1865.] of the Iron-built Armour-plated Ship* Pervenetz.' 189 



14. Comparing these values with those in Table I., we see the great 

 changes which the magnetism of the ship had undergone in the Victoria 

 Docks. 



15. The ship having her head to the east instead of to the west, all the 

 GPs had changed from to +, and having had her head to north instead of 

 south, all the 33's had diminished. 



16. From the same cause we see that Z at the stern increases, at the 

 how diminishes ; at d there is an increase of Z, owing to the machinery 

 under that part of the deck. 



1 7. At one point in the main deck Z is negative, showing that the up- 

 ward vertical force of the ship was greater than the vertical force of the 

 earth. The great apparent change in H arises from the part of the ship 

 which was south in building, and which consequently attracted the north 

 end of the ship, having been directed to the north, and increasing instead 

 of diminishing the directive force. 



18. The force of the ship was greatest when the ship was first placed 

 with her head in the new position, and greatly diminished afterwards, as 

 will be seen from the following Table. 



Value of 5.', ship's head at N. 55 E. 



19. On leaving the Thames for the Baltic the ' Pervenetz ' had five 

 compasses : 



1. The Standard, in the position b, but 7 feet 6 in. above the upper 

 deck. 



2. The Bridge Compass. 



3 & 4. Two Binnacle Compasses. 

 5. The Main-deck Compass. 



20. The following Table of the Coefficients is derived from observa- 

 tions made in the Thames on the 3rd of August. 



