IIS' THE IRON SHIPS OF THE ROYAL NAVY. 
357 
judicious position of the compass, so as to ensure small errors while on an even keel, 
the errors arising from the ship’s heel will be so proportionally reduced, as not practically 
to affect the navigation of the ship in the hands of a prudent seaman. 
In concluding this Report, which in some of its details will, I trust, be found to 
narrow the grounds of inquiry in this interesting branch of science, so important in its 
practical relations to a maritime nation rapidly expanding its iron commercial navy, I 
beg leave to record the material assistance I have derived from the researches of the 
Astronomer Royal and Archibald Smith, Esq., on the subject of a ship’s magnetism. 
Without their skilful analysis and mathematical demonstrations, and much personal 
assistance rendered by the latter gentleman, I could not have approached the subject, 
and can therefore claim but little merit, — except that due to the labours of a lengthened 
computation, and some practical experience and close observation, — in the elucidation 
of whatever principles may be received as sound in practice and as additions to science. 
I have the honour to be. 
Sir, 
Your obedient Servant, 
Fredk. J. Evans, Master R.N. 
To Captain Washington, R.N., 
Hydrographer to the Admiralty. 
