR) position. After the positions have been 

 entered on the log sliects the positions and 

 serial numbers of the BT observations are 

 plotted in India ink, on H. O. 5050 Series 

 Strategic Plotting Sheets. Give the ship's 

 name and number, cruise name and number, 

 beginning and ending dates of the cruise, and 

 the sheet number on each sheet. 



14-61 BT No.— The BT number is stamped 

 on the nose of each instrument. As each BT 

 has a different number, be sure to check this 

 before each observation to make sure the 

 proper instrument is being used. Record the 

 BT number for each observation. 



14-62 Depth. — Record the sonic sounding 

 in fathoms for each observation. It is impor- 

 tant to determine the deptii just prior to mak- 

 ing a BT lowering. More than one BT has 

 been lost because the operator learned the hard 

 way that there were only 25 fathoms when he 

 thought there were 1,200 fathoms. 



14-63 Speed. — Give the speed of the ship 

 in knots for each observation. If the ship is 

 lying to when an observation is made show the 

 speed as zero. 



14-64 Surf. Temp. — The surface temper- 

 ature of the sea water is recorded in degrees 

 and tenths Fahrenheit. Example: 53.4° F. 

 After the temperature value, indicate whether 

 it was obtained by a bucket sample (B) or by 

 the engine room injection temperature (I). 

 The bucket sample is recommended. Special 

 bucket thermometers are supplied for U. S. 

 Navy surveys by the Hydrographic Office. 

 These are more accurate tlian the standard 

 thermometers issued with the BT kits and are 

 to be used in place of the latter. 



14-65 Air Temp. — Record the dry bulb and 

 wet bulb air temperatures in degrees and tenths 

 Fahrenheit. Example: 57.3° F. 



14-66 Barometer. — Record the barometric 

 pressure in inches of mercury to hundredths 

 of an inch. Example: 29.53. 



14-67 Weather by Symbols. — Record the 

 state of the weather at the time of the BT 

 observation, using the code given in table 1. 



14-68 Clouds. — Record the type of clouds 

 present at the time of the BT observation, using 

 the code given in table 2. Record the amount 

 of cloud cover at the time of the BT observa- 

 tion, using the code given in table 3. 



14-69 Visibility. — Record the condition of 

 visibility at the time of the BT observation, 

 using the code given in table 4. 



14-70 Sea. — Record the height of the sea 

 at the time of the BT observation, using the 

 code given in table 5. 



14-71 Wire Out. — Give the amount of 

 wire paid out from the winch during a BT 

 lowering. Use the maximum figure indicated 

 by the winch counter. Although the counter 

 actually records revolutions of the winch drum, 

 it approximates the number of feet of wire 

 paid out. 



14-72 Sample Number. — If a sample of 

 sea water is taken at the same time as the BT 

 observation, record the sample bottle number 

 in this space. 



14-73 Observer's Initials. — The observer 

 should initial the last column. If further 

 remarks are required, make an asterisk (*) 

 opposite the observer's initials and record the 

 remarks on the back of the log sheet. 



14-74 SHIPPING INSTRUCTIONS.— 

 Upon completion of a cruise, carefully pack all 

 slides, log sheets, and BT track charts, and mail 

 them together to: 



The Hydrographer 



U. S. Navy Hvdrographic Office 



Washington 25, D. C. 



Attn: Code 5430 



OCEANOGRAPHIC LOG SHEET C, PRNC-NHO-1190 

 (Rev. 12-53) 



DISSOLVED OXYGEN DETERMINATION 



14-75 GENERAL REMARKS.— The C- 



sheet is used for the chemical analyses and 

 calculations involved in the determination of 

 dissolved oxygen content of sea water samples 

 b}^ the Winkler method. Complete instruc- 

 tions for this method are given in chapter 13. 

 Study those instructions carefully before at- 

 tempting to use this log sheet. 



144 



14-76 THE LOG SHEET.— A sample log 

 sheet is shown in figure 14-4. Print all entries 

 accurately and neatly. 



14-77 " The Log Sheet Headings.— Fill in 



the ship's name and number, cruise name and 

 number, and station number. The chemists 

 name and the date of the analyses should be 

 entered in the proper spaces. The name, or 



H. O. 607 



