Letter from George Gabriel Stokes, Lensfield Cottage, Cambridge, to Charles Vernon Boys Professor Turner has told him that Boys had no indication of heat radiation from the dark part of the Moon. Stokes considers this only to be expected, as rock is a bad conductor. It would be better to try during a lunar eclipse shortly after the dark part of the Moon had been exposed to direct sunlight. Lord Rosse mentioned a similar but unsuccessful trial in a Philosophical Transactions paper. There is one partial lunar eclipse on 13 June and Stokes describes how this might be favourable for Boys's observations. 20 March 1900