604 Communication to the Board oj Trade [June, 



rather by requiring that the ship shall have a navigating-compass distinct 

 from, and in addition to, the steering-compass. 



" It is therefore recommended that every iron passenger-ship should be 

 required to have a standard compass distinct from the steering-compass in 

 a selected situation at a certain distance from all masses of iron ; that, 

 whether corrected or not, the original deviations of the standard compass 

 should not in ordinary cases exceed a certain limited amount ; and that on 

 each occasion of the compass being adjusted, a table of the deviations 

 should be furnished to the Master and returned to the Board of Trade ; 

 and that if corrected by magnets, a return should be made of the position 

 of the magnets and of every subsequent alteration of their position. Pro- 

 vision may be made for exceptional cases, in which it may be found im- 

 practicable to place the standard compass in a position where the original 

 deviation is within the limit, by requiring in such cases a special certificate 

 from the central authority. 



" It may be here observed, as regards many practical matters connected 

 with the adjustment of the compass in particular ships, in which at present 

 great diversity of practice prevails, that an organized department under a 

 skilful superintendent in constant communication with the ports, would 

 probably be of the greatest service, not merely in laying down rules, but in 

 giving advice and suggestions to naval constructors, compass-makers and 

 adjusters, and producing a uniform system of adjustment at the different 

 ports, which would be generally understood by shipmasters. Advice from 

 the same source would be not less useful to the authorities in the different 

 ports in suggesting means of facilitating the adjustment by meridian-marks 

 on shore, laying down moorings, &c. It would probably be one of the 

 first duties of the superintendent of such a department to acquaint himself 

 thoroughly with the methods practised at the different ports, and to give 

 such suggestions, either in the form of reports to the Board of Trade, or in 

 private communications, or both, as might appear to him advisable. Such 

 a superintendent would also be available as an assessor in investigations 

 into the loss of iron vessels, in cases in which there is any possibility of the 

 loss having been occasioned by compass-error. 



" 2. The advancement of the science of the Deviation of the Compass. 



" Whatever difference of opinion exists as to the advantage or necessity 

 of a Standard Compass as regards the safety of particular ships, there is 

 none as to its being indispensable for any scientific inquiry into the amount 

 of the deviation and of its constituent parts and its changes. It is from 

 the Tables of the deviation of such compasses, and such compasses alone, 

 observed at different times and places, and systematically reduced and dis- 

 cussed, that those numerical results can be obtained which promise to be so 

 useful in securing in iron ships a place for the Standard Compass where the 

 deviation is of a safe and manageable amount, and in guarding against the 

 dangers which arise from changes in the magnetism of recently built ships. 

 It is from the recorded deviations of such compasses that on the loss of a 



