hydkographee's instructions. 7 



on this system of correction and improvement in our pre- 

 sent charts from Harvey Bay along the narrow navigation 

 which is generally known by the name of the In-shore 

 Passage, between the coast and the Barrier Keefs, a very 

 great benefit wiU be conferred on those masters of vessels 

 who would be the more readily inclined to adopt that 

 channel, if certain parts of it were so clearly delineated, 

 and the soundings so spread on either side of the tracks, 

 that they could sometimes continue under sail during the 

 night. However necessary it was, and is, to contribute 

 as much as possible to the safety of those vessels who 

 choose the outer voyage by the Barrier Reefs, it is not the 

 less our duty to facilitate the navigation of the In-shore 

 Passage to aU vessels who prefer its tranquillity and security 

 to the risk of the former; and your labours for the 

 accompUshment of this object wiU prove to be of peculiar 

 importance when steam communication between Singa- 

 pore and Sydney shall be established. 



" In the general and searching examination of those 

 parts of the Coral Sea which are likely to be traversed by 

 ships steering for Torres Strait, you will be obliged to 

 regulate your movements by the periodic changes of the 

 weather and monsoons — probably beginning to windward, 

 and dropping gently to leeward by close and well-arranged 

 traverses, and by spreading out your three vessels to a con- 

 venient distance apart. This great expanse of sea, which 

 may be said to stretch from Lord Howe's Island to New 

 Caledonia and to the Louisiade, woidd no doubt require 

 many years work in order to accomphsh that object ; but, 

 by dividing it into definite zones or squares, and by ftdly 

 sifting those which you may undertake, a certain quantity 

 of distinct knowledge will be gained. Navigators in cross- 

 ing those zones wiU then be sure of their safety, and future 

 surveyors wiU know exactly on what parts to expend their 

 labours. 



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