developement of magnetical properties in steel and iron , &c. 221 
extraordinary power of Knight's magnets are well known ; 
though the secret of their manufacture died with him, and no 
effect at all comparable, has, I believe, been since produced. 
Is it not probable that he may have employed a process of 
this description ?* 
* I am indebted for this thought to a suggestion of Sir Hi Davy’s, in a conver- 
sation on these experiments. 
W. S. Jun\ 
On board the ship Baffin, off Iceland, 
August 27, 1823. 
