[Humphrey Lloyd, Irish physicist, Provost of Trinity College, Dublin.] Autograph Letter Signed ('H Lloyd') to Alfred Fox, regarding his 'paper on Magnetical Observations' and Fox's brother's 'instrument', i.e. Robert Were Fox's magnetic dip compass.

The recipient was a brother of the geologist and inventor Robert Were Fox the Younger (1789-1877), whose magnetic dip compass, constructed in the previous year, is the 'instrument' referred to at the end of the letter. (Fox's compass was used by Sir James Clark Ross on his Antarctic expedition, and was later used to discover the position of the South magnetic pole.) 1p, 4to. In fair condition, aged and creased, with traces of paper mount adhering to one edge, and repair to a closed tear with archival tape. Several folds. Beneath Lloyd's signature at the foot of the letter is part of his seal in red wax. Lloyd writes that he has 'much pleasure in transmitting to [Fox] a copy of the paper on Magnetical Observations which [he has] desired'. Lloyd has 'in practice somewhat modified the details of the method here pointed out – and at the last meeting of the British Association [he has given] a brief account of the method so modified – which will appear in the forthcoming volume of the Transactions'. He ends by thanking him 'for the description which you have sent me of your brother's instrument'.