817 



HYDROGRAPHIC MANUAL 



Page 768 



Figure 182.— Facsimile of Statistics stamp with entries properly made. 



817. Other Sounding Records 



Two experimental forms of Soiiiuling Kecords have been devised, whose use is 

 under consideration for echo soundings recorded graphically. Although the arrange- 

 ment is radically difierent from Form 275, many of the column headings are the same, 

 and the same instructions should be followed in using them. 



The principal innovations in the new forms are that two are used, the soundings 

 being recorded separately from the position data and other data, and that data are 

 recorded horizontally instead of vertically. The data in the separate volumes are 

 correlated by time and position numbers. 



In the form in which the position data are recorded, the names of the stations and 

 angles of a three-point fix are recorded on one horizontal line — left object, left angle, 

 center object, right angle, and right object. Cuts are recorded in a similar manner. 

 One blank horizontal line is left between positions. The bottom characteristics are 

 recorded in the "Remai'ks" column. 



The form in which the soundings are recordetl is intendetl for the temporary use of 

 the hydrographer in inking the soundings on the ])oat sheet. It is not to be used as an 

 official record of soundings, the fathogram itself serving for this purpose and the sound- 

 ings being plotted and inked on the smooth sheet from the fathogram. (See 562.) 



In the new form the soundings are recorded on a horizontal line, which is divided 

 into 10 numbered columns. Soimdings are recorded on the asstnnption that all are 

 equally spaced. The position number and the time of the position are recorded. The 

 times of intermediate soundings are omitted. The sounding on the position is entered 

 in the first column, which may be considered the zero cohimn, and the successive columns 

 are numbered from 1 to 9. For example, if five equally spaced soinidings are taken 

 between two successive positions, they are entered on a horizontal line in columns 

 numbered 1 to 5, a line being drawn through the remaining spaces. If more than nine 

 soundings occur between positions they can be entered on a second line, the tenth sound- 

 ing after the position being entered in the first column, nimibered 10. 



If an occasional shoal or deep sounding needs to be interpolated between two 

 soundings at regular intervals, it can be inserted above the line with a caret below to 

 indicate this. The form is of no value where many soundings have to be recorded at 

 ii-regular intervals. 



One blank horizontal line should be left between entries. If a reduction for tide 

 is necessary for boat-sheet soundings, it may generally be made mentally as the sound- 

 ings are inked on the boat sheet. If it is necessary to reduce the soundings arithmeticall}^ 

 for tide before they are inked on the boat sheet, enough l)iank horizontal spaces should 

 be left in the record for this reduction, the reduced soundings being entered vertically 

 below the corresponding soundings before reduction. 



