526 Correspondence on Magnetism of Ships, [Nov. 30, 



which has been adopted in all countries which directed their attention to 

 this subject. 



" Although indirectly the introduction of this compass into the Royal 

 Navy has been the cause of much improvement in the compasses of the 

 Mercantile Marine, there is still room for improvement. At present much 

 expense is incurred in matters which are merely ornamental, and in some 

 cases prejudicial. Probably much advantage would be derived from a 

 model compass being fixed upon, which at a moderate price would supply 

 the Mercantile Marine with the great desideratum of a compass of suffi- 

 cient delicacy and accuracy. Considering that a few notes relating to the 

 efficient points of a compass may prove useful, these notes will be found as 

 Appendix III. 



"There are yet two features in the ' Compass question' which appear 

 to me as being worthy of consideration in any system that may be con- 

 templated for assimilating the practice of the Mercantile Marine to that 

 of the Royal Navy. These are, 



" 1st. As to the efficiency of those who engage to perform the adjust- 

 ments. 

 " 2nd. The periods for examining the adjustments. 



" By constant practice, but without any very clear knowledge of the 

 principles of magnetism, several [skilful adjusters of compasses are to be 

 found at some of the great mercantile ports. These ' adjusters ' must, 

 from their practice, be now well known to the Board of Trade Surveyors. 

 The registration of their names, and of the firms employing them, either 

 by the local Marine Boards or by Lloyd's Committee, might be a desirable 

 step to take as a preliminary measure. 



" The arrangements for swinging ships, I have also heard, are either 

 defective, or practically do not exist, at most of the mercantile ports ; might 

 not the Board of Trade Surveyors report upon the nature of existing 

 arrangements, and the means generally adopted by the ' adjusters ?' 



" As to the periods for examining the adjustments, the recommenda- 

 tions of the Liverpool Compass Committee (see page 40, 3rd Report, 1861) 

 appear to me to fully meet the case, and have such an important bearing 

 on the secure navigation of iron ships, that I gladly bring them again to 

 notice. 



" ' There appears sufficient reason for requiring that a new iron sailing 

 ship or steamer should be swung immediately before each of the first two 

 or three voyages ; that all iron vessels should be swung immediately 

 before the first voyage following any considerable amount of repair, when- 

 ever a change has been made in the position of the standard compass ; 

 when there is a change of Captain, unless the new Captain had charge of 

 the vessel during the preceding voyage as Chief Officer.' 



" In conclusion I must observe that the present state and prospects of 

 the science and practice of the correction of the compass make it impos- 

 sible to offer with confidence any complete set of suggestions as to the 



