Page 777 records and reports 8311 



a. Page heading and day letter. — Entries in the spaces provided at the top of the page shall be 

 made to agree with those in the Sounding Iiecord. The instructions in 812 and 8121 should be fol- 

 lowed. The day letter shall be entered in color as in the Sounding Record. 



b. Position number. — Different series of consecutive numbers for corresponding positions and 

 bombs shall no long(;r be used while sounding. The position number as recorded in the Sounding 

 Record shall be entered in the space provided for the "Bomb number." Every care must be exercised 

 to ensure that the position numbers in the two Records agree. To this end position numbers 

 should be communicated between the chronograph station and the plotting station in accordance 

 with 6813. Position numbers will not run consecutively in the Bomb Record because in R.A.R. 

 many supplemental positions may be numbered in the Sounding Record at which no R.A.R. distances 

 are obtained (see 6812). 



c. Time of position data. — The time that the bomb strikes the water is the official time of 

 position. It shall be noted on the clock at the chronograph station and entered in the space provided. 

 The clock shall be compared frequently with the sounding clock, and adjusted if necessary, so that 

 the two clocks never differ by more than a few seconds. (See 6811.) 



d. Speed of ship, fuse interval, and ship'^i run correction. — The speed of the ship (in knots) at the 

 time of the position should be entered in the appropriate space and the fuse interval (in seconds) 

 should be entered in the space immediately below this. The ship's run correction (6853(d)) is deter- 

 mined from a table and entered in the space provided. 



e. Station names. — The R.A.R. station uames are entered in the spaces provided, in the order of 

 proximity of the stations to the position, the nearest station being listed first. Abbreviations may 

 be used after the first position on each page, initial letters sufficing if there is no duplication. 



/. Initial interval and scaled times. — The initial interval (6853(6)) and the scaled time for each 

 station (6853(c)) are taken from the chronograph tape to hundredths of a second and entered in the 

 "Scaled" column, under the double column headed "Times (seconds)." 



g. Elapsed time. — The scaled time, initial interval, and ship's run correction should be summed 

 for each station to find the elapsed time (6S53(e)), which is entered in the "Elapsed" column under 

 the double column headed "Times (seconds)." When returns are received from more than two 

 stations, the initial interval and the ship's run correction need be entered only on the left-hand page, 

 their sum being carried over and entered in an a})propriate space on the right-hand page. 



The clarity of the record on the chi'onograph tape should be indicated for each 

 station in the space provided below the other recorded data. The amplitude of the 

 sound received at each shore station (6816) should also be recorded in the space provided. 

 On the ''Remarks" line should be recorded any general information relating to the 

 operation as a whole. 



Spaces are provided at the bottom of each right-hand page in which the initials of 

 the persons performing the operations should be entered. 



In R.A.R. surveys, buoy stations are frequently located by R.A.R. distances from 

 or to the buoy to be located. These data should be recorded in the Bomb Record and 

 clearly identified by a notation in the margin of the left-hand page, as shown in figin-e 

 184. 



Bomb positions during a taut-wire measurement for the purpose of determining 

 the velocity of sound experimentally should likewise be identified. Such bomb posi- 

 tions should be numbered so they cannot possibly be confused with position numbers. 

 They should all be indexed on the first or second page following the title page of volume 

 No. 1 of the Bomb Records. 



Before a survey controlled by R.A.R. can be plotted, the velocity of sound which is 

 to be used for each distance at each position must be entered in the Bomb Record. 

 These velocities should be entered in the left-hand column imder the heading "Dis- 

 tances (meters)"; the right-hand column should be reserved for possible future changes. 

 It is not necessary to enter velocities in the Bomb Record for R.A.R. distances taken 

 for the purpose of locating buoy stations. At some convenient place in the Bomb 



