Copy letter from Robert William Frederick Harrison, to Dr Thomas Muir, Fellow of the Royal Society Reports with reference to Muir's quaternion bibliography that the Society has done all the it can with the slips received. The remainder are those which the Society was unable to find at any of the London Libraries including the British Museum, Mathematical Society, Patent Office, et cetera. Asks whether he should return the slips or whether he should wait until Muir sends the rests of the slips in his hands. 9 January 1903