Letter from [Randal Mowbray Thomas Rawdon Berkeley, 8th Earl of] Berkeley, Foxcombe, near Oxford, to [Joseph] Larmor He asks if Larmor would mind reading an enclosure [not present] and if it is worth sending to Nature. He does not remember the idea from his little reading of biology. It might be hepful and some physiologist or biologist might be able to tell, if Larmor could pass it on. The interferometer shows signs of coming up to his requirements, noting that they have had a 'tough job' with it. 30 December 1909