378 



HYDROGRAPHICAL SURVEYING [chap. xvii. 



Signs for 



Week 



Days. 



Other 

 Symbols. 



DELINEATION, SYMBOLS, AND COLOURING. 



The annexed specimen chart, taken from the " Admiralty 

 Manual," shows the method of delineation employed in fair 

 chart- work. 



The follo\\ ing symbols are in use in surveying, in field-books, 

 and rough charts. 



The days of the week are thus symbohzed by the astrono- 

 mical signs of the planets. 



Colouring. 



Sunday 

 Monday . . 

 Tuesday . . 

 Wednesday 

 Thursday .. 

 Friday 

 Saturday . . 



Sun's Day 

 Moon's Day . 

 Teut's Day . 

 Woden's Day 

 Thor's Day , 

 Friga's Day . 

 Saturn's Day 



The following signs are useful in the field-books. 



Objects in line, called transit 

 Station, where angles are taken 

 Zero, from which angles are measured 

 Single altitude Sun's lower limb .. 



.. A 



.. « 



.. Q 



„ 'ipper „ C5 



Double „ „ lower limb in artificial horizon Q 



„ upper „ „ ,, D 



Sun's right limb ,, .. .. .. .. (3 



„ left „ .. .. .. .. .. 13 



Sun's centre . . .. .. .. •. .. Q) 



Eight extreme, or tangent, as of an island .. -> 



Left „ „ „ , ^ 



Zero correct „ „ ,. •• •• Z. K. 



Windmill „ „ „ „ .. .. S 



Water-level.. .. .. .. .. .. w, 1. 



Whitewash .. .. .. .. .. .. w. w. 



Some charts are worked up by Indian ink alone in all parts ; 

 in others, colour is used to assist the delineation of the different 

 parts, Indian ink being always used over the colour, in exactly 

 the same manner as if there was no groundwork. 



A wash of some colour on the land helps to throw it up 

 very much ; but care is very necessary in giving this edging 

 that it be not too deep, and that too much water is not used, 



