Letter from George Biddell Airy, Playford near Ipswich to Edward Sabine Airy refers to a ‘discrepancy’ raised by Sabine. Airy has great confidence in the needles but has concerns regarding the personal talents of the observers. Airy has given thought to arranging the instrument so that the readings can be taken from a distance (such as with the Transit circle) and intends to schedule a plan. Discussion on errors of results and possible effects of magnetic circle. Once Airy has returned he would Sabine to contact [John] Welsh and any other persons who can be relied upon to take the dip at Greenwich with Sabine and Biddell’s instruments. 27 December 1856