1^\GK 024 



INDEX 



Reference 

 Sea water— Continued. ^"• 



Specific gravity of (see also Salinil y of sea 



water and Specific gravity of sea 



water) ^ 4753 



Siis|ien(led iiarticles in , effect on velocity 



of sound 63 



iciiiptTiilure (see Temi)erature, sea water) 



Ihcrinofiraph . . _. 478 



turbulence, effect on sound transmission ._ G23 



W'locity of sound in (see Velocity of sound) 



Se<'on(lary submarine features, terminology _ 1682(/, ( 

 Sediments, sea bottom (see also Silted areas) 



Classification 3845 



Classificalion by size 3845 



Descriptive Report requirements 842.S' 



illustrated on fathogram • .- ' ^^ 



Ocean basin | .»„ 



Semiannual report required. _. 8516 



Semiportable installation of echo-sounding in- 

 struments ... 544 



Separation of echo-sounding acoustic units 



Compensating for by changes in depth 



scale . 556 



Definition 556 



Echo soundings corrected for (.formula) _ 556 



Echo soundings, effect on l„~ 



Ignoring , . 556 



Index adjustments, effect of on 556 



Transceiver has no 556 



Transmitted signal, effect on 556 



Transmitted signal, example of effect on 556 



Serial temperatures (see also Temperature (sea 

 water) serial) 



Definition 6321 



Form for plotting 5611 



Sets, lettering, mechanical 17231 



Settlement, definition 553 



Settlement and squat 553 



adjustment 55 



at time of bar check 557 



on 312 Fathometer 5543 



deteiTn ination 553 



by sounding 553 



with level and rod 553 



determined for each survey vessel 553 



Factor affecting 553 



Ignoring 553 



Index adjustment for 553 



Effect on soundings not underway 553 



Magnitude of 553 



Sextant(s) 



adjustments 4516 



angle(s) (see also Cuts, sextant, and Three- 

 point fix) 452 



Calling out plainly 4623 



Control buoys located by , precautions 



required 251 



Errors in (see Sextant errors, and Sound- 

 ing Record errors) 



from rolling and pitching vessel 4521 



Horizontal 4521 



between buoys out of sight of land 4522 



Noting compass azimuth of one buoy.. 4522 



between faint objects 4522 



changing rapidly, measuring. __ 4521 



Estimating in advance 4522 



Finding in a sextant .. _ 4522 



Lai'ge divided between two observ- 

 ers 4523 



Large , measuring 4523 



Measuring 4521 



"Misses", reported as 4522 



Upside down, sextant held 4522 



Inclined (see Inclined sextant angles) 



Range, two objects on 2513 



Reading at night _._ 4525 



Repeating important ..- 251 



Small 



errors {2382 



Index error eliminated from 4517 



Sun azimuths, measuring 4526 



Sun, use of shade glasses ._■ 4524 



Third required at detached positions.. |?gg 



Verifying sextant reading 4521 



Vertical (see also Stars, finding in sex- 

 tant) 4524 



Celestial body with appreciable dia- 

 meter 4524 



Ensuring the verticality of 4524 



I'age 



412 

 .^7-1 



417 



.i()7 



304 

 304 

 790 



MV, 

 .54,5 

 30ti 

 413 

 790 



,525 

 524 

 525 

 505 

 524 

 525 

 526 

 525 

 524 

 525 



579 

 529 

 431 

 004 

 ,513 

 513 

 507 

 52fi 

 517 

 513 

 514 

 514 

 513 

 513 

 513 

 513 

 513 

 513 



308 

 386 



309 

 308 

 369 

 370 

 309 

 308 

 309 

 369 



370 

 370 

 308 

 370 

 309 



114 

 371 

 111 



90 

 366 

 367 

 372 

 371 

 112 

 711 

 369 



371 

 370 



Adjusting ■ 



Se\tant(s) — Continued, 

 angle(s)-continued. Reference 



Vertical— Continued. No. 



.Marking when sextant is vertical . 4524 



Measuring 4524 



arc, cleaning 4313 



Astronomic (see Sextant, navigating) 



calibration . __ 4518 



Celcstiiil objects, finding in 4524 



Description, general 451 



Distances by (see Sextometer, and Verti- 

 cal angles) 



distances, formula for correction of 2382 



eccentricity error 4515(6) 



errors 4515 



Adjustable 4515 



Unadjustable 4515 



fix (see Three-point fix) 



Flashlight, read by 4525 



graduation errors 4515(a) 



Ilydrographic 



adjusted and verified daily. . 4517 



Description, ifeneral 4513 



Dimensions 4513 



not tested before issue 4515 



Illumination for night use, equipped 



with 4525 



index error 4517 



determination, methods of 4517 



mirrors (see also Mirrors) 4514 



Adjusting 4516 



Description, general 4514 



Glass 



Cleaning after use . .. 4514n 



Disadvantages 4514o 



Prismatic error in 4514n 



Round , British type 4514n 



Specifications {4515(f) 



Hoi-izou 4514 



/4516 

 \4517 



Index ■ 4514 



Adjusting 4516 



Sizes differ for navigating and hydro- 

 graphic sextants 14513 



Stellite , advantages 45146 



Navigating 



constants 2382 



Description, general 4512 



Dimensions 4512 



shade glasses 



/3384A 

 - \4515(f) 



Testing 4515 



Use 4524 



tested at Naval Observatory 4515 



used for astronomic observations 3384 



180° angles, for 4523 



Original use 4524 



Principles of 4511 



Prism 4523 



Shade for observing sun direct 4526 



Surveying (see Sextant, hydrographic) 



telescope 

 Astronomic observations, must be ac- 

 curately focused for 4524 



Use in measuring horizontal angles 4521 



Telescope, binocular 

 advantageous in astronomic observation. . _ 3387A 



magnification 4512 



No adjustment for 4515 



Test for eccentricity and graduation errors. . 4518 



Theory of 4511 



triangulation 

 Control buoys anchored to form triangles, 



located by 2554 



Control buoys, line of, located by 2553 



Control in unimportant waterways located 



by 2462 



Use (see also Astronomic observations; Cuts, 

 sextant; Horizontal control; Sextant 

 angles; Three-point fix; and Vertical 



angles) 451 



verified at end of day's work 816 



Sextometer 



Description 2382 



distances 



Conversion table for 2382 



Formula for computing 2382 



Formula for correction to 2382 



Sextant triangulation combined with . 2462 



method 



Description 2382 



Where authorized 2382 



Errors caused by ■ 



Page 

 370 

 370 

 332 



307 

 371 

 361 



97 

 365 

 365 

 365 

 365 



372 

 365 



367 

 363 

 363 

 365 



371 

 366 

 367 

 364 

 366 

 364 



364 

 364 

 364 

 364 

 364 

 365 

 364 

 366 

 366 

 364 

 366 



363 

 364 

 365 



97 

 362 

 362 



241 

 305 

 365 

 371 

 365 

 240 

 370 

 370 

 362 

 370 

 372 



371 



368 



248 

 363 

 366 

 367 

 362 



136 

 134 



361 

 767 



97 

 108 



