On the Secondary Deflections Produced in a Magnetized Needle by an Iron Shell, in Consequence of an Unequal Distribution of Magnetism in Its Two Branches. First Noticed by Captain J. P. Wilson, of the Honourable East India Company's Ship Hythe

P. Barlow
1827 Philosophical Transactions of the Royal Society of London  
doi:10.1098/rstl.1827.0021 fatcat:ifkavrbbibaa7oswsg3drjxibm